| Animal Research: |
| Toxicological ences : an official journal of the Society of Toxicology, 2007, 97(1):214. | | Effects of Kava Alkaloid, Pipermethystine, and Kavalactones on Oxidative Stress and Cytochrome P450 in F-344 Rats.[Reference: WebLink] | Kava-containing products remain popular in the United States and continue to be sold in health food stores and ethnic markets regardless of the fact that it was banned in Western countries such as Germany, France, Switzerland, Australia, and Canada, following reports of alleged hepatotoxicity. It is therefore critical to establish efficacy and verify adverse effects and/or herb-drug interactions for kava-kava (Piper methysticum). We have previously demonstrated that kava alkaloid, Pipermethystine (PM), abundant in leaves and stem peelings, induces mitochondrial toxicity in human hepatoma cells, HepG2, as compared with the bioactive components, kavalactones (KL), abundant in the rhizome.
METHODS AND RESULTS:
The current study compared short-term toxic effects of PM in Fischer-344 (F-344) rats to acetone-water extracts of kava rhizome (KRE).
CONCLUSIONS:
Treatment of F-344 rats with PM (10 mg/kg) and KRE (100 mg/kg) for 2 weeks failed to elicit any significant changes in liver function tests or cause severe hepatic toxicity as measured by lipid peroxidation and apoptosis markers such as malondialdehyde, Bax, and Bcl-2. However, PM-treated rats demonstrated a significant increase in hepatic glutathione, cytosolic superoxide dismutase (Cu/ZnSOD), tumor necrosis factor α mRNA expression, and cytochrome P450 (CYP) 2E1 and 1A2, suggesting adaptation to oxidative stress and possible drug-drug interactions. |
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| Structure Identification: |
| Phytochemistry, 2003, 63(2):193-198. | | Piperidine alkaloids from Piper methysticum.[Reference: WebLink] |
METHODS AND RESULTS:
Pipermethystine (1), 3alpha,4alpha-epoxy-5alpha-Pipermethystine (2) and awaine (3) were isolated from the aerial parts of kava (Piper methysticum G. Forster, Piperaceae) and identified by HRMS and NMR spectroscopic analysis. 1 was concentrated in the stem peelings and leaves. 2 and 3 are new alkaloids with 2 found only in cv. Isa among the 11 cultivars examined, and 3 occurred primarily in young leaves of all cultivars.
CONCLUSIONS:
The stem peelings have been used in recent years as a source of kavalactones in kava dietary supplement industry. Quantitative aspects of these piperidine alkaloids in P. methysticum and their potential activities on human physiology are discussed. |
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