Role of vitamin c as an antioxidant in cadmium chloride induced testicular damage.

Cadmium is one of the most toxic heavy metals and potential for human exposure has generally increased with increase in industrial usage of this element. The purpose of the present study was to determine anti-oxidative role of vitamin C against cadmium chloride induced oxidative stress on rat testis. Adult male rats(n=6/group) were divided into five groups ,one control (Gr.I- 0.9% Saline treated) & two untreated experimental & two pretreated experimental groups. The untreated groups were injected with single dose of 0.5 & 1 mg /kg bw cadmium chloride (Gr.II &Gr.III) intraperitoneally. Vitamin C (30mg/kg bw,ip) was orally administered for 30 days prior to the exposure to 0.5 and 1mg/kg bw(Gr,IIa &Gr.IIIA) of cadmium chloride. In all the groups, rats were sacrificed 15 days after the final cadmium chloride or saline administration and the changes in the testicular weight and testicular level of Melonaldehyde , glutathione & superoxide dismutase were studied. Exposure to cadmium chloride lead to significant decrease in the testicular weight& level of GSH & SOD and increase in the level of testicular MDA compared to normal control. Pretreatment with vitamin C (30mg/kg bw) significantly prevented the increase in MDA level of the testis & ameliorated the fall in GSH & SOD as well as testicular weight compared to 0.5mg/kg bw cadmium chloride group. But pretreatment with vitamin C did not show any beneficial effect with 1mg/kg bw cadmium treated group. The study reports the antioxidative role of vitamin C in ameliorating lower doses of cadmium chloride induced testicular damage.

The involvement of amygdala nucleus in chronic stress induced changes on ingestive behavior of wistar rats.

Organisms are constantly subjected to stimuli that can be construed as stressors. Stress regulation is a highly integrated process controlled largely by the brain. The role of amygdala in stress tolerance has attracted continued interest because of its central role in processing emotional information. In the present study, the Wistar albino rats were subjected to chronic swimming (physical) stress and chronic immobilization (psychological) stress for 60 days with or without bilateral lesions of the nucleus of amygdala. Their food intake, water intake and body weight were measured. Exposure to stressors significantly decreased the body weight, food and water intake whereas amygdala lesioning significantly increased the body weight (P<0.001), food intake (P<0.001) and water intake (P<0.001).However, the stress induced decrease observed in the body weight and food intake of the amygdala lesioned groups was significantly more (P<0.001) during immobilization stress than swimming stress. It can be concluded that amygdala nucleus appears to play a prominent role in minimizing the stress induced changes in the food intake and body weight; and this role was more evident in immobilization stress than a physical stress. Thus, the present study support the notion that the amygdala nucleus play a definite role in minimizing stress induced changes in the ingestive behavior and its role in psychological stress is more prominent.

Semecarpus anacardium L, nuts inhibit lipopolysaccharide induced NO production in rat macrophages along with its hypolipidemic property.

Traditionally S. anacardium is used for rejuvenation, rheumatoid arthritis, fever and neurological disorders. In the present study it was observed that a fraction of S. anacacrdium at dose of 1 mg/100 g body wt, significantly reduced serum cholesterol from 378.87 mg/dl in the rats fed with atherogenic diet (AD) to 197.99 mg/dl (45-52%) in the rats fed with AD diet and increased serum HDL-cholesterol (33-37%). The same fraction also inhibited LPS induced NO production in the culture activated rat peritoneal macrophages in the dose dependent manner with IC50 value at 50 ng/ml of the culture medium. The drug in the above doses was completely safe and non-toxic, (no change in the enzymes), to liver and kidney functions.

Antioxidant property of Smilex china Linn.

Smilex china Linn. (Smilacaceae Syn Liliaceae) has special pharmacognostic feature as its root is multiseriate, with sclerenchymatic pericycle. The alcoholic extract of rhizome of S. china shows significant protection against FeSO4 induced lipid peroxidation in rat liver homogenate, but has no effect on the rate of oxidation of reduced glutathione. This fraction scavenges the superoxide and hydroxyl radicals, but the effect was more towards the removal of superoxide than that of hydroxyl radicals. Thus it could be concluded that rhizome of S. china has strong antioxidant property.

