High concentration of magnolol induces hepatotoxicity under serum-reduced conditions

Magnolol reduces myocardial injury induced by renal ischemia and reperfusion

BACKGROUND

Magnolol is a component of the bark of Magnolia officinalis, which is a traditional herbal remedy used in China. In this study, we investigated whether magnolol can reduce myocardial injury induced by renal ischemia and reperfusion (I/R).

METHODS

Renal I/R was elicited by a 60-minute occlusion of the bilateral renal arteries and a 24-hour reperfusion in Sprague-Dawley rats. Magnolol was administered intravenously 10 minutes before renal I/R to evaluate its effects on myocardial injury induced by renal I/R.

RESULTS

Renal I/R significantly increased the serum levels of creatine phosphokinase (CPK), lactate dehydrogenase (LDH), and cardiac troponin I and caused myocardial damage. The terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling-positive nuclei and caspase-3 activation was significantly increased in the myocardium, indicating increase of apoptosis. Echocardiography revealed left ventricular dysfunction, as evidenced by reduction of left ventricular ejection fraction and left ventricular fractional shortening. Furthermore, serum levels of tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, and IL-6 were significantly elevated, while the IL-10 level was suppressed. However, intravenously, pretreatment with magnolol at doses of 0.003 and 0.006 mg/kg 10 minutes before renal I/R significantly prevented the increases of CPK, LDH, and cardiac troponin I levels, as well as the histological damage and the apoptosis in the myocardium. Echocardiography showed significant improvement of left ventricular function. Furthermore, the increases in TNF-α, IL-1β, and IL-6 and the decrease in IL-10 were significantly limited, while Bcl-2 was increased and Bax was decreased in the myocardium. Phosphorylation of Akt and extracellular signal-regulated kinases 1 and 2 was increased, while phosphorylation of p38 and c-Jun N-terminal kinase was reduced.

CONCLUSION

Magnolol reduces myocardial injury induced by renal I/R. The underlying mechanisms for this effect might be related to modulation of the production of pro- and anti-inflammatory cytokines and the limiting of apoptosis.

A case of hepatitis induced by herbal medicine in non-small cell lung cancer patient treated by a combination of immunotherapy and chemotherapy

INTRODUCTION

Consumption of complementary and alternative medicine (CAM) is widely described in cancer patient. However, their composition is not clearly defined and the proofs of safety or effectiveness are quite low. We reported here the case of a CAM-induced hepatitis.

CASE SUMMARY

A 33-years-old men with Non-Small Cell Lung Cancer and treated by combination of immunotherapy and chemotherapy developed hepatitis during 5 months. Viral and iatrogenic etiologies were excluded.

MANAGEMENT AND OUTCOME

Medication reconciliation found concomitant utilisation of CAM. Some of the plants which composed CAM were found to be possible hepatotoxic. After discontinuation of this CAM, liver fonctions normalized. Close monitoring of liver function showed no other hepatitis.

DISCUSSION

CAM induced hepatotoxicity was suspected. Medication reconciliation included CAM is needed in cancer patient to detect drug interactions and CAM side effects to improve cancer patient management.

Magnolol: A Neolignan from the Magnolia Family for the Prevention and Treatment of Cancer

The past few decades have witnessed widespread research to challenge carcinogenesis; however, it remains one of the most important health concerns with the worst prognosis and diagnosis. Increasing lines of evidence clearly show that the rate of cancer incidence will increase in future and will create global havoc, designating it as an epidemic. Conventional chemotherapeutics and treatment with synthetic disciplines are often associated with adverse side effects and development of chemoresistance. Thus, discovering novel economic and patient friendly drugs that are safe and efficacious is warranted. Several natural compounds have proved their potential against this dreadful disease so far. Magnolol is a hydroxylated biphenyl isolated from the root and stem bark of Magnolia tree. Magnolol can efficiently prevent or inhibit the growth of various cancers originating from different organs such as brain, breast, cervical, colon, liver, lung, prostate, skin, etc. Considering these perspectives, the current review primarily focuses on the fascinating role of magnolol against various types of cancers, and the source and chemistry of magnolol and the molecular mechanism underlying the targets of magnolol are discussed. This review proposes magnolol as a suitable candidate that can be appropriately designed and established into a potent anti-cancer drug.

The effect of magnolol on Ca2+ homeostasis and its related physiology in human oral cancer cells

OBJECTIVE

Magnolol, a polyphenol compound from herbal medicines, was shown to alter physiology in various cell models. However, the effect of magnolol on Ca²⁺ homeostasis and its related physiology in oral cancer cells is unclear. This study examined whether magnolol altered Ca²⁺ signaling and cell viability in OC2 human oral cancer cells.

