The influences of purple sweet potato anthocyanin on the growth characteristics of human retinal pigment epithelial cells

Purple sweet potato anthocyanin extract regulates redox state related to gut microbiota homeostasis in obese mice

This study explored the advantageous effects of purple sweet potato anthocyanin extract (PSPAE) on redox state in obese mice. The normal chow diet (NCD) group, high-fat/cholesterol diet (HCD) group, and three groups based on HCD and added with low, middle, and high dose of PSPAE (PAL, PAM, and PAH) were raised for 12 weeks. High dose of PSPAE treatment decreased the elevations of the body weight by 24.7%, serum total cholesterol by 48.3%, serum triglyceride by 42.4%, and elevated serum activities of glutathione peroxidase by 53.3%, superoxide dismutase by 57.8%, catalase by 75.4%, decreased serum contents of malondialdehyde by 27.1% and lipopolysaccharides by 40.5%, as well as increased caecal total short-chain fatty acid by 2.05-fold. Additionally, PSPAE depressed toll-like receptor 4 (TLR-4), nuclear factor kappa-B (NF-κB), interleukin 6, tumor necrosis factor α, and preserved nuclear factor erythroid-2-related factor 2 (Nrf2) gene expression. Similarly, the protein expression of Nrf2 was enhanced, while TLR-4 and p-NF-κB/NF-κB were depressed by PSPAE treatment. Moreover, PSPAE administration promoted the protection of intestinal barrier function and rebuilt gut microbiota homeostasis by blooming g_Akkermansia, g_Bifidobacterium, and g_Lactobacillus. Furthermore, antibiotic interference experiments showed that the gut microbiota was indispensable for preserving the redox state of PSPAE. These results suggested that PSPAE administration could be an opportunity for improving HCD-induced obesity and the redox state related to gut dysbiosis. PRACTICAL APPLICATION: Purple sweet potato anthocyanin has diverse pharmacological properties. It is applicable for individuals to consume extracts (as pills or other forms) from raw purple sweet potato if they want to improve obesity or redox state.

Ultrahigh Pressure Facilitates the Acylation of Malvidin and Chlorogenic Acid to Increase the Stability and Protective Effect of Malvidin Derivatives on H2O2-Induced ARPE-19 Cells

We explored the effects of ultrahigh-pressure technology and chlorogenic acid on the color stability and structure-activity relationship of malvidin (MV). Experimental conditions were optimized through single-factor experiments and response surface analysis at a pressure of 300 MPa, mass ratio of MV to chlorogenic acid of 1:3.64 (w/w), and time of 5 min. Compared with MV, MV derivatives showed higher stability and in vitro antioxidant activity. X-ray diffraction analysis, UV-vis spectroscopy, Fourier transform infrared spectroscopy, high-performance liquid chromatography, and mass spectrometry were conducted to determine the structures of MV derivatives for the first time. Ultrahigh pressure facilitated acylation of chlorogenic acid and MV and produced four new MV derivatives. Analysis of the effect of malvidin-3-O-6-(acrylic acid-(2-hydroxy, 4-carboxy-cyclohexanol) ester)-guaiacol (Mv3ACEC) on ARPE-19 cells exposed to H₂O₂ by RNA transcriptome sequencing showed that Mv3ACEC simultaneously inhibited various inflammatory and apoptotic signal transduction pathways, exerted a synergistic effect, and partly inhibited cell apoptosis through the MAPK signaling pathway. Therefore, the results show that ultrahigh pressure will cause acylation of chlorogenic acid and MV to produce four new MV derivatives, and MV derivatives protect ARPE-19 cells from H₂O₂-induced oxidative stress.

Regulatory effect of non-starch polysaccharides from purple sweet potato on intestinal microbiota of mice with antibiotic-associated diarrhea

Antibiotic treatment causes antibiotic-associated diarrhea (AAD), which is usually accompanied by disorders of the intestinal flora, aggravating the patient's condition. Recently, more attention has been devoted to the ability of plant polysaccharides to improve the body's flora and enhance immunity. However, reports on whether purple sweet potato polysaccharides (PSPPs) can improve AAD are scarce. This study aimed to extract a non-starch polysaccharide from purple sweet potato and analyze its structure and ability to regulate the intestinal flora of mice with AAD. The diarrhea model was established via intragastric administration of lincomycin and different concentrations of PSPPs (0.1 g kg-1, 0.2 g kg-1, and 0.4 g kg-1) to Balb/C mice. The results showed that PSPP was a pyran polysaccharide with 1 → 2, 1 → 2, 6, 1 → 4, 1 → 4, 6 glycosidic bonds in an α-configuration. In vivo experiments showed that PSPP could relieve diarrhea and improve the structural damage in the ileum caused by lincomycin hydrochloride. In addition, treatment with PSPPs decreased the levels of IL-1β, IL-6 and TNF-α but increased the level of IL-10 in the intestines of mice (p < 0.01). The results of 16S rRNA sequencing showed that PSPPs changed the composition and diversity of the intestinal flora of mice with AAD. In addition, PSPP treatment increased the content of short-chain fatty acids (p < 0.01). These results revealed that PSPPs regulated the intestinal flora, balanced fatty acid metabolism, and relieved the symptoms of diarrhea to a certain extent in mice.

Purple Sweet Potato Extract extends lifespan by activating autophagy pathway in male Drosophila melanogaster

INTRODUCTION

Purple sweet potato is a nutritive food rich in anthocyanins that possess antioxidant effects. Drosophila melanogaster owns short growth cycle, fast reproduction, less chromosomes, more mutants, small individuals, therefore, which is an appropriate genetic model organism.

