Monthly Archives: November 2011

Background: Resveratrol, a constituent of red wine, and γ-tocotrienol, a constituent of palm oil are important for cardioprotection. Although MicroRNAs are known regulators for genes involved in cardiac remodeling the regulatory pathway involving microRNA has not been studied so far.

Methods: We explored the cardioprotection by resveratrol, longevinex and γ tocotrienol in ischemia/reperfusion(I/R) model of rat and determined miRNA profile from isolated RNA. Systemic analyses of miRNA array and theirs targets were determined using a number of computational approaches.

Results: Resveratrol and γ-tocotrienol, either alone or in combination, modulated the expression pattern of miRNAs close to the control level based on PCA analyses. Differential expression was observed in over 75 miRNAs, some of them, such as miR-21 and miR-20b (antiangiogenic) were previously implicated in cardiac remodeling. The target genes for the highest differentially expressed miRNA include genes of various molecular function such as TGFβ1-Smad3 signaling pathway, inflammation and their transcription factors, which may play key role in reducing I/R injury. Administration of antagomiR-20 attenuated I/R induced VEGF and HIF1α level.

Conclusion: All the interventions treated for 3 weeks lead to significant cardioprotection against ischemia/reperfusion injury. A unique signature of miRNA profile is observed in control heart pretreated with resveratrol or γ-tocotrienol. We have determined specific group of miRNA in heart that have altered during IR injuries. Most of those altered microRNA expressions modulated close to their basal level in resveratrol or longevinex treated I/R rat. Interestingly, resveratrol and γ-tocotrienol resulted in synergestic action.

The anti-inflammatory role of vitamin E in prevention of osteoporosis

Nazrun AS, Norazlina M, Norliza M, Nirwana SI.

Adv Pharmacol Sci. 2012;2012:142702. Epub 2011 Nov 17.

There is growing evidence that inflammation may be one of the causal factors of osteoporosis. Several cytokines such as IL-1, IL-6, RANKL, OPG, and M-CSF were implicated in the pathogenesis of osteoporosis. These cytokines are important determinants of osteoclast differentiation and its bone resorptive activity. Anticytokine therapy using cytokine antagonists such as IL-receptor antagonist and TNF-binding protein was able to suppress the activity of the respective cytokines and prevent bone loss. Several animal studies have shown that vitamin E in the forms of palm-derived tocotrienol and α-tocopherol may prevent osteoporosis in rat models by suppressing IL-1 and IL-6. Free radicals are known to activate transcription factor NFκB which leads to the production of bone resorbing cytokines. Vitamin E, a potent antioxidant, may be able to neutralise free radicals before they could activate NFκB, therefore suppressing cytokine production and osteoporosis. Vitamin E has also been shown to inhibit COX-2, the enzyme involved in inflammatory reactions. Of the two types of vitamin E studied, tocotrienol seemed to be better than tocopherol in terms of its ability to suppress bone-resorbing cytokines.