The effect of curcumin supplementation on circulating adiponectin and leptin concentration in adults: a GRADE-assessed systematic review and meta-analysis of randomised controlled trials.

Curcumin is a phytocompound found in the root of turmeric, a common herbal ingredient in many Asian cuisines. The compound contains anti-inflammatory activity, which is mediated through an upregulation of adiponectin and reduction of leptin. Results of randomised controlled trials (RCT) have shown that the effects of curcumin on adipokines are conflicting. Therefore, the current systematic review and meta-analysis of RCT were conducted with the aim of elucidating the role of curcumin supplementation on serum adiponectin and leptin. The search included PubMed, Embase, Cochrane Library, Scopus, Web of Science and Google Scholar from inception to August 2023. For net changes in adipokines, standardised mean differences (SMD) were calculated using random effects models. Thirteen RCT with fourteen treatment arms were eligible for inclusion in this meta-analysis. Curcumin supplementation was effective in increasing serum adiponectin (SMD = 0·86, 95 % CI (0·33, 1·39), P < 0·001; I2 = 93·1 %, P < 0·001) and reducing serum leptin (SMD = -1·42, 95 % CI (-2·29, -0·54), P < 0·001; I2 = 94·7 %, P < 0·001). In conclusion, curcumin supplementation significantly increased circulating adiponectin and decreased leptin levels in adults.

The effects of purslane (Portulaca oleracea) on glycemic indices: A GRADE-assessed systematic review and meta-analysis of randomized controlled trials.

Although several studies have revealed the benefits of purslane on glycemic indices, the results of some studies reject such effect. Therefore, aim of this meta-analysis of randomized controlled trials (RCTs) was to assess the effects of purslane supplementation on glycemic indices. Scientific international databases as Scopus, Web of Sciences, PubMed, Embase, and the Cochrane library were searched up to December 2022. For net changes in glycemic indices, weighted mean differences (WMDs) were calculated using random-effects models. Purslane supplementation had a statistically significant reduction in fasting blood glucose [FBG, WMD: -6.37; 95% CI: -9.34, -3.40, p < 0.001]. In addition, purslane did not significant effect on serum levels of insulin [WMD: -0.74; 95% CI: -2.58, 1.10; p = 0.430], homeostasis model assessment for insulin resistance [HOMA-IR, WMD: -0.25; 95% CI: -0.88, 0.37, p = 0.429], and QUICKI [WMD: -0.01; 95% CI: -0.01, 0.03, p = 0.317] compared with the control group. The results of our meta-analysis revealed a beneficial effect of purslane supplementation as a tool to decrease FBG levels, but not to HOMA-IR, insulin, and QUICKI levels. However, future high-quality, long-term clinical trials are needed to confirm our results.