A Comparative Study on the Antioxidant and Antidiabetic Activities off Ethanolic Leaf Extracts of Psidium Guajava L. Varieties

Abstract

Antioxidants play an important role in protecting the cell from damage caused by oxidative stress (OS). Plants have potential phytochemicals, which possess antioxidant properties. The present study was designed to investigate the screening of phytochemcials, antioxidant, and antidiabetic properties of ethanolic leaf extracts of Psidium guajava varieties (Lucknow 49 and TRY G1). The leaf extracts were screened for various phytochemicals (alkaloids, flavonoids, saponin, phenols and glycosides) and antioxidant activities. Antidiabetic actives were evaluated by in vitro analysis using standard protocols. The antioxidant activities were determined by DPPH (1,1-diphenyl-2-picrylhydrazine) radical scavenging assay, superoxide radical scavenging assay and nitric oxide radical scavenging assay methods. The phytochemicals screening of the extracts revealed the presence of alkaloids, flavonoids, saponin, phenols, tannins, and glycosides. Among the varieties, Lucknow 49 had higher level of α-amylase inhibitor activity of 62.46 and α -glucosidase inhibitor activity of 98.40 at 100 μg/mL than TRY G1. Both the varieties of the extracts showed antioxidant activities in dose dependent manner, and values were compared with standard ascorbic acid. Lucknow 49 showed the maximum DPPH (60.68%), superoxide radical (65.67%) and nitric oxide radical(61.36%) scavenging activities than TRY G1 variety. The IC50 values of the variety Lucknow 49 were also confirmed antioxidant potentials. The results indicate that both the varieties of Psidium guajava had significant antioxidant and antidiabetic potentials, hence the plant leaves could serve as effective antidiabetic agents and potent free radical scavengers, which may be used for pharmaceutical applications. However, further exploration is necessary for effective usage in both traditional and modern system of medicines.