HÀM LƯỢNG POLYPHENOL TỔNG, HOẠT TÍNH KHÁNG OXI HÓA, KHÁNG KHUẨN VÀ KHÁNG NẤM CỦA CAO CHIẾT LÁ ỔI SẺ (Psidium guajava L.)

Abstract

Guava leaves, a common source of raw material in the Mekong Delta, possess various biological activities such as antioxidant, antibacterial, anti-inflammatory, antidiabetic, and anti-diarrheal properties. However, this rich and naturally regenerative medicinal source has not been efficiently and properly exploited. This study investigated the total polyphenol content, antioxidant, antibacterial, and antifungal activities of methanol extract of guava leaves by maceration method. Antioxidant activity was performed by DPPH and ABTS methods, while antibacterial and antifungal activities were tested by the dilution method for concentration. The results showed that guava leaf extract had the strongest antioxidant activity on the DPPH method (EC₅₀=19.36µg/mL) and the most effective inhibition against Gram-positive bacterium Staphylococcus aureus (IC₅₀=64.00±4.57µg/mL). These findings open up avenues for the development of natural biologically active products from guava leaves.