Identification of natural substances with antioxidant properties is ongoing research for addressing issues related to oxidative stress especially attributed to environmental effects. Our previous study demonstrated that Lateolabrax japonicus peptides (LPH), rich in Glu, Gly, and hydrophobic amino acids, exhibited remarkable antioxidant activity in vitro, with though its action mechanism yet to be revealed. Therefore, to assess the in vivo antioxidative properties of LPH, we employed H₂O₂ to generate oxidative stress in Drosophila melanogaster model. Results indicated that LPH significantly prolonged the lifespan of Drosophila subjected to oxidative stress mostly mediated via LPH's enhancement of the antioxidant defense system and intestinal functions. Antioxidant effects were manifested by a decrease in malondialdehyde (MDA) levels, elevated superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) activities, decreased levels of reactive oxygen species (ROS) in intestinal epithelial cells, and the preservation of intestinal length. LPH effectively controlled the excessive proliferation and differentiation of oxidative stress-induced Drosophila intestinal stem cells. At the gene level, LPH upregulated the expression of antioxidant-related Nrf2 genes while concurrently downregulated mTOR expression level. Furthermore, high-throughput 16S rDNA sequencing revealed that the addition of LPH significantly influenced the diversity and abundance of the intestinal microbiota in H₂O₂-induced Drosophila. These findings provide a deeper understanding of the antioxidative mechanism of LPH, suggesting its potential applications in food industry and to be assessed using other in vivo oxidative stress models.

The purpose of this study was to explore the potential of the development and application of Paecilomyces hepiali, a fungus with edible and medicinal value, as a foodborne antioxidant and anti-aging agent. Its n-butanol extract (PHE) from rice cultures was selected for anti-aging experiment because of significant free radical scavenging activity in vitro. In vivo, PHE could significantly prolong the mean lifespan, 50 % survival days, and the maximum lifespan of Drosophila on a high-fat diet. It is amazing that the mean lifespan increased from 19.1 days to 32.9 days, 50 % survival days increased from 15.7 days to 34.3 days, and the maximum lifespan extended from 44.7 days to 52.7 days, when the high-fat female Drosophila model was fed with 10 μg/mL PHE. Further research showed that PHE reduced the accumulation of peroxide products and increased the activity of antioxidant enzymes. Then, through antioxidant activity tracking, dimerumic acid (compound 1, the IC₅₀ value of 3.4 μg/mL on DPPH free radicals scavenging activity), 4, 5-dihydroxy-3-methoxypentanoic acid (compound 2, new compound), and thymidine (compound 3) were isolated from PHE. It is worth mentioning that dimerumic acid, the major antioxidant compound of PHE (content up to 3 %), was discovered in P. hepiali for the first time. It was concluded that PHE showed excellent anti-aging activity at a very low concentration on fat diet-induced high fat Drosophila melanogaster, and dimerumic acid may be its main material basis. These results indicated that PHE had the potential to be developed as antioxidant and anti-aging agent in the healthcare industry.

Paecilomyces hepiali is a fungus with edible and pharmaceutic value, isolated from Ophiocordyceps sinensis. Its main bioactive constituents contain alkaloids, cyclic dipeptides, steroids, organic acids, and polysaccharides. Due to the huge development potential of P. hepiali in the field of food and medicine, it has been developed into a variety of products that cater to the needs of the public. In this paper, the chemical constituents and their pharmacological effects of P. hepiali are reviewed, which can provide reference for the development and application of P. hepiali.