Electrochemical evidence of nitrate release from the nitrooxy compound 4-((nitrooxy) methyl)-3-nitrobenzoic acid and its antinociceptive and anti-inflammatory activities in mice

Dietary nitrate supplementation to enhance exercise capacity in patients with COPD: Evidence from a meta-analysis of randomized controlled trials and a network pharmacological analysis

OBJECTIVE

The potential effects of nitrate in patients with chronic obstructive pulmonary disease (COPD) have attracted increased research interest. However, previous clinical trials have reported inconsistent results, and consecutive meta-analyses have failed to reach a consensus. Since some randomized controlled trials have recently been conducted that can provide more evidence, we performed an updated meta-analysis.

METHODS

A comprehensive literature search was conducted using PubMed, the Cochrane Library, Embase, and Web of Science databases to identify trials that assessed the efficacy and safety of nitrate in patients with COPD. The Revman 5.3 software was used for data analysis. Mean difference (MD) or standardized mean difference (SMD) with 95 % confidence interval (CI) was used as the effect measure, and forest plots were used to display individual and pooled results. Network pharmacology analysis was conducted to investigate the potential mechanisms of nitrate action in COPD.

RESULTS

Eleven studies involving 287 patients were included in this meta-analysis. The results indicated that dietary nitrate supplementation increased plasma nitrate and nitrite concentrations and fractional exhaled nitric oxide in patients with COPD. Nitrate improved exercise capacity [SMD = 0.38, 95 % CI = 0.04-0.72] and endothelial function [MD = 9.41, 95 % CI = 5.30-13.52], and relieved dyspnea in patients with COPD. Network pharmacology identified AKT1, IL1B, MAPK3, and CASP3 as key treatment targets.

CONCLUSION

Dietary nitrate supplementation could be used as a potential treatment for patients with COPD, especially to increase their exercise capacity. The underlying mechanisms may be related to AKT1, IL1B, MAPK3, and CASP3.

Design and synthesis of novel aza-ursolic acid derivatives: in vitro cytotoxicity and nitric oxide release inhibitory activity

Aim: Inducible nitric oxide synthase (iNOS) is a validated target for anti-inflammatory treatment. Based on the authors' previous work, novel aza-ursolic acid derivatives were designed and synthesized and their inhibitory activities against lipopolysaccharide (LPS)-induced nitric oxide (NO) release from RAW264.7 cells was evaluated. Materials & results: 16 novel derivatives were screened for their in vitro inhibitory activity against NO release using Griess assays and the cytotoxicity was evaluated using MTT assays. The presence of furoxan joined to the A-ring of ursolic acid and N-methylpiperazine groups in the lead compound was identified for anti-inflammatory activity, and compound 21b showed 94.96% inhibition of NO release at 100 μM with an IC50 value of 8.58 μM. Conclusion: Compound 21b has potential anti-inflammatory activity with low cytotoxicity that warrants further preclinical study and evaluation.