The beneficial effect of soybean (Glycine max (L.) Merr.) leaf extracts in adults with prediabetes: a randomized placebo controlled trial

Abstract

The present study investigated the effects of soybean leaf extracts (SLEs) on blood glucose, insulin resistance, body fat and dyslipidemia in prediabetes subjects, and compared them with the effects of banaba extracts (BE) which is known to ameliorate diabetes in several animals and clinical studies. Overweight subjects with mild hyperglycemia (fasting blood glucose level of 100-125 mg dL(-1)) were randomly assigned to three groups and administered four capsules containing starch (2 g per day, Placebo), BE (300 mg per day, 0.3% corosolic acid) or SLE (2 g per day) during regular meals for 12 weeks. The SLE as well as BE significantly decreased the baseline-adjusted final blood glucose, HbA1c, HOMA-IR and transaminase levels compared to the placebo group. The body weight, BMI and WHR were not different between the groups, but the baseline-adjusted final body fat content and waist circumference were lower in the BE and SLE groups than in the placebo group. Furthermore, the baseline-adjusted final plasma triglyceride concentration was lower in the BE and SLE groups compared to the placebo group. There were no significant differences in plasma total cholesterol and LDL-cholesterol concentrations between the groups. However, the SLE, but not the BE, significantly increased the plasma HDL-cholesterol concentration and the ratio of HDL-cholesterol to total cholesterol after 12 weeks of supplementation compared to the placebo group, while the atherogenic index was decreased. Taken together, these data suggest that SLE may play an important role in improving blood glucose, insulin resistance, adiposity, and dyslipidemia in prediabetes subjects consuming their habitual diet, similar to or better than BE.

Soy Leaf Extract Containing Kaempferol Glycosides and Pheophorbides Improves Glucose Homeostasis by Enhancing Pancreatic β-Cell Function and Suppressing Hepatic Lipid Accumulation in db/db Mice

“…Subfraction S-5 was subjected to CC on Sep-Pak C18, eluted with 20−25% aqueous MeOH, and then separated by RP preparative HPLC and eluted with 11% aqueous acetonitrile to afford compounds 4 (15.6 mg) and 5 (8.0 mg). Isolated KGs were identified using the UV spectra gathered during HPLC DAD monitoring ( Figure 1A−C), 1 H and 13 C NMR data (Supporting Information, Tables S1 and S2), and ESI-MS data and were consistent with previously reported data. 14,17,18 For chemical structure elucidation of KGs 1−5, see the Supporting Information.…”

Beneficial Effects of Pterocarpan-High Soybean Leaf Extract on Metabolic Syndrome in Overweight and Obese Korean Subjects: Randomized Controlled Trial

“…Additionally, Choi et al [28] have demonstrated that supplementation with 70% ethanol extracts of soybean leaf has body fat-lowering effect in prediabetic patients, while Kim et al [29] reported that 95% ethanol extracts of soybean leaf had a minimal effect on % body fat in overweight subjects. However, in the present study, the body weight, BMI, and body fat content were not significantly different compared to baseline after 12 weeks.…”

“…In a previous study, soy leaf exhibited non-HDL-cholesterol lowering effects in hamsters [26]—as well as ethyl acetate extracts of soybean leaves, including pterocarpan—ameliorated the insulin sensitivity and improved the plasma glucose levels in high-fat diet (HFD)-induced type 2 diabetic mice [27]. We have also reported that the supplementation with soybean leaves (2 g/day) is beneficial for lowering the fasting blood glucose and plasma triglyceride levels in adult subjects with prediabetes [28], while another study found that soybean leaves supplementation (2 g/day) failed to promote weight-loss [29]. However, little is known about the exact mechanisms associated with the anti-metabolic disease action of a pterocarpan-high soybean leaf extract (PT), especially in terms of integrating transcriptional profiles and phenotypic biomarkers from human subjects.…”

Improvement of Triglyceride Levels through the Intake of Enriched-β-Conglycinin Soybean (Nanahomare) Revealed in a Randomized, Double-Blind, Placebo-Controlled Study

“…In addition, TG level was substantially decreased at week 8 but it was elevated at week 12 in the placebo group. Placebo soybean also contained various functional components such as soy protein, fiber, and isoflavone [4,5], therefore these components might decrease TG levels in placebo group at week 8. However, the effectiveness of TG reduction by ingestion of placebo soybean was observed dissipating at week 12.…”

“…It has been reported that soybeans, which contain many bioactive components, such as isoflavones and soy protein have health benefits [4,5]. Soybeans significantly lower body mass index (BMI), blood pressure (BP), and serum cholesterol levels in humans [6].…”