Batra, MunishNeeraj Kumar2022-01-172022-01-172021-12https://krishikosh.egranth.ac.in/handle/1/5810180906The present study investigated the pathological effects of nanosilver at NOAEL dose in Wistar rats for a period of 90 days. A total of 35 rats of 6 weeks age were divided randomly into group 1 (control group) and group II (treatment group). Group 1 rats were administered nanosilver orally at NOAEL dose (30 mg/kg). In group II rats, most of rats were dull and lethargic and there was decrease in feed intake. A significant time dependent decrease in body weight. Blood parameters shows decrease in packed cell volume (PCV), haemoglobin (Hb), and total erythrocyte count (TEC). Morphology of erythrocytes is normocytic hypochromic anaemia with increase central pallor. Erythrocytic indices shows significant changes including MCH and MCH values were significant increased while MCHC shows nonsignificant changes in treated rats as compared to control rats. Other blood parameters like total leucocyte count (TLC) and total thrombocyte count (TTC) shows significant increase in value in treated group as compared to control. In differential leucocyte count, lymphocyte count was significantly decreased but neutrophil showed significant increase in value while eosinophils, monocytes and basophils showed nonsignificant variation in both groups throughout experiment. Other blood parameters like absolute neutrophil count (ANC) showed significant increase in value while absolute lymphocyte (ALC) was significantly decrease in treated group as compared to control. In biochemical profile there was significant increase in serum aspartate aminotransaminase (AST), alanine aminotransaminase (ALT), and cholesterol while other parameters like total serum protein, serum gamma globulin, serum albumin, serum globulin, and serum glucose showed decrease in value in treated group as compared to control. Other biochemical parameters like serum calcium and serum phosphorus showed nonsignificant changes in both groups throughout experiment. Grossly group I rats shows non-significant changes while group II rats show red patches in liver, red discoloration in lungs and mild congestion in heart. Histopathologically, no significant lesions could be in any organ of group I rats while in group II rats revealed congestion, thrombus formation, and degeneration of hepatocytes in liver, thickening of interalvular wall, emphysema, congestion and increase number of mononuclear cells in lungs. kidneys revealed the congestion of glomerular capillaries, interstitial haemorrhage, and coagulative necrosis. Heart of group II rats revealed congestion, necrosis, and mild enema in cardiac muscle fibres. Other organs like , spleen, uterus and testis showed non-significant changes. Collectively, these observations indicated that nanosilver at NOAEL dose has toxic effects on heath including serum biochemicals and tissue changes. The observations regarding pathomorphological alterations indicates that liver, kidneys, and lungs, were the most affected organs in nanosilver toxicity. Mild effect on heart was also observed. Collectively our results suggest that nanosilver have toxic effects even at NOAEL dose on the repeated exposure. The use of silver nanoparticles should be used restricted or avoided.EnglishThesis