Literature Analysis of the Preparation Elements of Animal Models of Skin Photoaging and the Data of Subjects

Objective To analyze the modeling elements and subjects of the animal model of skin photoaging, and to provide a reference for the preparation and improvement of the model and a basis for the scientific evaluation of the subject. Methods By searching and collecting relevant literature on the preparation of animal models of skin photoaging from 2010 to 2022 in the China National Knowledge Infrastructure, Wanfang Database, and PubMed database, the model animal species, gender, modeling method, modeling cycle, radiation source and its distance from the modeling site, cumulative radiation volume, detection indicators, and subjects (drugs or treatments) recorded in the literature were collated and summarized, and a database was established for statistical analysis. Results 257 articles that met the inclusion criteria were selected. Among them, the most common animal model was SKH-1 hairless mice, followed by SD rats and KM mice; the gender of animals was mainly female, medium-wave ultraviolet B (UVB) was often used as the radiation source, the distance between the radiation source and the modelling site was mostly 30 cm, and the modelling period was usually 40-60 days. The cumulative dose of long-wave ultraviolet A (UVA) was between 100-150 J/cm2, and the cumulative dose of UVB was between 5-10 J/cm2. The tests used after model establishment were skin histopathological examination, skin tissue homogenization, fibre staining, immunoblotting, etc. Subjects included Chinese herbal medicines, Chinese herbal extracts, Chinese patent medicines, Chinese herbal compound medicines, chemical drugs, biological agents and other treatments, while the animal model of skin photoaging was also used for clinical efficacy studies of external Chinese medicine, physiotherapy and positive control drugs. Conclusion In skin photoaging animal experiments, female SKH-1 hairless mice are often used, and UVB is used as the radiation source. The modeling period is usually 40-60 days, and the minimum erythema dose (MED) is incremented week by week. The cumulative UVB irradiation dose ranges from 0 to 10 J/cm2, which has the advantages of high success rate, good reproducibility and high similarity with clinical disease

Immunomodulatory Effects of Hydrolyzed Seawater Pearl Tablet (HSPT) on Th1/Th2 Functionality in a Mice Model of Chronic Obstructive Pulmonary Disease (COPD) Induced by Cigarette Smoke

Chronic obstructive pulmonary disease (COPD) is predicted to become the third leading cause of death around the world. The present study is designed to investigate whether hydrolyzed seawater pearl tablet (HSPT) has immunoregulatory effects on the Th1/Th2 functionality in cigarette smoke-induced COPD model mice. The determination of the amino acid composition of HSPT was carried out by high-performance liquid chromatography (HPLC) with precolumn phenylisothiocyanate (PITC) derivatization. COPD model mice were constructed by cigarette smoking (CS) treatment and HSPT was administered. HSPT inhibited the infiltration of inflammation in the airway of the lung, reduced influx of eosinophils (EOSs), lymphocytes (LYMs), neutrophils (NEUs), and macrophages (MACs) in the bronchoalveolar lavage fluid (BALF), decreased the levels of IFN-γ, IL-2, IL-4, and IL-10 in the serum and lung, and decreased the expression of aforementioned cytokines in the spleen and lung in CS-treated mice. Besides, HSPT also had the ability to reduce the amount of CD3+CD4+ T cells and modulate the Th1/Th2 balance. Taken together, this study supports the consensus that CS is a critical factor to induce and aggravate COPD. HSPT could regulate the balance of Th1/Th2 in CS-induced COPD model mice, indicating its effects on inhibiting the development of COPD.</jats:p

Inhibitory Effect of Seawater Pearl Hydrolysate on UVA-Induced Photoaging of Human Skin Fibroblasts

This study is an investigation into the inhibitory effect of seawater pearl hydrolysate (SPH) on the UVA-induced photoaging of human skin fibroblast (HSF) cells, and the mechanism thereof. HSF cells were cultured and irradiated with a UVA 0–50 J·cm−2 dose gradient. The cell inhibition rate was detected using the CCK8 method, and the half-inhibitory dose was determined. Based on this, the dose of UVA irradiation for the follow-up experiment was selected to establish a photoaging model of the HSF cells. The cells were divided into a normal (N) group, UVA-irradiated (UVA) group, SPH low dose (SPHL) group, SPH medium dose (SPHM) group, and SPH high dose (SPHH) group. The photoaging model of HSF cells was established by UVA irradiation in the UVA, SPHL, SPHM, and SPHH groups; the SPHL, SPHM, and SPHH groups were treated with SPH at concentrations of 50, 100, and 200 mg·L−1, respectively, at the same time. After 24 and 48 h of culture, the reactive oxygen species (ROS) level of the HSF cells was detected by flow cytometry, and the required culture time of the HSF cells for the follow-up experiment was selected. The malondialdehyde and glutathione contents, as well as the activities of the superoxide dismutase, catalase, and glutathione peroxidase in the HSF cells, were detected by biochemical methods. The levels of expression of MMP-1 and collagen I protein in HSF cells were detected by the western blot test, the extent of aging of HSF cells was detected by β-galactosidase staining, and the apoptosis level of HSF cells was detected by flow cytometry. The results show that SPH inhibits the UVA-induced photoaging of HSF cells in a dose-dependent manner within a certain concentration range, and the effect of a concentration of 200 mg·L–1 was the most significant. The mechanism is related to improving the antioxidant activity of photoaging HSF cells to eliminate excessive ROS. It can inhibit apoptosis, reduce the protein expression of MMP-1, and effectively control the degradation of collagen I protein in photoaging HSF cells. Therefore, SPH offers potential for use in sunscreen cosmetics.</jats:p

