Toxicity Test of n-Hexane and Ethanol Extracts of Physic Nut Leaves (Jatropha curcas) Using the Brine Shrimp Lethality Test (BSLT) Method

Abstract

Indonesia is a megadiverse country with tremendous potential for medicinal plant development. One traditionally utilized plant is Jatropha curcas L., whose leaves are known to contain various secondary metabolites. This study aimed to determine the cytotoxic activity of n-hexane and ethanol extracts of J. curcas leaves using the Brine Shrimp Lethality Test (BSLT) against Artemia salina Leach larvae and to identify their secondary metabolite profiles. The study was conducted as a laboratory experiment through sequential maceration extraction using n-hexane and 96% ethanol. Phytochemical screening was performed for flavonoids, phenols, steroids, tannins, and alkaloids. Toxicity was assessed against A. salina larvae at concentrations of 100, 200, 300, 400, and 500 ppm, and LC₅₀ values were determined by probit analysis. The n-hexane extract yielded 6.2%, while the ethanol extract yielded 14.3%, suggesting that the polar solvent extracted a greater quantity of compounds from the plant material. Phytochemical screening revealed that solvent polarity governed the secondary metabolite profile: the n-hexane extract contained flavonoids and steroids, whereas the ethanol extract exhibited a broader spectrum comprising flavonoids, phenols, tannins, and alkaloids. BSLT results showed that the ethanol extract (LC₅₀ 74.184 ppm) was nearly five times more toxic than the n-hexane extract (LC₅₀ 342.294 ppm). Both extracts were classified as toxic based on LC₅₀ values below 1000 ppm. The superior cytotoxic activity of the ethanol extract is likely attributable to its diverse polar compounds, particularly flavonoids, phenols, tannins, and alkaloids, which are recognized contributors to toxicity mechanisms against test organisms.