Therapeutic effects of statins on osteoarthritis: A review.

Osteoarthritis (OA) is a progressive joint disease. The etiology of OA is considered to be multifactorial. Currently, there is no definitive treatment for OA, and the existing treatments are not very effective. Hypercholesterolemia is considered a novel risk factor for the development of OA. Statins act as a competitive inhibitor of the ß-hydroxy ß-methylglutaryl-CoA (HMG-CoA) reductase and are widely used to manage hypercholesterolemia. Inhibition of HMG-CoA reductase results in reduced synthesis of a metabolite named mevalonate, thereby reducing cholesterol biosynthesis in subsequent steps. By this mechanism, statins such as atorvastatin and simvastatin could potentially have a preventive impact on joint cartilage experiencing osteoarthritic deterioration by reducing serum cholesterol levels. Atorvastatin can protect cartilage degradation following interleukin-1ß-stimulation. Atorvastatin stimulates the STAT1-caspase-3 signaling pathway that was shown to be responsible for its anti-inflammatory effects on the knee joint. Simvastatin had chondroprotective effects on OA in vitro by reducing matrix metalloproteinases expression patterns. In this study, we tried to review the therapeutic effects of statins on OA.

Curcumin and Endothelial Function: Evidence and Mechanisms of Protective Effects.

BACKGROUND: The endothelium is a large paracrine organ regulating cell growth, vascular tone and thrombogenicity as well as platelet and leukocyte interactions. Endothelial function can be assessed by noninvasive techniques [e.g. flow-mediated vasodilation, nitroglycerin-mediated dilation and pulse wave velocity] and measuring specific circulating biomarkers [cell adhesion molecules, endothelial microparticles and endothelial progenitor cells]. Impaired endothelial function plays a key role in the development of atherosclerosis, arterial hypertension, heart failure, ischemia-reperfusion injury, Alzheimer's disease and other conditions. Endothelial function is also involved in growth and proliferation of tumor cells. METHODS: We performed a literature review and assessed the role of the natural polyphenol, curcumin, as a potential inexpensive, well-tolerated, and safe agent for improving endothelial function. RESULTS: Curcumin exerts several positive pharmacological effects; these include anti-inflammatory, antioxidant, anti-hypertensive, anti-cancer, antiviral, anti-infective and wound-healing properties. Specifically, curcumin's anti-inflammatory effects are thought to be caused by reducing trans-endothelial monocyte migration by reduction of mRNA and protein expression of intercellular adhesion molecule-1, vascular cell adhesion molecule-1 and P-selectin and by modulating NFκB, JNK, p38 and STAT-3 in endothelial cells. Dietary curcumin supplementation can also increase antioxidant activity through the induction of heme oxygenase-1, a scavenger of free radicals, and by reduction of reactive oxygen species and Nox-2. CONCLUSIONS: Curcumin appears to improve endothelial function but additional research is needed to determine the precise mechanism(s) and biomarkers involved in curcumin's therapeutic effects on endothelial dysfunction.