Showing papers in "Indian Journal of Experimental Biology in 2004"

In vitro antioxidant studies of Annona squamosa Linn. leaves.

Abstract: The free radical scavenging potential of the leaves of A. squamosa was studied by using different antioxidant models of screening. The ethanolic extract at 1000 microg/ml showed maximum scavenging of the radical cation, 2,2-azinobis- (3-ethylbenzothiazoline-6-sulphonate) (ABTS) observed upto 99.07% followed by the scavenging of the stable radical 1,1-diphenyl, 2-picryl hydrazyl (DPPH) (89.77 %) and nitric oxide radical (73.64%) at the same concentration. However, the extract showed only moderate scavenging activity of superroxide radicals and antilipid peroxidation potential, which was performed using rat- brain homogenate. The findings justify the therapeutic applications of the plant in the indigenous system of medicine, augmenting its therapeutic value.

Nuclear transcription factor NF-kappa B: role in biology and medicine.

Abstract: The inducible transcription factor nuclear factor-kappa B (NF-kappaB) plays a central role in regulation of many immune, inflammatory and carcinogenic responses. While normal activation of NF-kappaB is required for cell survival and immunity, aberrant regulation of NF-kappaB leads to development of many pathological states especially those involved in acute inflammation. Recent advances in our knowledge of the signaling mechanisms those control the activation of NF-kappaB highlights the intriguing aspect of NF-kappaB regulation, namely the ability of many different signal transduction pathways originating from a wide variety of inducing mechanisms to converge on a single target, the NF-kappaB/IkappaB complex. In this review we summarize our current understanding of the NF-kappaB signaling pathways, their role in various cellular responses and the potential of using NF-kappaB as a therapeutic target in modern medicine.

Protective effect of Terminalia chebula against experimental myocardial injury induced by isoproterenol.

Abstract: Cardioprotective effect of ethanolic extract of Terminalia chebula fruits (500 mg/kg body wt) was examined in isoproterenol (200 mg/kg body wt) induced myocardial damage in rats. In isoproterenol administered rats, the level of lipid peroxides increased significantly in the serum and heart. A significant decrease was observed in the activity of the myocardial marker enzymes with a concomitant increase in their activity in serum. Histopathological examination was carried out to confirm the myocardial necrosis. T. chebula extract pretreatment was found to ameliorate the effect of isoproterenol on lipid peroxide formation and retained the activities of the diagnostic marker enzymes.

Protective effect of ginger, Zingiber officinale Rosc on experimental atherosclerosis in rabbits.

Abstract: The effects of air dried ginger powder (0.1g/kg body weight, po, for 75 days) were studied on experimentally induced atherosclerosis in rabbits by cholesterol feeding (0.3g/kg body weight, po). Cholesterol feeding for 75 days lead to distinct development of atheroma in the aorta and coronary arteriesof the rabbits and this was significantly inhibited by about 50% following ginger administration. There was distinct decrease in lipid peroxidation and enhancement of fibrinolytic activity in ginger treated animals. However, ginger did not lower blood lipidsto any significant extent. This distinct protection from the development of atherosclerosis by ginger is probably because of its free radical scavanging, prostaglandin inhibitory and fibri properties.

Antioxidant effect of Boerhavia diffusa L. in tissues of alloxan induced diabetic rats.

Abstract: Administration of B. diffusa leaf extract (BLEt; 200 mg/kg) for 4 weeks resulted in a significant reduction in thiobarbutric acid reactive substances and hydroperoxides, with a significant increase in reduced glutathione, superoxide dismutase, catalase, glutathione peroxidase and glutathione--S-transferase in liver and kidney of alloxan induced diabetic rats. The results suggest that BLEt has remarkable antidiabetic activity and can improve antioxidant status in alloxan induced diabetic rats.

