Ginseng Extract Attenuates the Injury from Ultraviolet Irradiation for Female Drosophila melanogaster through the Autophagy Signaling Pathway.

Ginseng is an ancient medicinal and edible plant with many health benefits, and can serve as a drug and dietary supplement, but there are few relevant studies on its use to ease ultraviolet (UV) irradiation damage. After 0.8 mg/mL ginseng extract (GE) was added to the medium of female Drosophila melanogaster subjected to UV irradiation, the lifespan, climbing ability, sex ratio, developmental cycle, and antioxidant capacity of flies were examined to evaluate the GE function. In addition, the underlying mechanism by which GE enhances the irradiation tolerance of D. melanogaster was explored. With GE supplementation, female flies subjected to UV irradiation exhibited an extension in their lifespan, enhancement in their climbing ability, improvement in their offspring sex ratio, and restoration of the normal development cycle by increasing their antioxidant activity. Finally, further experiments indicated that GE could enhance the irradiation tolerance of female D. melanogaster by upregulating the gene expressions of SOD, GCL, and components of the autophagy signaling pathway. Finally, the performance of r4-Gal4;UAS-AMPKRNAi flies confirmed the regulatory role of the autophagy signaling pathway in mitigating UV irradiation injury.

Structure characteristics of low molecular weight pectic polysaccharide and its anti-aging capability by modulating the intestinal homeostasis.

Pectic polysaccharide has attracted increasing attention for their potential biological properties and applications in health industries. In this study, a low-molecular-weight pectic polysaccharide, POS4, was obtained from citrus peel. The structure of POS4 was preliminarily analyzed by gel-permeation chromatography, monosaccharide analysis, infrared spectroscopy (IR) and nuclear magnetic resonance spectroscopy (NMR). Results showed that the molecular weight of POS4 was 4.76 kDa and it was a galacturonic acid enriched pectic polysaccharide. The anti-aging activity in vivo showed that POS4 could notably prolong the average lifespan of fruit flies by suppressing the generation of reactive oxygen species (ROS). Further studies demonstrated that POS4 could enhance intestinal homeostasis by modulating gut microbiota in a positive way and regulating autophagy associated genes. Taken together, we proposed that galacturonic acid enriched low molecular weight pectic polysaccharide have great potential in the development of healthy foods such as anti-aging health care products.

Protective Effect of Bilberry Anthocyanin Extracts on Dextran Sulfate Sodium-Induced Intestinal Damage in Drosophila melanogaster.

Inflammatory bowel disease (IBD) is a chronic recurrent disease that can be controlled by various natural extracts. Anthocyanins (ANCs) from bilberry have significant antioxidant capacity and are widely used as food colors and antioxidants. In this study, we investigated the protective effects of bilberry anthocyanin extracts (BANCs) against dextran sulphate sodium (DSS)-induced intestinal inflammation in a Drosophila melanogaster (D. melanogaster) model, and the effects on the lifespan, antioxidant capacity, intestinal characteristics, and microbiome and gene expression profiles were analyzed to elucidate the underlying biological mechanisms. In DSS-induced normal and axenic D. melanogaster, BANCs significantly increased the survival rate, maintained the intestinal morphology and integrity, and reduced the number of dead intestinal epithelial cells and the ROS level of these cells. BANC supplementation had no significant effect on the intestinal microflora of DSS-induced D. melanogaster, as demonstrated by a 16S rDNA analysis, but improved the antioxidant capacity by activating the relative gene expression of NRF2 signaling pathways in the intestine of D. melanogaster with DSS-induced inflammation. Therefore, the results demonstrate that BANCs effectively alleviate intestinal inflammatory injury induced by DSS and improve the antioxidant capacity of D. melanogaster by modulating NRF2 signaling pathways, and could thus promote the application of BANCs as functional foods.

Inhibition of Liver Cancer HepG2 Cell Proliferation by Enzymatically Prepared Low-molecular Citrus Pectin.