Therapeutic Effect of Seawater Pearl Powder on UV-Induced Photoaging in Mouse Skin

The objective of this study was to investigate the therapeutic effect of seawater pearl powder (SPP) on ultraviolet (UV) irradiation-induced photoaging in mouse skin. The protein and trace elements in SPP were detected by liquid chromatography-mass spectrometry, atomic fluorescence spectrometry, and inductively coupled plasma-atomic emission spectrometry. The effect of SPP on treating skin damage resulting from UV-induced photoaging was observed by gross physical appearance and histopathological analysis. Oxidative stress and melanin synthesis were analyzed using biochemical method. Western blotting was applied to analyze the phosphorylation and expression levels of matrix metalloproteinase-1 (MMP-1), collagen I, and proteins involved in the mitogen-activated protein kinase (MAPK) signaling pathways (p38, ERK, and JNK). The results show that SPP has a significant therapeutic effect on UV-induced photoaging of skin and improves and restores appearance and tissue structure of mouse skin. The major mechanism may be related to reduction of expression level of MMP-1 and enhancement of collagen I production via inhibition of MAPK signaling pathway after scavenging of excess reactive oxygen species (ROS) in the UV-induced photoaged skin of mice. Meanwhile, it may also be involved in reducing melanin content by inhibiting tyrosinase activity after scavenging excess ROS in the UV-induced photoaged skin of mice. Therefore, SPP could be a good substance to treat photoaging skin. Taking cost-effectiveness and efficacy into consideration, the optimal concentration of SPP for treating photoaging skin could be 100 mg/g.</jats:p

Effects of volatile organic compounds on postharvest brown rot control and sensory quality of peach fruit(挥发性有机化合物对桃果实采后褐腐病控制及感官品质的影响)

Peach fruit is susceptible to Monilinia fructicola during storage and logistics, leading to occurrence of brown rot and fruit quality deterioration. However, the regulatory effects of volatile organic compounds (VOCs) on brown rot remain unclear. This study analyzed the antifungal effects of major VOCs in ripe peach fruit on M. fructicola. The results showed that 12 VOCs involving carvacrol and (E)-2-hexenal were identified to have significant inhibitory effects on the growth of M. fructicola on media. Further research was conducted on the regulatory effects of 12 VOCs on postharvest brown rot of peach fruit. The results showed that the fumigation treatment with VOCs could effectively inhibit the growth of M. fructicola and delay the occurrence of brown rot. Among them, volatile aldehydes exhibited positive effects on maintaining fruit quality. Fumigation with 25 μL/L (E)-2-hexenal significantly inhibited the growth of M. fructicola and reduced brown rot symptoms in peach fruit. Meanwhile, the fruit appearance, ethylene release rate, hardness, total soluble solid content and sensory quality indicators were not affected, therefore maintaining the merchant ability of peach fruit during the postharvest storage. In summary, (E)-2-hexenal has the potential to be developed as a plant-based fungicide, offering quality assurance for the peach fruit supply chain.(桃果实在采后贮藏物流过程中易受到果生链核盘菌（Monilinia fructicola）的侵染，导致褐腐病发生和果实品质劣变，有关的挥发性有机化合物（volatile organic compounds, VOCs）对褐腐病的调控效果尚不清楚。本研究分析了成熟桃果实中主要VOCs对果生链核盘菌的抑菌效果，结果表明，香芹酚、反-2-己烯醛等12种VOCs可以显著抑制病原菌在培养基上的生长。进一步开展上述12种VOCs对桃果实采后褐腐病的调控效应研究，结果表明，采用VOCs熏蒸处理可以有效抑制果生链核盘菌的生长，延缓褐腐病发生，其中挥发性醛类物质对果实品质的保持效果较好。采用25 μL/L反-2-己烯醛熏蒸处理可以显著抑制果生链核盘菌生长，减轻褐腐病症状，同时不影响果实外观、乙烯释放速率、硬度、总可溶性固形物含量和感官品质指标，有效维持桃果实在采后贮藏过程中的商品性。综上所述，反-2-己烯醛具有开发为植物源抑菌剂的潜力，可为桃果实供应链提供品质保障。