Detection of Volatiles by HS-SPME-GC/MS and Biological Effect Evaluation of Buddha's Hand Fruit

The present work aimed to chemically characterize and evaluate the antiradical power and biological effects of Citrus medica var. sarcodactylus essential oil (EO) and hydrolate (Hy) from exocarp as well as methanol extracts, from both exocarp and mesocarp (EEX and MEX). The whole fresh fruit was also investigated by SPME-GC/MS to describe its volatile composition. EO and Hy were analyzed by GC/MS and HS-GC/MS techniques, respectively. Limonene and gamma-terpinene were found to be the most abundant compounds both in the fresh parts of the fruit and in the EO, while alpha-terpineol and terpinen-4-ol were in the Hy. The extracts were also rich in furan and coumarin derivatives. A good antiradical activity of all samples except Hy was detected both against ABTS center dot+ than DPPH center dot, removed up to about 50%. The antibacterial activity against Bacillus cereus and Escherichia coli was evaluated by microwell dilution method to determine MIC and MBC values. EEX and MEX showed efficacy at very high concentrations against both tested bacteria. The MIC value of EO against B. cereus was 0.5% v/v, while Hy was not able to inhibit the bacterial growth at the tested concentrations. Cytotoxicity investigated on the HL60 leukemia cell line by MTT assay provided an EC50 of 1.24% v/v for EO. Interesting activity of Hy was also observed.

Automated summary

The present study chemically characterized the volatile composition of Citrus medica var. sarcodactylus fruit and evaluated the antiradical power, antibacterial activity, and cytotoxicity of its essential oil, hydrolate, and methanol extracts. The results showed that limonene and gamma-terpinene were the most abundant compounds in the fruit, and the essential oil exhibited good antiradical and antibacterial activities. The hydrolate did not show antibacterial activity, while the methanol extracts from both the exocarp and mesocarp had high efficacy against the tested bacteria. The extracts also showed cytotoxicity against leukemia cells.