Identification and preparation of selenium‐containing peptides from selenium‐enriched Pleurotus eryngii and their protective effect on lead‐induced oxidative damage in NCTC1469 hepatocytes

Abstract

AbstractBACKGROUNDLead (Pb) is a highly toxic and persistent substance that easily accumulates in living organisms, eliciting cellular toxicity and oxidative stress. Some selenium‐containing proteins and peptides prepared from plant extracts are beneficial for protecting the body's health and resisting external disturbances. In the present study, selenium‐containing peptide species were prepared from selenium‐enriched Pleurotus eryngii protein hydrolysates and to evaluate the benefits of selenium‐containing peptides on Pb‐induced oxidative stress in NCTC1469 hepatocytes.RESULTSTrypsin was selected as primary enzyme to hydrolyze the selenium‐enriched protein (SPH). The optimal hydrolysis conditions were: hydrolysis time, 1.5 h; initial pH 8.0. The SPH was digested by trypsin and then purified by ultrafiltration, gel filtration chromatography and reversed‐phase HPLC to obtain the selenium‐containing peptides SPH‐I‐2. Furthermore, SPH‐I‐2 was analyzed and a number of total 12 selenium‐containing peptides were identified by liquid chromatography‐tandem mass spectroscopy. The NCTC1469 cell culture study showed that selenium‐containing peptides were capable of reducing reactive oxygen species levels and regulating the Keap1/Nrf2 pathway by upregulating Nrf2, HO‐1, GCLC, GCLM and NQO1 genes and downregulating Keap1 genes. Moreover, selenium‐containing peptides were also able to suppress Pb‐induced elevated levels of nitric oxide (NO), lactate dehydrogenase (LDH), malondialdehyde (MDA), increase antioxidant enzyme activity and alleviate cell apoptosis.CONCLUSIONThe present study indicated that the selenium‐containing peptides could protect cells from Pb2+‐induced oxidative stress. © 2023 Society of Chemical Industry.