Potential Bioactivity of Guava Leaf Extract (Psidium guajava L.) as a Natural Therapeutic Agent: A Review

Guava leaves (Psidium guajava L.) are rich in bioactive compounds such as flavonoids, tannins, saponins, and terpenoids. These compounds contribute to the plant's traditional and medicinal use, showing promise as a phytopharmaceutical for treating various ailments.

Guava leaf extract exhibits significant antidiabetic activity by inhibiting the alpha-amylase enzyme, regulating glucose uptake, and improving insulin sensitivity. As an antioxidant, it effectively scavenges free radicals, with studies showing efficacy comparable to or better than standard controls.

The extract demonstrates strong antibacterial effects against pathogens like E. coli and V. cholerae, largely attributed to its tannin content. Its anti-inflammatory properties are linked to the stabilization of cell membranes, helping to mitigate inflammatory responses.

Guava leaf extract serves as an immunomodulator by enhancing macrophage phagocytic activity. Additionally, it shows potential anticancer activity by inducing apoptosis and inhibiting cancer signaling pathways, specifically showing effectiveness against leukemia, tongue carcinoma, and multiple myeloma cells.

The extract acts as an effective antidiarrheal by reducing gut inflammation and balancing intestinal ions, primarily through the action of quercetin. Various extraction methods, including maceration, Soxhlet, and ultrasonic techniques, have been studied to optimize the recovery of these beneficial bioactive compounds.