RESUMO
The present study aimed at investigating the in-vitro oxidation of acrylonitrile [ACN] to cyanide [CN] by prostaglandin H synthase [PHS]. Detection of CN is considered a marker for free radical intermediates involved in ACN-induced toxicity. First, most favorable circumstances for ACN oxidation were characterized: pH [4.5], temperature [37 degree C] and time of incubation [60 min.]. In addition, the concentrations of ACN, PHS and H2O2 in incubation mixtures were assessed for further reaction characterization. The reaction maximum velocity [Vmax] was calculated to be 582.75 pmol CN/mL/min and the Michaelis-Menten constant [Km] was 149.25 µmol ACN. Adding PHS inhibitors; resveratrol, quercetin, indomethacin or troloc-C to the reaction mixtures significantly reduced the rate of ACN oxidation. In conclusion, the present study demonstrates the ability of PHS to oxidize ACN to CN and provides a clue for the explanation of ACN target toxicity
RESUMO
Medicago sativa L. [Alfalfa] is traditionally used to treat diabetes. This study was designed to investigate the potential antihyperlipidemic and antihyperglycemic activity of M. sativa sprouts in streptozotocin [STZ] induced diabetes via i.p. injection of 55mg/kg of STZ. Experimental animals were divided into the following groups: GP1 [normal], GP2 [STZ-hyperlipidemic], GP3 [rouvastatin], GP4 [metformin], GP 5-9 [diabetic treated with methanolic, petroleum ether, chloroform, ethyl acetate and butanol extracts]. The administration of the total methanolic extract [500 mg/kg], the petroleum ether [32.5mg] and butanol fractions [60mg] for 4 weeks significantly decreased [p<0.05] triglycerides [TG], total cholesterol [TC], low-density lipoproteins [LDL] and very low density lipoproteins [VLDL] in comparison to rouvastatin. Petroleum ether fraction proved to exhibit the best activity as antihyperlipidemic agent [12.23%]. On the other hand, ethyl acetate fraction retained the best activity [vs. metformin] as antihyperglycemic agent. Histopathological evidences on liver, pancreas and spleen were in agreement with the abovementioned results. Purification, characterization, and identification of isolated compounds from the active fractions afforded 9 compounds: beta-sitosterol and stigmasterol from the petroleum ether fraction; 10-hydroxy-coumestrol, apigenin, genistein, p-hydroxybenzoic- acid, 7, 4?- dihydroxyflavone, quercetin-3-glucoside and sissotrin from the ethyl acetate fraction