Phytochemical and antioxidant studies of Albizia Zygia (DC) Jf Macbride and Trema Orientalis (LINN) Blume

Abstract

Oxidative stress and its attendant health challenges are on the increase. To find a plant-based solution to the challenges, phytochemical and antioxidant properties of the leaf extracts of Albizia zygia (AZ) and Trema orientalis (TO) were investigated. Phytochemical screening of the leaves of AZ and TO was done using standard methods. Hexane, ethyl acetate, and methanol extracts of AZ (AZH, AZE, and AZM) and TO (TOH, TOE, and TOM) were evaluated for their free radical scavenging power in comparison with ascorbic acid (AA), using five different methods. In the DPPH antioxidant assay, AZH, AZE, AZM, TOH, TOE, TOM, and AA had IC₅₀ values of 2.06, 0.28, 0.60, 0.93, 0.40, 0.34, and 0.22 µg/mL respectively. In the ABTS assay, AZH, AZE, AZM, TOH, TOE, TOM, and AA had IC₅₀ values of 1.86, 0.41, 1.58, 2.29, 1.70, 0.73, and 0.27 µg/mL respectively. In the H₂O₂ antioxidant assay, AZH, AZE, AZM, TOH, TOE, TOM and AA had IC₅₀ values of 0.130, 0.040, 0.220, 1.04, 0.044, 0.038, and 0.040 mg/mL respectively. The results of the studies established that both AZ and TO leaves contain tannins, flavonoids, reducing sugars, cardiac glycosides, saponins, terpenoids, and alkaloids, while combined anthraquinones was found in AZ only. Both AZ and TO are rich in phytochemicals with antioxidant properties. The antioxidant assays showed that AZE extract had the highest antioxidant activity compared to other extracts. This study submits that A. zygia and T. orientalis possess potent antioxidant principles that could be developed for the management of oxidative stress.