Study of the possible protective effects of Nigella sativa on some experimentally induced cardiac, renal and liver diseases in rats

This work was designed to declare the possible protective effects of Nigella sativa "crushed seeds" on experimentally induced renal hypertension, myocardial infarction, renal and hepatic toxicities in male albino rats. The results of the present study demonestrated that Nigella sativa. [N.S] orally for four weeks [l80mg/kg/day] produced significant diastolic hypotensive effect in control normal rats and prevented development of renal hypertension when was administered simultaneously with left renal artery ligation in rats. This hypotensive effect of N.S most probably may be due to inhibition of Ca[++] ion entry via slow Ca[++] channels, inhbition of eicosanoids synthesis and increase release of endothelium derived relaxing factors. However, oral pretreatment with N.S for 4 weeks did not produce significant protective effect in isoprenaline-induced myocardial infarction. Simultaneous administration of N.S with gentamicin sulphate [60mg/kg SC once/day] produced signficant protective effect on renal functions manifested by reduction in serum levels of urea and creatinine [as indicators for kidney function]. This may be explained on the ability of N.S to act as free radical scavenger and to stimulate DNA and protein synthesis that improve tissue regeneration. Additionally, enhanced glutathione, DNA and protein synthesis can explain the protective effect of N.S against acetaminophen-induced hepatotoxicity in rats. Furthermore, N.S significantly decreased the renal and hepatic histopathological toxic changes induced by gentamicin or acetaminophen respectively, but did not be able to normalize them long term administration of N.S may modulate the reactivity of the blood vessels to different endogenous vasoactive agents which may be the cause of renal hypertension and may be also used in the prophylaxis against drugs-induced nephrotoxicity and hepatotoxicity. Accordingly, N.S as a medicinal plant has wide range of health promotion and can play a role in the prophylaxis against drugs induced organs toxicity

Dielectric properties and microhardness of some commercial types of dental glass ionomer cements

This study deals with four different dental glass ionomer cements. The aim of this present work was to study the electrical properties and microhardness for these materials, to show the correlation between these properties and to reach the most suitable one as regard tested properties. The results showed that the microhardness is inversely proportional to dielectric loss and the dielectric is proportional to AC conductivity indicating that the mechanism of dielectric polarization is similar to that of conduction. The results indicated that the dielectric and conductivity decreased with increasing temperature for all samples except for [Granitec Ionomer I] which gave a relatively constant values of epsilon[-] = 10[-5] and delta = beta x 10[-6] Ohm[-1] Cm[-1] and it can be concluded that this cement is the best one as regard electrical and hardness properties with respect to others under investigation