METHODS

Cytosolic Ca²⁺ concentrations ([Ca²⁺]_i) in suspended cells were measured by using the fluorescent Ca²⁺-sensitive dye fura-2. Cell viability was examined by 4-[3-[4-lodophenyl]-2-4(4-nitrophenyl)-2H-5-tetrazolio-1,3-benzene disulfonate] water soluble tetrazolium-1 (WST-1) assay.

RESULTS

Magnolol at concentrations of 20-100 μM induced [Ca²⁺]_i rises. Ca²⁺ removal reduced the signal by approximately 50%. Magnolol (100 μM) induced Mn²⁺ influx suggesting of Ca²⁺ entry. Magnolol-induced Ca²⁺ entry was partially suppressed by protein kinase C (PKC) regulators, and inhibitors of store-operated Ca²⁺ channels. In Ca²⁺-free medium, treatment with the endoplasmic reticulum Ca²⁺ pump inhibitor 2,5-di-tert-butylhydroquinone (BHQ) abolished magnolol-evoked [Ca²⁺]_i rises. Conversely, treatment with magnolol abolished BHQ-evoked [Ca²⁺]_i rises. Inhibition of phospholipase C (PLC) with U73122 partially inhibited magnolol-induced [Ca²⁺]_i rises. Magnolol at 20-100 μM decreased cell viability, which was not reversed by pretreatment with the Ca²⁺ chelator 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid-acetoxymethyl ester (BAPTA/AM).

CONCLUSIONS

Together, in OC2 cells, magnolol induced [Ca²⁺]_i rises by evoking partially PLC-dependent Ca²⁺ release from the endoplasmic reticulum and Ca²⁺ entry via PKC-sensitive store-operated Ca²⁺ entry. Magnolol also caused Ca²⁺-independent cell death. Therefore, magnolol-induced cytotoxicity may not be involved in activation mechanisms associated with intracellular Ca²⁺ mobilization in oral cancer cells.

Magnolol Reduces Renal Ischemia and Reperfusion Injury via Inhibition of Apoptosis

Magnolol, a constituent of the bark of Magnolia officinalis, has been reported to decrease myocardial stunning and infarct size. In this study, we investigated whether magnolol can reduce renal ischemia and reperfusion (I/R) injury. Renal I/R, induced by a 60-min occlusion of bilateral renal arteries and a 24-h reperfusion, significantly increased blood urea nitrogen (BUN) and creatinine levels, and caused histological damage to the kidneys of rats. Apoptosis, as evaluated by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) staining and caspase-3 activation, was significantly increased in the kidneys. Furthermore, serum levels of tumor necrosis factor-[Formula: see text] (TNF-[Formula: see text]), interleukin-1β (IL-1β), and interleukin-6 (IL-6) were significantly elevated, while the interleukin-10 (IL-10) level was suppressed. However, intravenous pretreatment with magnolol at doses of 0.003[Formula: see text]mg/kg and 0.006[Formula: see text]mg/kg 10[Formula: see text]min before renal I/R significantly limited the increases of BUN, creatinine, the histological damage, and apoptosis in the kidneys. The increases in TNF-[Formula: see text], IL-1β, and IL-6, and the decrease in IL-10 were also significantly inhibited. Additionally, magnolol increased Bcl-2 and decreased Bax in the kidneys. Phosphorylation of the prosurvival kinases, including Akt and extracellular signal-regulated kinases 1 and 2 (ERK1/2), was elevated, while phosphorylation of the pro-apoptotic mitogen-activated protein kinases, including p38 and c-Jun N-terminal kinase (JNK), was suppressed. In conclusion, magnolol reduces renal I/R injury. The underlying mechanisms for this effect might be related to the prevention of apoptosis, possibly via the inhibition of both extrinsic and intrinsic apoptotic pathways, including the reduction of TNF-[Formula: see text] production and the modulation of pro- and anti-apoptotic signaling elements.

Magnolol suppresses the proliferation and invasion of cholangiocarcinoma cells via inhibiting the NF-κB signaling pathway

BACKGROUND

Magnolol has shown the potential anticancer properties against a variety of cancers. However, the role of magnolol in cholangiocarcinoma (CCA) cells is unknown. In this study, we assessed the effect of magnolol on the CCA cells.

METHODS

CCA cells were treated with magnolol in the absence or presence of TNFα, the activator for NF-κB. After co-incubation with magnolol, cell proliferation and growth were examined by MTT, colony formation and xenograft tumors; cell cycle was analyzed by flow cytometry; cell migration and invasion were detected by wound healing and transwell assays; the expression of PCNA, Ki67, CyclinD1, MMP-2, MMP-7 and MMP-9 and NF-κB pathway were evaluated by using Western blot.

RESULTS

Magnolol inhibited the abilities of CCA cell growth, migration and invasion accompanying with a decreased expression of PCNA, Ki67, MMP-2, MMP-7 and MMP-9 (all P<0.05).

