Toxicity study on clinacanthus nutans leaf extract using danio rerio embryos
Plants are believed to have various medicinal benefits from their constituents, but they might also give toxic effects to the human's body. Clinacanthus nutans that belongs to Acanthaceae family, which has been reported to have an antidiabetic and antioxidant effect. The study has been done to determine the toxic level and the lethal concentration of non-polar extract of C. nutans leaves using zebrafish embryos. Crude extract of 80% methanolic solution was further partitioned to obtain the n-hexane fraction. Upon spawning and fertilization, the eggs were collected, transferred into a 96-well plate, and incubated with the n-hexane fraction at different concentrations ranging from 15.63-500 µg/ml prepared in 2% DMSO. The median lethal concentration (LC50) was calculated to be 75.49 µg/mL using probit analysis. The reading is considered toxic to the embryos. The heartbeat rate was measured using DanioScope software, and the mortality and survival rate were assessed by microscopic observation at 24, 48, 72, and 96 hours post-fertilization. Some of the morphological defects observed include less pigmentation, crooked backbone, dented tail, and oedema. The n-hexane fraction's profiling using gas chromatography-mass spectroscopy (GC-MS) analysis showed the presence of some fatty acids, organic acid, and sterols, which is known to be toxic in synergism.