Purpose: To investigate the antioxidant effect of the methanol extract of Psidium guajava L. fruit. Methods: Freshly harvested fruits of Psidium guajava were washed, and pulverized, and then 10 g of milled fruit puree was homogenized with 100 mL of methanol and centrifuged to obtain the supernatant. Catalase (CAT) activity, glutathione (GSH), and malondialdehyde (MDA) levels were determined by spectrophotometry. The findings were subjected to correlation and regression analysis. Results: Levels of catalase, glutathione, and malondialdehyde were 0.074 ± 0.0021 U/L, 0.0764 ± 0.0021 mmol/g, protein and 1.0931 ± 0.1573 μmol/L, respectively. Positive correlation was detected between MDA levels and GSH, CAT and GSH, and GSH and MDA levels. Predicted values of MDA were obtained from GSH and CAT activity. Conclusion: Psidium guajava L. exerts antioxidant activity which is linked to changes in MDA levels. It may therefore be considered a promising source for the development of active pharmaceutical ingredients with antioxidant properties.
AÇIKGÖZ et al. (Fri,) studied this question.