Efficacy of Berberis vulgaris and Berberis integerrima on glycemic indices and weight profile in type 2 diabetic patients: A systematic review and meta-analysis of randomized controlled trials

Type 2 diabetes mellitus (T2DM) is a multifactorial lifelong condition. Berberis vulgaris (BV) and Berberis integerrima (BI) regulate glucose levels with minimal adverse effects. In this systematic review and meta-analysis, we evaluate the effect of BV and BI on glycemic indices, weight, and body mass index (BMI) against placebo.

Four electronic databases were searched till September 24, 2023. Inclusion criteria for studies were: (a) T2DM patients; (b) berberis (vulgaris/integerrima) therapy as intervention; (c) control group of placebo or metformin; (d) outcomes including fasting blood glucose (FBG) levels, glycated hemoglobin (HbA1c%), Homeostatic Model Assessment for Insulin Resistance (HOMA-IR), fasting serum insulin (FSI), 2-h postprandial glucose (2hPPG), fructosamine, weight, and BMI; (e) randomized controlled trials (RCTs). Data was pooled using a random-effects analysis model on Review Manager. The inverse variance statistical method was applied keeping weighted mean difference (WMD) as the effect measure. The Cochrane risk of bias tool evaluated the risk of bias. A p-value of less than 0.05 was considered significant.

Nine RCTs comprising 547 patients were included. Significant reduction was noted with berberis therapy in FBG (WMD: −14.52; 95% CI = −22.97, −6.07; P = 0.0008); HbA1c % (WMD: −0.30; 95% CI = −0.53, −0.07; P = 0.01); HOMA-IR (WMD: −0.97; 95% CI = −1.56, 0.37; P = 0.001). No significant differences were noted between the two groups in 2hPPG (WMD: 6.52; 95% CI = −21.57, 34.61; P = 0.65); FSI (WMD: −0.79; 95% CI = −1.80, 0.22, P = 0.13); Fructosamine (WMD: −12.57; 95% CI = −40.74, 15.60; P = 0.38); Weight (WMD: −1.89; 95% CI = −4.55, 0.76; P = 0.16) and BMI (WMD: −0.12; 95% CI = −0.90, 0.65; P = 0.76).

The data showed significant reduction in FBG and improved insulin levels but limited effects were observed in other glycemic indexes. More extensive RCTs are required globally to achieve a holistic comprehension of the connection between berberis and T2DM.