Antitumour activity of some plants from Meghalaya and Mizoram against murine ascites Dalton's lymphoma

Abstract: Total five plants, three from Mizoram (Dillenia pentagyna, Ageratum conyzoides, Blumea lanceolaria) and two from Meghalaya (Potentilla fulgens, Taxus baccata) were studied for their antitumour activity against murine ascites Dalton's lymphoma (DL) in vivo. Only three plants showed the different magnitude of antitumour activity. Out of these three plants, the antitumour activity was maximally observed with the methanol extract of the stem bark of D. pentagyna as compared to the aqueous extract of the roots of A. conyzoides and aqueous extract of the root of P. fulgens. An increase in glutathione levels in Dalton's lymphoma cells was observed during tumour growth. Changes in glutathione and protein levels were also investigated in the liver and Dalton's lymphoma cells of tumour-bearing mice following the treatment with the extract of D. pentagyna which showed the highest antitumour activity as compared to the other two plant extracts. Glutathione in the liver and DL cells of treated tumour-bearing mice was found to be decreased. The protein concentration in liver and DL cells decreased mainly at 96 hr of treatment. It may be concluded that the natural product of D. pentagyna promises to be more active against Dalton's lymphoma than others and the decrease in glutathione level may be one of the important steps in resulting this antitumour effect.

Quercetin attenuates thermal hyperalgesia and cold allodynia in STZ-induced diabetic rats.

Abstract: Neuropathic pain is one of the important microvascular complications of diabetes. Oxidative stress and superoxide play a critical role in the development of neurovascular complications in diabetes. Aim of the present study was to evaluate the effect of quercetin, a bioflavonoid on thermal nociceptive responses in streptozotocin (STZ)-induced diabetic rats assessed by tail-immersion and hot plate methods. After 4-weeks of a single intravenous STZ injection (45 mg/kg body weight), diabetic rats exhibited a significant thermal hyperalgesia and cold allodynia along with increased plasma glucose and decreased body weights as compared with control rats. Chronic treatment with quercetin (10 mg/kg body weight; p.o) for 4-weeks starting from the 4 t h week of STZ-injection significantly attenuated the cold allodynia as well as hyperalgesia. Results indicate that quercetin, a natural antioxidant, may be helpful in diabetic neuropathy.

Larvicidal activity of plant extracts used alone and in combination with known synthetic larvicidal agents against Aedes aegypti.

Abstract: Larvicidal activity of acetone and petroleum ether extracts of four plants Murraya koenigii, Coriandrum sativum, Ferula asafoetida, Trigonella foenum graceum and synthetic larvicides Fenthion and Temephos used alone and in combination was carried out against A. aegypti larvae under laboratory conditions. Optimum values were found out by using different concentrations of each plant (ranged 25 ppm-900 ppm) and both synthetic larvicides (ranged 0.01-7.5 ppm). The synergistic study was carried out by using 0.05 ppm of Temephos and Fenthion with 25ppm of M. koenigii, F. asafetida, T. foenum graceum and 100 ppm of C. sativum. All the plants showed potential synergistic activity although showed comparatively poor larvicidal activity when tested individually.

Antioxidant and nitric oxide synthase activation properties of Auricularia auricula.

Abstract: In vitro evaluation of antioxidant activities of Auricularia auricula showed significant inhibition of lipid peroxidation, and potent hydroxyl radical scavenging activity when compared with standard drug catechin. IC5o value of crude, boiled and ethanolic extracts of A. auricula represented 403, 510, and 373 microg/ml respectively in case of hydroxyl radical scavenging activity and 310, 572 and 398 microg/ml respectively in case of lipid peroxidation. Furthermore, crude, boiled and ethanolic extracts also increase significantly nitric oxide production (664, 191 and 850 pmole/mg dry wt/hr respectively) over the control. The present results revealed that A. auricula had potential therapeutic use.

Effect of Bacopa monniera and Azadirachta indica on gastric ulceration and healing in experimental NIDDM rats.

