African Polyherbal Formulations for Type 2 Diabetes: A Systematic Review and Meta-Analysis of Efficacy, Mechanisms, and Therapeutic Potential

Type 2 diabetes (T2D) remains a major public health challenge in Africa, where limited healthcare access and the high cost of conventional therapies sustain reliance on African traditional medicine (ATM). This systematic review and meta-analysis evaluated the efficacy, mechanisms of action, and safety of African polyherbal formulations for T2D management. This systematic review and meta-analysis was conducted in accordance with PRISMA 2020 guidelines, following a protocol registered with PROSPERO (CRD420251168831). We searched PubMed, Scopus, ScienceDirect, Web of Science, and Google Scholar for studies published between 1 January 2011 and 31 December 2024. Seventeen studies met the inclusion criteria. Polyherbal formulations consistently improved glycaemic control, insulin sensitivity, antioxidant status, and lipid profiles. Meta-analysis of 10 preclinical studies demonstrated a significant reduction in fasting blood glucose compared with that of diabetic controls (SMD = −5.22, 95% CI: −5.55 to −4.89; p < 0.001; I2 = 93.88%). Proposed mechanisms included β-cell protection, stimulation of insulin secretion, inhibition of α-amylase and α-glucosidase, and attenuation of oxidative stress. Safety data were limited and inconsistently reported. Human evidence was limited to one quasi-experimental clinical study and one acute human OGTT study. African polyherbal formulations demonstrate promising antidiabetic potential; however, methodological heterogeneity, limited phytochemical characterisation, inadequate safety assessment, and scarce clinical evidence highlight the need for standardised preclinical studies and well-designed clinical trials to support evidence-based integration into healthcare.