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Addition of citrus leaf extract (CLE) into frying oil was found to be renoprotective in rats that consumed heated palm oil diet. This study examined the effects of dietary CLE supplementation on renal vasoactive substances in rats given heated palm oil diet. Forty-two male Sprague-Dawley rats were randomly split and fed with (i) control, (ii) fresh palm oil (FPO), (iii) FPO + CLE, (iv) five-time-heated palm oil (5HPO), (v) 5HPO+CLE, (vii) ten-time-heated palm oil (10HPO) and (vii) 10HPO+CLE diets for 16 weeks. CLE was added into diet at 0.15% (w/w). CLE decreased renal angiotensin-converting enzyme, inducible nitric oxide synthase and angiotensin II expressions in rats given heated oil diets, but only decreased renal NADPH oxidase activity in the 5HPO group. Supplementation of citrus leaf extract has shown beneficial effects in regulating renal vasoactive substances in rats consumed heated palm oil diet.

The use of repeatedly heated frying oil is hazardous to health, due to oxidative process that occurs in the oil. Addition of an additive with antioxidant property could lessen the detrimental effects of repeated frying in the oils. Citrus leaf extract (CLE) supplementation was reported to possess antioxidant and blood pressure-lowering properties. Our study aimed to determine the effects of CLE addition into frying oil in rats fed with repeatedly heated oil diet. Seven groups of male Sprague-Dawley rats were given fresh and heated oil diets (five-time- and ten-time-heated palm oil), with and without the CLE addition for 16 weeks. CLE addition decreased peroxide value and augmented the total phenolics content in the heated oils. CLE addition reversed the negative effects of heated oil on nitric oxide level, systolic blood pressure, and vascular reactivity. In conclusion, these findings show that CLE has the ability to reduce oxidative damage caused by thermal degradation in frying oil and subsequently lowers the risk of hypertension in rats that consumed heated oil.

The prolonged intake of diet containing repeatedly heated vegetable oil can cause hypertension in the long run. In this study, the effects of citrus leaf extract (CLE) supplementation on vascular reactivity, plasma nitrite, and aortic structure in hypertensive rats that consumed were investigated by the consumption of repeatedly heated vegetable oil. Male Sprague Dawley rats (n = 56) were divided into 7 groups corresponding to the respective diets. For 16 weeks, 1 group was given standard rat chow (control) while other groups were given diets containing 15% w/w of palm oil, fresh palm oil (FPO), palm oil heated 5 times (5HPO), and palm oil heated 10 times (10HPO), with or without the incorporation of 0.15% w/w CLE (FPO+CLE, 5HPO+CLE, or 10HPO+CLE). Plasma nitrite levels were measured before and at 16 weeks of treatment. After 16 weeks, the rats were sacrificed and aortae were harvested for measuring vascular reactivity and for microscopic study. CLE supplementation had significantly reduced the loss of plasma nitrite and attenuated the vasoconstriction response to phenylephrine in the 5HPO group but not in the 10HPO group. However, CLE had no significant effect on the vasorelaxation response to acetylcholine and sodium nitroprusside. The elastic lamellae of tunica media in 5HPO, 10HPO, and 10HPO+CLE groups appeared disorganised and disrupted. Obtained findings suggested that CLE was able to enhance nitric oxide bioavailability that might dampen the vasoconstriction effect of phenylephrine.

Prolonged consumption of heated palm oil causes detrimental effects on cardiovascular system, liver and kidneys. The detrimental effects of heated oils are associated with oxidative stress; hence the role of antioxidants in attenuating heated oil-induced effects has been widely studied. The aim of the present study was to determine the effects of polyphenol-rich Citrus leaf extract (CLE) on renal oxidative stress parameters, renal function and kidney histological changes in rats fed with heated palm oil. Fifty-six male Sprague-Dawley rats (n=56) were divided into seven groups. The control group was given normal rat chow, while other groups were fed with 15% weight/weight (w/w) palm oil-enriched diet of either fresh palm oil (FPO), five-time-heated palm oil (5HPO) or ten-time-heated palm oil (10HPO); with or without the addition of CLE (0.15%, w/w) supplementation. After 16 weeks, the rats were sacrificed and the kidneys were harvested for analysis. CLE supplementation improved heated palm oil-induced oxidative stress parameters in the kidneys, shown by reduced levels of renal thiobarbituric acid (TBARS) and renal nicotinamide adenine dinucleotide phosphate (NADPH) oxidase in 5HPO and 10HPO groups. Renal haem oxygenase levels were restored with CLE supplementation in the heated oil groups. Decreased serum creatinine was observed in 5HPO group with CLE supplementation, but not in 10HPO group. Heated oil caused mild interstitial inflammation with vascular congestion in 5HPO and 5HPO+CLE groups, while 10HPO group had moderate inflammation and vascular congestion. CLE supplementation in 10HPO group was able to reduce these changes as only mild interstitial inflammation and congestion was observed. CLE has the potential to reduce renal oxidative stress parameters, improve renal function and reduce renal inflammation possibly mediated via its antioxidant properties.