Abstract: Gastric ulcers were induced in normal/NIDDM rats by various physical (2 hr cold restraint stress and 4 hr pylorus ligation) and chemical agents (ethanol, 1 ml/200 g, oral, 1 hr before; aspirin, 200 mg/kg, oral, 4 hr) and duodenal ulcers were induced by cysteamine (40 mg/200 g). Ulcer healing activity was studied in gastric ulcers induced by acetic acid (50%) and HCI (0.6 M). The result indicated that in both, normal and NIDDM rats, B. monniera extract (BME, 20-100 mg/kg) did not show any significant effect on blood glucose level, while A. indica (AIE, 250-1000 mg/kg) significantly decreased it. However, both BME (50 mg/kg) and AIE (500 mg/kg) showed significant anti-ulcer and ulcer-healing activities in normal and NIDDM rats. Further, the present results also indicated that the ulcer protective effects of BME was more pronounced in non-diabetic, while that of AIE was more in NIDDM rats. The anti-ulcer and ulcer-healing activities of BME and AIE may be due to their effects on various mucosal offensive and defensive factors, and correction of blood sugar level by AIE may help to have more ulcer protective effect in NIDDM rats.

Hypolipidemic effect of Coriandrum sativum L. in triton-induced hyperlipidemic rats.

Abstract: In the biphasic model of triton-induced hyperlipidemia, C. sativum at a dose of 1g/kg body weight reduced cholesterol and triglycerides levels in both synthesis and excretory phases in rats, and the results were comparable with that of Liponil, a commercially available herbal hypolipidemic drug. The results suggest that coriander decreases the uptake and enhances the breakdown of lipids. From the study it can be assumed that coriander has the potential to be popularized as a household herbal remedy with preventive and curative effect against hyperlipidemia.

Antibacterial and antidiarrhoeal effects of alkaloids of Holarrhena antidysenterica WALL.

Abstract: The alkaloids from the ethanolic extract of H. antidysenterica seeds were evaluated for their antibacterial activity against clinical isolates of enteropathogenic Escherichia coli (EPEC) in vitro, and their antidiarrhoeal activity on castor oil-induced diarrhoea in rats, in vivo. The plasmid DNA, whole cell lysate and outer membrane protein profile of a clinical isolate of EPEC was determined in presence of alkaloids of H. antidysenterica. The disc diffusion and agar well diffusion methods were used to evaluate the antibacterial efficacy. The alkaloids showed strong antibacterial activity against EPEC strains. In castor oil-induced diarrhoea, alkaloids reduced the diarrhoea with decrease in the number of wet faeces in pretreated rats at a dose of 200-800 mg/kg. The loss of plasmid DNA and suppression of high molecular weight proteins were observed on alkaloids treatment. Taking into account the multiple antibiotic resistance of EPEC, the results suggest usefulness of alkaloids of H. antidysenterica seeds as antibacterial and antidiarrhoeal agents.

Vitamin E prevents nonylphenol-induced oxidative stress in testis of rats.

Abstract: In the present study we have investigated if administration of nonylphenol-induced oxidative stress in various subcellular fractions of adult rat testis and the effect of vitamin E on reactive oxygen species mediated nonylphenol toxicity. Male rats were administered orally with nonylphenol at 1, 10 and 100 microg/kg body weight per day for 45 days with and without supplementation of vitamin E (20 mg/kg body weight). In nonylphenol-treated rats the activities of antioxidant enzymes superoxide dismutase and glutathione reductase decreased significantly while the levels of lipid peroxidation increased significantly in the crude homogenate and in the mitochondrial and microsome-rich fractions of testis. Co-administration of nonylphenol and vitamin E did not cause changes in the activities of antioxidant enzymes in various subcellular fractions of rat testis. The results suggest that graded doses of nonylphenol elicit depletion of antioxidant defence system in rat testis, indicating nonylphenol induced oxidative stress in the testis of rats which could be reversed by the administration of vitamin E.

Effect of Aloe vera (L.) Burm. fil. leaf gel and pulp extracts on kidney in type-II diabetic rat models.

