Acute and sub-acute toxicity studies of hydro-alcoholic extract of dried fruits of Piper longum Linn in Wistar rats

Abstract

The current study evaluated the prospective toxicity of hydroalcoholic extract of Piper longum L. (HEPL) dried fruits with acute and sub-acute oral administration in Wistar rats. During acute toxicity study, female rats were orally administered with HEPL at a single dose of 300 mg/kg and repeated dose of 2000 mg/kg (OECD guidelines-423). Subacute toxicity of HEPL (250, 500, and 1000 mg/kg p.o.) was studied with the control group (1% CMC) by daily dosing in Wistar rats of both sexes for 28 days. To assess reversibility, other satellite groups were kept for another two weeks post-treatment. The acute toxicity study showed no lethal effects, and toxicity signs and LD₅₀ transpire more significantly than 2000 mg/kg. In subacute toxicity study, oral administration of extract for 28 days; caused no significant changes in body weights; food and water consumption of rats were observed. In addition, no toxic effects of the extract on rats for hematological and biochemical parameters were observed. Histopathological analysis revealed no signs of degeneration for kidneys, testis, and ovaries; however liver showed mild multifocal hepatocellular necrosis with infiltration of inflammatory cells in rats treated with 1000 mg/kg of HEPL. These results showed that 250 mg/kg and 500 mg/kg were found safe, in addition to some liver toxicity was found for 1000 mg/kg. It is concluded that the oral LD₅₀ of HEPL was more significant than 2000 mg/kg and is considered safe. Hence, Piper longum is safe in the short and long term for an oral dose.