Diabetes, a chronic metabolic disorder, is characterized by persistent hyperglycemia. This study aimed to evaluate the hypoglycemic and antioxidant activities of lactic acid bacteria strains isolated from humans and food products and investigate the probiotic properties of the selected four strains. The hypoglycemic activity of the isolated strains was examined by evaluating the α-glucosidase and α-amylase inhibitory activities. The antioxidant activity was measured using the DPPH, ABTS, and FRAP assays. Four strains (Lactiplantibacillus plantarumMG4229, MG4296, MG5025, andLacticaseibacillus paracaseiMG5012) exhibited potent α-glucosidase inhibitory (>75%) and α-amylase inhibitory (>85%) activities, which were comparable to those of acarbose (>50%; 1000 μg/mL). Similarly, the radical scavenging and antioxidant activities of the four strains were comparable to those of ascorbic acid (50 μg/mL). Additionally, the probiotic properties of the four selected strains were examined based on acid and bile salt tolerance, auto-aggregation ability, and antibiotic resistance. The four strains were resistant to pH 2 (>50% of survivability) and 0.5% bile salt (>80% of survivability). Therefore, we suggest that the selected strains with hypoglycemic, antioxidant, probiotic properties can potentially prevent diabetes.

Background: Cordyceps militaris has been used as a traditional medicine in Asian countries for a long time. Different types of Cordyceps extract were reported to have various pharmacological activities including an anti-cancer effect. We investigated the inhibitory effect of Cordyceps militaris ethanol extract on a human colorectal cancer-derived cell line, RKO. Methods: RKO cells were treated with various concentrations of nucleosides-enriched ethanol extract of Cordyceps militaris for 48 h and cytotoxicity was measured using a CCK-8 assay. Then, xenograft Balb/c nude mice were injected with RKO cells and subsequently orally administered with ethanol extract of Cordyceps militaris every day for 3 weeks to examine the inhibitory effect on tumor growth. Lastly, the effect of Cordyceps militaris on cell cycle as well as apoptosis was measured using flow cytometry. Also, the expression of p53, caspase 9, cleaved caspase-3, cleaved PARP, Bim, Bax, Bak, and Bad were detected using western blot assay. Results: RKO cells were highly susceptible to the ethanol extract of Cordyceps militaris (CME) and the growth of RKO cells-derived tumor was significantly delayed by the treatment of Cordyceps militaris. Cordyceps militaris induced cell cycle arrest in G2/M phase (untreated; 20.5 %, CME 100 μg/ml; 61.67 %, CME 300 μg/ml; 66.33 %) and increased early apoptosis (untreated; 1.01 %, CME 100 μg/ml; 8.48 %, CME 300 μg/ml; 18.07 %). The expression of p53, cleaved caspase 9, cleaved caspase-3, cleaved PARP, Bim, Bak, and Bad were upregulated by the treatment of Cordyceps militaris. Conclusion: Ethanol extract of Cordyceps militaris was highly cytotoxic to human colorectal carcinoma RKO cells and inhibited the growth of tumor in xenograft model. The anti-tumor effect of Cordyceps militaris was associated with an induction of cell cycle arrest and mitochondrial-mediated apoptosis.

Background: Excessive consumption of dietary fat is closely related to obesity, diabetes, insulin resistance, cardiovascular disease, hypertension, and non-alcoholic fatty liver disease. Recently, probiotics have been highly proposed as biotherapeutic to treat and prevent diseases. Previously, there are studies that demonstrated the beneficial effects of probiotics against metabolic disorders, including obesity and diabetes. Objective: We investigated the anti-obesity effect and mechanism of action of four human-derived lactic acid bacterial (LAB) strains (Lacticaseibacillus rhamnosus MG4502, Lactobacillus gasseri MG4524, Limosilactobacillus reuteri MG5149, and Weissella cibaria MG5285) in high-fat diet (HFD)-induced obese mice. Design: Obesity was induced in mice over 8 weeks, with a 60% HFD. The four human-derived LAB strains (2 × 108 CFU/mouse) were orally administered to male C57BL/6J mice once daily for 8 weeks. Body weight, liver and adipose tissue (AT) weights, glucose tolerance, and serum biochemistry profiles were determined. After collecting the tissues, histopathological and Western blot analyses were conducted. Results: Administration of these LAB strains resulted in decreased body weight, liver and AT weights, and glucose tolerance. Serum biochemistry profiles, including triglyceride (TG), total cholesterol, low-density lipoprotein cholesterol, and leptin, pro-inflammatory cytokines, improved. Hepatic steatosis and TG levels in liver tissue were significantly reduced. In addition, the size of adipocytes in epididymal tissue was significantly reduced. In epididymal tissues, Limosilactobacillus reuteri MG5149 and Weissella cibaria MG5285 groups showed a significantly reduced expression of lipogenic proteins, including peroxisome proliferator-activated receptor γ, CCAAT/enhancer-binding protein α, fatty acid synthase (FAS), and adipocyte-protein 2. In addition, sterol regulatory element-binding protein 1-c and its downstream protein FAS in the liver tissue were significantly decreased. These strains attenuated fat accumulation in the liver and AT by upregulating the phosphorylation of AMP-activated protein kinase and acetyl-CoA carboxylase in HFD-fed mice. Conclusion: We suggest that L. reuteri MG5149 and W. cibaria MG5285 could be used as potential probiotic candidates to prevent obesity.

In this study, lactic acid bacteria (LAB) strains derived from human and fermented food sources were examined to identify their properties related to obesity, as well as establish their safety and stability as probiotics. LAB (Lacticaseibacillus rhamnosus MG4502, Lactobacillus gasseri MG4524, Limosilactobacillus reuteri MG5149, and Weissella cibaria MG5285) exhibited antioxidant activity through DPPH (>26.1%) and ABTS (>40.1%) radical scavenging assays and α-glucosidase inhibitory activities (>60.3%), respectively. The LAB strains promoted anti-adipogenesis by reducing lipid accumulation in 3T3-L1 cells by Oil Red O staining (>70.3%). In addition, we found that these LAB strains were resistant to simulated gastric and intestinal fluids (pH 3, 4, 7, and 8) and showed potential for health promotion, based on hemolysis, cell adhesion, antibiotic susceptibility, and enzyme production. Thus, LAB may be used as probiotic ingredients with beneficial effects.