Objective　Kaempferia parviflora is a plant belonging to the family Zingiberaceae. Its rhizome has been used in strength precision drugs and tonics and has been reported to exhibit prevention effect on metabolic diseases in mice. In this study, we examined the safety and efficacy of Kaempferia parviflora extract（SIRTMAX^®）on obesity, glucose and lipid metabolism, and arterial stiffness in human.
Methods　We performed a randomized double-blind, placebo-controlled crossover clinical study. Twentycseven healthy volunteers were given either a test product containing 100 mg of SIRTMAX^® or a placebo by oral administration for 7 weeks.
Results　Body weight and fasting blood glucose declined significantly（P＝0.0033, and P＝0.04）in the SIRTMAX^® group. For the subjects whose HbA1c values（NGSP）were more than 5.4％, improvement trends in the fasting blood glucose（127.9±17.8 mg/dL before and 120.7±14.9 mg/dL after ingestion）and the cardio-ankle vascular index（CAVI, 8.0±0.2 before and 7.8±0.2 after ingestion）were observed in the SIRTMAX^® group. Furthermore, only a slight increase in the production of advanced glycation end products（AGEs）was observed in the SIRTMAX^® group（26.0±3.4μg/mL before and 27.4±1.8μg/mL after ingestion, P＝0.64）, compared with a significant increase in the placebo group（22.4±2.6μg/mL before and 29.1±2.1μg/mL after ingestion, P＝0.02）. No abnormal values were observed during the test.
Conclusion　SIRTMAX^® had the ameliorative effects on body weight and blood glucose level for all 27 subjects, and improved the vascular function for the subjects with mild hyperglycemia（HbA1c≧5.4％）. No severe adverse effects caused by SIRTMAX^® were found during the test.