Background: Prasaprohyai remedy (PSPR) is a Thai traditional medicine that has long been used to treat the common cold and fever. Previous studies revealed that PSPR powder can relieve allergic rhinitis symptoms as effectively as Loratadine. The usual dose was 3,000 mg/day; however, if the extract could be used it may be possible to reduce the dosage. Therefore, it is necessary to find out if the administration of PSPR ethanolic extract to healthy volunteers is safe.

Objective: To study the safety of PSPR ethanolic extract in healthy volunteers.

Materials and Methods: The present study was a randomized, open-labelled, trial for safety assessments in 24 healthy volunteers. The volunteers were divided into two groups, one group receiving 3x100 mg/day and the other group receiving 3x200 mg/day before meal for 6 weeks. The blocked randomization was done by a computer program with equal distribution of genders. The experiment with group 2 started
after finishing with group 1. There was a wash-out period after week 6th. All volunteers were followed-up in the 3rd week, 6th week and 8th week to evaluate the safety of the medicine.

Results: There was no toxicity of PSPR to the liver and kidney. The results on blood glucose, lipid profile and complete blood count were normal.

Conclusion: The PSPR remedy ethanolic extract capsules at 300 and 600 mg/day were safe to use in healthy volunteers for 6 weeks, with mild side effects. Oral administration was recommended after meals.

Keywords: Prasaprohyai remedy, Safety, Complementary medicine, Herbal extract