Treatment of dermatitis from parthenin

Composites and some other plants containing sesquiterpene lactones, frequently cause allergic contact dermatitis in man. No treatment is available to control this disease successfully. We have used an amino acid, cysteine, to treat allergic contact dermatitis in guinea pigs sensitized to parthenin, a major sesquiterpene lactone of an allergenic weed, Parthenium hysterophorus L. Cysteine treatment of the allergic reaction induced by parthenin resulted in (a) reduced time of recovery and (b) reduced intensity of the skin reaction.     

Treatment of dermatitis caused by the sesquiterpene lactone helenin

Many sesquiterpene lactones, terpenoid compounds present in members of the Compositae (Asteraceae) family of plants, are known to cause allergic contact dermatitis. There is no treatment of this skin disease. We report on the use of an amino acid, L-cysteine, to control dermatitis in guinea pigs sensitized to the sesquiterpene lactone, helenin. The cysteine treatment of allergic reactions induced by helenin reduced the recovery time of the animals by about 50%. The effect of cysteine treatment might be explained by: cysteine reaction with free helenin, and substitution of skin proteins from the protein-helenin complex by cysteine through competitive reactions. Cysteine treatment present a new promising way for control of this type of allergy in humans.     

Cross-reactivity between sesquiterpene lactones related to parthenin in parthenin-sensitized guinea pigs

The naturally-occurring sesquiterpene lactone, parthenin, is responsible for a high incidence of allergic contact dermatitis in India. Cross-sensitivity tests on guinea pigs sensitized to parthenin indicate a relatively high immunological specificity for this low molecular weight hapten. Coronopilin and damsin, sesquiterpene lactones most similar to parthenin, gave positive reactions but other structurally related lactones such as dihydroisoparthenin, tetra-hydroparthenin, tetraneurin-A, hysterin, helenalin, and tenulin, or hymenin, a diastereoisomer of parthenin, were negative.