Effects of ginseng berry saponins from panax ginseng on glucose metabolism of patients with prediabetes: A randomized, double-blinded, placebo-controlled, crossover trial

Background: Prediabetes strongly increases the risk of type 2 diabetes and cardiovascular events. However, lifestyle intervention, the first-line treatment for prediabetes currently, was inconsistently beneficial for glucose metabolism, and the conventional medicines, such as metformin, is controversial for prediabetes due to the possible side effects.

Purpose: This study was designed to evaluate the effects of Zhenyuan Capsule, a Chinese patented medicine consisting of ginseng berry saponins extracted from the mature berry of Panax Ginseng, on the glucose metabolism of prediabetic patients as a complementary therapy.

Study design and methods: In this randomized, double-Blinded, placebo-controlled, crossover trial, 195 participants with prediabetes were randomized 1:1 to receive either placebo followed by Zhenyuan Capsule, or vice versa, alongside lifestyle interventions. Each treatment period lasted 4 weeks with a 4-week washout period in between. The primary outcomes were the changes in fasting plasma glucose (FPG) and 2-h postprandial plasma glucose (2-h PG) from baseline. Secondary outcomes includes the changes in fasting and 2-h postprandial insulin and C-peptide, the homeostatic model assessment-insulin resistance (HOMA-IR) index and quantitative insulin sensitivity check index (QUICKI) from baseline. Blood lipids and adverse events were also assessed.

Results: Compared with placebo, Zhenyuan Capsule caused remarkable reduction in 2-h PG (-0.98 mmol/l) after adjusting treatment order. Zhenyuan Capsule also reduced the fasting and 2-h postprandial levels of insulin and C-peptide, lowered HOMA-IR index (-1.26), and raised QUICKI index (+0.012) when compared to placebo. Additionally, a significant increase in high density lipoprotein cholesterol (HDL-C; +0.25 mmol/l) was found in patients with Zhenyuan Capsule. No serious adverse event occurred during the study.

Conclusions: Among prediabetic patients, Zhenyuan Capsule further reduced 2-h PG level, alleviated insulin resistance and raised HDL-C level on the background of lifestyle interventions. The study protocol is registered with the Chinese Clinical Trial Registry (ChiCTR2000034000).