Inhibition of Reactive Oxygen Species (ROS) and Nitric Oxide (NO) by Gelidium elegans Using Alternative Drying and Extraction Conditions in 3T3-L1 and RAW 264.7 Cells

Probiotic Properties and Antioxidant Activity In Vitro of Lactic Acid Bacteria

The properties of probiotics such as lactic acid bacteria (LAB) have been widely studied over the last decades. In the present study, four different LAB species, namely Lactobacillus gasseri ATCC 33323, Lacticaseibacillus rhamnosus GG ATCC 53103, Levilactobacillus brevis ATCC 8287, and Lactiplantibacillus plantarum ATCC 14917, were investigated in order to determine their ability to survive in the human gut. They were evaluated based on their tolerance to acids, resistance to simulated gastrointestinal conditions, antibiotic resistance, and the identification of genes encoding bacteriocin production. All four tested strains demonstrated high resistance to simulated gastric juice after 3 h, and the viable counts revealed declines in cell concentrations of less than 1 log cycle. L. plantarum showed the highest level of survival in the human gut, with counts of 7.09 log CFU/mL. For the species L. rhamnosus and L. brevis, the values were 6.97 and 6.52, respectively. L. gasseri, after 12 h, showed a 3.96 log cycle drop in viable counts. None of the evaluated strains inhibited resistance to ampicillin, gentamicin, kanamycin, streptomycin, erythromycin, clindamycin, tetracycline, or chloramphenicol. With regard to bacteriocin genes, the Pediocin PA gene was identified in Lactiplantibacillus plantarum ATCC 14917, Lacticaseibacillus rhamnosus GG ATCC 53103, and Lactobacillus gasseri ATCC 33323. The PlnEF gene was detected in Lactiplantibacillus plantarum ATCC 14917 and Lacticaseibacillus rhamnosus GG ATCC 53103. The Brevicin 174A and PlnA genes were not detected in any bacteria. Moreover, the potential antioxidant activity of LAB's metabolites was evaluated. At the same time, the possible antioxidant activity of metabolites of LAB was first tested using the free radical DDPH^• (a, a-Diphenyl-β-Picrylhydrazyl) and then evaluated with regard to their radical scavenging activity and inhibition against peroxyl radical induced DNA scission. All strains showed antioxidant activity; however, the best antioxidant activity was achieved by L. brevis (94.47%) and L. gasseri (91.29%) at 210 min. This study provides a comprehensive approach to the action of these LAB and their use in the food industry.

Antioxidant Activity and Probiotic Properties of Lactic Acid Bacteria

Oxidative stress, which can cause imbalance in the body by damaging cells and tissues, arises from the immoderate production of reactive oxygen species (ROS)/reactive nitrogen species (RNS). Therefore, external supplements having antioxidant activity are required for reducing oxidative stress. In our study, we investigated DPPH and ABTS radical scavenging ability, and the inhibition effect on the nitric oxide (NO) production of 15 food-derived bacterial strains in LPS-activated RAW264.7 cells. Among these LAB strains, eight strains with an excellent inhibition effect on NO production were selected through comparisons within the same genera. Moreover, the selected strains, including Leuconostoc mesenteroides MG860, Leu. citreum MG210, Pediococcus acidilactici MG5001, P. pentosaceus MG5078, Weissella cibaria MG5090, Levilactobacillus brevis MG5306, Latilactobacillus curvatus MG5020, and Latilactobacillus sakei MG5048 diminished the inducible nitric oxide synthase (iNOS)/cyclooxygenase-2 (COX-2) expression. In addition, the stability and adhesion ability of the eight LAB strains in the gastrointestinal tract were determined. In conclusion, the selected strains have potential as new probiotics with antioxidant effects.

Efficacy and safety of Gelidium elegans intake on bowel symptoms in obese adults: A 12-week randomized double-blind placebo-controlled trial

BACKGROUND/AIMS

Gelidium elegans (GE) is known to have antiobesity effects and beneficial effects on functional bowel symptoms in preclinical studies. The aim of this study was to determine the efficacy and safety of GE intake on bowel symptoms in obese human adults.

METHODS

This 12-week single-center randomized double-blind placebo-controlled study was performed from September 2016 to May 2017. Consecutive obese subjects were randomly assigned (1:1) to either GE (1 g) or placebo (1 g) once daily group for 12 weeks. Patients' bowel symptoms were evaluated using the Bristol Stool Form Scale, Constipation Scoring System (CSS), and Patient Assessment of Constipation-Symptoms (PAC-SYM) questionnaire.

RESULTS

The stool symptom score of PAC-SYM significantly improved in the GE group compared with the placebo group after the 12-week treatment (P = .041). Abdominal discomfort score of CSS significantly decreased at 12 weeks compared to that at baseline in the GE group (P = .003), but not in the placebo group (P = .398). In addition, abdominal discomfort score of CSS slightly decreased in the GE group compared with the placebo group after the 12-week treatment (P = .060). However, stool consistency, total CSS score, and PAC-SYM score did not change significantly in both GE group and the placebo group over the 12-week treatment period.

