Antioxidant Properties of Jatropha curcas L. Seed Shell and Kernel Extracts

The purpose of this study was to determine the antioxidant activity of the seed shells and kernels of Jatropha curcas L. The extracts obtained from five solutions (0%–95% ethanol) were tested and compared. Overall, the antioxidant capacity of seed shell extracts was higher than that of seed kernel extracts. The seed shell extract obtained using 95% ethanol exhibited the best antioxidant activity among the five solutions. The half-maximal inhibitory concentration (IC50) of 1,1-diphenyl-2-picrylhydrazyl and free radical scavenging ability of 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) were 13.63 ± 0.15 and 6.75 ± 0.51 μg/mL, respectively. The reduction ability and total phenol content were 95.14 ± 27.04 μg ascorbic acid equivalents/mg of extract and 536.33 ± 8.62 μg gallic acid equivalents/mg of extract, respectively. In in vitro cytotoxicity assays, solutions with less than 250 μg/mL of seed shell extract had no major cytotoxicity. The seed shell of Jatropha curcas L. can be used as an antioxidant material and has potential for biomedical applications.