Study on the Safety of Thunbergia laurifolia Lindl. Extract Capsule by Oral Administration on Healthy Volunteers Phase I

Abstract

The purposes of this clinical trial phase I were to study the safety and side effects of Thunbergia laurifolia Lindl. water extract at dose 600 milligram per day, calculated by probabilistic multiplication method to be a Reference Dose (RfD), on 10 healthy volunteers, which was permitted by ethical review committee Faculty of Medicine, Thammasat University. Five males and 5 females’ healthy volunteers, age between 20-29 years old, received 600 milligram water extract of Thunbergia laurifolia Lindl. orally per day in the morning for 14 days and washout period for 14 days. The CRF and TMSE were performed and analyzed using descriptive statistic for data base and side effects, and the safety results were determined by physical examination and laboratory tests analyzed by inferential statistic, repeated measures ANOVA statistic was used.

The results of total 10 volunteers were followed at D1, D7, D14, and 14 days for washed out period, showed that the physical examination had no abnormal fi nding, the TMSE score were not difference from the baseline. However some volunteers about 2:10 cases increased the appetite, 1:10 case had more excretions, fecal and urine. The laboratory results found that RBC, WBC counts, RFT, Cholinesterase, and Lead level were in normal interval, although the lymphocyte level slightly increased in 2 cases at D7, AST and ALT levels also slightly increased, but all still in normal ranges.

In conclusion, oral administration of Thunbergia laurifolia Lindl. water extract capsule at dose 600 milligram/day for 14 days on healthy volunteers were safe to carried on phase II and III clinical trial. As AST and ALT were slightly increased, but all at 95%CI still in normal ranges, it is only needed to keep an eye on.

Key words: Clinical trial, Thunbergia laurifolia Lindl., Cholinesterase