Skip to main content

Magnolia Bark Extract

Scientific Name(s): Magnolia officinalis Rehd. et Wils.
Common Name(s): "Hu-bak", Magnolia bark

Medically reviewed by Drugs.com. Last updated on May 23, 2022.

Clinical Overview

Use

Most literature sources are from Japanese and Chinese foreign-language publications, clinical studies are on the efficacy of magnolia bark extract (MBE) are limited. Documentation on the materials and extracts for several studies is also limited. In vitro and animal studies document potential efficacy as an antibacterial, anti-inflammatory, and anticancer agent, as well as for use with Alzheimer disease, depression, diabetes, and menopause.

Dosing

MBE is commercially available in the United States and throughout Europe. Dosage varies depending on the condition treated, with weight loss products containing MBE available mostly in powder form. Several strengths are available for Relora, a patented blend marketed as "a natural stress management supplement" that includes MBE. Dosing recommendations include taking a 300 mg capsule of Relora 2 to 3 times per day. One small, randomized, controlled study treated patients with one 60 mg tablet of MBE daily to help relieve menopausal symptoms.

Contraindications

Avoid use if hypersensitivity exists for any of the components in MBE. No absolute contraindication could be found in the medical literature.

Pregnancy/Lactation

Avoid use during pregnancy and lactation because of limited clinical data. An animal study found that honokiol and magnolol blocked uterine contractions in rat uterus.

Interactions

None well documented.

Adverse Reactions

No dermatologic adverse effects were documented with topical application of magnolol and honokiol; however, several cases of allergic dermatitis have been documented in case reports. In one small clinical trial, a patient dropped out because of a number of adverse reactions, including heartburn, shaking hands, perilabial numbness, sexual dysfunction, and thyroid dysfunction.

Toxicology

Some sources document case reports of progressive interstitial renal fibrosis in patients consuming an herbal blend containing M. officinalis.

Scientific Family

Source

Numerous documented medicinal properties are associated with 2 major phenolic constituents, magnolol and honokiol, from the stem bark of M. officinalis Rehd. Et Wils.1, 2 Concentration variations of magnolol and honokiol exist in bark sourced from different provinces in China, as recorded in The Pharmacopoeia of the People's Republic of China. The plant is primarily indigenous to China and found at elevations of 200 to 3,000 meters.3

History

MBE has been used for over 1,000 years as a folk medicine in Asia.4, 5 In traditional Asian medicine, MBE has been prescribed for treating acute pain, headaches, diarrhea, allergies, asthma, and gynecological disorders. It has also been used to treat fever, anxiety, nervous disorders, depression, muscular pain, abdominal fullness, constipation, and thrombotic stroke.6, 7, 8, 9 In Chinese and Japanese folk medicine, MBE has been used to treat bronchitis and emphysema.10

Chemistry

Magnolol and honokiol are the 2 primary active phenolic constituents of MBE.1, 2, 3

Uses and Pharmacology

Most literature sources are from Japanese and Chinese foreign-language publications, and clinical studies on the efficacy of magnolia bark extract are limited. Documentation on the materials and extracts for several studies is also limited. In vitro and animal studies document potential efficacy as an antibacterial, anti-inflammatory, and anticancer agent, as well as for use with Alzheimer disease, depression, diabetes, and menopause.

Alzheimer disease

In vitro and animal data

Magnolol and honokiol exhibited central depressant effects by producing sedation, ataxia, muscle relaxation, and a loss of the righting reflex in young chicks.(19) The compound 4-O-methylhonokiol (4-O-MH) promoted neurite outgrowth in a concentration-dependent manner in cultured embryonic neuronal cells. The compound also increased expression of neurotrophins, which are believed to promote neurite outgrowth.(20) An ethanol extract of M. officinalis and 4-O-MH suppressed beta amyloid peptide (eg, Aβ1–42)–induced memory impairment in mice, perhaps by inhibiting neuronal cell death, and increased reactive oxygen species expression.(21) The compound 4-O-MH may also inhibit activation of the mitogen-activated protein kinase (MAP kinase) pathway, which is important in neuronal cell death.(22) An ethanol extract of M. officinalis and 4-O-MH improved memory impairment induced by scopolamine in a dose-dependent manner.(23)

Antibacterial

In vitro data

In an agar dilution study, honokiol and magnolol inhibited (minimum inhibitory concentration [MIC] = 25 mcg/mL) the growth of periodontal pathogens Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Micrococcus luteus, and Bacillus subtilis(11) and were less potent than tetracycline. MBE, honokiol, and magnolol were all effective against killing bacteria responsible for halitosis and formation of dental caries (ie, Streptococcus mutans).(11, 12, 13) The MIC ranged from 8 to 31 mcg/mL for magnolol, honokiol, and MBE against Porphyromonas gingivalis, Fusobacterium nucleatum, and S. mutans. Mint candies containing MBE 0.2% reduced oral bacteria by 99.9% within 5 minutes of treatment. Similar antibacterial activity was demonstrated with MBE chewing gum.(12) The antibacterial activity of MBE may include nonionic surface agent activity leading to disruption of the cell membrane and lipid protein interface.(13)

Honokiol and magnolol inhibited the growth of acne-causing bacteria Cutibacterium acnes and Cutibacterium granulosum.(14) Both phenolic compounds also reduced inflammation by inhibiting the secretion of interleukin-8 and tumor necrosis factor alpha (TNF-alpha) induced by P. acnes. A human skin irritation test in 30 healthy patients demonstrated no adverse effects from topical application of the phenolic compounds.

