Brine shrimp lethality and acute toxicity tests of different hydro-methanol extracts of Anacardium occidentale using in vitro and in vivo models: a preliminary study

The antimicrobial, antifungal, antiprotozoal, anthelminthic, and antiviral activities of various part of Anacardium occidentale have been reported in vitro. However, there are no records or documentation on the potential cytotoxicity and acute toxicity effects of the extracts using in vivo study. The present study was conducted to evaluate the cytotoxicity and acute toxicity effects of stem bark, root, stem, and leave extracts using in vivo and in vitro models. Plant materials were extracted using cold maceration in 70% hydro-methanol, and the extracts were concentrated under hot air oven at 40 °C. In brine shrimp lethality assay, five concentrations of each extract (10, 100, 250, 500, and 1000 ppm) were used. Each of the concentration was tested in triplicate and mortality of Artemia salina was monitored for 24 h post exposure. Sea water was used in control group. Acute toxicity testing was conducted according to the method of Organisation for Economic Co-operation and Development (OECD) using 2-week-old cockerels. Dose-probing tests were used to determine the median lethal dose (LD₅₀). Four measures of acute toxicity tests were used, 3000, 1500, 750 and 375 mg/kg in 2-week-old cockerels. The LC₅₀ was estimated using Fumey probit analysis. The LC₅₀ of the four extracts were 336.34, 338.72, 486.36, and 657.62 ppm for stem bark, roots, stem, and leave, respectively. Acute toxicity tests did not show any sign of toxicity as no mortality was recorded in the four extracts. The treatment with all the plant extracts did not cause any morphological changes in the internal organs of the chickens grossly when compared to the control group. The study showed that the extracts of A. occidentale contain bioactive compounds which may be cytotoxic in vitro and non-toxic in vivo and can be used in ethnomedicine.