Abstract

HPLC STANDARDIZATION OF PSIDIUM GUAJAVA L. LEAVES CULTIVATED IN EGYPT AND INVESTIGATION OF IN VITRO ANTIOXIDANT ACTIVITY

*Fatema R. Saber

ABSTRACT

Common guava is widely cultivated in Egypt for its fruits, while the leaves are reported to exhibit several biological activities. This study is focusing on HPLC standardization of guava leaf extract using its major isolate quercetin. The quercetin content as resulted from HPLC quantification was 0.0489 ± 0.001 µg/g dried extract. Furthermore, in vitro antioxidant activity was evaluated using FRAP and ABTS assays. Our results showed the powerful antioxidant potential of guava leaves as revealed by 284.00±7.22 and 290.82±13.57 µM Trolox equivalent/mg extract, in ABTS and FRAP assays, respectively. Our results could support the proper use of guava leaf in pharmaceutical and cosmetic preparation as natural antioxidant.

Keywords: Psidium guajava L., HPLC, quercetin, in vitro antioxidant, FRAP, ABTS.