Effect of Thunbergia laurifolia Herbal Tea on Glucose Homeostasis in Healthy Volunteers: A Single-Arm Phase I Study.

BACKGROUND: Thunbergia laurifolia (TL) is a commonly used herbal medicine in Thailand and in other Asian countries. TL has been approved as a Thai traditional medicine for detoxifying poisons, and the list of possible adverse effects includes hypoglycemia. TL showed hypoglycemic effect in animals possibly due to antioxidant effect and beta-cell preservation. However, the safety of TL herbal tea and its effects on glucose homeostasis have never been investigated in humans. METHODS: Twenty healthy volunteers (10 men and 10 women) drank TL herbal tea 3 times/day for 2 weeks. Ten subjects took TL herbal tea 9 grams daily. After the safety of TL herbal tea was established, 10 more subjects took TL 12 grams daily. Clinical and biochemical tests were assessed at baseline and at 2 weeks. RESULTS: Mean age was 34.9 ± 10.2 years, and mean body mass index was 27.5 ± 5.8 kg/m2. Baseline and posttreatment plasma concentrations were as follows: fasting plasma glucose (89 ± 6 vs. 89 ± 7 mg/dL), fructosamine (213 ± 32 vs. 212 ± 33 µmol/L), fasting insulin (8.8 [IQR: 5.9-18.4] vs. 10.4 [IQR: 7.4-15.2] µU/mL), HOMA-B (101.6 [IQR: 82.3-189.8] vs. 120.4 [IQR: 93.2-153.2]), and HOMA-IR (1.1 [IQR: 0.8-2.3] vs. 1.4 [IQR: 0.9-2.0]), all respectively. There were no significant changes in these parameters, including body weight, blood pressure, lipid profile, and C-reactive protein. No serious adverse events were observed during the study period. CONCLUSIONS: TL herbal tea at doses of 9 and 12 grams daily had good tolerability without any significant adverse effects on fasting plasma glucose level or other glucose homeostasis parameters measured.

In vitro protective effects of plants frequently used traditionally in cancer prevention in Thai traditional medicine: An ethnopharmacological study.

ETHNOPHARMACOLOGICAL RELEVANCE: Thai traditional medicine (TTM) has been used widely in cancer management in Thailand. Although several Thai medicinal plants were screened for pharmacological activities related to cancer treatment, such evidence still suffers from the lack of linking with TTM knowledge. AIM OF THE STUDY: To document knowledge and species used in cancer prevention in TTM and to preliminary investigate pharmacological activities related to the documented knowledge of twenty-six herbal drugs used in cancer/mareng prevention. METHODS: Fieldwork gathering data on TTM concept and herbal medicines used in cancer prevention was performed with TTM practitioners across Thailand. Later, water and ethanol extracts from twenty-six herbal drugs mentioned as being used in cancer prevention were screened for their protective effect against tert-butyl hydroperoxide-induced cell death in HepG2 cells. Then active extracts were investigated for their effects on NQO1 activity, glutathione level, and safety in normal rat hepatocytes. RESULTS: The fieldwork helped in the development of TTM cancer prevention strategy and possible experimental models to test the pharmacological activities of selected medicinal plants. Fifteen plant extracts showed significant protective effect by restoring the cell viability to 40-59.3%, which were comparable or better than the positive control EGCG. Among them, ethanol extracts from S. rugata and T. laurifolia showed the most promising chemopreventive properties by significantly increased NQO1 activity, restored GSH level from oxidative damage, as well as showed non-toxic effect in normal rat hepatocytes. CONCLUSION: TTM knowledge in cancer prevention was documented and used in the planning of pharmacological experiment to study herbal medicines, especially in cancer, inflammation, and other chronic diseases. The proposed strategy should be applied to in vivo and clinical studies in order to further confirm the validity of such a strategy. Other traditional medical systems that use integrated approaches could also apply our strategy to develop evidence that supports a more rational uses in traditional medicine.

Understanding cancer and its treatment in Thai traditional medicine: An ethnopharmacological-anthropological investigation.

ETHNOPHARMACOLOGICAL RELEVANCE: Thai traditional medicine (TTM) is widely practiced in Thailand and continues to gain importance in cancer management, but little is known about the TTM practitioners' emic concepts and practice. AIM OF THE STUDY: With this study we firstly aim to document the practice of cancer treatment and prevention by TTM practitioners and, secondly, to evaluate how such traditional concepts and practices are correlated with biomedical ones. This in turn can form the basis for developing novel strategies for designing pharmacological experiments and longer term strategies to develop TTM practice. METHODS: Semi-structured interviews with 33 TTM practitioners were performed in five provinces in different regions of Thailand. The following information were recorded; basic information of informants, descriptions of cancer (mareng in Thai), causes, diagnosis, treatment, and prevention. Plants used in the treatment and prevention of mareng were also collected. RESULTS: Using an in depth ethnographic approach four representative case studies to assist in a better understanding of the characteristics of mareng, its diagnosis, treatment, and prevention are reported here. Five characteristics of mareng - waste accumulation (khong sia), chronic illnesses (krasai), inflammation (kan aksep), bad blood (luead) and lymph (namlueang), and the imbalance of four basic elements (dhatu si) - have been identified. Explanatory models of cancer in TTM were linked with biomedical concepts and relevant pharmacological actions. Traditional uses and available scientific evidence of medicinal plants mentioned in the case studies for the treatment or prevention of mareng are presented and discussed. CONCLUSION: Here for the first time five main characteristics of cancer based on Thai traditional medical concepts are analysed. Our findings are relevant not only for the planning of clinical studies or pharmacological experiment in the search for novel compounds for cancer treatment and prevention, but also for the integration of Thai traditional medicine in cancer care.