Evaluation of the Antioxidant, Antihyperglycemic, and Haemolytic Activities of Hydroalcoholic Extracts of Red and White Pithecellobium dulce Aril at Different Stages of Ripening.

Abstract

Pithecellobium dulce Benth. commonly known in Mexico as "guamúchil", has been used to treat different diseases due to its pharmacological attributes. P. dulce arils are an important source of metabolites, with antioxidant and antihyperglycemic activities. Scarce studies have evaluated the antioxidant capacity, total phenolic content (TPC), and total anthocyanin content (TAC) in the red aril variety at different maturity stages, to our knowledge, no one has evaluated these properties in the white aril variety. The antihyperglycemic activity at different stages of ripening in P. dulce has not yet been reported. Also, its biosafety in human erythrocytes remains unexplored. This study assessed the in vitro antioxidant, antihyperglycemic, and haemolytic activities of red and white P. dulce aril hydroalcoholic extracts at different stages of ripening. The red mature aril (MRA) hydroalcoholic extracts presented the higher TPC (3103.2 ± 429.5 mgGAE·100 g^-1), flavonoid content (TFC) (98.8 ± 4.7 mgQE·100 g^-1) and TAC (31.4 ± 8.0 mgC3G·100 g^-1). White and immature red arils did not show TAC. The MRA extract showed the highest antioxidant capacity (53,097.2 ± 2,810.4 µmolTE·100 g^-1), and inhibitory activity on α-glucosidase enzyme (IC₅₀ = 53.38 ± 6.63 µg·mL^-1). The immature red aril (IRA) extract showed the highest inhibitory activity versus the α-amylase enzyme (IC₅₀ = 24.10 ± 0.89 µg·mL^-1). All extracts presented non-haemolytic activity (< 2.0% haemolysis). In conclusion, the MRA extract could be a promising constituent in functional foods focused to manage inflammatory diseases or diabetes mellitus type 2, due to its high antioxidant capacity and antihyperglycemic activity. Furthermore, the non-haemolytic activity suggests that the MRA extract is potentially safe for human use, especially in drug formulations or biomedical applications.