MBE may also have antimicrobial activity against Helicobacter pylori.(12)

Clinical data

Chewing sugarless gum containing either MBE (0.17%) + xylitol or xylitol without MBE was shown to improve mutans streptococci levels and bleeding on probing significantly better than control. However, MBE + xylitol reduced mutans streptococci concentrations (P=0.04) and bleeding upon probing (P=0.04) significantly better than xylitol without MBE.(71)

Anti-inflammatory

In vitro and animal data

Magnolol reduced swelling and inflammation in edema induced by carrageenan, compound 48/80, polymyxin B, and reversed passive Arthus reaction in mice.(15) When compared with dexamethasone, magnolol did not increase glycogen levels in the liver. The mechanism of action appears to involve reducing the levels of eicosanoid mediators rather than affecting glucocorticoid activity or steroid hormone activity from the adrenal gland.(15, 16)

In mice, honokiol and magnolol reduced inflammatory pain by blocking the inflammatory mediators substance P and prostaglandin E2, and the neurotransmitter glutamate.(17) Honokiol inhibited several signal transduction cascades (eg, protein kinase C, mitogen-activated protein kinase, nuclear transcription factor kappa-B) involved with regulating inflammatory mediator and gene expression.(18)

Antioxidant

In vitro and animal studies document potent antioxidant activity for magnolol and honokiol in protecting against myocardial and cerebral ischemia by inhibiting neutrophil infiltration and reactive oxygen species production.(48, 49, 50)

Antiviral

Magnolol and honokiol have weak activity against HIV-1 in human peripheral blood mononuclear cells.(51)

Anxiety

Extracts of M. officinalis may have benzodiazepine-like activity as documented by a strong affinity on the benzodiazepine-binding site of the gamma aminobutyric acid (GABA) receptor. Honokiol also interacts with the GABA receptor and exhibited activity similar to that of diazepam.(8, 52)

Asthma

Magnolol may stimulate corticosterone secretion by the adrenal gland, a mechanism similar to the action of exogenous glucocorticoids in the treatment of asthma.(58)

Atherosclerosis

Magnolol inhibited expression of monocyte chemoattractant protein-1 in vascular smooth muscle cells, which contributes to the development of atherosclerosis and re-stenosis.(53) Magnolol also induced apoptosis(53) and inhibited cell viability in TNF-alpha cytokine(54)-stimulated vascular smooth muscle cells. Magnolol's antioxidant activity appears to also play a role in preventing atherosclerotic vascular disease.(55, 56) Antiplatelet activity relaxes vascular smooth muscle by releasing endothelium-derived relaxing factor and inhibiting calcium influx through voltage-gated calcium channels.(57)

Bone metabolism

In vitro data

An ethanolic Magnolia bark extract was observed to inhibit osteoclastogenesis without affecting osteoblast differentiation in vitro.(77)

Cancer

In vitro and animal data

Honokiol induced apoptosis and inhibited angiogenesis via the Bcl-2 and caspase-3 pathway in ovarian tumor cells.(24) Honokiol increased apoptotic DNA fragmentation in cultured human prostate cancer cells irrespective of their androgen responsiveness or p53 status and inhibited growth of an androgen-independent p53 mutant cell line xenograft in mice without causing weight loss or any other adverse reactions.(25) Magnolol inhibited growth and induced apoptosis, and G1- and G2/M phase cell cycle arrest in human urinary bladder cancer 5637 cells by activating extracellular signaling.(26) Magnolol inhibited growth of human malignant melanoma A375-S2 cells by both the death receptor pathway and the mitochondrial pathway.(27) Honokiol reduced cell survival and inhibited growth in human chondrosarcoma cells, a malignant primary bone tumor.(28) The anticancer activity involves mitochondria dysfunction and induced cell death mediated by increased endoplasmic reticulum stress, eventually resulting in apoptosis. Honokiol induced apoptosis and inhibited HeLa cell proliferation through many proteins and multiple pathways.(29)

Magnolol induced apoptosis in human lung cancer CH27 cells through activation of signaling pathways responsible for cell death, including regulation of the Bcl-2 family proteins and release of cytochrome c from mitochondria into the cytosol, leading to activation of the caspase cascade.(30)

Magnolol and honokiol exhibited cytostatic rather than cytotoxic effects on HL-60 leukemia cells. Both compounds also enhanced vitamin D3 and all-trans-retinoic acid induced HL-60 leukemic cell differentiation.(31)

Magnolol suppressed growth of cultured human U373 malignant glioblastoma cells by inhibiting DNA synthesis and activating apoptosis. Magnolol is able to cross the blood brain barrier, as documented by pharmacokinetic studies in rats.(32)

Honokiol alone inhibited the growth of human lung cancer A549 in lung carcinoma models, and when combined with cisplatin, enhanced antitumor efficacy by increasing apoptosis and inhibition of angiogenesis.(33) Honokiol inhibited several human breast cancer cell lines, as well as drug-resistant breast cancer cell lines. The mechanism involved inhibition of cell proliferation, induced cell cycle arrest, and apoptosis. Honokiol also enhanced the proapoptotic activity of lapatinib or rapamycin in her-2 over-expressed or low-expressed breast cancer models.(34)

