Guava (Psidium guajava L.) Leaves: Nutritional Composition, Phytochemical Profile, and Health-Promoting Bioactivities

Guava leaves (Psidium guajava L.) are a rich source of bioactive compounds frequently used in traditional medicine to treat conditions such as diabetes, diarrhea, inflammatory disorders, and respiratory issues. Often considered agricultural waste, these leaves are gaining attention in the pharmaceutical and nutraceutical sectors for their therapeutic properties.

Guava leaves contain a comprehensive nutritional profile, including proteins, carbohydrates, vitamins (C and B), and essential minerals like calcium, potassium, and magnesium. Key chemical components include polysaccharides (which exhibit antidiabetic and antioxidant effects), essential oils (rich in caryophyllene and limonene), and a significant concentration of phenolic compounds such as quercetin, which provides antioxidant and metabolic benefits.

The biological activity of guava leaf extract is driven by its diverse array of secondary metabolites. Research highlights significant anticancer and antitumor potential, particularly against colon, breast, cervical, and prostate cancers. Bioactive compounds like psiguadials and flavonoids work by inhibiting tumor angiogenesis, inducing apoptosis, and modulating cell signaling pathways.

Due to their low cost and high density of health-promoting compounds, guava leaves are highly promising for the development of functional foods and complementary medicines. Future research is focused on isolating specific chemical components to develop targeted therapies and mitigate challenges like drug resistance in modern medicine.