In vitro antioxidant capacities of eight different kinds of apples and their effects on lipopolysaccharide-induced oxidative damage in mice

In the present study, the DPPH and ABTS⁺ radical scavenging activity of eight types of apples decreased (P < 0.05) during the 70-day storage at 4°C. The Fushi (F2) apples from Xin Jiang showed the highest radical scavenging activity. For in vivo study, 40 male Kunming mice (body weight 20–25 g) were selected and randomly assigned to four groups (10 mice per group). The F2 groups (F2S, F2 + sterile saline and F2L, F2 + lipopolysaccharide) were administered with 0.3 mL F2 filtrate via gastric intubation daily for 28 days. The control groups (CS, CON + sterile saline and CL, CON + lipopolysaccharide) were treated with sterile saline at the same volume. At day 29, mice of F2L and CL groups were injected with 100 μg/kg body weight of lipopolysaccharide (LPS) intraperitoneally, while those of F2S and CS groups were injected equal volume of sterile saline. In comparison to the CS group, the CL group showed a decrease (P < 0.05) in serum, liver, and hepatic mitochondrial antioxidant capacity, reduction (P < 0.05) in the expression of hepatic antioxidant-related genes, and an increase (P < 0.05) in serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), malondialdehyde (MDA), protein carbonyl (PC), and reactive oxygen species (ROS). In comparison to the CL group, the F2L group showed lower (P < 0.05) levels of serum ALT, AST, and ROS, higher (P < 0.05) level of serum, liver, and hepatic mitochondrial antioxidant capacity, increased mitochondrial membrane potential (MMP), and enhanced (P < 0.05) expression of hepatic antioxidant-related genes. These results suggest that F2 may exert protective effect against LPS-induced oxidative damage by improving the antioxidant capacity.