A Randomized Controlled Trial of R-Form Verapamil Added to Ongoing Metformin Therapy in Patients with Type 2 Diabetes.

CONTEXT: There is a medical need for effective insulin-independent antidiabetic drugs that can promote pancreatic ß-cell function and have a low risk of hypoglycemia in type 2 diabetes mellitus (T2DM) patients. R-form verapamil (R-Vera), which is able to enhance the survival of ß-cells and has higher cardiovascular safety margin compared with racemic verapamil, was developed as a novel approach for T2DM treatment. OBJECTIVE: This randomized, double-blind, placebo-controlled clinical trial was designed to evaluate the efficacy and safety of 3 dosages of R-Vera added to ongoing metformin therapy in T2DM patients who had inadequate glycemic control on metformin alone. METHODS: Participants were randomly assigned in an equal ratio to receive R-Vera 450, 300, or 150 mg per day, or matching placebo, in combination with metformin. The primary endpoint was change in hemoglobin A1c (HbA1c) after 12 weeks of treatment. RESULTS: A total of 184 eligible participants were randomized to receive either R-Vera or placebo plus metformin. At week 12, significant reductions in HbA1c were observed for R-Vera 300 mg/day (-0.36, P = 0.0373) and 450 mg/day (-0.45, P = 0.0098) compared with placebo. The reduction in HbA1c correlated with decreasing fasting plasma glucose levels and improved HOMA2-ß score. Treatment with R-Vera was well tolerated with no hypoglycemic episodes occurring during the trial. CONCLUSION: Addition of R-Vera twice daily to ongoing metformin therapy significantly improved glycemic control in T2DM patients. The favorable efficacy and safety profile of R-Vera 300 mg/day can be considered as the appropriate dose for clinical practice.

Evaluating the antidiabetic effects of R-verapamil in type 1 and type 2 diabetes mellitus mouse models.

The global incidence of diabetes mellitus (DM) is increasing. Types 1 and 2 DM are associated with declining ß-cell function. Verapamil (50% S-verapamil and 50% R-verapamil) can treat DM by downregulating thioredoxin-interacting protein (TXNIP), which induces islet ß-cell apoptosis. However, it may also induce cardiovascular side effects as S-verapamil is negatively inotropic. In contrast, R-verapamil only weakly induces adverse cardiac effects. In this study, we aimed to determine the antidiabetic efficacy and cardiovascular safety of R-verapamil. We examined R- and S-verapamil binding through in vitro studies. Streptozotocin-induced type 1 and db/db type 2 DM mouse models were used to assess the antidiabetic efficacy of verapamil. IL-6, blood glucose (BG), Txnip expression, and ß-cells were evaluated in streptozotocin-induced diabetic mice, while body weight, BG, and serum insulin were measured in the db/db mice. In the type 1 DM study, 100 mg/kg/day R-verapamil and racemic verapamil lowered BG, downregulated Txnip expression, and reduced ß-cell apoptosis. In the type 2 DM study, the optimal R-verapamil dosage was 60 mg/kg/day and it lowered BG and raised serum insulin. However, efficacy did not increase with R-verapamil dosage. R-verapamil combined with metformin/acarbose improved BG and serum insulin more effectively than metformin/acarbose alone or verapamil combined with acarbose. R-verapamil had weaker cardiovascular side effects than S-verapamil. R-verapamil was 9.0× and 3.4× less effective than S-verapamil at inhibiting atrial inotropy and ileal contractility, respectively. It was also 8.7× weaker than S-verapamil as an agonist of somatostatin receptor type 2 (SSTR2), inhibiting ileal neurogenic contraction. Hence, R-verapamil may be an optimal DM treatment as it is safe, improves glycemic control, and preserves ß-cell function both as monotherapy and in combination with metformin or acarbose. R-Verapamil has potential for delaying or arresting DM progression and improving patients' quality of life.

Effect of citronellol and the Chinese medical herb complex on cellular immunity of cancer patients receiving chemotherapy/radiotherapy.

Leukopenia and immunity impairment usually occur during cancer therapy. Citronellol, an oil soluble compound derived from the geranium, has anticancer and antiinflammatory properties, as well as promoting wound healing. Ganoderma lucidum, Codonopsis pilosula and Angelicae sinensis are traditional Chinese herbs, all of which have proven immunomodulatory functions in laboratory-based research. This randomized, double-blind, placebo-controlled study examined whether the Chinese medicinal herb complex (CCMH; a mixture of citronellol and extracts of G. lucidum, C. pilosula and A. sinensis) improves the immune cell counts of cancer patients receiving chemotherapy and/or radiotherapy. A total of 105 cancer patients receiving chemotherapy or radiotherapy were enrolled. The quantities of immune cells in the blood of the subjects were determined before and after 6 weeks of cancer treatment, with either CCMH or a placebo. CCMH significantly reduced the depletion of leukocytes (14.2% compared with 28.2%) and neutrophils (11.0% compared with 29.1%). Analysis of the lymphocyte phenotype revealed that the patients receiving the placebo had reduced CD4 lymphocytes and natural killer (NK) cells than the CCMH-treated patients. Treatment with CCMH for patients receiving chemotherapy and/or radiotherapy may improve their immune function, improving their ability to fight off the cancer, as well as any secondary infections that could compromise their treatment and their health.