Effect of Semecarpus anacardium nuts on lipid peroxidation.

Alcoholic extract of pericarp showed significant protection against FeSO4 induced lipid peroxidation, as compared with whole native nut and seeds. Mechanism of action may be through metal chelation or activation of endogenous antioxidant enzymes, because the extract did not show hydroxyl and super oxide anion scavenging property. Further in vitro experiments against FeSO4, it did not maintain the level of reduced glutathione.

Effect of N-2-mercaptopropionylglycine in limiting myocardial reperfusion injury following 90 minutes of ischemia in dogs.

Present study was designed to examine the effectiveness of N-2-mercaptopropionyl glycine (MPG) on oxygen free radical (OFR) mediated reperfusion injury. Twenty dogs underwent 90 min of left anterior descending (LAD) coronary artery occlusion followed by 4 h of reperfusion. In control animals (n = 12), 115 ml of saline was infused through left atrium at the onset of reperfusion whereas treated animals (n = 8) received loading dose of MPG (40 mg/kg) infused through left atrium for 1 h followed by maintenance dose (25 mg/kg) for remaining 3 hours. Percentage area of necrosis vis-a-vis area at risk and percentage necrosis in left ventricular mass in MPG treated animals was significantly lower in comparison to control animals. Reperfusion in control group increased the lipid peroxidation and lowered glutathione (GSH) and superoxide dismutase (SOD) activity. MPG treatment significantly lowered the lipid peroxidation whereas GSH and SOD levels in necrotic zone were higher than in control. The above results suggest that MPG can offer a significant cardioprotection against oxidative stress in canine model.

Molecular approach to ayurveda.

In ayurvedic system of medicine, it is considered that a living system is made of panch-mahabuta, in the form of Vata, pitta and kapha at the physical level and satwa, raja and tama at the mental level. This covers the psychosomatic constitution and commonly known as the Tridosh theory. The imbalance in these body humours is the basic cause of any type of disease manifestation. Till date, several objective parameters have been proposed to monitor the level of these basic humours but none of them is complete. In this exercise, now it is proposed to consider free radical theory of diseases as one of the objective parameters. To be more specific, vata can be monitored in terms of membrane bound signal transduction, pitta as the process of phosphorylation and de-phosphorylation of different proteins (signalling moieties and enzymes) and kapha can be viewed as the degree of gene expression as protein synthesis. This can be correlated with the ojas of the body or total body defence mechanism.

Role of alcoholic extract of shoot of Hypericum perforatum Linn on lipid peroxidation and various species of free radicals in rats.

The alcoholic extract of the shoot of H. perforatum shows strong antioxidant property. It possesses the iron chelation property with more affinity to the ferrous form. It has scavenging property for both superoxide and for hydroxyl radicals but the response is more towards the superoxide radicals. Thus in addition to the anti-depressant property it has strong antioxidant property also.

Comparison of the antioxidant action of the alcoholic extract of Rubia cordifolia with rubiadin.

The inhibition of FeSO4 induced lipid peroxidation in rat liver by alcoholic extract of Rubia cordifolia and by one of its constituent rubiadin (1, 3-dihydroxy-2-methyl anthraquinone) (pure form) has been compared. Both have been found to inhibit lipid peroxidation in a dose dependent manner. Whereas the former shows both oxidising and reducing properties with Fe2+ and Fe3+, the latter shows oxidising property only by converting Fe2+ to Fe3+. The former inhibits the oxidation of reduced glutathione while the latter does not.

Serum estradiol and testosterone levels following acute myocardial infarction in men.