Parkia speciosa Hassk is a plant found abundantly in Southeast Asia region. Its seeds with or without pods and roots have been used in traditional medicine in this region to treat hypertension. Therefore, we aimed to investigate the potential effect of the plant empty pod extract on hypertension development and changes in heart induced by N(G)-nitro-l-arginine methyl ester (l-NAME) administration in rats. Twenty-four male Sprague Dawley rats were divided into four groups. Groups 1 to 3 were given l-NAME (25mg/kg, intraperitoneally) for 8 weeks. Groups 2 and 3 were also given Parkia speciosa empty pods methanolic extract (800mg/kg, orally) and nicardipine (3mg/kg, orally), concurrently with l-NAME. The last group served as the control. l-NAME reduced plasma nitric oxide level and therefore, increased systolic blood pressure, angiotensin-converting enzyme and NADPH oxidase activities as well as lipid peroxidation in the heart. Parkia speciosa extract and nicardipine treatments had significantly prevented the elevations of blood pressure, angiotensin-converting enzyme, NADPH oxidase activities and lipid peroxidation in the heart induced by the l-NAME. Parkia speciosa extract but not nicardipine prevented the reduction in plasma nitric oxide level caused by l-NAME. In conclusion, Parkia speciosa empty pods methanolic extract has a potential to prevent the development of hypertension possibly by preventing the loss of plasma nitric oxide, as well as has cardioprotective effects by reducing angiotensin-converting enzyme activity and oxidative stress in the heart in rats administered l-NAME.

Background : Cosmos caudatus (Ulam Raja) is an appetizer (ulam) eaten with rice in Malaysia. Previous studies showed that Cosmos caudatus possess high antioxidant content. Nrf2 is a transcription factor which regulates the expression of phase II enzymes and antioxidant proteins. The aim of this study is to investigate the effects of Cosmos caudatus aqueous extract (UR) on the expression of Nrf2 target genes in mice liver. Methods : ICR white mice were treated for 21 days with different doses of UR (100, 500, 1000 mg/kg) through oral gavage. Control mice were only given distilled water. After 21 days, the mice were sacrificed and their livers harvested. Total RNA was extracted, reverse transcribed and subjected to qPCR to detect Nrf2 target genes expression. Results : Administration of 100 mg/kg UR significantly increased NQO1 expression in mice liver. Administration of 500 mg/kg UR significantly increased HO-1 liver expression. Administration of 100 and 500 mg/kg UR significantly increased GSTA1 liver expression. Administration of 500 and 1000 mg/kg UR significantly increased GSTM3 liver expression, whereas GSTP and GSTM1 liver expression was significantly decreased at similar doses . Administration of all doses of UR significantly decreased the expression of GSTA3 , SOD3 and GCLC in mice liver. Conclusion : UR administration mostly resulted in downregulation of Nrf2 target genes. However, conclusive evidence can only be made through the use of Nrf2 knockout mice or by performing Nrf2 nuclear translocation studies.

Prolonged consumption of repeatedly heated vegetable oil increases blood pressure. This study aimed to determine the effects of Citrus leaf extract, (CLE) on blood pressure, blood pressure-regulating enzymes and mediators, as well as aortic histomorphometry in heated palm oil induced-hypertension. Male Sprague Dawley rats ( n = 56) were divided into seven groups; control group was given normal diet and the other groups were fed with palm oil-enriched diet (15% w/w) either fresh (FPO), five-time-heated (5HPO) or ten-time-heated (10HPO) with or without CLE (0.15%, w/w) supplementation. CLE supplementation reduced the heated oil-raising effect of blood pressure, plasma TBARS, thromboxane and angiotensin-1 converting enzyme in 5HPO but not in 10HPO group. CLE increased serum heme oxygenase-1 in both 5HPO and 10HPO groups. CLE supplementation reduced the increase in aortic intima-media thickness, intima-media area and circumferential wall tension in 5HPO group but not in 10HPO group. These findings suggested that CLE supplementation reduces the blood pressure-raising effects of 5HPO and vascular damage, possibly through its antioxidant effect by modulating vasoactive mediators and blood pressure-regulating enzymes.

Menopause, a cessation of menstrual bleeding, is directly related to serious illness confined to cardiovascular disease (CVD) such as hypertension and stroke. The oestrogen withdrawal and consumption of high cholesterol diet has a detrimental effect on cardiovascular function and metabolism in menopausal women. The present study was aimed to develop the hypertensive rat model in the ovariectomised Sprague Dawley rats fed with 2% cholesterol diet following a short term period. Eighteen Sprague-Dawley rats were randomly divided into three groups; Sham control (sham), ovariectomized control fed with normal diet (Ovx +N), ovariectomized rats fed with 2% cholesterol diet (Ovx + Cho) for four weeks. At the end of the study, the food intake and body weight were measured. The systolic, diastolic and mean blood pressure was determined. OVX+Cho showed significant increase in physiological changes such as body weight and food intake compared to Ovx+N group. The significant increase in systolic, diastolic and mean blood pressure was observed in Ovx+Cho group. Based on the above findings, it is believed that feeding cholesterol diet for four weeks (short term) results in significant increase in the blood pressure, food intake and body weight in the ovariectomised rats.

The use of repeatedly heated vegetable oil for cooking is commonly practiced to reduce the cost of food preparation. This practice is not only restricted in domestic use but by also by food vendors. Repeatedly heated oil may have detrimental effects on health as heating produces harmful products of lipid peroxidation, which have been believed to be responsible in the pathogenesis of many diseases like cardiovascular disease and cancer. Consumption of heated vegetable oil may increase the risk of cardiovascular disease via affecting serum lipid profiles, blood pressure, and promoting atherosclerosis. The use of repeatedly heated oil may cause hypertension, promote atherosclerosis, osteoporosis, and may affect liver and kidney structure and function. Studies have reported that fresh palm and soy oils had no detrimental effects on cardiovascular-related risk factors, bone, kidney, and liver. Fresh palm and soy oils help to protect vascular and bone structures in estrogen-deficient subjects; however, the protective effect is lost when the oil is repeatedly heated. Furthermore, heated oil increases the levels of total cholesterol and LDL-cholesterol, blood pressure, vascular, liver and kidney inflammation, vascular and bone structural changes that predispose to atherosclerosis and osteoporosis. Thus, these findings suggest that intake of repeatedly heated oil is detrimental to health as it may increase risk of cardiovascular disease, osteoporosis, steatosis, and renal histological changes.

