Hancornia speciosa stem bark extract increases hepatic glutathione in rats fed a hypercaloric diet

Diet-induced obesity is associated with hepatic oxidative stress, and reduced glutathione (GSH) is one of the major intracellular non-enzymatic antioxidants involved in maintaining redox homeostasis. The stem bark of Hancornia speciosa (mangabeira), a native Brazilian Cerrado species, contains phenolic compounds, including catechin, epicatechin, procyanidin B2, and phlorizin. However, its effects on hepatic antioxidant defenses remain poorly understood. This study aimed to evaluate the effects of H. speciosa stem bark extract on hepatic antioxidant defenses and markers of oxidative damage in rats fed a hypercaloric diet. Male Wistar rats were allocated to four groups (n = 6–7): control diet (C), control diet plus extract (CM), hypercaloric diet (H), and hypercaloric diet plus extract (HM). The extract was administered daily by oral gavage for 14 weeks in a gel formulation (2 mL, 640 mg/kg body weight, subsequently increased to 3 mL, 820 mg/kg after the animals reached 350 g). Groups C and H received the vehicle gel. Hepatic superoxide dismutase (SOD), glutathione peroxidase (GPx), and myeloperoxidase (MPO) activities, as well as GSH, vitamin C, and protein carbonyl levels, were determined spectrophotometrically. Data were expressed as mean ± SD and analyzed by two-way ANOVA (diet × extract). The hypercaloric diet increased hepatic GPx activity by 48% (F(1,24) = 9.33, p = 0.0059) and vitamin C levels by 23% (F(1,23) = 6.27, p = 0.0198). Extract administration increased hepatic GSH levels by 27% (F(1,24) = 4.71, p = 0.04), independently of diet. No significant effects were observed on SOD or MPO activities or protein carbonyl levels (p > 0.05). The increases in GPx activity and vitamin C levels suggest an adaptive antioxidant response to the hypercaloric diet, whereas the increase in GSH following extract administration indicates modulation of hepatic antioxidant defenses. However, the mechanisms underlying these changes and their implications for oxidative damage remain to be established. In conclusion, H. speciosa stem bark extract increased hepatic GSH levels regardless of dietary condition, suggesting its potential to modulate hepatic antioxidant defenses.

Funding: This study was financed in part by CAPES (Finance Code 001).