The present study examined serum testosterone and estradiol levels on the day of admission, 5th and on 10th day following acute myocardial infarction in men. Controls were matched for age and body mass index. Testosterone levels were low on the day of admission and remained statistically unchanged on 5th and 10th day as compared to controls. On the contrary, estradiol levels were significantly higher on the day of admission. A significant decrease in estradiol concentration in comparison to the levels on the day of admission was observed on 10th day post myocardial infarction. However, the estradiol levels on 10th day were significantly higher than control subjects. The results of the study suggest that in acute myocardial infarction, hyperestrogenemia is associated with hypotestosteronemia.

Effect of N-acetylcysteine on myocardial infarct size following ischemia and reperfusion in dogs.

The present study was designed to examine the role of N-acetylcysteine (NAC) on free radical mediated reperfusion injury in canine model. Fourteen dogs underwent 90 min of left anterior descending coronary artery (LAD) occlusion followed by 4 h of reperfusion. Treated animals received loading dose of NAC (250 mg/kg) at the time of reperfusion upto 1 h followed by maintenance dose (70 mg/kg) for remaining 3 h through left atrial line. Infarct size, myocardial tissue lipid peroxidation, superoxide dismutase (SOD) and glutathione (GSH) levels were measured at the end of reperfusion in treated (n = 7) and untreated animals (n = 7). Left ventricular end diastolic pressure was significantly lower in treated animals compared to untreated group. SOD and GSH levels in myocardial tissue at risk and in infarcted zone were similar in both groups. However, in NAC treated animals the lipid peroxidation was significantly lower in comparison to untreated control animals. Infarct size in the area at risk, percent left ventricular necrosis and myocardial tissue preservation were not significantly different in treated and untreated animals. These results suggests that N-acetylcysteine infusion at the time of reperfusion following 90 min of ischemia and 4 h of reperfusion fails to offer significant cardioprotection against free radical damage but it can improve ventricular performance by decreasing pre load.

Effect of superoxide dismutase and acidified sodium nitrite on infarct size following ischemia and reperfusion in dogs.

The effects of superoxide dismutase (SOD) alone or in combination with acidified sodium nitrite (NaNO2), a liberator of nitric oxide were examined in dogs after ischemia and reperfusion. Animals were divided into five groups. Left anterior descending coronary artery was occluded for 90 min followed by 4 hours of reperfusion with or without therapeutic interventions given preceding reperfusion. Left ventricular end diastolic pressure (LVEDP), left ventricular systolic pressure (LVSP) and ECG changes were monitored throughout the study. Area at risk was defined by Evans blue and area of infarction by incubation in triphenyltetrazolium. Myocardial tissue lipid peroxidation was measured in ischemic and non-ischemic zones. There was no evidence of infarction until ninety minutes of ischemia. Percentage area of necrosis vis-a-vis area at risk percentage necrosis in left vertricular mass was significantly low in animals treated with combination of SOD and NaNO2 in comparison with isolated treatment with saline, SOD or NaNO2. LVEDP increased significantly following ischemia and remained unchanged during saline reperfusion. Treatment with SOD, NaNO2 in isolation or its combination significantly lowered LVEDP. Maximum increase in tissue lipid peroxidation was observed in saline and NaNO2 treated animals. SOD alone or in combination with NaNO2 significantly lowered the lipid peroxidation. The results clearly demonstrate that reperfusion can cause necrosis in ischemic myocardium. Combined treatment with SOD and NaNO2 offers significant cardioprotection against oxidative stress.

Effect of alpha-tocopherol pretreatment on infarct size following 90 minutes of ischemia and 4 hours of reperfusion in dogs.

The present study was designed to evaluate the effects of pretreatment with antioxidants on free radical mediated reprefusion injury. Five dogs were fed with alpha-tocopherol (1000 IU/kg, bw) for ten days prior to 90 min of left anterior descending coronary artery occlusion followed by 4 hours of reperfusion. Infarct size, serum and myocardial lipid peroxidation were measured in pretreated and in untreated animals. Infarct size, as percentage of myocardial tissue at risk in alpha-tocopherol pretreated animals was 5.86+/-0.83 and was 39.35+/-7.58 in the untreated animals. Following reprefusion in untreated group, the values of serum and myocardial tissue lipid peroxidation were significantly higher than observed values in alpha-tocopherol treated animals. alpha-tocopherol pretreatment significantly reduced the myocardial infarct size and percent necrosis in the left ventricular mass in comparison to the untreated animals. These results suggest that alpha-tocopherol pretreatment possibly helps in reducing infarct size.

