title: Possible Mechanism of Action of the Antiallergic Effect of an Aqueous Extract of Heliotropium indicum L. in Ovalbumin-Induced Allergic Conjunctivitis.
abstract: 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 (p ≤ 0.001) low clinical score of allergic conjunctivitis. Ovalbumin-specific IgG and IgE as well as total serum IgE also decreased significantly (p ≤ 0.01-0.001). 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.
authors.affiliation: Discipline of Optometry, School of Health Sciences, College of Health, University of KwaZulu-Natal, Durban 4041, South Africa ; Department of Optometry, School of Allied Health Sciences, University of Cape Coast, Cape Coast, Ghana.
authors.forename: Samuel
authors.initials: S
authors.lastname: Kyei
authors.affiliation: Discipline of Optometry, School of Health Sciences, College of Health, University of KwaZulu-Natal, Durban 4041, South Africa ; Department of Pharmacology, Faculty of Pharmacy and Pharmaceutical Sciences, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.
authors.forename: George Asumeng
authors.initials: GA
authors.lastname: Koffuor
authors.affiliation: Discipline of Optometry, School of Health Sciences, College of Health, University of KwaZulu-Natal, Durban 4041, South Africa.
authors.forename: Paul
authors.initials: P
authors.lastname: Ramkissoon
authors.affiliation: Department of Optometry, School of Allied Health Sciences, University of Cape Coast, Cape Coast, Ghana.
authors.forename: Samuel
authors.initials: S
authors.lastname: Abokyi
authors.affiliation: Department of Pathology, Komfo Anokye Teaching Hospital, Kumasi, Ghana.
authors.forename: Osei
authors.identifier: 0000-0002-7400-2952
authors.initials: O
authors.lastname: Owusu-Afriyie
authors.affiliation: Department of Optometry, School of Allied Health Sciences, University of Cape Coast, Cape Coast, Ghana.
authors.forename: Eric Addo
authors.initials: EA
authors.lastname: Wiredu