Honokiol-hydrogel reduced the number of pleural tumor foci and prolonged survival time in malignant pleural effusion–bearing mice when compared with controls. The mechanism involved inhibition of angiogenesis, and histological analysis of the pleural tumors revealed application of the gel increased the rate of apoptosis.(35)

Cardiac arrhythmia

Honokiol reduced the infarct zone, duration of ventricular tachycardia, and ventricular fibrillation in coronary ligated rats.(59) The cardioprotective effect may be associated with increased nitric oxide synthesis.(60)

Cataracts

Honokiol inhibited hydrogen peroxide–induced apoptosis in human lens epithelial cells by modulating various signaling pathways in cataract formation.(61)

Depression

In vitro and animal data

A mixture of honokiol and magnolol at 20 and 40 mg/kg inhibited stress-induced decreases of serotonin in the frontal cortex, hippocampus, striatum, hypothalamus, and nucleus accumbens in mice. The mixture also increased serotonin metabolite levels in the frontal cortex, striatum, and nucleus accumbens at 40 mg/kg. Honokiol and magnolol also reduced elevated corticosterone concentrations and normalized hypothalamic–pituitary–adrenal hyperactivity and reduced platelet adenylyl cyclase activity by upregulating the cyclic adenosine monophosphate pathway.(36)

Experimentally induced depression in mice was inhibited by magnolol and its metabolite hydroxydihydromagnolol.(37) An ethanol extract of a traditional Chinese medicine containing M. officinalis exhibited antidepressant effects in mice similar to the effects of fluoxetine.(38) In a stress-induced model in rats, the combination of honokiol, magnolol, and ginger oil exhibited antidepressant effects. Honokiol and magnolol increased serotonin levels in numerous brain regions, while ginger reduced gastric mucosa cholecystokinin and serum gastrin levels.(39)

Diabetes

In vitro and animal data

Magnolol reduced metabolic parameters common in diabetic nephropathy, such as blood glucose, plasma insulin, sorbitol, and advanced glycation end products in an experimental type 2 diabetes rat model. Magnolol also attenuated upregulation of renal transforming growth factor beta 1, which plays a key role in the pathogenesis of diabetic nephropathy, and reduced expression of extracellular matrix protein as type IV collagen.(40) In mature adipocytes, magnolol improved insulin sensitivity by increasing basal and insulin stimulated glucose uptake through peroxisome proliferator-activated receptors.(41) KIOM-4, a plant extract obtained from M. officinalis, protected pancreatic beta cells against streptozotocin-induced oxidative damage.(42) KIOM-4 induced a rate-limiting enzyme through the extracellular regulated kinase pathway, which resulted in cytoprotection against diabetic conditions and increased insulin release from the pancreas. Another plant extract combination containing M. officinalis, KIOM-79, inhibited xylose-induced lens opacity.(43) KIOM-79 also protected human lens epithelial-B3 cells from the toxic effects of high glucose levels by inhibiting transforming growth factor beta, which is involved in the pathophysiology of ocular damage. An antioxidant mechanism may be involved with KIOM-79, protecting against oxidative stress-induced apoptosis in diabetic retinopathy.(44)

GI effects

Animal data

Gastroprotective effects against dysmotility, antibiotic-induced gut microbial dysbiosis, and ethanol-induced gastric mucosal damage has been demonstrated with Magnolia bark extract in rodent models.(78, 79) In the antibiotic-induced gut microbial dysbiosis model, Magnolia extract restored normal intestinal flora with significantly higher diversity of gut microbes compared to untreated dybiotic controls (P<0.001) and no difference to healthy controls.(78) Similarly, Magnolia bark extract significantly (P<0.05) protected against ethanol-induced gastric injury in a dose-dependent manner, producing up to an 87% reduction in ulcer area, while the positive control (omeprazole) produced a 97% reduction in ulcer area. Effects appeared to be related to antioxidant as well as anti-inflammatory (ie, TNF-alpha, interleukin [IL]-1beta, IL-6) activity.(79)

Gynecological disorders

Honokiol and magnolol blocked calcium-dependent uterine oscillatory contractions in rat uterus.(5) The mechanism may be associated with blocking receptor-operated cation and voltage-operated calcium channels.(5)

Liver disease

Magnolol reduced acetaminophen-induced liver damage in rats by inhibiting lipid peroxidation and formation of reactive oxygen species.(6) Honokiol reversed the effects of induced alcoholic fatty liver in rats by inhibiting lipid accumulation or fatty acid synthesis.(62)

Menopause

Clinical data

A small, controlled, randomized, multicenter study examined the effects of 2 formulations, one containing magnolia bark extract (60 mg) and magnesium (50 mg), in symptomatic menopausal women with sleep or mood alterations. The magnolia extract and magnesium combination appeared to be effective in reducing psychoaffective and sleep disturbances from menopause.(45) A small pilot study examined the effects on body weight from a dietary supplement containing extracts of M. officinalis and Phellodendron amurense in 28 premenopausal women. The supplement reduced evening cortisol levels and may have improved systolic blood pressure as well as perceived stress.(46) Another randomized, placebo-controlled trial indicated that the same dietary supplement may reduce mild transitory anxiety in premenopausal women.(46, 47) Postmenopausal women with mild affective symptoms, borderline anxious-depressive behaviors, and/or sleep disorders were enrolled in a randomized, controlled trial (n=634) that compared the activity of isoflavones + lactobacilli with and without MBE. After 12 weeks, the addition of MBE provided a significant improvement in insomnia, irritability, and libido at 4, 8 and 12 weeks.(70)

