A clinical study phase I on safety of Thai medicinal formula “Benjalokawichien (Ha-Rak)” and each plant component extract.

Abstract

Introduction: To investigate safety profi les of extracted materials of Thai medicinal formula “Benjalokawichien(Ha-Rak)” and each plant component as being contact allergens or contact irritants to human skin.

Methods: Clinical safety was studied of ethanolic extract in the medicinal formula “Benjalokawichien (Ha-Rak)”and its each plant component. Total phenolic content of the extract was determined using FolinCiocalteu’s reagent. Anti-allergic and anti-IgE effect were determined as inhibitory activity on β-hexosaminidase release. The allergic reaction and irritation reaction in normal human skin were testedusing closed patch test under occlusion, where TRUE test^® was used as control.

Results: The extracted material of the medicinal formula “Benjalokawichien (Ha-Rak)” and each plant componentcontained phenolic content with good anti-IgE effect. Ten healthy adults 4 males, 6 females aged21-28 years; (mean ± SD of volunteer = 24.9 ± 2.024 years) were patch tested. No irritationreaction was found from the medicinal formula “Benjalokawichien” and all of each plant componentextracts. The medicinal formula “Benjalokawichien (Ha-Rak)” showed no allergic reaction to allvolunteers. The results showed 3 volunteers had positive allergic reaction to Harrisonia perforata Merr.and 1 volunteer to Capparis micracantha DC.. Doubtful reaction was found in 2 volunteers to Ficusracemosa Linn. and 1 volunteer to Clerodendrum petasites S. Moore and Tiliacora triandra Diels.. In TRUE test^® sets showed no irritation. The highest positive allergic reagent was thiomersal 5 volunteers,following by nickel sulphate 3 volunteers and 1 volunteer each to colophony, cobalt chloride,mercaptobenzothiazole and thiuram mix. The results showed 2 volunteers had doubtful reaction toquaternium-15 and 1 volunteer each to neomycin sulphate, wool alcohol, carba mix, fragrance mix,thiomersal, ethylenediamine dihydrochloride.

Conclusion: Ethanolic extract of Thai medicinal formula “Benjalokawichien (Ha-Rak)”contained phenolic content withgood anti-IgE effect. The tests showed no irritation nor allergic reaction to human skin, so this maybe highest safety and suitable for drug preparation and other products of external skin treatment.Extract of Harrisonia perforata Merr. Root and Capparis micracantha DC. root caused allergic reactionwhich may not be safe to use as active ingredient for topical preparation for skin. Contact allergiceffect of extract of the other each plant components need further study.

Key words: Clinical safety study, Human skin patch test, Thai medicinal formula “Benjalokawichien”