BACKGROUND: Low-molecular citrus pectin (LCP) is a pectin polysaccharide with low molec-ular weight, low degree of crux, and no branching. It is obtained by degrading natural citrus pectin (CP) through physical, chemical and enzymatic methods. LCP has received considerable attention in recent years due to its potential applications in the medical and biological fields. METHODS: In our previous study, LCP was prepared from CP by using recombinant Bacillus subtilis pectate lyase B. Monosaccharide comparative analysis revealed that the galacturonic acid content of LCP was higher than that of CP. The cell viability effect of LCP was elucidated by using HepG2 cells and the Cell Counting Kit-8 (CCK-8) assay. Terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) staining, Annexin V-FITC/PI staining, and flow cytometer propidium iodide stain-ing were performed to detect the effects of LCP on apoptosis and cell cycle arrest in HepG2 cells. Mi-tochondrial membrane potential (MMP) was observed through 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethyl-imidacarbocyanine assay. RESULTS & DISCUSSION: The Mw of the prepared LCP was 7.6 kDa, which was significantly lower than that of CP (140 kDa). Cell viability decreased with the increase in the concentration of LCP. The half-inhibitory concentration of 1.46 ± 0.02 mg/mL was determined. Treatment with 1.6 mg/mL LCP in-duced the apoptosis of HepG2 cells with the inhibition rate of 83.10% ± 4.72%, and the cell cycle was arrested in the S phase. Furthermore, the MMP of HepG2 cells decreased with the increase in LCP concentration. CONCLUSION: The enzymatically prepared LCP could inhibit the proliferation of HepG2 cells. This study provided a partial experimental basis and reference for LCP to become a potential functional food for anti-liver cancer.

Carrageenan Oligosaccharides Extend Life Span and Health Span in Male Drosophila Melanogaster by Modulating Antioxidant Activity, Immunity, and Gut Microbiota.

Carrageenan oligosaccharide (CAO), the hydrolysate of carrageenan from marine red algae, is used as a prebiotic additive or medical material. In this study, male Drosophila melanogaster was used as an animal model to explore the possibility that CAO can extend the life span through its relationship with antioxidation, immunity, and gut microbiota in vivo. The results show that a certain amount of CAO effectively prolonged the average life span and improved the climbing vitality and fecundity of male Drosophila. In addition, 0.125% CAO in the diet significantly increased the activity of Cu,Zn-superoxide dismutase (Cu,Zn-SOD) and catalase (CAT), reduced the content of malondialdehyde (MDA), and significantly repressed the expression of nuclear factor kappa B (NF-κB) gene in old male Drosophila tissues. In the intestinal microbiota analysis, 0.125% CAO in the diet increased the diversity of gut microbiota and improved the abundance of Commensalibacter at the genus level in Drosophila on the 40th day. The above results indicated that CAO supplementation could extend the life span of male Drosophila by improving antioxidant activity, immunity, and by regulating intestinal microflora.

Anti-aging Effect of Agar Oligosaccharide on Male Drosophila melanogaster and its Preliminary Mechanism.

Agar oligosaccharide (AOS) is a marine prebiotic with apparent anti-inflammatory, antioxidant and anti-tumor effects. During this study, different doses of AOS are added to a basal diet to evaluate its effects on the lifespan, motor vigor and reproduction of male Drosophila melanogaster. Additionally, the activities of Cu,Zn-superoxide dismutase (Cu,Zn-SOD) and catalase (CAT) and the malondialdehyde (MDA) content in male Drosophila are examined on the 10th, 25th and 40th days. The fly midguts are removed on the 10th and 40th days for analyses of the intestinal microbial community by 16S rDNA sequencing and the expression level of intestinal immunity genes by quantitative real-time PCR (RT-PCR). The results show that AOS significantly prolonged the average and maximum lifespan and increased the antioxidant capacity of male Drosophila. Additionally, AOS significantly regulated the structure of the intestinal flora of "old" flies (40 days) and upregulated the expression of immune deficiency (IMD) genes to improve the intestinal immunity, which could be beneficial for delaying aging in old flies. The above-described results provide a theoretical basis for the application of AOS, a type of marine oligosaccharide, as a nutritional supplement or immunomodulator.