Oral health

A double-blind, randomized, controlled interventional trial (n=120) in Italy investigated the effect of MBE on factors related to dental caries, such as cariogenic bacteria (especially mutans streptococci), fermentable carbohydrates intake, plaque acidity, and saliva flow. MBE was delivered by means of a sugar-free chewing gum containing xylitol, which itself has also been shown to exhibit caries preventative activity. Enrolled participants were adults at high risk of dental caries and were randomized to MBE (0.17%) + xylitol, xylitol, or a control group. Participants were instructed to chew 1 or 2 pieces of gum for 5 minutes 3 times daily for 30 days (5 pieces/day); this regimen delivered 11.9 mg/day of magnolol and 2.2 g/day of honokiol. After 30 days, MBE + xylitol and xylitol gums provided significant protection against plaque acidity (P=0.01 and P=0.04, respectively) compared to baseline, with protection by MBE also being significantly better than control (P=0.04) Additionally, both MBE + xylitol and xylitol gums improved mutans streptococci levels and bleeding upon probing significantly better than control. However, compared to xylitol, MBE + xylitol significantly reduced mutans streptococci concentrations (P=0.04) and bleeding upon probing (P=0.04).(71)

In 2 double-blind, randomized, placebo-controlled trials in Italy, the acute effect of MBE plus zinc acetate on halitosis was evaluated via 2 doseforms: a sugarless gum and a sugarless tablet. A total of 123 and 100 adults completed the respective trials. Although the gum and tablet test products provided significant reductions in oral volatile sulfur compounds within 10 minutes and 1 hour compared to controls, the investigators did not provide data on MBE without zinc; the latter of which itself has been shown to have protective effects against the development of volatile sulfur compounds and halitosis. Both delivery forms were well tolerated with no reported problems.(74, 75) A 2017 systematic review of chewing gum and its impact of halitosis parameters (ie, volatile sulfur compounds, organoleptic scores) in adults evaluated 10 trials that exhibited high heterogeneity; no study was at low risk of bias in all analysis items. The study summarized above was the only study included that evaluated magnolia bark extract.(73)

Seizure

Honokiol and magnolol inhibited excitatory amino acid-evoked cation signals and N-methyl-D-aspartate acid (NMDA)–induced seizures.(63) Honokiol was more selective in blocking the NMDA receptor and demonstrated greater inhibition against NMDA-induced seizures.

Sepsis

Magnolol prevented hypotension, bradycardia, and multiple organ failure induced by lipopolysaccharide in rats.(64) Potential mechanisms of action include: reducing the plasma TNF-alpha and nitrate/nitrite concentrations, suppressing organ superoxide anion level, and suppressing the blood coagulation cascade and expression of inflammatory genes.

Dosing

MBE is commercially available in the United States and throughout Europe, as documented by Internet search engines. Dosage varies depending on the condition treated, with weight loss products containing MBE available mostly in powder form. Several strengths are available for Relora, a patented blend marketed as "a natural stress management supplement" that includes MBE. Dosing recommendations include taking a 300 mg capsule of Relora 2 to 3 times per day. A small, randomized, controlled study treated patients with one 60 mg tablet of MBE daily to help relieve menopausal symptoms.45

Pregnancy / Lactation

Avoid use during pregnancy and lactation because of limited clinical data. An animal study documented that honokiol and magnolol blocked calcium-dependent uterine oscillatory contractions in rat uterus.5

Interactions

Drug-herb interactions are documented in animals and in vitro. Based on these limited data, caution is advisable in patients self-medicating with MBE. Magnolol may interact with acetaminophen; one study documented reduced acetaminophen-induced liver damage in rats.6 Additive adverse reactions with antiplatelet medications may occur.57 MBE and honokiol may interact with benzodiazepines.8, 52 Magnolol may stimulate corticosterone secretion58 or increase steroid medication concentrations.65

Adverse Reactions

No adverse dermatologic effects were documented with topical application of magnolol and honokiol.14 In one small clinical trial, a patient dropped out because of a number of adverse reactions, including heartburn, shaking hands, perilabial numbness, sexual dysfunction, and thyroid dysfunction.46 A few cases of allergic contact dermatitis have been reported in 4 patients who presented with a variety of symptoms, including vesicular, edematous, pruritic, scaly, and/or erythematous lesions after applying cosmetic creams containing M. officinalis bark extract. All patients’ hypersensitivity were validated with positive reactions to patch testing.72, 76

Toxicology

Dietary administration of MBE in rats at doses of up to 480 mg/kg in a 21-day study and 240 mg/kg in a 90-day study resulted in no clinically important toxicity.7 Some sources document the development of progressive interstitial renal fibrosis in patients consuming an herbal blend containing M. officinalis.66, 67 In vitro studies demonstrate no genotoxic effects from MBE in chromosomal aberration assays.68 One study documented that magnolol in liver graft preservation enhanced apoptotic events under cold preservation instead of preserving hepatocyte integrity.69