CONCLUSIONS

GE treatment for 12 weeks improved the stool symptom score on the PAC-SYM and abdominal discomfort score on the CSS in obese adults. However, further research is needed in large-scale human studies.

Aqueous extract of Dipsacus asperoides suppresses lipopolysaccharide-stimulated inflammatory responses by inhibiting the ERK1/2 signaling pathway in RAW 264.7 macrophages

ETHNOPHARMACOLOGICAL RELEVANCE

Dipsaci Radix, which is the dried root of Dipsacus asperoides C. Y. Cheng and T. M. Ai (Dipsacaceae), is used to treat back pain and blood stasis syndrome in Korean traditional medicine.

AIM OF THE STUDY

To understand the mechanisms responsible for the pharmacological activities of D. asperoides, we investigated the inhibitory effect of D. asperoides on lipopolysaccharide (LPS)-induced inflammation in mouse macrophages RAW 264.7 cells.

MATERIALS AND METHODS

Aqueous extract of D. asperoides (AEDA) was prepared by boiling D. asperoides in water and then administered to LPS treated RAW 264.7 cells. Cell viabilities were measured using an MTT assay, and protein levels were determined by western blotting. The ROS scavenging activity of AEDA was measured using a DCFH-DA assay and levels of nitric oxide (NO) were determined using a NO assay. The nuclear translocations of NF-κB and Nrf2 were investigated immunocytochemically, and pro-inflammatory cytokines in supernatant were evaluated by ELISA.

RESULTS

Treatment with AEDA suppressed the expressions of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in LPS-stimulated RAW 264.7 macrophages. AEDA also reduced ROS, pro-inflammatory cytokine (IL-6 and IL-1β) levels, and iNOS-derived NO and COX-2-derived prostaglandin E2 release to medium, and suppressed the phosphorylation and degradation of IκB and the activation of NF-κB in macrophages. Furthermore, treatment with AEDA inhibited the ERK1/2 pathway but not the JNK or p38 MAPK pathways. In addition, AEDA significantly promoted Nrf2 translocation from cytoplasm to nucleus and up-regulated the expression of HO-1.

CONCLUSION

These results suggest that AEDA has anti-inflammatory and anti-oxidative effects through the inhibition of NF-κB and ERK1/2 and the activation of Nrf2/HO-1 in macrophages.

A synthetic Nitraria alkaloid, isonitramine protects pancreatic β-cell and attenuates postprandial hyperglycemia

OBJECTIVE

The extracts of Nitraria genus are composed of Nitraria alkaloids and have been used traditionally as a hypoglycemic medicine. However, the efficacy and precise mechanism of Nitraria alkaloids remain largely unknown.

METHODS

Previously, we reported the total synthesis of (+)-isonitramine, one of Nitraria alkaloids. In this study, we investigated the anti-diabetic potential of isonitramine in diabetes mellitus and its underlying molecular mechanism in carbohydrate catabolism in vitro and in vivo.

RESULTS

Isonitramine exerted significant inhibitory effect on α-glucosidases but not α-amylase in vitro. In zebrafish, isonitramine alleviated the streptozotocin (STZ)-induced postprandial hyperglycemia and protected the pancreatic damages against alloxan-induced oxidative stress in vivo. Also, isonitramine induced insulin without any toxicities and downregulated phosphoenolpyruvate carboxykinase (PEPCK), which catalyzes the first committed step in gluconeogenesis.

CONCLUSION

Taken together, isonitramine inhibited α-glucosidase activity and PEPCK expression, while increased insulin expression, resulting in attenuating the postprandial hyperglycemia. Also, isonitramine protected the pancreas from ROS-mediated toxicities. Therefore, isonitramine may be a new drug candidate for the treatment of diabetes mellitus.

Macroalgae of Izmir Gulf: Dictyotaceae exhibit high in vitro anti-cancer activity independent from their antioxidant capabilities

In this study, 24 marine macroalgae collected from the coastline of Izmir Gulf were examined for their antioxidant activities and their effects on cell proliferation. Crude extracts were obtained from samples with cold methanol extraction. Antioxidant activity was evaluated as 2,2-diphenyl-1-picryl-hydrazyl (DPPH) radical scavenging activity and total phenolic content (TPC); growth inhibitory effects of the extracts were determined by using WST-8. Amongst the species, Polysiphonia denuata (Rhodophyta) and Cystoseira species (Phaeophyceae) have been noticed by their high DPPH radical scavenging activities and TPCs. As expected, there was a strong correlation between these tests. Dictyota dichotoma (Phaeophyceae) showed the highest anti-cancer activity on MCF-7 cells with an IC₅₀ of 17.2 ng mL^-1. Flow cytometry analyses demonstrated that D. dichotoma methanolic extract strongly induced apoptosis. This extract exhibited moderate viability inhibition on MCF10A cells (IC₅₀: 49.3 ng mL^-1), suggesting a potential use of the extracts or its compounds for cancer therapy. There was no correlation between anti-cancer potential and antioxidant content of the extracts.