SCRATCHING THE SURFACE OF UNDERSTANDING HOW CERTAIN PLANT EXTRACTS CAN PREVENT POISON IVY INDUCED CONTACT DERMATITIS RASH

Jewelweed, Impatiens capensis, reduces rash development following poison ivy (PI) exposure, Toxicodendron radicans. Soaps also minimize s poison ivy rash; in p articular, Saponins are natural soaps. Saponins in I. capensis were identified as active components in preventing PI dermatitis. The Sienna group isolated 1,2,4-trihydroxynaphthalene- 1-O-glucoside (THNG), a presumptive precursor of the active component from I. capensis. ONU researchers activated THNG with ß-glucosidase, yielding 1,2,4-trihydroxynaphthalene (THN).In this IRB-approved study, PI was brushed onto forearms of 25 volunteers in 6 locations. PI exposed areas were treated with: distilled water, 10% Dawn® dish soap, THN from jewelweed at 1x and 2x the natural concentration, and saponin-containing, MeOH extract from leaves of Verbascum thapsus, and common mullein which has reported anti-inflammatory activity. Rash development was tracked for 14 days and scored on a scale of 0 to 14. After 1 week, 5 people (20%) had no dermatitis and 4 people had severe rash in all areas. Week 1 mean scores of remaining participants indicated no difference between water wash (5.1 ±3.9) and 10% dawn (5.9 ±3.6) (t = - 0.86; p = 0.20). Neither mullein nor jewelweed extracts exhibited dose dependent responses. Mullein (5.9 ± 3.8) was not significantly different from water or soap [ (tu = -1.60; p = 0.068); tn = - 0.05; p = 0.48, respectively]; which is expected as the saponins act as natural soaps. Thus, mullein saponins are not potential candidates for treating PI rash at natural concentrations. However, worsening of the rash with (6.6 ± 4.4) THN was observed [jewelweed vs water (tn = - 1.86; p = 0.044)] and developed earlier than PI alone indicating either a sensitivity to the THN itself or synergistic exacerbation of the rash. Sensitivity to jewelweed has been previously noted.