Pathological studies on Pteris cretica (L.) fern-Bovine Papilloma Virus infection in Syrian Golden Hamsters (Mesocricetus auratus)

Abstract

Pteris cretica (L.) commonly known as Cretan brake is widely distributed in nature and considered as potential environmental carcinogen. However, only limited literature is available on this fern commonly taken by cattle while grazing. It is known that in cattle Bovine papilloma virus (BPV) induced benign tumours are converted into malignant with interaction of ptaquiloside (Pta) present in ferns. In the present investigation, we evaluated the pathological effects of
P. cretica (PC)-BPV infection in laboratory model hamster. Though toxic principle Pta was detected in fern samples but quercetin could not be found. Tumours were successfully induced in hamsters by cutaneous wart suspension and histopathologically diagnosed as fibroma and lipofibroma. Histopathologically, hamsters showed mild to moderate vascular changes in vital organs, multiple cysts, degenerative changes, bile duct hyperplasia and necrosis in liver, haemorrhages and haemosiderosis in spleen, hypersecretory activity and prominent Peyer’s patches in ileum, degenerative changes and presence of eosinophilic casts in renal tubules. Ultrastructural study revealed apoptosis in hepatocytes, abundance of variable shaped mitochondria in renal tubular lining epithelial cells and enterocytes showed abundance of mitochondria and cytoplasmolysis in the fern fed groups. Almost all the hamsters from BPV, fern and virus infection (PC+BPV) groups developed similar type of tumorous growths. The visible growths in the hamsters of these groups were either single or double large sized except multiple tumorous growths in one hamster from PC+BPV group. However, multiple palpable subcutaneous nodules were developed at the site of scarification in all the hamsters of BPV and PC+BPV groups. Our findings suggest that the Pta containing P. cretica feeding induced hepatotoxic and nephrotoxic lesions in hamsters, but effects of P. cretica-BPV infection were found negligible.