References

Disclaimer

This information relates to an herbal, vitamin, mineral or other dietary supplement. This product has not been reviewed by the FDA to determine whether it is safe or effective and is not subject to the quality standards and safety information collection standards that are applicable to most prescription drugs. This information should not be used to decide whether or not to take this product. This information does not endorse this product as safe, effective, or approved for treating any patient or health condition. This is only a brief summary of general information about this product. It does NOT include all information about the possible uses, directions, warnings, precautions, interactions, adverse effects, or risks that may apply to this product. This information is not specific medical advice and does not replace information you receive from your health care provider. You should talk with your health care provider for complete information about the risks and benefits of using this product.

This product may adversely interact with certain health and medical conditions, other prescription and over-the-counter drugs, foods, or other dietary supplements. This product may be unsafe when used before surgery or other medical procedures. It is important to fully inform your doctor about the herbal, vitamins, mineral or any other supplements you are taking before any kind of surgery or medical procedure. With the exception of certain products that are generally recognized as safe in normal quantities, including use of folic acid and prenatal vitamins during pregnancy, this product has not been sufficiently studied to determine whether it is safe to use during pregnancy or nursing or by persons younger than 2 years of age.

More about magnolia bark extract

Related treatment guides

1. Youn UJ, Chen QC, Jin WY, et al. Cytotoxic lignans from the stem bark of Magnolia officinalis. J Nat Prod. 2007;70(10):1687-1689.17918910
2. Shen CC, Ni CL, Shen YC, et al. Phenolic constituents from the stem bark of Magnolia officinalis. J Nat Prod. 2009;72(1):168-171.19086868
3. Tong, ZK, Zeng YR & Si JP. Variation, heredity and selection of effective ingredients in Magnolis officinalis of different provenances. J Forestry Res. 2002;13(1):7-11.
4. Shin TY, Kim DK, Chae BS, Lee EJ. Antiallergic action of Magnolia officinalis on immediate hypersensitivity reaction. Arch Pharm Res. 2001;24(3):249-255.11440086
5. Lu YC, Chen HH, Ko CH, Lin YR, Chan MH. The mechanism of honokiol-induced and magnolol-induced inhibition on muscle contraction and Ca2+ mobilization in rat uterus. Naunyn Schmiedebergs Arch Pharmacol. 2003;368(4):262-269.14504686
6. Chen YH, Lin FY, Liu PL, et al. Antioxidative and hepatoprotective effects of magnolol on acetaminophen-induced liver damage in rats. Arch Pharm Res. 2009;32(2):221-228.19280152
7. Liu Z, Zhang X, Cui W, et al. Evaluation of short-term and subchronic toxicity of magnolia bark extract in rats. Regul Toxicol Pharmacol. 2007;49(3):160-171.17692445
8. Squires RF, Ai J, Witt MR, Kahnberg P, et al. Honokiol and magnolol increase the number of [3H] muscimol binding sites three-fold in rat forebrain membranes in vitro using a filtration assay, by allosterically increasing the affinities of low-affinity sites. Neurochem Res. 1999;24(12):1593-1602.10591411
9. Jeong SI, Kim YS, Lee MY, et al. Regulation of contractile activity by magnolol in the rat isolated gastrointestinal tracts. Pharmacol Res. 2009;59(3):183-188.19121392
10. Konoshima T, Kozuka M, Tokuda H, et al. Studies on inhibitors of skin tumor promotion, IX. Neolignans from Magnolia officinalis. J Nat Prod. 1991;54(3):816-822.1659613
11. Ho KY, Tsai CC, Chen CP, Huang JS, Lin CC. Antimicrobial activity of honokiol and magnolol isolated from Magnolia officinalis. Phytother Res. 2001;15(2):139-141.11268114
12. Greenberg M, Urnezis P, Tian M. Compressed mints and chewing gum containing magnolia bark extract are effective against bacteria responsible for oral malodor. J Agric Food Chem. 2007;55(23):9465-9469.17949053
13. Greenberg M, Dodds M, Tian M. Naturally occurring phenolic antibacterial compounds show effectiveness against oral bacteria by a quantitative structure-activity relationship study. J Agric Food Chem. 2008;56(23):11151-11156.19007234
14. Park J, Lee J, Jung E, et al. In vitro antibacterial and anti-inflammatory effects of honokiol and magnolol against Propionibacterium sp. Eur J Pharmacol. 2004;496(1-3):189-195.15288590