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.

Consumption of corn oil for cooking purpose is gaining popularity. The present study examined the effect of heated corn oil on blood pressure and its possible mechanism in experimental rats. Thirty male Sprague-Dawley rats were randomly divided into 5 groups and were fed with the following diets, Group I was fed with basal diet only; whereas group II,III,IV and V were fed with basal diet fortified with 15% (w/w) either fresh, once-heated, five-times-heated or ten-times-heated corn oil, respectively for 16 weeks. Body weight, blood pressure were measured at baseline and weekly interval for 16 weeks. Inflammatory biomarkers which included soluble intracellular adhesion molecules (sICAM), soluble vascular adhesion molecules (sVCAM) and C reactive protein (CRP), were measured at baseline and the end of 16 weeks. The rats were sacrificed and thoracic aorta was taken for measurement of vascular reactivity. There was significant increase in the blood pressure in the groups fed with heated once, five-times (5HCO) and ten-times-heated corn oil (10-HCO) compared to the control. The increase in the blood pressure was associated with an increase in CRP, sICAM and sVCAM, reduction in vasodilatation response to acetylcholine and greater vasoconstriction response to phenylephrine. The results suggest that repeatedly heated corn oil causes elevation in blood pressure, vascular inflammation which impairs vascular reactivity thereby predisposing to hypertension. There is a need to educate people not to consume corn oil in a heated state.

INTRODUCTION Captopril is an angiotensin-converting enzyme inhibitor, which is used as an antihypertensive agent and has shown antioxidant properties. This study aims at determining the effects of captopril on factors affecting gastric mucosal integrity in aspirin-induced gastric lesions. MATERIAL AND METHODS Eighteen male Sprague-Dawley (200-250 g) rats that were given aspirin (40 mg/100 g body weight) were divided into three groups: the control, captopril (1 mg/100 g body weight daily) and ranitidine (2.5 mg/100 g body weight twice daily) groups. Ranitidine and captopril were given orally for 28 days. Rats in all groups were sacrificed and the parameters measured. RESULTS Captopril reduced gastric acidity, and increased gastric glutathione (GSH) and prostaglandin E2 (PGE2) significantly in comparison to the control group. Captopril also reduced malondialdehyde (MDA) and gastric lesions insignificantly compared to the control group. Ranitidine healed the lesions significantly compared to the control group. There was no difference between ranitidine and captopril on the severity of lesions, gastric acidity, MDA and GSH. Captopril increased PGE2 compared to ranitidine (p < 0.05). CONCLUSIONS Captopril has desirable effects on the factors affecting gastric mucosal integrity (acidity, PGE2 and GSH) and is comparable to ranitidine in ulcer healing.

Hypertension increases the risk for a variety of cardiovascular diseases, including stroke, coronary artery disease, heart failure, and peripheral vascular disease. The increase in oxidative stress has been associated with the pathogenesis of hypertension. Increase of blood pressure is due to an imbalance between antioxidants defence mechanisms and free radical productions. Excessive production of reactive oxygen species reduces nitric oxide bioavailability leading to an endothelial dysfunction and a subsequent increase in total peripheral resistance. Hypertension can cause few symptoms until it reaches the advanced stage and poses serious health problems with lifelong consequences. Hypertensive patients are required to take drugs for life to control the hypertension and prevent complications. Some of these drugs are expensive and may have adverse reactions. Hence, it is timely to examine scientifically, complimentary therapies that are more effective and with minimal undesirable effects.Nigella sativa(NS) and its active constituents have been documented to exhibit antioxidant, hypotensive, calcium channel blockade and diuretic properties which may contribute to reduce blood pressure. This suggests a potential role of NS in the management of hypertension, and thus more studies should be conducted to evaluate its effectiveness.

Considering the increasingly strong footing of the role of vascular wall inflammation in hypertension, immunohistochemistry has become an important method to investigate the inflammatory responses in circulatory system. Immunohistochemistry is a method used to recognise the presence and location of constituents of tissues (as antigens) in situ by means of corresponding labelled antibodies. The principle of immunohistochemistry lies on the immunoreaction between antibodies to bind specifically to their corresponding antigens. Since it is done on a tissue rather than measuring inflammatory biomarker levels in serum, immunohistochemistry gives an overview of an intact tissue in the aspect of the localisation of a particular protein (i.e. in nucleus, cellular membrane or cytoplasm) and thus the expressions of inflammatory biomarkers may indicate what they are doing in vivo. In addition, the continuing advance in computer-aided image analysis has shifted immunohistochemistry from a traditional ‘merely descriptive’ technique to a quantitative measurement. Digital image evaluation enables measurements of protein activation by quantifying the colour density of positive immunostaining on a tissue. Therefore, immunohistochemistry is advantageous in providing not only qualitative but also semi-quantitative or quantitative information of protein expressions.

OBJECTIVES: The goal of this study was to determine the possible mechanism that is involved in the blood pressure-raising effect of heated vegetable oils. METHODS: Adult male Sprague-Dawley rats were divided into 11 groups; the control group was fed with rat chow, and the other groups were fed with chow that was mixed with 15% weight/weight palm or soy oils, which were either in a fresh form or heated once, twice, five, or ten times. Blood pressures were measured at the baseline and throughout the 24-week study. Plasma nitric oxide levels were assessed prior to treatment and at the end of the study. Following 24 weeks, the rats were sacrificed to investigate their vascular reactivity using the thoracic aorta. RESULTS: Palm and soy oils had no detrimental effects on blood pressure, and they significantly elevated the nitric oxide contents and reduced the contractile responses to phenylephrine. However, trials using palm and soy oils that were repeatedly heated showed an increase in blood pressure, enhanced phenylephrine-induced contractions, reduced acetylcholine- and sodium nitroprusside-induced relaxations relative to the control and rats that were fed fresh vegetable oils. CONCLUSIONS: The blood pressure-raising effect of the heated vegetable cooking oils is associated with increased vascular reactivity and a reduction in nitric oxide levels. The chronic consumption of heated vegetable oils leads to disturbances in endogenous vascular regulatory substances, such as nitric oxide. The thermal oxidation of the cooking oils promotes the generation of free radicals and may play an important contributory role in the pathogenesis of hypertension in rats.

