Skin Irritation and Allergic Testing of Thai Herbal Extracts (Ha-Rak with Turmeric) in Healthy Volunteers

Abstract

Introduction: Ha-Rak is a well-known Thai remedy orally taken for fever. The powder has been used for topical application against dermatitis. In this study, turmeric powder of equal amount was
added to Ha-Rak powder yielding Prasakhaminchan of Ha-Rak remedy. Previous studies of both Ha-Rak remedy and turmeric had established safety profiles on rat and human skin. However,
no study has been done on the safety profile of Prasakhaminchan of Ha-Rak remedy on human skin. Therefore, this study was to investigate the skin irritation and allergic testing of Thai herbal
extracts (Ha-Rak with turmeric) in healthy volunteers.

Method: Various concentrations (0.25-10% w/w) of Ha-Rak extract, turmeric extract, Prasakhaminchan of Ha-Rak extract in white petrolatum and in cream base were prepared. A patch test was
performed on 30 healthy volunteers for 48 hours. The skin reactions were evaluated after 48 hours and also 72 hours.

Results: Only one person had slight (1+) allergic reaction to turmeric extract, Prasakhaminchan of Ha-Rak extract in white petrolatum and turmeric extract in cream base. There was no allergic
reaction to Ha-Rak extract and Prasakhaminchan of Ha-Rak extract in cream base. There was no irritation from Ha-Rak, turmeric and Prasakhaminchan of Ha-Rak extracts in white petrolatum
and in cream base.

Conclusion: Ha-Rak, turmeric and Prasakhaminchan of Ha-Rak extracts at 0.25-10 % w/w in cream base and in white petrolatum did not cause skin irritation, therefore they are safe to be used as topical medication for skin. However, people who has hypersensitivity to turmeric should avoid these medicaments.