Rubiadin, a new antioxidant from Rubia cordifolia.

Rubiadin, a dihydroxy anthraquinone, isolated from alcoholic extract of Rubia cordifolia, possesses potent antioxidant property. It prevents lipid peroxidation induced by FeSO4 and t-butylhydroperoxide (t-BHP) in a dose dependent manner. The per cent inhibition was more in the case of Fe2+ induced lipid peroxidation. The antioxidant property of the preparation has been found to be better than that of EDTA, Tris, mannitol, Vitamin E and p-benzoquinone.

Antilipid peroxidative property of Nardostachys jatamanasi.

Antiperoxidative property of N. jatamanasi was tested by using iron induced lipid peroxidation in 5% rat liver homogenate. The degree of peroxidation was quantitated by thiobarbituric acid reactive substance (TBARS) content. The extract provided protection against lipid peroxidation. The hexane fraction was more potent than the alcoholic extract. Results suggested antilipid peroxidative property of the plant.

Bacopa monniera Linn. as an antioxidant: mechanism of action.

Bacopa monniera, Linn. (Brahmi: Scrophulariaceae) an Ayurvedic medicine is clinically used for memory enhancing, epilepsy, insomnia and as mild sedative. For the first time the effect of alcohol and hexane fraction of Brahmi has been studied on FeSO4 and cumene hydroperoxide induced lipid peroxidation. Alcohol fraction showed greater protection with both inducers. Results were compared with known antioxidants tris, EDTA and a natural-antioxidant vitamin E. The effect of Brahmi was also examined on hepatic glutathione content. The mechanism of action could be through metal chelation at the initiation level and also as chain breaker. The results suggested that Brahmi is a potent antioxidant. The response of Brahmi was dose dependent. Tris, an hydroxyl trapper did not show any protection in comparison to Brahmi where as EDTA and vitamin E did protect against FeSO4. In experimental conditions 100 micrograms Brahmi extract (alcoholic) was equivalent to 247 micrograms of EDTA (0.66 microM) and 58 micrograms of vitamin E. Interestingly Brahmi only slightly protected the autooxidation and FeSO4 induced oxidation of reduced glutathione on lower doses 100 micrograms/ml and below, but on higher concentrations it enhanced the rate of oxidation.

Role of Tamra bhasma, an Ayurvedic preparation, in the management of lipid peroxidation in liver of albino rats.

Hepatoprotective effect of Tamra bhasma has been studied on cumene hydroperoxide (CHP) induced peroxidation, reduced glutathione content and superoxide dismutase (SOD)-in rat liver homogenate. The drug was orally given for 8 days which showed significant reduction in the level of malondialdehyde (MDA) production at different concentrations of cumene hydroperoxide in vitro. Glutathione content was maintained upto seventy minutes and SOD activity was enhanced to 166%. These animals did not show any rise in serum GOT and GPT. On similar doses no histological changes were observed in liver. The results suggested that Tamra bhasma is a strong antioxidant drug and could be used in the management of lipid peroxidation with no detectable adverse effect.

Assessment of endocrine response of Inula racemosa in relation to glucose homeostasis in rats.

Alcoholic extract of the root of I. racemosa lowers blood glucose and enhances liver glycogen without increasing plasma insulin in rats. There is also no increase in degree of degranulation of the beta cells of pancreas. In similar conditions it does not show any effect on activity of adrenal gland. However, thyroid gland undergoes activation at the later stage (delayed response). It appears that hypoglycemic response of I. racemosa is not due to enhanced secretion/synthesis of insulin; the action may be at the peripheral level by potentiating the insulin sensitivity.