Antioxidant activity, total phenolic content and total flavonoid content of ethanolic leaf extract of Psidium guajava l.

Abstract

This study evaluated the in vitro antioxidant activity, total phenolic content (TPC), and total flavonoid content (TFC) of ethanolic guava (Psidium guajava L.) leaf extract collected from Savar, Dhaka. The extract showed concentration-dependent DPPH radical scavenging activity, with an IC₅₀ value of 169.04 µg/mL, TPC of 471.17 ± 50.40 mg GAE/g, and TFC of 132.01 ± 11.17 mg QE/g. Strong correlations between antioxidant activity and phenolic and flavonoid contents suggest their contribution to the extract’s antioxidant properties. The findings highlight guava leaves as an inexpensive source of natural antioxidants and support further investigation into their therapeutic potential.