Hypercholesterolaemia, increase in lipid peroxidation and hyperhomocysteinaemia may contribute to the pathogenesis of atherosclerosis. This study was performed to examine the effects of repeatedly heated palm oil mixed with 2% cholesterol diet on atherosclerosis in oestrogen-deficient postmenopausal rats. Ovariectomy causes disruption of tunica intima layer of the rat aorta simulating a postmenopausal condition in females. Twenty-four ovariectomized female Sprague–Dawley rats were divided into four groups. The control group received 2% cholesterol diet without palm oil. A diet with 2% cholesterol content fortified with fresh, once-heated and five-times-heated palm oil was given to the other treatment groups. The rats were sacrificed at the end of 4 months of study and the aortic arch tissue was processed for histomorphometry and electron microscopy. On observation, there was disruption of the intimal layer of the ovariectomized rat aorta. There was no obvious ultrastructural change in the aorta of the rats fed with fresh palm oil. The ultrastructural changes were minimal with once-heated palm oil, in which there was a focal disruption of the endothelial layer. The focal disruption was more pronounced with five-times-heated palm oil. The results of this study show that the ingestion of fresh palm oil may have a protective effect on the aorta but such a protective action may be lost when the palm oil is repeatedly heated. The study may be clinically important for all postmenopausal women who are susceptible to atherosclerosis.

Palm oil used worldwide contains considerable amounts of antioxidants, namely, vitamin E and carotenes. The purpose of the study was to observe the effect of heated palm oil on blood pressure and observe the cardiac histological changes in rats.Forty male Sprague Dawley rats were divided equally into four groups and given treatment as follows: (i) basal diet (control group); (ii) basal diet fortified with 15% weight/weight (w/w) fresh palm oil (FPO); (iii) basal diet fortified with 15% w/w palm oil heated five times (5HPO); (iv) basal diet fortified with 15% w/w palm oil heated ten times (10HPO). Treatment duration was 16 weeks. Blood pressure was measured at baseline and at monthly intervals for 4 months using the tail-cuff method. After 16 weeks of study, the rats were killed and the hearts were taken out. The specimens were sectioned longitudinally and stained with hematoxylin and eosin for light microscopy.The FPO group did not show any significant changes in blood pressure and histological study. There was a significant increase (p0.05) in blood pressure in the 5HPO and 10HPO groups. However, blood pressure in the 10HPO group was higher than in the 5HPO group. Histological sections of the heart showed necrosis in cardiac tissue in the 5HPO and 10HPO groups with the latter group showing more damage.Fresh palm oil has no deleterious effects on blood pressure and cardiac tissue but prolonged consumption of repeatedly heated palm oil may result in an increase in blood pressure level with necrosis of cardiac tissue.

Repeated heating of soy oil may promote lipid peroxidation. Oxidized unsaturated fatty acids may contribute to the pathogenesis of atherosclerosis, especially in estrogen-deficient states. This study was performed to explore the deleterious effects of repeatedly heated soy oil on the development of atherosclerosis using ovariectomized rats, which represent an estrogen-deficient state. Twenty-four female Sprague-Dawley rats were ovariectomized and were divided equally into four groups. The control group was fed with 2% cholesterol diet without any oil. The three treatment groups each received 2% cholesterol diet fortified with fresh, once-heated or five-times-heated (repeatedly heated) soy oil, respectively. Serum thiobarbituric acid reactive substances (TBARS), lipid profile and homocysteine levels were measured prior to ovariectomy and at the end of four months. Ovariectomized rats treated with repeatedly heated soy oil showed significant increases in lipid peroxidation and low-density lipoprotein (LDL) levels. Treatment with once-heated or repeatedly heated soy oil caused a significant increase in total cholesterol, while fresh soy oil caused significant reduction in homocysteine level as compared to other groups. Repeatedly heated soy oil caused significant increases in TBARS and LDL as compared to fresh oil. The higher level of homocysteine in the ovariectomized rats fed with repeatedly heated oil, as compared to those fed with fresh oil, also suggests the repeatedly heated oil contributes to the development of atherosclerosis. Importantly, the protective effect of the soy oil may be lost once it was being repeatedly heated. In conclusion, the consumption of repeatedly heated oil may predispose to atherosclerosis in estrogen-deficient states.

Virgin coconut oil (VCO) contains high antioxidant activity which may have protective effects on the heart in hypertensive rats.The study investigated the effects of VCO on blood pressure and cardiac tissue by measuring angiotensin-converting enzyme (ACE) activity and its histomorphometry in rats fed with a heated palm oil (HPO) diet.Thirty-two male Sprague-Dawley rats were randomly divided into four groups: (i) control, (ii) orally given VCO (1.42 ml/kg), (iii) fed with a HPO (15%) diet, and (iv) fed with a HPO diet and supplemented with VCO (1.42 ml/kg, po) (HPO+VCO) for 16 weeks. Blood pressure was measured monthly. After 16 weeks, rat hearts were dissected for lipid peroxidation (TBARS) and ACE activity measurement and histomorphometric study.Systolic blood pressure was significantly increased in the HPO group compared with the control starting at week eight (112.91 ± 1.32 versus 98.08 ± 3.61 mmHg, p 0.05) which was prevented by VCO supplementation (91.73 ± 3.42 mmHg). The consumption of HPO increased TBARS and ACE activity in heart, which were inhibited by VCO supplementation. The increases in the myofiber width and area as well as nuclear size reduction in the HPO group were significantly prevented by VCO supplementation.These results suggested that VCO supplementation possesses a cardioprotective effect by preventing the increase in blood pressure via an antioxidant mechanism and remodeling in rats fed repeatedly with a HPO diet.