15. Wang JP, Hsu MF, Raung SL, Chen CC, Kuo JS, Teng CM. Anti-inflammatory and analgesic effects of magnolol. Naunyn Schmiedebergs Arch Pharmacol. 1992;346(6):707-712.1336574
16. Wang JP, Ho TF, Chang LC, Chen CC. Anti-inflammatory effect of magnolol, isolated from Magnolia officinalis, on A23187-induced pleurisy in mice. J Pharm Pharmacol. 1995;47(10):857-860.8583356
17. Lin YR, Chen HH, Lin YC, Ko CH, Chan MH. Antinociceptive actions of honokiol and magnolol on glutamatergic and inflammatory pain. J Biomed Sci. 2009;16:94.19832997
18. Chao LK, Liao PC, Ho CL, et al. Anti-inflammatory bioactivities of honokiol through inhibition of protein kinase C, mitogen-activated protein kinase, and the NF-kappaB pathway to reduce LPS-induced TNFalpha and NO expression. J Agric Food Chem. 2010;58(6):3472-3478.20192217
19. Watanabe K, Watanabe H, Goto Y, Yamaguchi M, Yamamoto N, Hagino K. Pharmacological properties of magnolol and honokiol extracted from Magnolia officinalis: central depressant effects. Planta Med. 1983;49(10):103-108.17405027
20. Lee YK, Choi IS, Kim YH, et al. Neurite outgrowth effect of 4-O-methylhonokiol by induction of neurotrophic factors through ERK activation. Neurochem Res. 2009;34(12):2251-2260.19557513
21. Lee JW, Lee YK, Lee BJ, et al. Inhibitory effect of ethanol extract of Magnolia officinalis and 4-O-methylhonokiol on memory impairment and neuronal toxicity induced by beta-amyloid. Pharmacol Biochem Behav. 2010;95(1):31-40.20004682
22. Lee YK, Choi IS, Ban JO, et al. 4-O-methylhonokiol attenuated β-amyloid-induced memory impairment through reduction of oxidative damages via inactivation of p38 MAP kinase. J Nutr Biochem. 2010;22(5):476-486.20688501
23. Lee YK, Yuk DY, Kim TI, et al. Protective effect of the ethanol extract of Magnolia officinalis and 4-O-methylhonokiol on scopolamine-induced memory impairment and the inhibition of acetylcholinesterase activity. J Nat Med. 2009;63(3):274-282.19343477
24. Li Z, Liu Y, Zhao X, et al. Honokiol, a natural therapeutic candidate, induces apoptosis and inhibits angiogenesis of ovarian tumor cells. Eur J Obstet Gynecol Reprod Biol. 2008;140(1):95-102.18440692
25. Hahm ER, Arlotti JA, Marynowski SW, Singh SV. Honokiol, a constituent of oriental medicinal herb magnolia officinalis, inhibits growth of PC-3 xenografts in vivo in association with apoptosis induction. Clin Cancer Res. 2008;14(4):1248-1257.18281560
26. Lee SJ, Cho YH, Park K, et al. Magnolol elicits activation of the extracellular signal-regulated kinase pathway by inducing p27KIP1-mediated G2/M-phase cell cycle arrest in human urinary bladder cancer 5637 cells. Biochem Pharmacol. 2008;75(12):2289-2300.18468578
27. You Q, Li M, Jiao G. Magnolol induces apoptosis via activation of both mitochondrial and death receptor pathways in A375-S2 cells. Arch Pharm Res. 2009;32(12):1789-1794.20162409
28. Chen YJ, Wu CL, Liu JF, et al. Honokiol induces cell apoptosis in human chondrosarcoma cells through mitochondrial dysfunction and endoplasmic reticulum stress. Cancer Lett. 2010;291(1):20-30.19880244
29. Ling B, Liang SF, Xu YH, et al. Differential proteomic analysis of HeLa cells treated with Honokiol using a quantitative proteomic strategy. Amino Acids. 2008;35(1):115-122.18157584
30. Yang SE, Hsieh MT, Tsai TH, Hsu SL. Effector mechanism of magnolol-induced apoptosis in human lung squamous carcinoma CH27 cells. Br J Pharmacol. 2003;138(1):193-201.12522090
31. Fong WF, Tse AK, Poon KH, Wang C. Magnolol and honokiol enhance HL-60 human leukemia cell differentiation induced by 1,25-dihydroxyvitamin D3 and retinoic acid. Int J Biochem Cell Biol. 2005;37(2):427-441.15474987
32. Chen LC, Liu YC, Liang YC, Ho YS, Lee WS. Magnolol inhibits human glioblastoma cell proliferation through upregulation of p21/Cip1. J Agric Food Chem. 2009;57(16):7331-7337.19645506
33. Jiang QQ, Fan LY, Yang GL, et al. Improved therapeutic effectiveness by combining liposomal honokiol with cisplatin in lung cancer model. BMC Cancer. 2008;8:242.18706101
34. Liu H, Zang C, Emde A, et al. Anti-tumor effect of honokiol alone and in combination with other anti-cancer agents in breast cancer. Eur J Pharmacol. 2008;591(1-3):43-51.18588872
35. Fang F, Gong C, Qian Z, et al. Honokiol nanoparticles in thermosensitive hydrogel: therapeutic effects on malignant pleural effusion. ACS Nano. 2009;3(12):4080-4088.19921811
36. Xu Q, Yi LT, Pan Y, et al. Antidepressant-like effects of the mixture of honokiol and magnolol from the barks of Magnolia officinalis in stressed rodents. Prog Neuropsychopharmacol Biol Psychiatry. 2008;32(3):715-725.18093712
