Kava feeding in rats does not cause liver injury nor enhance galactosamine-induced hepatitis.
DiSilvestro RA, Zhang W, DiSilvestro DJ.
Human Nutrition, The Ohio State University, 345 Campbell Hall, 1787 Neil Avenue, Columbus, OH 43210-1295, United States. disilvestro.1@osu.edu
Kava, like a number of herbals, has been associated with causing liver damage based on limited evidence. In contrast, the present study found that in rats, 3 mo feedings of two types of kava extracts (an acetone extract and an ethanol extract of the Samoan kava cultivar Ava Laau) at three different doses (31.25, 62.5 and 133 mg/kg diet) produced no liver injury based on serum markers of liver damage (sorbitol dehydrogenase activities, bile acid concentrations, and beta-glucuronidase activities) and serum lipid peroxide readings. In fact, for some measurements and some kava doses, the injury marker readings were below control values. Moreover, for these same parameters, kava feeding did not enhance the effects of the hepatotoxin galacatosamine (500 mg/kg ip); some kava doses even showed modest protection against liver injury. Liver histology analysis showed no signs of kava causing or enhancing liver injury. Thus, this study does not support the concept that kava produces or aggravates liver injury.
(Source: ScienceDirect)
Safety of ethanolic kava extract: Results of a study of chronic toxicity in rats.
Sorrentino L, Capasso A, Schmidt M.
Department of Experimental Pharmacology, University Frederico II, Via D Montesano 49, I-80131 Napoli, Italy. ludovico.sorrentino@unina.it
BACKGROUNDS: Recently, potential liver toxicity was discussed with the intake of kava extract preparations (Piper methysticum) as anxiolytic drugs. The aim of this study was to test chronic toxicity in rats by oral application of an ethanolic kava full extract. METHODS: Wistar rats of both sexes were fed 7.3 or 73 mg/kg body weight of ethanolic kava extract for 3 and 6 months. The animals were examined for changes in body weight, hematological and liver parameters, and macroscopical and microscopical histological changes in the major organs. RESULTS: No signs of toxicity could be found. CONCLUSIONS: The results are in accordance with the medical experience regarding the use of kava preparations and the long tradition of kava drinking in the South Pacific island states. Specifically, the results do not back the suspicion of potential liver toxicity.
from source: 1: Phytomedicine. 2006 Sep;13(8):542-9. Epub 2006 Aug 14.
Evaluation of commercial kava extracts and kavalactone standards for mutagenicity and toxicity using the mammalian cell gene mutation assay in L5178Y mouse lymphoma cells
Paul Whittakera, 
, 
, Jane J. Clarkeb, Richard H.C. Sanb, Joseph M. Betzc, Harold E. Seifriedd, Lowri S. de Jagera and Virginia C. Dunkela
aCenter for Food Safety and Applied Nutrition, Food and Drug Administration, 5100 Paint Branch Parkway, HFS-717, College Park, MD 20740-3835, United States
bBioReliance, Rockville, MD, United States
cOffice of Dietary Supplements, National Institutes of Health, Bethesda, MD, United States
dNational Cancer Institute, National Institutes of Health, Bethesda, MD, United States
Received 11 May 2007; accepted 17 July 2007. Available online 31 July 2007.
Abstract
Kava (Piper methysticum) is a member of the pepper family and has been cultivated by South Pacific islanders for centuries and used as a social and ceremonial drink. Traditionally, kava extracts are prepared by grinding or chewing the rhizome and mixing with water and coconut milk. The active constituents of kava are a group of approximately 18 compounds collectively referred to as kavalactones or kava pyrones. Kawain, dihydrokawain, methysticin, dihydromethysticin, yangonin, and desmethoxyyangonin are the six major kavalactones. Kava beverages and other preparations are known to be anxiolytic and are used for anxiety disorders. Dietary supplements containing the root of the kava shrub have been implicated in several cases of liver toxicity in humans, including several who required liver transplants after using kava supplements. In order to study the toxicity and mutagenicity, two commercial samples of kava, Kaviar and KavaPure, and the six pure kavalactones including both d-kawain and dl-kawain, were evaluated in L5178Y mouse lymphoma cells. Neither the kava samples nor the kavalactones induced a mutagenic response in the L5178Y mouse lymphoma mutation assay with the addition of human liver S9 activation.
Safety of ethanolic kava extract: Results of a study of chronic toxicity in rats
L. Sorrentinoa, , , A. Capassob and M. Schmidtc
aDepartment of Experimental Pharmacology, University Frederico II, Via D. Montesano 49, I-80131 Napoli, Italy
bDepartment of Pharmaceutical Sciences, University of Salerno, Via Ponto Don Melillo, I-84084 Fisciano, Salerno, Italy
cHerbresearch Germany, Wartbergweg 15, D-86874 Tussenhausen, Germany
Abstract
Backgrounds
Recently, potential liver toxicity was discussed with the intake of kava extract preparations (Piper methysticum) as anxiolytic drugs. The aim of this study was to test chronic toxicity in rats by oral application of an ethanolic kava full extract.
Methods
Wistar rats of both sexes were fed 7.3 or 73 mg/kg body weight of ethanolic kava extract for 3 and 6 months. The animals were examined for changes in body weight, hematological and liver parameters, and macroscopical and microscopical histological changes in the major organs.
Results
No signs of toxicity could be found.
Conclusions
The results are in accordance with the medical experience regarding the use of kava preparations and the long tradition of kava drinking in the South Pacific island states. Specifically, the results do not back the suspicion of potential liver toxicity.
