Table of Contents
Journal of Allergy
Volume 2015, Article ID 245370, 7 pages
Research Article

Possible Mechanism of Action of the Antiallergic Effect of an Aqueous Extract of Heliotropium indicum L. in Ovalbumin-Induced Allergic Conjunctivitis

1Discipline of Optometry, School of Health Sciences, College of Health, University of KwaZulu-Natal, Durban 4041, South Africa
2Department of Optometry, School of Allied Health Sciences, University of Cape Coast, Cape Coast, Ghana
3Department of Pharmacology, Faculty of Pharmacy and Pharmaceutical Sciences, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
4Department of Pathology, Komfo Anokye Teaching Hospital, Kumasi, Ghana

Received 17 July 2015; Revised 23 October 2015; Accepted 25 October 2015

Academic Editor: William E. Berger

Copyright © 2015 Samuel Kyei et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Heliotropium indicum is used traditionally as a remedy for conjunctivitis in Ghana. This study therefore evaluated the antiallergic potential of an aqueous whole plant extract of Heliotropium indicum (HIE) in ovalbumin-induced allergic conjunctivitis and attempted to predict its mode of action. Clinical scores for allergic conjunctivitis induced by intraperitoneal ovalbumin sensitization (100 : 10 μg OVA/Al(OH)3 in phosphate-buffered saline [PBS]) and topical conjunctival challenge (1.5 mg OVA in 10 μL PBS) in Dunkin-Hartley guinea pigs were estimated after a week’s daily treatment with 30–300 mg kg−1 HIE, 30 mg kg−1 prednisolone, 10 mg kg−1 chlorpheniramine, or 10 mL kg−1 PBS. Ovalbumin-specific IgG and IgE and total IgE in serum were estimated using Enzyme-Linked Immunosorbent Assay. Histopathological assessment of the exenterated conjunctivae was also performed. The 30 and 300 mg kg−1 HIE treatment resulted in a significantly () low clinical score of allergic conjunctivitis. Ovalbumin-specific IgG and IgE as well as total serum IgE also decreased significantly (–0.001). The conjunctival tissue in HIE treated guinea pigs had mild mononuclear infiltration compared to the PBS-treated ones, which had intense conjunctival tissue inflammatory infiltration. HIE exhibited antiallergic effect possibly by immunomodulation or immunosuppression.