37. Nakazawa T, Yasuda T, Ohsawa K. Metabolites of orally administered Magnolia officinalis extract in rats and man and its antidepressant-like effects in mice. J Pharm Pharmacol. 2003;55(11):1583-1591.14713371
38. Luo L, Nong Wang J, Kong LD, Jiang QG, Tan RX. Antidepressant effects of Banxia Houpu decoction, a traditional Chinese medicinal empirical formula. J Ethnopharmacol. 2000;73(1-2):277-281.11025166
39. Qiang LQ, Wang CP, Wang FM, et al. Combined administration of the mixture of honokiol and magnolol and ginger oil evokes antidepressant-like synergism in rats. Arch Pharm Res. 2009;32(9):1281-1292.19784585
40. Sohn EJ, Kim CS, Kim YS, et al. Effects of magnolol (5,5'-diallyl-2,2'-dihydroxybiphenyl) on diabetic nephropathy in type 2 diabetic Goto-Kakizaki rats. Life Sci. 2007;80(5):468-475.17070554
41. Choi SS, Cha BY, Lee YS, et al. Magnolol enhances adipocyte differentiation and glucose uptake in 3T3-L1 cells. Life Sci. 2009;84(25-26):908-914.19376135
42. Kang KA, Kim JS, Zhang R, Piao MJ, Chang WY, Kim KC et al. Protective mechanism of KIOM-4 against Streptozotocin induced diabetic cells: involvement of heme oxygenase-1. Biotechnol Bioprocess Eng. 2009;14(3):295-301.
43. Kim NH, Kim YS, Jung DH, Kim JS. KIOM-79 prevents xylose-induced lens opacity and inhibits TGF-beta2 in human lens epithelial cells cultured under high glucose. J Ethnopharmacol. 2010;130(3):599-606.20561927
44. Kim OS, Kim J, Kim CS, Kim NH, Kim JS. KIOM-79 prevents methyglyoxal-induced retinal pericyte apoptosis in vitro and in vivo. J Ethnopharmacol. 2010;129(3):285-292.20362656
45. Mucci M, Carraro C, Mancino P, et al. Soy isoflavones, lactobacilli, Magnolia bark extract, vitamin D3 and calcium. Controlled clinical study in menopause. Minerva Ginecol. 2006;58(4):323-334.16957676
46. Garrison R, Chambliss WG. Effect of a proprietary Magnolia and Phellodendron extract on weight management: a pilot, double-blind, placebo-controlled clinical trial. Altern Ther Health Med. 2006;12(1):50-54.16454147
47. Kalman DS, Feldman S, Feldman R, Schwartz HI, Krieger DR, Garrison R. Effect of a proprietary Magnolia and Phellodendron extract on stress levels in healthy women: a pilot, double-blind, placebo-controlled clinical trial. Nutr J. 2008;7:11.18426577
48. Lee YM, Hsiao G, Chen HR, Chen YC, Sheu JR, Yen MH. Magnolol reduces myocardial ischemia/reperfusion injury via neutrophil inhibition in rats. Eur J Pharmacol. 2001;422(1-3):159-167.11430926
49. Liou KT, Shen YC, Chen CF, Tsao CM, Tsai SK. Honokiol protects rat brain from focal cerebral ischemia-reperfusion injury by inhibiting neutrophil infiltration and reactive oxygen species production. Brain Res. 2003;992(2):159-166.14625055
50. Liou KT, Shen YC, Chen CF, Tsao CM, Tsai SK. The anti-inflammatory effect of honokiol on neutrophils: mechanisms in the inhibition of reactive oxygen species production. Eur J Pharmacol. 2003;475(1-3):19-27.12954355
51. Amblard F, Delinsky D, Arbiser JL, Schinazi RF. Facile purification of honokiol and its antiviral and cytotoxic properties. J Med Chem. 2006;49(11):3426-3427.16722664
52. Koetter U, Barrett M, Lacher S, Abdelrahman A, Dolnick D. Interactions of Magnolia and Ziziphus extracts with selected central nervous system receptors. J Ethnopharmacol. 2009;124(3):421-425.19505549
53. Chen JH, Wu CC, Hsiao G, Yen MH. Magnolol induces apoptosis in vascular smooth muscle. Naunyn Schmiedebergs Arch Pharmacol. 2003;368(2):127-133.12898128
54. Kim HM, Bae SJ, Kim DW, et al. Inhibitory role of magnolol on proliferative capacity and matrix metalloproteinase-9 expression in TNF-alpha-induced vascular smooth muscle cells. Int Immunopharmacol. 2007;7(8):1083-1091.17570325
55. Ou HC, Chou FP, Sheu WH, Hsu SL, Lee WJ. Protective effects of magnolol against oxidized LDL-induced apoptosis in endothelial cells. Arch Toxicol. 2007;81(6):421-432.17216433
56. Chen YL, Lin KF, Shiao MS, Chen YT, Hong CY, Lin SJ. Magnolol, a potent antioxidant from Magnolia officinalis, attenuates intimal thickening and MCP-1 expression after balloon injury of the aorta in cholesterol-fed rabbits. Basic Res Cardiol. 2001;96(4):353-363.11518191
57. Teng CM, Yu SM, Chen CC, Huang YL, Huang TF. EDRF-release and Ca+(+)-channel blockade by magnolol, an antiplatelet agent isolated from Chinese herb Magnolia officinalis, in rat thoracic aorta. Life Sci. 1990;47(13):1153-1161.2172682