Abstract: Significant degenerative changes were observed in the kidney tissue of untreated neonatal streptozotocin (n0STZ)-induced type-II diabetic rats. These degenerative changes were diminished in the kidney tissue of diabetic animals given glibenclamide and Aloe leaf gel and pulp extracts. Kidney lipid peroxidation levels were increased in diabetic rats compared to healthy rats; these levels were higher in rats treated with glibenclamide than in those which received Aloe extracts. Serum urea and creatinine levels were higher in diabetic rats in comparison to healthy rats. The administration of Aloe gel extract and glibenclamide decreased serum urea and creatinine levels in comparison to diabetic controls. Only A. vera leaf gel extract showed improvement both in histological and biochemical parameters suggesting a protective effect of A. vera on mild damage caused by type-II diabetes on kidney tissue.

Antioxidant effect of curcumin in selenium induced cataract of Wistar rats.

Abstract: Wistar rat pups treated with curcumin, a natural constituent of Curcuma longa before being administered with selenium showed no opacities in the lens. The lipid peroxidation, xanthine oxidase enzyme levels in the lenses of curcumin and selenium co-treated animals were significantly less when compared to selenium treated animals. The superoxidase dismutase and catalase enzyme activities of curcumin and selenium co-treated animal lenses showed an enhancement. Curcumin co-treatment seems to prevent oxidative damage and found to delay the development of cataract.

Isolation, characterization and optimization of antifungal activity of an actinomycete of soil origin.

Abstract: About 312 actinomycetes were isolated from soil samples on chitin agar. All these isolates were purified and screened for their antifungal activity against pathogenic fungi. Out of these, 22% of the isolates exhibited activity against fungi. One promising isolate with strong antifungal activity against pathogenic fungi was selected for further studies. This isolate was from Pune, and was active against both yeasts and molds. Various fermentation parameters were optimized. Based on morphological and biochemical parameters, the isolate was identified as Streptomyces. The correlation of antifungal activity with growth indicated growth dependent production of antimetabolite. Maximum antifungal metabolite production (600 units/ml) was achieved in the late log phase, which remained constant during stationery phase, and it was extracellular in nature.

Effect of different intensities of swimming exercise on testicular oxidative stress and reproductive dysfunction in mature male albino Wistar rats.

Abstract: Swimming exercise for 1, 2 and 3 hr for 5 days/week for consecutive 4 weeks, results in a significant reduction in testicular, epididymal, prostetic, seminal vesicle somatic indices; epididymal sperm count, sperm motility; preleptotine spermatocytes, mid pachytene spermatocytes and stage 7 spermatids; plasma levels of testosterone, luteinizing hormone; testicular delta5, 3beta-hydroxysteroid dehydrogenase, 17beta-hydroxysteroid dehydrogenase; testicular superoxide dismutase, catalase, glutathione peroxidase, glutathione-s-transferase and glutathione along with significant elevation in malondialdehyde in male albino rats. However, no significant change was noted in final body weight, spermatogonia-A and plasma level of follicle stimulating hormone. The results that oxidative stress develops with the increasing of exercise intensity, which may interfere in male reproductive activities.

Antisnake venom activity of ethanolic seed extract of Strychnos nux vomica Linn.

Abstract: The whole seed extract of S. nux vomica (in low doses) effectively neutralized Daboia russelii venom induced lethal, haemorrhage, defibrinogenating, PLA2 enzyme activity and Naja kaouthia venom induced lethal, cardiotoxic, neurotoxic, PLA2 enzyme activity. The seed extract potentiated polyvalent snake venom antiserum action in experimental animals. An active compound (SNVNF) was isolated and purified by thin layer chromatography and silica gel column chromatography, which effectively antagonised D. russelii venom induced lethal, haemorrhagic, defibrinogenating, oedema, PLA2 enzyme activity and N. kaouthia induced lethal, cardiotoxic, neurotoxic, PLA, enzyme activity. Polyvalent snake venom antiserum action was significantly potentiated by the active compound. Spectral studies revealed it to be a small, straight chain compound containing methyl and amide radicals. Detailed structure elucidation of the compound (SNVNF) is warranted before its clinical trials as a snake venom antagonist.

