Allergy to periwinkle pollen (Catharanthus roseus G. Don.)

Abstract

Catharanthus roseus G. Don. (CR) or periwinkle plants are widely grown/ cultivated as garden plants in the tropics ard subtropics. In spite of its predominantly entomophilous nature, CR pollen had been reported to be airborne and allergenic, The objective of this study was to discover the seasonal changes of CR pollen concentration in air, to determine its potential to Cause respiratory allergy and to analyze its allergenic components. A 2-year aerobiological survey was conducted with a Burkard 7-day sampler in all agricultural farm in the suburban zone of Calcutta city where CR pollen was found to be almost perennial with 3.6-5.4% contribution to the aeropollen load. Skill prick test was conducted oil 282 respiratory allergic individuals living within a 15 kill radius of the study area. 29.8% of them were positive to CR pollen. Among them, 80.9% were directly involved in gardening. The whole pollen extract was subjected to gel filtration in a Sephacryl S-200 column. Among 5 elated fractions, fraction I showed optimum IgE-reactivity in ELISA-inhibition. The fraction I shows 4 protein components in SDS-PAGE, within which 3 (40-66 kD molecular mass) were found to be IgE-reactive in immunoblotting using patient scra. It can be concluded that CR pollen can trigger IgE-mediated respiratory allergy in the people living ill close proximity.