Antidiabetic, antihyperlipidemic and antioxidant potential of methanol extract of Tectona grandis flowers in streptozotocin induced diabetic rats

AbstractObjectiveTo investigate antidiabetic, antihyperlipidemic and antioxidant activity of methanol extract of Tectona grandis (T. grandis) flowers (METGF) in streptozotocin (STZ) induced diabetic rats to supports its traditional use.MethodsAcute toxicity study of METGF was carried out in rat to determine its dose for the antidiabetic study. Oral glucose tolerance test (OGTT) was performed to evaluate METGF effect on elevated blood glucose level. Diabetes was induced in rats by administration of STZ (60 mg/kg, ip.) and it was confirmed 72 h after induction. METGF was orally given to the diabetic rats up to 28 days and blood glucose level were estimated each week. On 28 day of the experiment, diabetic rats were sacrificed after the blood collection for the biochemical parameters analysis and liver, kidney was collected to determine antioxidants levels.ResultsIn acute toxicity, METGF did not show toxicity and death up to a dose 2 000 mg/kg in rats. Administration of METGF 100 and 200 mg/kg significantly (P<0.001) reduced blood glucose levels in OGTT and STZ-induced diabetic rats. Both doses of METGF treatment significantly (P<0.001, P<0.01 and P<0.05) increased body weight, serum insulin, haemoglobin (Hb) and total protein levels in diabetic rats. Also, MEGTF treatment reduced elevated glycosylated haemoglobin (HbA1c) and other biochemical parameters levels significantly (P<0.001) in diabetic rats. Altered lipid profiles and antioxidants levels were reversed to near normal in diabetic rats treated with METGF.ConclusionsThese results concluded that METGF possesses antidiabetic, antihyperglycemic and antioxidant activity which supports its traditional use

A Review of Metallothionein Isoforms and their Role in Pathophysiology

The Metallothionein (MT) is a protein which has several interesting biological effects and has been demonstrated increase focus on the role of MT in various biological systems in the past three decades. The studies on the role of MT were limited with few areas like apoptosis and antioxidants in selected organs even fifty years after its discovery. Now acknowledge the exploration of various isoforms of MT such as MT-I, MT-II, MT-III and MT-IV and other isoforms in various biological systems

Expression of Metallothionein, P53 and Antioxidant Enzymes by Selenium and Vitamin D3 during Diethyl Nitrosamine-Induced Rat Liver Preneoplasia: Effect of selenium on nitrosamine-induced rat liver preneoplasia

Many studies have proved that the dietary micronutrient has an inhibitory effect against experimentally induced rat hepatocarcinogenesis. The present work is an attempt to understand combined effect of selenium (Se) and vitamin D3 (vit D3) on some potential protein expression markers of carcinogenesis, such as metallothionein (MT), P53 and antioxidant levels during diethyl nitrosamine (DEN) induced (200mg/kg in 0.9% NaCl; IP) rat liv er preneoplasia. In a short term regimen combined supplementation of Se and vit D3 at a dose of 8 ppm in water and 0.3 μl/100μl in propylene glycol, respectively, suppressed the formation of DNA comets (28.40%), thereby indicating its non- genotoxicity at this particular dose. Se and vit D3 administration throughout the study reduced relative liver weight. Modular incidence were 22.7% when compared to the carcinogen control. However, treatment with Se and vit D3 showed significant expressions of MT and P53 which studied at four sequential time points. An increased immunopositive of P53 protein (1.3±0.56% p&lt;0.02) was found in Se and vit D3 together treated rat liver with an elevated apoptotic labeling index (A1; p&lt;0.001) as documented by TUNEL assay. The positive results of MT expression at various time intervals suggest that, Se and vit D3 together mediated suppression of MT may be associated with induction of apoptosis. The results thus provide evidence for the first time in support of thepotential role of combined supplementation of Se and vit D3 on induction of P53 apoptosis with concurrent suppression of MT in order to have an understanding. Regardless of the mechanism, based on the results reported in this study, both Se and vit D3 could be considered a potential cancer chemopreventive agents whose effect is presumably based on inhibition of growth of the neoplastic cells by coordinated regulations of different biochemical markers and enzymes studied herein