Bacopa monniera Linn. extract modulates antioxidant and marker enzyme status in fibrosarcoma bearing rats.

Abstract: Antioxidative property and tumor inhibitive property of B. monniera (20mg/kg body wt, sc) was examined in 3-methylcholanthrene induced fibrosarcoma rats. Antioxidant enzymes such as catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx) and the levels of glutathione (GSH) and the rate of lipid peroxidation (LPO) in the liver and kidney tissues were assessed. A significant increase was noted for the rate of LPO with a corresponding decrease in the antioxidant enzyme status in fibrosarcoma bearing rats. In fibrosarcoma bearing rats, the tumor markers like lactate dehydrogenase (LDH), creatine kinase (CK), alanine transaminase (ALT), aspartate transaminase (AST) and sialic acid (SA) were increased in the serum. Treatment with B. monniera extract significantly increased the antioxidant enzyme status, inhibited lipid peroxidation and reduced the tumor markers. It can be concluded that B.monniera extract promotes the antioxidant status, reduces the rate of lipid peroxidation and the markers of tumor progression in the fibrosarcoma bearing rats.

Isolation and identification of marine chitinolytic bacteria and their potential in antifungal biocontrol

Abstract: Chitinolytic marine bacterial strains (30) were isolated from the sea dumps at Bhavnagar, India. They were screened as chitinase producers on the basis of zone of clearance on chitin agar plates incorporated with calcofluor white M2R for the better resolution. Out of these, three strains namely, Pseudomonas sp., Pantoea dispersa and Enterobacter amnigenus showed high chitinase production. They were also found to produce proteases and therefore have a good potential for use as antifungal biocontrol agents for the control of fungal plant pathogens. These strains could degrade and utilize the mycelia of Macrophomina phaseoliena (Tassi) Goidanich and Fusarium sp. In vitro, these strains could inhibit the growth of Fusarium sp. and M. phaseolina. The culture filtrate inhibiting hyphal elongation was observed microscopically.

Fetal growth and development: roles of fatty acid transport proteins and nuclear transcription factors in human placenta.

Abstract: In the feto-placental unit, preferential transport of maternal plasma arachidonic acid (20:4n-6) and docosahexaenoic acid (22:5n-3) across the placenta is of critical importance for fetal growth and development. More than 90 per cent of the fat deposition in the fetus occurs in the last 10 weeks of pregnancy. All of the n -3 and n -6 fatty acid structures acquired by the fetus have to cross the placenta and fetal blood are enriched in long chain polyunsaturated fatty acids (LCPUFA) relative to the maternal supply. Fatty acids cross the placental microvillous and basal membranes by simple diffusion and via the action of membrane bound (FAT, FATP and p-FABPpm) and cytoplasmic fatty acid-binding proteins (FABPs). The direction and magnitude of fatty acid flux is mainly dictated by the relative abundance of available binding sites. The existence of a fatty-acid-transport system comprising multiple binding proteins in human placenta may be essential to facilitate the preferential transport of maternal plasma fatty acids in order to meet the requirements of the growing fetus. The critical importance of long-chain fatty acids in cellular homeostasis demands an efficient uptake system for these fatty acids and their metabolism in tissues. In fact, involvement of several nuclear transcription factors (PPARgamma, LXR, RXR, and SREBP-1) is critical in the expression of genes responsible for fatty acids uptake, placental trophoblast differentiation and hCG production. These indicate that these receptors are potential regulators of placental lipid transfer and homeostasis. This review discusses importance of nuclear receptors and fatty acid binding/transport proteins in placental fatty acid uptake, transport and metabolism.

Arsenic induced free radical toxicity in brain of mice.

