Nephroprotective effect of the hydromethanolic extract and fractions of Viola serpens Wall. Histological and hematological evidence.

The current study was planned to examine the nephroprotective effect of the crude extract and its various fractions of Viola serpense Wall against paracetamol-induced toxicity in rabbits. The serum creatinine levels of all fractions, as well as the crude extract, were found to have a greater effect. The effect on urine urea by the n-hexane, ethyl acetate, n-butanol and aqueous fraction in high doses (300 mg/kg b.wt.) and crude extract and chloroform in low doses (150 mg/kg bwts.) were comparatively more effective and comparable to silymarin. The creatinine clearance of the fractions except for chloroform, aqueous at 300 mg/kg and the hydro-methanolic extracts at both doses were highly significant. The histological structures of kidneys in crude extract and chloroform-treated groups showed more improvement at the lower doses. The fractions n-hexane, ethyl acetate and n-butanolic exhibited an inverse dose relationship in the histology of the kidney. However, the aqueous fraction showed a dose-dependent nephroprotective effect. Finally, the crude extract and fractions significantly improved paracetamol-induced nephrotoxicity in rabbits.

Evidence and prospective of plant derived flavonoids as antiplatelet agents: Strong candidates to be drugs of future.

Platelets are involved in hemostasis, inflammation, and thrombosis processes. Following a vascular damage, the endothelium releases protein factors, allowing the adhesion of subendothelium to platelets. Then platelets are activated, leading to the secretion of biologically-active ligands including thromboxane A2, adenosine diphosphate and serotonin. Aspirin, clopidogrel and warfarin are the most common drugs used to meet the challenges of platelet aggregation. However, these agents face issues with aspirin resistance and bleeding. New therapeutically effective and safe agents are therefore strongly needed, and natural substances could be ideal candidates. Flavonoids, a chemically diverse group of polyphenols, might be important in this regard. Consumption of flavonoids is responsible for several health-promoting properties. A number of flavonoids have shown outstanding preclinical antiplatelet effects through various mechanisms. Flavonoids could provide an ideal approach as templates for new, clinically-effective and safe antiplatelet agents due to their inherent safety and multiple useful pharmacological hits. This review aims to report data from literature regarding flavonoids with antiplatelet activity, with a particular focus on possible mechanisms of action, pharmacokinetic profiles and overall safety, thus providing a strong rationale for the design of selective and well-directed antiplatelet agents of natural origin.