OBJECTIVE

To investigate the anti-aging activity of Purple Sweet Potato Extract (PSPE) in male Drosophila melanogaster and explore the underlying mechanism.

RESULTS

PSPE-induced longevity was associated with improvements in climbing ability and tolerance to stressors such as paraquat and hydrogen peroxide (H₂O₂). Furthermore, PSPE supplementation increased the activity of superoxide dismutase (SOD) and catalase (CAT), as well as expression of SOD and CAT genes, but decreased malondialdehyde (MDA) content. Meanwhile, PSPE decreased the intestinal stem cells (ISCs) proliferation and improved intestinal homeostasis, which was measured by Smurf assay and colony-forming units (CFUs) measurement in aging flies. Additionally, PSPE markedly inhibited the expression of upstream genes AKT-1, PI3K and mTOR and elevated the downstream gene 4E-BP, which further activated the expression of autophagy-related genes (Atg1, Atg5, Atg8a and Atg8b). Moreover, the production of lysosomes increased, indicating that the autophagy pathway was activated.

CONCLUSION

The results provided direct evidence of PSPE anti-aging effects on an organism level, indicating PSPE could be developed for use in effective anti-aging products.

Hyaluronic acid promotes proliferation and migration of human meniscus cells via a CD44-dependent mechanism

PURPOSE

Treatment of meniscal injury is important for osteoarthritis (OA) prevention. Meniscus cells are divided between inner and outer cells, which have different characteristics and vascularity. We evaluated the effects of hyaluronic acid (HA) on the proliferation and migration of human inner and outer meniscus cells, and investigated the underlying healing mechanisms.

MATERIALS AND METHODS

Lateral menisci from 18 patients who underwent total knee arthroplasty were used. Meniscus cells were harvested from the outer and inner menisci and evaluated using migration and proliferation assays after treatment with HA or chondroitin sulfate (CS). The effects of HA on prostaglandin E2 (PGE2)-induced apoptosis and gene expression were evaluated.

RESULTS

Cell migration and proliferation were increased by HA in a concentration-dependent manner, in both inner and outer meniscus cells. PGE2-induced apoptosis and caspase-3/7 activity were suppressed by HA in both inner and outer meniscus cells, and these effects were blocked by an anti-CD44 antibody. COL2A1 and ACAN mRNA levels were upregulated following HA treatment of inner meniscus cells. MMP13 mRNA was downregulated following CS stimulation of both inner and outer meniscus cells. These results suggest that CS treatment suppresses the inflammatory reaction rather than providing meniscal restoration. The phosphatidylinositol 3-kinase (PI3K) and mitogen-activated protein kinase (MAPK) pathways were activated by HA in both types of meniscus cells; these effects were blocked by treatment with an anti-CD44 antibody.

CONCLUSIONS

HA promoted human meniscus regeneration by inhibiting apoptosis, promoting cell migration, and accelerating cell proliferation, potentially through the PI3K/MAPK pathway via the CD44 receptor.

Purple sweet potato anthocyanin exerts antitumor effect in bladder cancer

Bladder cancer (BC) is the most common malignant disease. The developing of economically sustainable and available agents for the treatment of BC is required. Purple sweet potato anthocyanin (PSPA) has been shown to have antitumor abilities. The present study aimed to evaluate the potential role of PSPA in BC treatment. CCK-8 assay was used to assess the viability of BC cells. Flow cytometry assays were performed to evaluate the mitochondrial membrane potential (MMP), cell apoptosis and cell-cycle distribution. Real-time PCR (RT-PCR) and western blot analysis were performed to determine the expression of the target genes. The results of this study revealed that PSPA reduced the viability of BC in a dose-dependent manner. The MMP collapse was aggravated by the PSPA treatment. The apoptosis rate was higher in the PSPA groups than that in the control group. The expression of the pro-apoptosis genes, including cleaved caspase-3, Fas, Fasl, Bcl-2-associated X proteins (Bax) and anti-apoptotic gene (Bcl-2) was induced and decreased by PSPA, respectively. The cell-cycle progression was suppressed by the presence of PSPA. The activation of the phosphatidylinositol-4,5-bisphosphate 3-kinase/Akt (PI3K/Akt) signaling pathway was suppressed by PSPA treatment during BC treatment. The PI3K/Akt signaling was closely related to the antitumor effect of PSPA in BC. The present study provided evidence regarding the treatment of BC and enhanced the understanding of the potential role that PSPA plays in cancer prevention.

Production of vinegar from purple sweet potato in a liquid fermentation process and investigation of its antioxidant activity

Acetobacter pasteurianus JST-S was screened from solid fermented grains of vinegar in China, identified by molecular analysis, and used for the production of purple sweet potato vinegar using purple sweet potato as the substrate. By orthogonal experiment, maximum total acid concentration (4.26% [v/v]) was achieved under optimized conditions as follows: fermentation time, 3.5 days; ethanol content, 9% v/v; and inoculum size, 8% v/v. During the production of purple potato vinegar, the anthocyanin concentration decreased from 652.07 to 301.73 μg/mL. The antioxidant activity of products, including diphenyl-picryl hydrazide radical-scavenging capacity (above 60%), reducing power (above 0.47), and hydroxyl radical-scavenging capacity (above 46%), showed positive linear regression (P < 0.01), which could be related with the changes in anthocyanin concentration and antioxidant activities at different stages of vinegar fermentation. The acetic acid and other non-phenolic antioxidants in purple sweet potato vinegar may have contributed to the antioxidant activities. Results of these studies may provide a reference for the industrial production of vinegar by liquid fermentation of purple sweet potato.