58. Wang SM, Lee LJ, Huang YT, Chen JJ, Chen YL. Magnolol stimulates steroidogenesis in rat adrenal cells. Br J Pharmacol. 2000;131(6):1172-1178.11082125
59. Tsai SK, Huang SS, Hong CY. Myocardial protective effect of honokiol: an active component in Magnolia officinalis. Planta Med. 1996;62(6):503-506.9000881
60. Tsai SK, Huang CH, Huang SS, Hung LM, Hong CY. Antiarrhythmic effect of magnolol and honokiol during acute phase of coronary occlusion in anesthetized rats: influence of L-NAME and aspirin. Pharmacology. 1999;59(5):227-233.10529654
61. Tang X, Yao K, Zhang L, Yang Y, Yao H. Honokiol inhibits H(2)O(2)-induced apoptosis in human lens epithelial cells via inhibition of the mitogen-activated protein kinase and Akt pathways. Eur J Pharmacol. 2011;650(1):72-78.20965163
62. Yin HQ, Kim YC, Chung YS, Kim YC, Shin YK, Lee BH. Honokiol reverses alcoholic fatty liver by inhibiting the maturation of sterol regulatory element binding protein-1c and the expression of its downstream lipogenesis genes. Toxicol Appl Pharmacol. 2009;236(1):124-130.19371623
63. Lin YR, Chen HH, Ko CH, Chan MH. Differential inhibitory effects of honokiol and magnolol on excitatory amino acid-evoked cation signals and NMDA-induced seizures. Neuropharmacology. 2005;49(4):542-550.15921707
64. Tsai YC, Cheng PY, Kung CW, et al. Beneficial effects of magnolol in a rodent model of endotoxin shock. Eur J Pharmacol. 2010;641(1):67-73.20519137
65. Fugh-Berman A. Herb-drug interactions. Lancet. 2000;355(9198):134-138.10675182
66. Vanherweghem JL, Depierreux M, Tielemans C, et al. Rapidly progressive interstitial renal fibrosis in young women: association with slimming regimen including Chinese herbs. Lancet. 1993;341(8842):387-391.8094166
67. Schmeiser HH, Bieler CA, Wiessler M, van Ypersele de Strihou C, Cosyns JP. Detection of DNA adducts formed by aristolochic acid in renal tissue from patients with Chinese herbs nephropathy. Cancer Res. 1996;56(9):2025-2028.8616845
68. Zhang B, Maniatis T, Song Y, et al. Evaluation of magnolia bark extract in chromosomal aberration assays. Mutat Res. 2008;654(2):133-137.18639484
69. Kao YH, Jawan B, Sun CK, et al. High concentration of magnolol induces hepatotoxicity under serum-reduced conditions. Phytomedicine. 2010;17(6):469-474.19683908
70. Agosta C, Atlante M, Benvenuti C. Randomized controlled study on clinical efficacy of isoflavones plus Lactobacillus sporogenes, associated or not with a natural anxiolytic agent in menopause. Minerva Ginecol. 2011;63(1):11-17.21311416
71. Campus G, Cagetti MG, Cocco F, et al. Effect of a sugar-free chewing gum containing magnolia bark extract on different variables related to caries and gingivitis: a randomized controlled intervention trial. Caries Res. 2011;45(4):393-399.21822018
72. Ghys K, De Palma A, Vandevenne A, Werbrouck J, Goossens A. Magnolia officinalis bark extract, a recently identified contact allergen in 'anti-ageing' cosmetics. Contact Dermatitis. 2015;73(2):130-132.25958774
73. Muniz FW, Friedrich SA, Silveira CF, Rösing CK. The impact of chewing gum on halitosis parameters: a systematic review. J Breath Res. 2017;11(1):014001.28212110
74. Porciani PF, Grandini S. The effect of zinc acetate and magnolia bark extract added to chewing gum on volatile sulfur-containing compounds in the oral cavity. J Clin Dent. 2012;23(3):76-79.23210417
75. Porciani PF, Grandini S, Chazine M. The effect of zinc lactate and magnolia bark extract added tablets on volatile sulfur-containing compounds in the oral cavity. J Clin Dent. 2014;25(3):53-56.26054178
76. Raison-Peyron N, Césaire A, Du-Thanh A, Dereure O. Allergic contact dermatitis caused by Magnolia officinalis bark extract in a facial anti-ageing cream. Contact Dermatitis. 2015;72(6):416-417.25801445
77. Park KR, Kim JY, Kim EC, Yun HM, Hong JT. RANKL-induced osteoclastogenesis is suppressed by 4-O-methylhonokiol in bone marrow-derived macrophages. Arch Pharm Res. 2017;40(8):933-942. doi:10.1007/s12272-017-0932-z28736799
78. Tian H, Zhao L, Zhang Q, et al. The therapeutic effects of Magnolia officinalis extraction on an antibiotics-induced intestinal dysbacteriosis in mice. Curr Microbiol. 2020;77(9):2413-2421. doi:10.1007/s00284-020-02056-632561976
79. Wang X, Fu S, Zhang C, et al. Gastroprotective effect of ethanol extracts from bark of Magnolia officinalis on ethanol-induced gastric mucosal damage in rats. Biomed Res Int. 2021;2021:6688414. doi:10.1155/2021/668841434159200

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.