In vivo antioxidant activity of Cinnamomum cassia leaf residues and their effect on gut microbiota of d‐galactose‐induced aging model mice

Abstract BACKGROUND To thoroughly explore the values of Cinnamomum cassia leaf residues (CcLR), their antioxidant activity in vivo and the relationship with gut microbiota were investigated using d ‐galactose‐induced aging mice. RESULTS Results showed that CcLR extract treatment exerted antioxidant activity by increasing the levels of superoxide dismutase ( P < 0.01) and glutathione peroxidase ( P < 0.05), as well as inhibiting the formation of malondialdehyde ( P < 0.01). Meanwhile, the inflammatory response was also alleviated as the ratio of pro‐inflammatory tumor necrosis factor‐α ( P < 0.01) and interleukin‐1β ( P < 0.01))/anti‐inflammatory cytokines (interleukin‐10; P < 0.05) in serum was decreased and the contents of inflammatory markers (induced nitrogen monoxide synthase and nitric oxide) in brain and liver tissues ( P < 0.01) were reduced. Moreover, through inhibiting acetylcholinesterase activity and improving choline acetyltransferase activity, the cholinergic system in aging mice recovered to levels comparable to the normal control group. In addition, 16S rRNA sequencing results demonstrated that CcLR extract promoted the growth of beneficial bacteria. In particular, Spearman correlation analysis revealed that the abundance of Colidextribacter was negatively correlated with serum superoxide dismutase ( P < 0.05, R = −0.943), and Helicobacter displayed a positive correlation with the content of brain nitric oxide ( P < 0.05, R = 0.899), suggesting that regulating gut microbiota might be one of the mechanisms for reducing oxidative stress, thus postponing the aging process. CONCLUSION It is suggested that CcLR extract could be used as a novel antioxidant and anti‐aging resource in the pharmaceutical and food industries. © 2022 Society of Chemical Industry.