Delineation of attenuation of oxidative stress and mutagenic stress by Murraya exotica L. leaves

BACKGROUND Murraya exotica L., a member of family Rutaceae is rich in biologically active secondary metabolites and also known for its ethnobotanical importance. With this in mind, the plant was chosen and leaves were extracted sequentially to obtain ethanol, hexane, chloroform, ethyl acetate, n-butanol and aqueous fractions. The extract/fractions were evaluated for total phenolic and flavonoid content by spectrophotometric methods. The UHPLC technique was employed for profiling the different polyphenolic compounds present in the extract/fractions. Furthermore, the extract/fractions were analysed for the antioxidant and antimutagenic activities using different in vitro assays. RESULTS It was observed that, among the different extract/fractions, ethyl acetate fraction exhibited maximum total phenolic content i.e. 119.6 mg of GAE/g whereas chloroform fraction showed maximum total flavonoid content i.e. 323.5 mg of RE/g. Likewise, UHPLC method also showed maximum number as well as amount of polyphenolic compounds in ethyl acetate fraction. It was further analyzed that the same fraction exhibited the maximum radical scavenging activity in all antioxidant assays. In Ames assay, ethyl acetate fraction again showed maximum antimutagenic activity of 97.70 % against the 2-aminofluorene mutagen in TA100 tester strain of Salmonella typhimurium. CONCLUSION Overall, among all the extract/fractions, ethyl acetate fraction was observed to be highly effective in scavenging the free radical as well as reducing the mutagenic effect of the mutagen. The maximum bioactivities of the ethyl acetate fraction may be linked to the presence of high number of polyphenolic compounds as shown by spectrophotometric as well as UHPLC methods.