Evaluation of the toxic effects of the aqueous extract of Niprineem tea in mice and rats

Abstract

Azadirachta indica is an important plant in traditional complementary and alternative medicine with decoctions (tea) being a common mode of administration. Herbal teas are frequently self-administered thus the need to prepare a standardized dosage form for the administration of such decoctions. The leaf of Azadirachta indica was formulated for administration as tea; thus, this study was designed to determine the safety profile of Niprineem tea. Oral acute and sub-chronic toxicity studies of the aqueous extract of Niprineem tea (NTE) were evaluated. The OECD (No 423) limit test was followed to determine the LD50 in Swiss albino mice, while OECD 407 guideline was used for the sub-chronic toxicity studies in Wistar rats. Acute administration of NTE did not cause detectable signs of toxicity in treated animals and no mortality was recorded. In the 28-day toxicity tests, there were no significant (p<0.05) changes in food and water intake, or urine and faecal output. Haematological analysis did not show deleterious effects in treated rats. Biochemical evaluation of indicators for renal and hepatic functions did not show significant changes after treatment with NTE. Likewise, histological tests did not result in structural changes in cells of the tissues of major organs. The results obtained suggest that Niprineem tea is relatively non-toxic and safe at the tested dose.