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2011 - 20144
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Subject: Veterinary Pharmacology and Toxicology × End date: 2016 × Start date: 2010 × Thesis Type: Ph.D ×
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    ThesisItemOpen Access
    ENDOCRINE DISRUPTING ACTIONS OF CADMIUM AND EXPERIMENTAL EVALUATION OF PROTECTION BY GREEN TEA EXTRACT
    (SRI VENKATESWARA VETERINARY UNIVERSITY TIRUPATI - 517 502. (A.P.) INDIA, 2014-05) SHIVAKUMAR, PABBATHI; GOPALA REDDY, A(MAJOR); SRINIVASA RAO, G; ANJANEYULU, Y; RAMANA REDDY, Y; UDAYA KUMAR, M
    ABSTRACT : An experimental study was conducted to evaluate the neuro-endocrine disrupting actions of cadmium and the effect of cadmium on the progeny that were born to cadmium exposed rats and to evaluate the protective role of green tea on neuro-endocrine disrupting actions of cadmium in Sprague dawley rats. Rats were randomly divided into 4 groups of 30 rats in each (male rats =12, female rats=18).Group 1 served as Sham control Group 2 treated with CdCl2, Group 3 treated with Green tea extract treatment and Group 4 Cd + green tea extract treatment. Blood was collected from all the groups at monthly intervals for analyzing sero-biochemistry (blood glucose, total cholesterol, HDL-cholesterol, triglycerides, total protein and albumin, biomarkers of cardiovascular, hepatic and renal pathology, and hormonal profile (thyroid profile, sex hormones). The key enzymes concerned with metabolism were assayed. Immune status was studied at the end of 3rd month by phytohaemagglutinin assay. Rats were subjected to neuro-behavioural studies at the end (Elevated plus maze and Morris water maze). Epididymal sperm count in males and estrous cycle pattern in females were studied. At the end of 3 months, 12 rats (6 males and 6 females) from each group were sacrificed to collect various organs and endocrine glands and subjected them to biochemical, histological and electron microscopic studies. Cadmium concentration was estimated in all the treated groups in kidney, testes, liver and brain at the end of 3 months. In all the groups, twelve (12) females were mated at the end of three months with male rats belonging to respective groups/treatments and the treatment was continued till 17th day of gestation. 50% of the pregnant rats in the respective groups were sacrificed on day 19 to study skeletal and soft tissue developmental anomalies and the rest were allowed to normal delivery. The pups of F1 generation from all the groups were kept till weaning (post-natal day 21) and were subjected to sero biochemical, neurobehavioural studies andthyroid hormone profile were estimated. There were significant alterations in sero-biochemistry biomarkers of cardiovascular, hepatic and renal pathology and hormonal profile thyroid profile, group 2 as compared to group 1.Treatment group revealed significant improvement in all the parameters as compared to group 2, while the combination treatment group 4 was found better The histological studies in group 2 revealed marked changes in all the organs studied, while groups 4 revealed moderate changes and groups 1 and 3 revealed no pathologically significant changes. The electron microscopy of kidney, testis and thyroid revealed marked alterations in architecture in group 2, while groups 4 revealed better architecture. There were no significant alteration in the TEM samples of the offspring and there were no skeletal abnormalities in the offspring as evidenced by skeletal staining. The results of the study revealed neuro-endocrine disrupting actions of cadmium and protctive role of green tea in cadmium toxicity. Further studies are warranted to know in detail on the endocrine disrupting actions of cadmium and protective role of green tea at various concentrations.
