SRIVIDYA .G (MAJOR)SRINIVASA RAO .GNAVEEN SWAROOP .MSAI PRATHYUSHA GAJULA2024-07-082024-07-082024-02https://krishikosh.egranth.ac.in/handle/1/5810211565The doxorubicin induced damage in coronary artery was studied initially in porcine coronary artery as in vitro model. The porcine heart was collected immediately after slaughter in chilled Krebs-Henseleit solution (pH-7.4). The Right coronary artery isolated was used for the in vitro experimentation. The RCA was placed in sterile petri dishes in Krebs-Henseleit solution and the total of four treatments with six replications was done. Group I served as control (Normal). Group II served as Doxorubicin control where the RCA was incubated in 40 µM doxorubicin for 3 h. Group III, IV and Group V, RCA were pre-incubated in 30 µM vitamin B6, tryptophan and naringenin for 1h respectively and received 40 µM doxorubicin for 3 h. After completion of treatment with doxorubicin, the tissue was utilized for biochemical and histomorphological examinations. Biochemical tests viz., GSH, SOD, TP and MDA were used to determine the status of oxidative damage. LDH and NO were estimated to determine the extent of cytotoxicity. There is a fall in total protein levels and antioxidant enzymes levels (GSH & SOD) in doxorubicin pre-treated group. Loss of endothelium and inflammatory changes were evidenced in doxorubicin treated coronary artery. There is raise in MDA, LDH and nitric oxide levels in doxorubicin pre-treated group. Pre-treatment with vitamin B6, tryptophan and naringenin caused a protective effect on doxorubicin treated coronary artery and restored the enzymes levels back to normal. Regeneration of endothelium was observed in all three treatment groups upon histomorphological examination. In the in vivo experimentation with rabbits, 36 rabbits of 1.5-2 kg body weight were randomly assigned to 6 groups of six rabbits in each group. Group I served as healthy normal animals and Group II rabbits were given doxorubicin @10mg/kg B,Wt intraperitoneally on 15th and 16th day of study. Group III animals received vitamin B6 @50 mg/kg B.Wt per orally for 14 days. Group IV and V received tryptophan (100 mg/kg B.Wt) and naringenin (100 mg/kg B.Wt) per orally for 14 days. Group VI served as an interplay group where the rabbits received vitamin B6 (50mg/kg B.Wt), tryptophan (100 mg/kg B.Wt) and naringenin (100 mg/kg B.Wt) for 14 days. On day 15 and 16, all groups of rabbits received doxorubicin @10mg/kg B.Wt intraperitoneally. On day 17 the rabbits were sacrificed using xylazine and ketamine anaesthesia and heart samples were collected in chilled Krebs-Hanseleit solution. Half portion of the heart tissues was used to prepare tissue homogenate to study antioxidant enzymes levels and the remaining half to study histomorphological alterations. Blood was collected during sacrifice to study heamatological parameters and the seperated serum was used to estimate calcium, phosphorous, nitric oxide and lactate dehydrogenase. There is a fall in levels of antioxidant enzymes (GSH and SOD), phosphorous, RBC, WBC, haemoglobin, platelets count where as there is elevation of MDA levels, calcium, nitric oxide and LDH levels in the doxorubicin treated rabbits. Gross morphological changes like pale heart, congestion of blood vessels and fatty change and histomorphological alterations like loss of endothelium, infiltration of inflammatory cells, vacuolation of cardiomyocytes were observed in doxorubicin treated rabbits. Pre-treatment with vitamin B6, tryptophan, naringenin and their combination restored the antioxidant enzymes levels, haematological and cytotoxicity markers. Normal architecture of the artery was preserved in these rabbits and gross changes were mild to moderate congestion. Rabbits of Group VI showed less damage which may be due to synergistic effect of vitamin B6, tryptophan and naringenin over doxorubicin damaged heart and coronary artery. Based on the above results, it is concluded that combination of vitamin B6, tryptophan and naringenin offered better protection on doxorubicin induced coronary artery damage.EnglishThesis