‘Ulam Raja’ or Cosmos caudatus is a common appetizer (ulam) consumed by the Malay community in Malaysia. However, in vivo studies pertaining to its antioxidant and chemoprotective properties are lacking. This study was done to determine the effects of Cosmos caudatus on detoxifying enzymes in extrahepatic organs (lungs, kidneys and stomach) in mice. Thirty adult male white mice were treated orally for 21 days with different doses of ‘Ulam Raja’ aqueous extract (UR) (100, 500, 1000mg/kg). The control group was given normal saline by oral gavage. Mice fed with diet containing 0.5% butylated hydroxyanisole (BHA) were used as positive control. After 21 days, the mice were sacrificed and extrahepatic organs were harvested. The activities of several detoxifying enzymes [catalase (CAT), superoxide dismutase (SOD), glutathione S-transferase (GST), DT-diaphorase (DTD)] were measured. Lipid peroxidation level was determined by measuring malondialdehyde (MDA) concentration. In lungs, 100, 500 & 1000 mg/kg UR oral supplementation resulted in significant increases in CAT, SOD and GST activities. DTD activity in lungs was significantly increased in mice treated with 1000mg/kg UR. MDA levels in lungs were significantly decreased in mice treated with 100mg/kg & 500 mg/kg UR but was significantly increased in mice treated with 1000mg/kg UR. In kidneys, DTD activity was significantly increased in mice treated with 1000mg/kg UR. In stomach, CAT activity was significantly increased in mice treated with 1000mg/kg UR. The results showed that Cosmos caudatus supplementation in mice could protect extrahepatic organs from xenobiotic and oxidative injury. This indicates that consumption of ‘Ulam Raja’ might be a useful chemoprotective measure.

Hypertension and atherosclerosis are among the most common causes of mortality in both developed and developing countries. Experimental animal models of hypertension and atherosclerosis have become a valuable tool for providing information on etiology, pathophysiology, and complications of the disease and on the efficacy and mechanism of action of various drugs and compounds used in treatment. An animal model has been developed to study hypertension and atherosclerosis for several reasons. Compared to human models, an animal model is easily manageable, as compounding effects of dietary and environmental factors can be controlled. Blood vessels and cardiac tissue samples can be taken for detailed experimental and biomolecular examination. Choice of animal model is often determined by the research aim, as well as financial and technical factors. A thorough understanding of the animal models used and complete analysis must be validated so that the data can be extrapolated to humans. In conclusion, animal models for hypertension and atherosclerosis are invaluable in improving our understanding of cardiovascular disease and developing new pharmacological therapies.

This study examined the effects of heated vegetable oils in estrogen deficient rats. Eighty female Sprague-Dawley rats were divided equally into eight groups and given treatment as follows: (I) intact (non- ovariectomised), basal diet (control group); (II) ovariectomised, basal diet; (III) ovariectomised, basal diet fortified with 15% weight/weight (w/w) fresh soya bean oil (FSO); (IV) ovariectomised, basal diet fortified with 15% weight/weight (w/w) soya bean oil heated once (1H-SO); (V) ovariectomised, basal diet fortified with 15% weight/weight (w/w) soya bean oil heated five times (5H-SO); (VI) ovariectomised, basal diet fortified with 15% weight/weight (w/w)fresh palm oil (FPO); (VII) ovariectomised, basal diet fortified with 15% weight/weight (w/w) palm oil heated once (1H-PO); (VIII) ovariectomised, basal diet fortified with 15% weight/weight (w/w) palm oil heated five times (5H-PO). Duration of treatment was 6 months. Blood was taken at baseline and monthly interval for 6 months for determination of serum lipid profiles and malondialdehyde (MDA) levels. Serum homocystein and interleukin-6 were assayed at baseline and after 6 months of study. At the end of the study the rats were killed and consistent segments of the ascending aorta were taken for histopathological examination. The specimens were sectioned transervely and stained with haematoxylin- eosin and Verhoeff van Gieson for light microscopy. Measurements of the intimal thickness and the ratio between tunica intima / tunica media were calculated using computerised image analyser. Heated and fresh palm oil cause transient changes in lipid profiles, whereas soya oil; fresh, heated once and heated five times as well as heated once palm oil caused an increase in serum LDL-cholesterol. Fresh and heated vegetable oils diet did not alter the ratio between tunica intima and tunica media, serum MDA and homocystein level. Histological study showed no obvious focal or diffuse atherosclerotic plague formation with an intact internal elastic lamina and no evidence of smooth muscle cell migration.

