Effectiveness of Medicinal Plants for Glycaemic Control in Type 2 Diabetes: An Overview of Meta-Analyses of Clinical Trials.

2021-11-26
Frontiers in pharmacology 12
- Merlin L Willcox
- Christina Elugbaju
- Marwah Al-Anbaki
- Mark Lown
- Bertrand Graz

PubMed: 34899340
DOI: 10.3389/fphar.2021.777561

Study Design

Type: Review
Population: patients with T2DM
Methods: MEDLINE, EMBASE, CINAHL and Cochrane Central were searched in October 2020. We included meta-analyses of randomised controlled clinical trials measuring the effectiveness of medicinal plants on HbA1c and/or Fasting Plasma Glucose (FPG) in patients with T2DM.

Aims: To rank the effectiveness of medicinal plants for glycaemic control in Type 2 Diabetes (T2DM). Methods: MEDLINE, EMBASE, CINAHL and Cochrane Central were searched in October 2020. We included meta-analyses of randomised controlled clinical trials measuring the effectiveness of medicinal plants on HbA1c and/or Fasting Plasma Glucose (FPG) in patients with T2DM. Results: Twenty five meta-analyses reported the effects of 18 plant-based remedies. Aloe vera leaf gel, Psyllium fibre and Fenugreek seeds had the largest effects on HbA1c: mean difference -0.99% [95% CI-1.75, -0.23], -0.97% [95% CI -1.94, -0.01] and -0.85% [95% CI -1.49, -0.22] respectively. Four other remedies reduced HbA1c by at least 0.5%: Nigellasativa, Astragalus membranaceus, and the traditional Chinese formulae Jinqi Jiangtang and Gegen Qinlian. No serious adverse effects were reported. Several other herbal medicines significantly reduced FPG. Tea and tea extracts (Camellia sinensis) were ineffective. However, in some trials duration of follow-up was insufficient to measure the full effect on HbA1c (<8 weeks). Many herbal remedies had not been evaluated in a meta-analysis. Conclusion: Several medicinal plants appear to be as effective as conventional antidiabetic treatments for reducing HbA1c. Rigorous trials with at least 3 months' follow-up are needed to ascertain the effects of promising plant-based preparations on diabetes.

Research Insights

Aloe Vera→Reduced Hemoglobin A1c
Four other remedies reduced HbA1c by at least 0.5%: Nigella sativa, Astragalus membranaceus, and the traditional Chinese formulae Jinqi Jiangtang and Gegen Qinlian.
Effect
Beneficial
Effect size
Moderate
Astragalus→Reduced Hemoglobin A1c
Four other remedies reduced HbA1c by at least 0.5%: Nigella sativa, Astragalus membranaceus, and the traditional Chinese formulae Jinqi Jiangtang and Gegen Qinlian.
Effect
Beneficial
Effect size
Moderate
Black Cumin→Reduced Hemoglobin A1c
Four other remedies reduced HbA1c by at least 0.5%: Nigella sativa, Astragalus membranaceus, and the traditional Chinese formulae Jinqi Jiangtang and Gegen Qinlian.
Effect
Beneficial
Effect size
Moderate
Fenugreek Seed→Reduced Hemoglobin A1c
Four other remedies reduced HbA1c by at least 0.5%: Nigella sativa, Astragalus membranaceus, and the traditional Chinese formulae Jinqi Jiangtang and Gegen Qinlian.
Effect
Beneficial
Effect size
Moderate
Psyllium Husk→Reduced Hemoglobin A1c
Four other remedies reduced HbA1c by at least 0.5%: Nigella sativa, Astragalus membranaceus, and the traditional Chinese formulae Jinqi Jiangtang and Gegen Qinlian.
Effect
Beneficial
Effect size
Moderate