TREATMENT

with magnolol induced cell cycle arrest in G1 phase with a downregulation of cell cycle protein CyclinD1 (all P<0.05). In addition, magnolol suppressed the expression of p-IκBα and p-P65 and the effect of magnolol on CCA cells could be inhibited by TNFα.

CONCLUSIONS

Magnolol could inhibit the growth, migration and invasion of CCA cells through regulation of NF-κB pathway, and these data indicate that magnolol is a potential candidate for treating of CCA.

Is there a potential of misuse for Magnolia officinalis compounds/metabolites?

OBJECTIVE

Magnolia bark contains magnolol, metabolized to tetrahydromagnolol and honokiol, with both GABA-ergic/cannabimimetic activities, hence of possible attraction to vulnerable individuals/recreational misusers.

METHODS

A literature review, assessment of related anecdotal online Magnolia misuse's reports and an overview of Magnolia products' online acquisition possibilities has been here described.

RESULTS

No peer-reviewed papers about Magnolia abuse/misuse/dependence/addiction were identified. Conversely, from a range of websites emerged potentially 3 groups of Magnolia misusers: (a) subjects with a psychiatric history already treated with benzodiazepines, being attracted to Magnolia bark as a "natural sedative"; (b) polydrug misusers, ingesting Magnolia with a range of other herbs/plants, attracted by the GABA-ergic/cannabimimetic activities; (c) subjects naive to the misusing drugs' scenario, perceiving Magnolia as a natural dietary supplement/weight-control compound.

CONCLUSIONS

To the best of our knowledge, this is the first paper commenting on the possible Magnolia derivatives' potential of misuse. Magnolia's recent increase in popularity, mainly as a sedative, may be arguably due to its peculiar pharmacological properties/acceptable affordability levels/virtually worldwide favorable legal status and customers' attraction to a product being perceived as "natural" and hence somehow "safe." Future/potent/synthetic magnolol and honokiol structural analogues could however contribute to increasing the number of synthetic GABA-ergic/cannabimimetic misusing compounds.

Protective effect of magnolol-loaded polyketal microparticles on lipopolysaccharide-induced acute lung injury in rats

Magnolol has shown inhibitory effects on NO production and TNF-alpha production in lipopolysaccharide (LPS)-activated macrophages and LPS-induced acute lung injury; however, the poor solubility of magnolol has hindered its clinical success. In this study, magnolol-loaded microparticles were prepared via single emulsion method from a polyketal polymer, termed PK3. The particle sizes of magnolol-loaded PK3 microparticle is 3.73 ± 0.41 μm, and was suitable for phagocytosis by macrophages and pulmonary drug delivery. PK3 microparticles exhibited excellent biocompatibility both in vitro and in vivo. More importantly, intratracheal delivery of these magnolol-loaded microparticles significantly reduced the lung inflammatory responses at low dosage of magnolol (0.5 mg/kg), and have great clinical potential in treating acute lung injury.

Anti-arthritic effects of magnolol in human interleukin 1β-stimulated fibroblast-like synoviocytes and in a rat arthritis model

Fibroblast-like synoviocytes (FLS) play an important role in the pathologic processes of destructive arthritis by producing a number of catabolic cytokines and metalloproteinases (MMPs). The expression of these mediators is controlled at the transcriptional level. The purposes of this study were to evaluate the anti-arthritic effects of magnolol (5,5'-Diallyl-biphenyl-2,2'-diol), the major bioactive component of the bark of Magnolia officinalis, by examining its inhibitory effects on inflammatory mediator secretion and the NF-κB and AP-1 activation pathways and to investigate its therapeutic effects on the development of arthritis in a rat model. The in vitro anti-arthritic activity of magnolol was tested on interleukin (IL)-1β-stimulated FLS by measuring levels of IL-6, cyclooxygenase-2, prostaglandin E(2), and matrix metalloproteinases (MMPs) by ELISA and RT-PCR. Further studies on how magnolol inhibits IL-1β-stimulated cytokine expression were performed using Western blots, reporter gene assay, electrophoretic mobility shift assay, and confocal microscope analysis. The in vivo anti-arthritic effects of magnolol were evaluated in a Mycobacterium butyricum-induced arthritis model in rats. Magnolol markedly inhibited IL-1β (10 ng/mL)-induced cytokine expression in a concentration-dependent manner (2.5-25 µg/mL). In clarifying the mechanisms involved, magnolol was found to inhibit the IL-1β-induced activation of the IKK/IκB/NF-κB and MAPKs pathways by suppressing the nuclear translocation and DNA binding activity of both transcription factors. In the animal model, magnolol (100 mg/kg) significantly inhibited paw swelling and reduced serum cytokine levels. Our results demonstrate that magnolol inhibits the development of arthritis, suggesting that it might provide a new therapeutic approach to inflammatory arthritis diseases.