Many structurally unrelated chemicals such as strong acids, alcohol or drugs damage the gastric mucosa and induce lesions in human and experimental animals (Miller 1983). Over 30 million people world-wide use non-steroidal anti-inflammatory drugs (NSAIDs) daily. Numerous human studies have shown that the use of NSAIDs is associated with various gastro-duodenal mucosal lesions (Somerville et al. 1986; Kendall & Peura 1993). The mechanisms by which aspirin and other NSAIDs produce acute and chronic gastro-duodenal mucosal injury are incompletely understood (Kauffman 1989). It has been suggested that the mechanism of aspirin-induced gastric lesion is mediated through lipid peroxidation (Granger et al. 1986). Alpha tocopherol (vitamin E) is a naturally occurring antioxidant in biological systems and is present in the cell membrane of various tissues, including the intestine and stomach (Solar 1959). Vitamin E prevents free-radical-induced injury by blocking the free radical chain reaction. The formation of experimental gastric lesions may be reduced through decreasing free radicals and minimizing lipid peroxidation (Granger et al. 1986). Previous studies have shown that deficiencies in vitamin E have resulted in peptic ulceration (Fajer et al. 1955) and that vitamin E supplementation to the diet has protective effects on the gastric mucosa (Howitt et al. 1958; Pihan et al. 1987). Serbinova & Packer (1994) have shown that tocotrienol is a more potent antioxidant than alpha tocopherol. ‘Palmvitee’ is a vitamin E concentrate from palm oil and it contains approximately 80% tocotrienol and 20% tocopherol (Nafeeza et al. 1996). Our earlier studies (Kamsiah et al. 1999; Nafeeza et al. 1999) have reported that palm vitamin E given at the dose of 150 mg/kg food for 3 weeks either before or after the induction of gastric lesions was able to accelerate the healing of ethanol-induced gastric injury in rats. However, the same dose of palm vitamin E could not prevent the ethanol-induced lesion in rats. In another study we also found that palm vitamin E and tocopherol in a dose of 300 mg/kg food given for duration of 8 weeks were equally effective in preventing aspirin-induced gastric lesions in rats (Fauzee et al. 2002). We postulated that the protective effect of palm vitamin E appears to be dependent on dose as well as the duration of feeding or treatment. It thus appears that a higher dose of vitamin E given over a longer period is required to obtain the preventive effect. In contrast, the healing effect of palm vitamin E can occur at a smaller dose over a shorter duration of treatment, which is 150-mg/kg food given for 3 weeks. The findings suggest the possibility that the effect of palm vitamin E or tocopherol on chemical -induced gastric lesions is dose-dependent. We undertook this study to ascertain whether the effects of palm vitamin E and tocopherol on gastric parameters and aspirin-induced gastric lesions are dependent on dose.

Forty (40) normotensive adult male Sprague-Dawley rats aged three months weighing 180-200 g were divided into 4 groups with 10 rats per group: (1) normotensive control; (2) hypertensive rats; (3) hypertensive rats treated with Nigella sativa (2.5 ml/kg/day); and (4) hypertensive rats treated with nicardipine (5 mg/kg/day). After acclimatization, the hypertensive rats of the group 2, 3 and 4 were induced to be hypertensive by giving NW–nitro-L-arginine methyl ester (L-NAME; 30 mg/kg/day) in their drinking water for consecutive 7 days. After one week, rats in the group 3 were given a daily oral dose of 2.5 ml/kg/day of Nigella sativa (NS) by oral gavage. Rats in the group 4 were given nicardipine (5 mg/kg/day) via oral gavages. All rats in this study received L-NAME continuously throughout the treatment duration. The blood pressure will be measured pre-treatment and weekly for 8 weeks using power lab. Blood was taken before and at the end of study for measurement of nitric oxide. At the end of 8 weeks, the rats are sacrificed and descending thoracic aorta was disserted for measurement of vascular reactivity, and intracellular adhesion molecules (ICAM-1) and vascular cell adhesion molecules (VCAM-1). Nigella sativa reduced both systolic and diastolic BP compared to control and L-name group. The BP lowering effect of NS was comparable to nicardipine a calcium antagonist. The blood pressure lowering effect of NS was accompanied with an increasing relaxation response to nitroprusside and acetylcholine and reducing vasoconstriction response to epinephrine. L-NAME and nicardipine on the other hand, reduced plasma nitric oxide concentration. In contrast, NS increased NO concentration. However, Nigella sativa had no significant effect on aortic VCAM- 1 and ICAM-1 expression. In conclusion; Nigella sativa oil reduces both systolic and diastolic blood pressure in L-NAME treated rats. The antihypertensive effect of NS was comparable to nicardipine. The BP lowering effect may be mediated via stimulating nitric oxide release from vascular endothelium.

Cardiovascular disease (CVD) is one of the leading major causes of morbidity and mortality worldwide. It may result from the interactions between multiple genetic and environmental factors including sedentary lifestyle and dietary habits. The quality of dietary oils and fats has been widely recognised to be inextricably linked to the pathogenesis of CVD. Vegetable oil is one of the essential dietary components in daily food consumption. However, the benefits of vegetable oil can be deteriorated by repeated heating that leads to lipid oxidation. The practice of using repeatedly heated cooking oil is not uncommon as it will reduce the cost of food preparation. Thermal oxidation yields new functional groups which may be potentially hazardous to cardiovascular health. Prolonged consumption of the repeatedly heated oil has been shown to increase blood pressure and total cholesterol, cause vascular inflammation as well as vascular changes which predispose to atherosclerosis. The harmful effect of heated oils is attributed to products generated from lipid oxidation during heating process. In view of the potential hazard of oxidation products, therefore this review article will provide an insight and awareness to the general public on the consumption of repeatedly heated oils which is detrimental to health.

