Effects of herbal tea (Platostoma palustre) on blood glucose regulation in vivo

Platostoma palustre jelly is a traditional food. Platostoma palustre has been used as folk medicine and is effective against heat-shock, hypertension and diabetes. Therefore, the aim of in vivo study was to determine the effects of herbal tea (Platostoma palustre) on blood glucose regulation. The commercial herbal tea (Platostoma palustre) was kindly provided by Yueta Agricultural Biotechnology Inc. Adult male 18 Institute of Cancer Research (ICR) mice [8 weeks old; body weight (BW) between 31-33 g] with specific pathogen-free conditions were used for this study. All ICR mice were divided respectively the normal control group (n = 6), the negative control group (n = 6), and the herbal tea group (n = 6). The ICR mice (the negative control group and the herbal tea group) were intraperitoneally injected with streptozotocin (65 mg/kg BW) and nicotinamide (230 mg/kg BW) for inducing the symptoms of hyperglycemia. In the herbal tea group, the herbal tea (10 mL/kg BW) was administrated to ICR mice by gavage. To monitor the blood glucose levels in ICR mice, blood was obtained from the tail of ICR mice, and blood glucose levels were determined using the external glucometer. Blood glucose measurements were conducted once in ICR mice before the experiment and were detected once per month after the experiment. Additionally, the change of ICR mice’ BW, the blood glucose of ICR mice, and the observation of ICR mice’ behavior were monitored and detected during the experiment. The results of this experiment showed · Weight change: the weight gain of the negative control group and the herbal tea group were significantly lower than those of the normal control group and there was no significant difference between the negative control group and the herbal tea group. · Fasting blood glucose and postprandial blood glucose: the fasting blood glucose of the negative control group was significantly higher than that of the normal control group, while the herbal tea group had a tendency to lower the fasting blood glucose, but there was no significant difference compared with the negative control group. The postprandial blood glucose level results showed that the negative control group was significantly higher than the normal control group. The postprandial blood glucose level of the herbal tea group was between the normal control group and the negative control group at the 4th week administration with the herbal tea. At the 8th week administration with the herbal tea, there was a significant difference compared with the negative control group. · Oral glucose tolerance test (OGTT): 4 to 12 weeks after hyperglycemia was induced, the blood glucose levels of the negative control group at each OGTT test point were significantly higher than those of the normal control group. The blood glucose level at the test point tended to decrease, but there was no significant difference from the negative control group. By calculating the area under the OGTT curve, it was found that the area under the curve of the negative control group was significantly higher than that of the normal control group, while the results of the herbal tea group at the 8th and 12th weeks were significantly lower than those of the negative control group. Taken all results together, the hyperglycemia was successfully induced in the experimental ICR mice. After administrating with the herbal tea, the fasting blood glucose level of the ICR mice tended to improve. In addition, a significant improvement was seen in the results of postprandial blood sugar and oral glucose tolerance test effectiveness. Therefore, based on the results of this experiment, it is speculated that drinking the herbal tea for 3 months has considerable potential for blood glucose regulation, which can be used as the basis for the development of related products of the herbal tea in the future.