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    ThesisItemOpen Access
    INTERACTION STUDIES ON GYMNEMA SYLVESTRE WITH GLIMEPIRIDE AND INSULIN IN EXPERIMENTAL DIABETES MELLITUS IN RATS
    (SRI VENKATESWARA VETERINARY UNIVERSITY TIRUPATI - 517 502. (A.P.) INDIA, 2013-12) Srikanth, M.K; GOPALA REDDY, A(MAJOR); BHARAVI, K; MADHAVA RAO, T; KONDAL REDDY, K; ANAND KUMAR, A
    ABSTRACT: An experimental study was conducted to evaluate the interaction of Gymnema sylvestre extract with insulin and glimepiride in diabetic Sprague dawley rats. Rats were randomly divided into 7 groups of 6 rats in each and blood glucose was estimated to ascertain group differences, if any. Group 1 was kept as normal control. Remaining 6 groups were induced diabetes by intraperitoneal injection of streptozotocin @ 40 mg/kg body weight. After 72 h, rats with blood glucose value of >200 mg/dl were included in the study (n=6). Treatment protocols were initiated 48 hrs post-confirmation of diabetes and continued for 2 months. Group 1: non-diabetic control, group 2: streptozotocin (40 mg/Kg i/p single dose)-induced diabetic (DM) control, group 3: Insulin treatment (4 U/kg b. wt. subcutaneously once daily), group 4: glimepiride treatment (4 mg/kg b. wt. orally once daily), group 5: Gymnema sylvestre methanolic leaf extract treatment ( 400 mg/kg b.wt. orally once daily), group 6: Insulin + Gymnema sylvestre methanolic leaf extract treatment (once daily) and group 7: glimepiride + Gymnema sylvestre methanolic leaf extract treatment (once daily). Blood glucose, body weights, sero-biochemical parameters, antioxidant profile in liver, kidney, brain and testis, ATPases, glucose 6 phosphate dehydrogenase (G6PD), cytochrome P450 (CYP450) activity and glycogen in liver, electron microscopy and histopathology of various tissues were studied at different time intervals. Also, pharmacokinetic interaction of glimepiride with Gymnema sylvestre extract was assessed. There were significant alterations in blood glucose, body weights and other biochemical parameters in diabetic control group 2 as compared to group 1. All the treated groups revealed significant improvement in all the parameters as compared to group 2, while the combination treatment in groups 6 and 7 was found better as compared to single agent-treated groups 3, 4 and 5. The histological studies revealed marked changes in group 2 in all the organs studied, while groups 3 to 5 revealed moderate changes and groups 6 and 7 revealed either minor changes or no pathologically significant changes. Group 1 was devoid of any histological alterations. The electron microscopy of kidney, pancreas and aorta revealed marked alterations in group 2, while groups 6 and 7 revealed better architecture. The pharmacokinetic study revealed the values of T1/2 (h), Ka (h-1), Ke (h-1) and Tmax (h) of glimepiride were siginificantly varied in Gymnema sylevestre pre-treated rats compared to normal rats administered with glimperide In conclusion, the study revealed that addition of Gymnema sylvestre leaf extract to insulin and glimepiride had positive pharmacodynamic interaction in improving the patho-biochemical alterations due to streptozotocin-induced diabetes mellitus in rats, which was evident from greater improvement in sero-biochemical and organ parameters in the groups that were treated using a combination of Gymnema sylvestre with either insulin or glimepiride as compared to individual agent-treated groups. Important pharmacokinetic parameters did not vary significantly when glimepiride was used in combination with Gymnema sylvestre leaf extract.
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    ThesisItemOpen Access
    TOXICODYNAMIC INTERACTION OF LEAD WITH CADMIUM AND THERAPEUTIC EVALUATION OF N-ACETYL L-CYSTEINE IN RATS
    (SRI VENKATESWARA VETERINARY UNIVERSITY TIRUPATI - 517 502. (A.P.) INDIA, 2011-07) ANlL KUMAR, B; GOPALA REDDY, A(MAJOR); RAVl KUMAR, P; MADHAVA RAO, T; ANAND KUMAR, A
    ABSTRACT: An experimental study was conducted to evaluate the molecular mechanisms of lead and cadmium toxicity and their toxicodynamic interaction, and to evaluate therapeutic potential of N-Acetyl L-cysteine (NAC) against the toxicity in Wstar rats. After an acclimatization period of 2 weeks, rats were randomly divided into 8 groups comprising of 6 rats in each. Group 1 was kept as normal control throughout the experimental period, 2 was given NAC @ 300 mg per kg body weight administered by oral gavage, 3 was given lead (lead acetate @ I000 ppm in feed), 4 was given cadmium (cadmium chloride @ 300 ppm in feed), 5 was given lead + cadmium as per above doses in feed, 6 was given lead + NAC as per above schedule, 7 was given cadmium + NAC as per above schedule, and group 8 was given lead + cadmium + NAC as per above schedule for 3 months. Body weights, haematology (TEC, TLC, Hb, PCV, MCH and MCHC), activity of 6-ALAD and erythrocytic SOD, sero-biochemical parameters (ALT, CPK, troponins, plasma TBARS and serum creatinine), antioxidant profile (GSH, GST, TBARS and protein carbonyls) in liver, kidney, heart, testis and brain, ATPases and tissue lipids in liver and brain, neurotransmitters (Ach and glutamate) in brain, CYP450, glycogen