Jingnan Miao

The growing demand for naturally derived multifunctional skincare agents has directed attention toward underutilized protein-rich bioresources. Pheretima, a traditional medicinal resource, is a promising but underexplored source of bioactive peptides. Here, response surface methodology (RSM) was used to optimize the extraction of Pheretima proteins (PPs). The optimal conditions (material-to-liquid ratio 1:7.1 (g/mL), pH 7.5, homogenization time 131.0 s) gave an extraction rate of 19.67%, in good agreement with the predicted 19.80%. The derived enzymatic peptides (PPEPs) were fractionated by ultrafiltration. The PPEPs > 3 kDa fraction showed the highest proline content, greater colloidal stability and a β-sheet-rich secondary structure. Crude PPEPs and all fractions showed strong antioxidant activity, and the PPEPs >3 kDa fraction most strongly inhibited tyrosinase and hyaluronidase. In female ICR mice with acute UVB-induced photodamage, topical PPEPs (repair and protection regimens) attenuated erythema, erosion, epidermal thickening and collagen fragmentation, reduced ROS and returned the UVB-induced compensatory elevation of Nrf2 toward control levels, suppressed IL-1β, IL-6 and TNF-α, and downregulated MMP9 and TRP1, with modulation of TGF-β1/Smad, p38 and AKT signaling. These results indicate that PPEPs are sustainable multifunctional ingredients with anti-photodamage and skin-whitening potential.

With the global population on the rise, an escalating interest exists in environmentally sustainable and friendly protein sources. Insects have emerged as multifaceted resources, viewed not only as potential food items, but also as sources of traditional medicines and proteins. This study utilized response surface methodology (RSM) to ascertain the optimal extraction conditions for proteins from Musca domestica used in toad feeding, denoted as MDPs-T. The yield of MDPs-T was elevated to 18.3% ± 0.2% under these optimized conditions. Subsequently, the particle size, ζ-potentials, and structures of MDPs-T were analyzed and compared with the proteins derived from Musca domestica fed on a normal diet (MDPs-ND). This comparative analysis utilized a range of advanced techniques, involving UV spectroscopy, Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), high-performance gel permeation chromatography (HPGPC), and scanning electron microscopy (SEM). The outcomes have revealed a marginal disparity in the physical and chemical properties between MDPs-T and MDPs-ND. Derosination led to a reduction in the particle size of the MDPs by 10.98% to 62.81%. MDPs-T exhibited a higher proportion of low-molecular-weight components relative to MDPs-ND. Additionally, in a comparative analysis of amino acids, MDPs-T displayed a greater abundance of essential and total amino acids relative to MDPs-ND. Consequently, MDPs-T holds potential as a valuable food supplement for human consumption or as a nutrient-rich feed supplement for animals.

Response surface methodology (RSM) was used to find the optimal extraction process of Oudemansiella raphanipies polysaccharides (ORPs). The results showed that the optimal extraction parameters were an alkali concentration of 0.02 mol/L, a ratio of material to liquid of 1:112.7 g/mL, an extraction temperature of 66.0 °C, and an extraction time of 4.0 h. Under the optimal conditions, the yield of ORPs was raised to 16.2 ± 0.1%. The antioxidant activities of ORPs–I~V were determined and compared, and ORPs–V was further purified by chromatography, with an average molecular weight (Mw) of 18.86 kDa. The structure of ORPs–V was determined by Fourier transform–infrared spectroscopy (FT–IR), monosaccharide analysis, and nuclear magnetic resonance (NMR) spectroscopy. The ORPs–V comprised fucose, rhamnose, arabinose, glucose, galactose, mannose, xylose, fructose, galacturonic acid, and glucuronic acid at a ratio of 1.73:1.20:1.13:2.87:8.71:2.89:1.42:0.81. Compared to other ORPs, ORPs–V showed the strongest antioxidant activities (ABTS radical cation, hydroxyl radical and DPPH scavenging activities, and reducing power), and were able to significantly increase the activities of superoxide dismutase, catalase, lactate dehydrogenase, and glutathione peroxidase. However, they reduced the malondialdehyde content in mice fed a high-fat diet. These results indicate that ORPs–V may be good anti–oxidant agents to be applied in functional foods.