Cardiovascular disease (CVD) is one of the leading major causes of morbidity and mortality worldwide. It may result from the interactions between multiple genetic and environmental factors including sedentary lifestyle and dietary habits. The quality of dietary oils and fats has been widely recognised to be inextricably linked to the pathogenesis of CVD. Vegetable oil is one of the essential dietary components in daily food consumption. However, the benefits of vegetable oil can be deteriorated by repeated heating that leads to lipid oxidation. The practice of using repeatedly heated cooking oil is not uncommon as it will reduce the cost of food preparation. Thermal oxidation yields new functional groups which may be potentially hazardous to cardiovascular health. Prolonged consumption of the repeatedly heated oil has been shown to increase blood pressure and total cholesterol, cause vascular inflammation as well as vascular changes which predispose to atherosclerosis. The harmful effect of heated oils is attributed to products generated from lipid oxidation during heating process. In view of the potential hazard of oxidation products, therefore this review article will provide an insight and awareness to the general public on the consumption of repeatedly heated oils which is detrimental to health.

The present study aims to examine the effects of a palm-oil-derived vitamin E mixture containing tocotrienol (approximately 70%) and tocopherol (approximately 30%) on plasma lipids and on the formation of atherosclerotic plaques in rabbits given a 2% cholesterol diet. Eighteen New Zealand White rabbits (2.2-2.8 kg) were divided into three groups; group 1 (control) was fed a normal diet, group 2 (AT) was fed a 2% cholesterol diet and group 3 (PV) was fed a 2% cholesterol diet with oral palm vitamin E (60 mg/kg body weight) given daily for 10 weeks. There were no differences in the total cholesterol and triacylglycerol levels between the AT and PV groups. The PV group had a significantly higher concentrations of HDL-c and a lower TC/HDL-c ratio compared to the AT group (P < 0.003). The aortic tissue content of cholesterol and atherosclerotic lesions were comparable in both the AT and PV groups. However, the PV group had a lower content of plasma and aortic tissue malondialdehyde (P < 0.005). Our findings suggest that despite a highly atherogenic diet, palm vitamin E improved some important plasma lipid parameters, reduced lipid peroxidation but did not have an effect on the atherosclerotic plaque formation.

Parkia speciosaHassk., or stink bean, is a plant indigenous to Southeast Asia. It is consumed either raw or cooked. It has been used in folk medicine to treat diabetes, hypertension, and kidney problems. It contains minerals and vitamins. It displays many beneficial properties. Its extracts from the empty pods and seeds have a high content of total polyphenol, phytosterol, and flavonoids. It demonstrates a good antioxidant activity. Its hypoglycemic effect is reported to be attributable to the presence ofβ-sitosterol, stigmasterol, and stigmast-4-en-3-one. The cyclic polysulfide compounds exhibit antibacterial activity, while thiazolidine-4-carboxylic acid possesses anticancer property. The pharmacological properties of the plant extract are described in this review. With ongoing research conducted on the plant extracts,Parkia speciosahas a potential to be developed as a phytomedicine.

The part related to “patients with mild hypertension [24]” was incorrectly indicated as “100 mg/kg and 200 mg/kg” in Table 1; here it is corrected. Table 1 Significant cardiovascular effects of NS and its constituents.

Nicardipine has been shown to have an anti-atherogenic effect in rabbits given a 2% cholesterol diet. Current evidence suggests that lipid peroxidation plays an important role in atherogenesis. This study examines the effect of nicardipine on lipid peroxidation in rabbits given a 2% cholesterol diet, 8 of these rabbits given nicardipine 0.5 mg/kg twice daily intramuscularly for ten weeks while the remaining untreated 6 were controls. After ten weeks, serum malondialdehyde in the control group was significantly higher compared to their baseline levels (P

This study was performed to explore the effects of virgin coconut oil (VCO) in male rats that were fed with repeatedly heated palm oil on blood pressure, plasma nitric oxide level, and vascular reactivity. Thirty-two male Sprague-Dawley rats were divided into four groups: (i) control (basal diet), (ii) VCO (1.42 mL/kg, oral), (iii) five-times-heated palm oil (15%) (5HPO), and (iv) five-times-heated palm oil (15%) and VCO (1.42 mL/kg, oral) (5HPO + VCO). Blood pressure was significantly increased in the group that was given the 5HPO diet compared to the control group. Blood pressure in the 5HPO + VCO group was significantly lower than the 5HPO group. Plasma nitric oxide (NO) level in the 5HPO group was significantly lower compared to the control group, whereas in the 5HPO + VCO group, the plasma NO level was significantly higher compared to the 5HPO group. Aortic rings from the 5HPO group exhibited attenuated relaxation in response to acetylcholine and sodium nitroprusside as well as increased vasoconstriction to phenylephrine compared to the control group. Aortic rings from the 5HPO + VCO group showed only attenuated vasoconstriction to phenylephrine compared to the 5HPO group. In conclusion, VCO prevents blood pressure elevation and improves endothelial functions in rats fed with repeatedly heated palm oil.

