Immunomodulatory role of Onychium contiguum, Cheilanthes farinosa ferns and their mixture in laboratory rats

Onychium contiguum and Cheilanthes farinosa are ferns which grow in plenty along with bracken fern which is major cause of enzootic bovine haematuria. The present study is envisaged to study the immunomodulatory role of these two ferns singly and in combination in laboratory rats. Male albino rats were divided into 4 groups of 5 rats each. First three groups were fed with Onychium (30%) Cheilanthes (30%) and mixture of both ferns (15% + 15%), respectively. Last group received standard fern free rations and served on control. Influence of these ferns on.the immune system was,evaluated by the assessment of humoral antibody titres (indirect ELISA) and delayed type hypersensitivity response against ovalbumin challenge after 135 days post feeding. Indirect ELISA showed significant decrease in antibody titre against ovalbumin in all the fern fed group on 7^th day after antigen injection. On 14^th day and 21^st day after antigen injection, antibody titre was reduced non-significantly in mixture, Onychium and Cheilanthes groups, respectively. Delayed type hypersensitivity reaction against ovalbumin measured in the ear pinna showed less thickness in fern fed rats compared to control after antigenic challenge. Histopathologically, engorged bood capillaries and lymphocytic infiltration in the ear pinna was seen indicative of delayed type hypersentivity reaction. It was concluded that O. contiguum, C. farinosa ferns and their mixture feeding, produced suppression of both antibody mediated and cell madiated immune response in laboratory rats.