and G6PD in liver, weight of testes, testicular LDH and sperm count, electron microscopy of kidney in cadmium exposed groups and histopathology of liver, kidney, testis and heart were studied. Also, interaction of lead and cadmium with zinc and copper in liver, kidney, heart, testis and brain was assessed. The present study revealed significant alterations in body weights, haematology, sero-biochemical parameters, antioxidant profile, ATPases, tissue lipid profile, neurotransmitter, CYPd50, glycogen, GGPD, weights of testes, testicular LDH, sperm count, and concentration of zinc and copper in toxic control groups 3, 4 and 5 as compared to control and NAC-treated groups. The toxic combination (Pb + Cd) group 5 showed significant alterations in most of the parameters studied as compared to Pb alone and Cd alone administered groups. All the NAC-treated groups revealed significant improvement in all the parameters. The histological studies of liver, kidney, testis and brain revealed marked changes in toxic control groups, while therapeutic groups revealed mild changes or no pathologically significant changes. Groups 1 and 2 were devoid of any alterations. The electron microscopy of kidney revealed marked alterations in kidney architecture in groups 4 and 5, while groups 7 and 8 revealed better architecture. The results of the investigation revealed that lead, cadmium' and their combination induced toxicity to the biological system due to the excess generation of free radicals and impairment of antioxidant defenses. Toxic effects were more pronounced in the group that received a combination of lead and cadmium suggesting positive toxicodynamic interaction. Use of NAC countered the adverse effects of lead and cadmium induced toxicity to a major extent suggesting its antioxidant potential owing to replenishment of tissue pool of GSH. Further, NAC administration reduced the extent of accumulation of lead and cadmium in various tissues.
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    ThesisItemOpen Access
    INTERACTION OF TRIGONELLA FOENUM GRAECUM WITH INSULIN AND GLIMEPIRIDE IN EXPERIMENTAL DIABETES MELLITUS IN RATS
    (SRI VENKATESWARA VETERINARY UNIVERSITY TIRUPATI - 517 502. (A.P.) INDIA, 2011-01) HARITHA, C; GOPALA REDDY, A(MAJOR); SRINIVASA RAO, G; ANJANEYULU, Y; MADHAVA RAO, T; RAMANA REDDY, Y
    ABSTRACT: An experimental study was conducted to evaluate the interaction of fenugreek seed powder with insulin and glimepiride in diabetic Sprague dawley rats. Rats were randomly divided into 7 groups of 8 rats in each and blood glucose was estimated to ascertain group differences, if any. Group 1 was kept as normal control. Remaining 6 groups were induced diabetes by intraperitoneal injection of streptozotocin @ 40 mg/kg body weight. After 72 h, rats with blood glucose value of >250 mg/dl were included in the study (n=8). Treatment protocols were initiated from day 2 post-confirmation of diabetes and continued for 8 wks. Group 1: non-diabetic control, group 2: streptozotocin (40 mg/Kg i/p single dose)-induced diabetic (DM) control, group 3: Insulin treatment (4 U/kg once daily), group 4: glimepiride treatment (4 mg/kg orally once daily), group 5: fenugreek seed powder treatment (1 g/kg orally once daily), group 6: Insulin + fenugreek seed powder treatment (once daily) and group 7: glimepiride + fenugreek seed powder treatment (once daily). Blood glucose, body weights, sero-biochemical parameters, antioxidant profile in liver, kidney, brain and testis, ATPases in liver and brain, relative weights of kidney and testes, electron microscopy of kidney and histopathology of various tissues were studied at different time intervals. Also, pharmacokinetic interaction of glimepiride with fenugreek seed powder was assessed. There were significant alterations in blood glucose, body weights and other biochemical parameters in diabetic control group 2 as compared to group 1. All the treated groups revealed significant improvement in all the parameters as compared to group 2, while the combination treatment groups 6 and 7 were found better as compared to single agent-treated groups 3 through 5. The histological studies revealed marked changes in all the organs studied, while groups 3 to 5 revealed moderate changes and groups 6 and 7 revealed either minor changes or no pathologically significant changes. Group 1 was devoid of any alterations. The electron microscopy of kidney revealed marked alterations in kidney architecture in group 2, while groups 6 and 7 revealed better architecture. Fenugreek seed powder treatment increased AUC and elimination half life of glimepiride in combination as compared to glimepiride-alone treated group, while the Cmax and tmax did not vary between groups 4 and 7. The results of the study revealed positive pharmacodynamic interaction between fenugreek and either insulin or glimepiride in improving the patho-biochemical alterations in diabetic rats. Further, there was a favourable pharmacokinetic interaction. Further studies are warranted to estimate P-gp and OATP activities along with CYP2C9 estimation for better understanding of pharmacokinetic interactions of fenugreek and glimepiride in diabetes mellitus.