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Vitamin K is essential for the carboxylation of the vitamin K-dependent proteins that are responsible for the suppression of matrix calcification. The use of vitamin K antagonists (VKAs) in patients with cardiovascular diseases could affect protein carboxylation and lead to the development of osteoarthritis (OA). This review aims to summarise the current evidence for the relationship between VKAs and OA. The literature search revealed that in observation studies, good vitamin K status, as reflected by the circulating level or protein carboxylation status of vitamin K, is associated positively with improved joint structural and functional indices and negatively associated with OA incidence. By contrast, in limited retrospective and prospective studies, the use of VKAs is associated positively with OA occurrence and knee/hip replacement. Pharmacological interactions between VKAs and various OA therapeutic agents exist and require careful monitoring and dosing. In conclusion, further epidemiological studies are warranted to verify the relationship between VKA use and OA to strengthen the evidence. Given that VKA use exerts potentially negative effects on joint health, intervention is required to protect the quality of life and mobility of patients.

The aim of this study was to assess the antioxidant effect of phytosterol from palm oil by studying its ability to improve antioxidant status of rats induced with oxidative stress by carbon tetrachloride (CCl4). The rats were divided into four groups of normal control (NC), carbon tetrachloride (CCl4), phytosterol (P) and phytosterol plus carbon tetrachloride (P+CCl4). The P and P+CCl4 groups received weekly phytosterol pre-treatment via subcutaneous injections at 140 mg/kg rat weight for 5 weeks while the NC and CCl4 groups only received olive oil (vehicle). Carbon tetrachloride at the dose determined by a preliminary study was given as single oral dose to induce lipid peroxidation in the CCl4 and P+CCl4 groups. After 24 hours, the rats were sacrificed and the heart, liver, kidney and lung were isolated for the determination of reduced glutathione (GSH) and oxidized glutathione (GSSG) levels. Carbon tetrachloride caused significant reduction in the GSH:GSSH ratio in all major organs. Phytosterol pre-treatment as in the P+CCl4 group significantly increased the GSH:GSSG ratio in major organs. The present findings indicate that phytosterols keep tissue glutathione concentration in normal levels which may indicate improving antioxidant status in major organs of the rats treated with carbon tetrachloride.

OBJECTIVES: This study was conducted to determine whether the blood pressure-lowering effect of Nigella sativa might be mediated by its effects on nitric oxide, angiotensin-converting enzyme, heme oxygenase and oxidative stress markers. METHODS: Twenty-four adult male Sprague-Dawley rats were divided equally into 4 groups. One group served as the control (group 1), whereas the other three groups (groups 2-4) were administered L-NAME (25 mg/kg, intraperitoneally). Groups 3 and 4 were given oral nicardipine daily at a dose of 3 mg/kg and Nigella sativa oil at a dose of 2.5 mg/kg for 8 weeks, respectively, concomitantly with L-NAME administration. RESULTS: Nigella sativa oil prevented the increase in systolic blood pressure in the L-NAME-treated rats. The blood pressure reduction was associated with a reduction in cardiac lipid peroxidation product, NADPH oxidase, angiotensin-converting enzyme activity and plasma nitric oxide, as well as with an increase in heme oxygenase-1 activity in the heart. The effects of Nigella sativa on blood pressure, lipid peroxidation product, nicotinamide adenine dinucleotide phosphate oxidase and angiotensin-converting enzyme were similar to those of nicardipine. In contrast, L-NAME had opposite effects on lipid peroxidation, angiotensin-converting enzyme and NO. CONCLUSION: The antihypertensive effect of Nigella sativa oil appears to be mediated by a reduction in cardiac oxidative stress and angiotensin-converting enzyme activity, an increase in cardiac heme oxygenase-1 activity and a prevention of plasma nitric oxide loss. Thus, Nigella sativa oil might be beneficial for controlling hypertension.

Background : It is a common practice to heat cooking oil and reuse it in order to cut expenses. The use of repeatedly heated cooking oil predisposes to various cardiovascular diseases. Virgin coconut oil (VCO) is reported to possess antioxidant action. Aim : The study aimed to determine the effect of heating of VCO on the blood pressure (BP) and inflammatory bio-markers. Methods : Thirty male Sprague-Dawley rats were divided into five groups and were fed with the following diet for 24 weeks: normal rat chow (control); chow +fresh VCO (FVCO); chow + VCO heated once (1HVCO); chow +VCO heated five times (5HVCO) and chow + VCO heated ten times (10HVCO). BP was measured at baseline and four weekly for 24 weeks. Blood was collected at baseline and at the end of study to measure plasma TXB 2 , PGI 2 , VCAM-1, ICAM-1 and LDH enzyme activity. Results : BP increased significantly in the 5HVCO and 10HVCO groups compared to the control and FVCO groups. The 5HVCO and 10HVCO diet caused a significant increase in the plasma TXB2 and a significant decrease in the plasma PGI 2 level. The plasma levels of VCAM-1, ICAM-1 and CRP were significantly increased in the 10HVCO group. Conclusion : Repeatedly heated VCO caused an elevation in the BP. The BP elevation was associated with a significant increase in the inflammatory bio-markers (VCAM-1, ICAM-1 and CRP), TXB 2 and a significant reduction in the plasma PGI 2 level.

Context: Many scientific reports have shown the involvement of oxidative stress and inflammation as well as diminished gastroprotective substances in the pathogenesis of gastric lesions using various models. Therefore, treatment with antioxidants like tocopherol and tocotrienol may afford beneficial effects in attentuating the formation of the gastric lesions.Objective: The aim of this work was to summarize documented reports on the effects of vitamin E on various models of gastric lesion.Methods: A literature search was performed from databases in Medline (PubMed), Web of Science, ScienceDirect, and Googlescholar from June to December 2013.Results and conclusion: The potential roles of tocopherol and tocotrienol in modifying the effects of ulcerogenic agents are discussed in this review. The protective effects of the vitamin E might involve ameliorating oxidative stress and inflammation as well as restoration of endogenous gastroprotective substances. This vitamin has the potential to be used as ...