The production of allergic eczematous contact deratitis (AECD) in humans due to exposure to dermatotoxic plant constituents poses a major clinical problem to dermatologists and immunologists. Recent published findings in our laboratory have established the structure identification and dermatotoxicity of numerous naturally-occurring chemicals that are present in native, agricultural and ornamental plants that pose occupational hazards. In some cases, we have established that the secondary constituents are more potent sensitizers than the """"""""urushiols"""""""" of Toxicodendron. In this project we propose to expand our experimental chemodermatological investigations to include numerous important economical plants, such as guayule (Parthenium argentatum), English Ivy (Hedera), the desert scorpion flower (Phacelia) and members of the sunflower (Asteraceae) family. We specifically propose to (i) elucidate the major contact allergens utilizing guinea pigs for our bioassays and maximization tests, (ii) determine the degree of cross-sensitization of structurally related compounds and (iii) develop in vitro and in vivo methods for elucidating their production, mode of antigen (skin or serum proteins) formation and the site(s) on cell membranes where the allergens are complexing. An understanding of the biotransformation and activation of contact allergens will lead to a greater understanding of skin inflammation states and immune responses of antigens. Also, the chemical investigation of important landscape plants, like english ivy, which is grown around elementary school district playgrounds, will permit us to understand the chemistry of the contact allergens, the degree of dermatitis among children and suggest the proper hyposensitization.
| Reynolds, G W; Gafner, F; Rodriguez, E (1989) Contact allergens of an urban shrub Wigandia caracasana. Contact Dermatitis 21:65-8 |
| Gafner, F; Epstein, W; Reynolds, G et al. (1988) Human maximization test of falcarinol, the principal contact allergen of English ivy and Algerian ivy (Hedera helix, H. canariensis). Contact Dermatitis 19:125-8 |
| Cavin, J C; Krassner, S M; Rodriguez, E (1987) Plant-derived alkaloids active against Trypanosoma cruzi. J Ethnopharmacol 19:89-94 |
| Reynolds, G W; Epstein, W L; Rodriguez, E (1986) Unusual contact allergens from plants in the family Hydrophyllaceae. Contact Dermatitis 14:39-44 |
| Martinez, M; Flores, G; Romo de Vivar, A et al. (1986) Guayulins C and D from guayule (Parthenium argentatum). J Nat Prod 49:1102-3 |
| Watkins, S F; Fronczek, F R; Chiari, G et al. (1985) Molecular structure of guayulin A. J Nat Prod 48:631-3 |
| Rodriguez, E; Aregullin, M; Nishida, T et al. (1985) Thiarubrine A, a bioactive constituent of Aspilia (Asteraceae) consumed by wild chimpanzees. Experientia 41:419-20 |
| Reynolds, G W; Proksch, P; Rodriguez, E (1985) Prenylated phenolics that cause contact dermatitis from glandular trichomes of Turricula parryi. Planta Med :494-8 |