Hypertension is a common health problem worldwide. According to the World Health Organization's Global Health Risks 2009; hypertension accounts for 13% of mortality globally. It is the major risk factor for cardiovascular diseases, including heart failure (Iyer et al. 2010). Dietary factors have been known to be playing an important role in hypertension. For instance, the consumption of a Mediterranean diet with an abundant source of monounsaturated fatty acids (MUFAs) from olive oil might reduce the prevalence of hypertension (Alonso et al. 2006). Nevertheless, the quality of vegetable oils consumed in the diet might also affect blood pressure. Vegetable oils are usually served in the thermally oxidized state because of the heat exposure during food preparation. Soriguer et al. 2003 reported that the risk of hypertension was positively associated with the intake of cooking oil polar compounds. Deep frying has become one of the most commonly used methods of the food preparation. In today's time deficient lifestyle, deep fried foods are gaining more popularity in daily diet because of their desirable sensory characteristics (Boskou et al. 2006). Deep frying is defined as the process of cooking foods by immersing them in edible oil at the temperature of 150–200 °C (Yamsaengsung & Moreira 2002). At the same time, the vegetable oils are also exposed to the air and moisture, in which they undergo a complex series physical and chemical deterioration known as ‘lipid oxidation’, like hydrolysis, polymerization and isomerization. This oxidative deterioration affects the chemical compositions of the vegetable oils by oxidizing its fatty acids (Marmesat et al. 2008), decreasing the free radical scavenging vitamin E contents (Rossi et al. 2007) and generating polar compounds and polymeric products (Romero et al. 2006; Bansal et al. 2010). In combination, these lipid oxidation products are detrimental to the endothelial cells. Moreover, during deep-frying process, it is common for the vegetable oils to be re-used repeatedly to cut the cost. The oxidation products may disturb the redox steady state (Boueiz & Hassoun 2009), causing an imbalance between the vasodilator prostacyclin (PGI2) and vasoconstrictor thromboxane A2 (TXA2) (Muzaffar et al. 2011). PGI2 protects against elevated blood pressure and leucocytes adhesion, and it is therefore considered to be cardioprotective. On the contrary, TXA2 amplifies platelet aggregation and triggers vasoconstriction, counteracting the effect of PGI2. Hypertension is associated with an imbalance between the vasoactive substances (Yamada et al. 1999). Additionally, excessive oxidant might cause inflammation, which may as well play an imperative part in the pathogenesis of hypertension (Ghanem & Movahed 2007). Endothelium is the major regulator of vascular health as well as the primary target of immunological attack in inflammatory responses. Vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecule-1 (ICAM-1) and lectin-like oxidized low-density lipoprotein receptor (LOX-1) are expressed by endothelium and are up-regulated in response to inflammatory insult (Chen et al. 2002; Kim et al. 2011). VCAM-1 and ICAM-1 mediate leucocytes binding to the endothelium. Infiltration of inflammatory molecules may disturb the normal function of endothelium in regulating blood pressure. On the other hand, enhanced expression of LOX-1, which acts as a cell receptor for endocytosis of oxidized low-density lipoprotein (Ox-LDL), may attenuate the endothelial function and cause hypertension (Ogura et al. 2009). Long-term intake of meal containing repeatedly heated oil has been reported to cause an increase in blood pressure (Leong et al. 2008). The present study was undertaken to investigate the possible inflammatory mechanisms involved in the increase in blood pressure following prolonged consumption of repeatedly heated soybean oil in experimental rats. We compared the effects between fresh, five-time-heated (5HSO) and 10-time-heated (10HSO) oils to see whether the changes were affected by the reheating frequency.

Deep frying is the most common and one of the oldest methods of food preparation worldwide. It involves heat and mass transfer. To reduce the expenses, the oils tend to be used repeatedly for frying. When heated repeatedly, changes in physical appearance of the oil will occur such as increased viscosity and darkening in colour [1], which may alter the fatty acid composition of the oil. Heating causes the oil to undergo a series of chemical reactions like oxidation, hydrolysis and polymerization [2]. During this process, many oxidative products such as hydroperoxide and aldehydes are produced, which can be absorbed into the fried food [3].

This study was performed to compare the oxidative quality of repeatedly heated palm and soybean oils, which were used to fry keropok lekors and potato chips.A kilogramme of keropok lekors or potato chips was fried in 2.5 L of palm or soybean oil at 180 °C for 10 minutes. The frying process was repeated once and four times to obtain twice-heated and five-times-heated oils. The peroxide value and fatty acid composition of the oils were measured.Frequent heating significantly increased the peroxide values in both oils, with the five-times-heated oils having the highest peroxide values [five-times-heated palm: 14.26 ± 0.41 and 11.29 ± 0.58 meq/kg vs fresh: 2.13 ± 0.00, F (3,12) = 346.80, P0.001; five-times-heated soybean: 16.95 ± 0.39 and 12.90 ± 0.21 meq/kg vs fresh: 2.53 ± 0.00 oils, F (3,12) = 1755, P0.001, when used to fry keropok lekors and potato chips, respectively]. Overall, both oils showed significantly higher peroxide values when keropok lekors were fried in them compared with when potato chips were fried. In general, the heated soybean oil had significantly higher peroxide values than the heated palm oil. Fatty acid composition in the oils remained mostly unaltered by the heating frequency.keropok lekors, when used as the frying material, increased the peroxide values of the palm and soybean oils. Fatty acid composition was not much affected by the frequency of frying or the fried item used.

Oil thermoxidation during deep frying generates harmful oxidative free radicals that induce inflammation and increase the risk of hypertension. This study aimed to investigate the effect of repeatedly heated palm oil on blood pressure, aortic morphometry, and vascular cell adhesion molecule-1 (VCAM-1) expression in rats. Male Sprague-Dawley rats were divided into five groups: control, fresh palm oil (FPO), one-time-heated palm oil (1HPO), five-time-heated palm oil (5HPO), or ten-time-heated palm oil (10HPO). Feeding duration was six months. Blood pressure was measured at baseline and monthly using tail-cuff method. After six months, the rats were sacrificed and the aortic arches were dissected for morphometric and immunohistochemical analyses. FPO group showed significantly lower blood pressure than all other groups. Blood pressure was increased significantly in 5HPO and 10HPO groups. The aortae of 5HPO and 10HPO groups showed significantly increased thickness and area of intima-media, circumferential wall tension, and VCAM-1 than other groups. Elastic lamellae were disorganised and fragmented in 5HPO- and 10HPO-treated rats. VCAM-1 expression showed a significant positive correlation with blood pressure. In conclusion, prolonged consumption of repeatedly heated palm oil causes blood pressure elevation, adverse remodelling, and increased VCAM-1, which suggests a possible involvement of inflammation.