Abstract: The present study was designed to investigate the ill vivo effects of oral administratio n of arsenic trioxide (As20 3; 0.5 and 1 mg/kg body weight/day for 45 days) on cerebral hemispheres and cerebellum in male mice, Mus musculus. Arsenic reduced the concentration of glutathione (GSH) in cerebral hemisphere and cerebellum at both the dose level s; whil e increased lipid peroxidation (LPO) in cerebral hemisphere and cerebellum regions. FuIther, the activiti es of antioxidant enzymes viz., superoxide di smutase and catalase also declined in these two regIOns with dose indicating oxidative stress. This effect is caused by the action of reactive oxygen spec ie s (ROS) induced by arsenic exposure.

Effect of simultaneous exposure to lead and cadmium on gonadotropin binding and steroidogenesis on granulosa cells: an in vitro study.

Abstract: Effects of lead (Pb) and cadmium (Cd) both alone or in combination on the binding of LH and FSH on isolated granulosa cells were studied. Granulosa cell s isolated from proestro us rats were incubated (in vitro) with lead acetate and I or cadmium acetate (0.03 !J.M of Pb or Cd) for I hr. LH binding was dropped to 84% in Pb treated cells, 72.5% in Cd treated cell s and 74.8% in combin ed meta l treated cell s compared to control. FSH binding dropped to 85.5 % in Pb treated cell s, 71.16% in Cd treated cell s and 72.5 % in combined metal treated cells compared to control. Activity of 17~ Hydroxy Steroid Dehydrogenase ( 17~HSDH ), a key steroidogenic enzy me was reduced by 52% in Cd and 37% in combined metal exposed cells whereas Pb exposed cells showed 3 1% reduction in the enzy me activity. Pretreatment with SH groups protectant s (glutathione [GSH], dithiothretol fDTT]) and zin c caused an ameriolation in enzyme activity whereas Zn pretreatment showed an increase in gonadotropin binding in metal exposed cell s. These results suggest that both Pb and Cd can cause a reduction in LH and FSH binding, which significantly alters steroid production in vitro and exerts a direct influence on granulosa cell function.

Antiinflammatory and antiulcer activities of phytic acid in rats.

Abstract: Maximum antiinflammatory activity of phytic acid (PA) was seen at an oral dose of 150 mg/kg in the carrageenan induced rat paw edema model. Although PA showed ability to prevent denaturation of proteins, it showed less antiinflammatory activity than ibuprofen. Ability of PA to bring down thermal denaturation of proteins might be a contributing factor in the mechanism of action against inflammation. PA, at all the doses tested, showed significant protection from ulcers induced by ibuprofen, ethanol and cold stress, with a maximum activity at 150 mg/kg. There was a significant increase in gastric tissue malondialdehyde levels in ethanol treated rats but these levels decreased following PA pretreatment. Moreover, pretreatment with PA significantly inhibited various effects of ethanol on gastric mucosa, such as, reduction in the concentration of nonprotein sulfhydryl groups, necrosis, erosions, congestion and hemorrhage. These results suggested that gastro-protective effect of PA could be mediated by its antioxidant activity and cytoprotection of gastric mucosa.

Effect of lupeol isolated from Crataeva nurvala Buch.-Ham. stem bark extract against free radical induced nephrotoxicity in rats.

Abstract: Lupeol, isolated from Crataeva nurvala stem bark in doses 40 and 80 mg/kg body weight, po, for 10 days, decreased the concentration of blood urea nitrogen, creatinine and lipid peroxidation and increased glutathione and catalase activities in cisplatin (5 mg/kg body weight, ip) induced nephrotoxicity in rats. The increased glutathione and catalase activities are indicative of antioxidant properties of lupeol.

Effect of propolis extract on acute carbon tetrachloride induced hepatotoxicity.

Abstract: Ethanolic extract of propolis was administered to rats intoxicated by carbon tetrachloride. Administration of bolus dose of CCl 4 (1.5 ml/kg, ip) resulted in elevation of serum transaminases and serum alkaline phosphataseactivities. Levels of hepatic lipid peroxidation were significantly increased. On the contrary, there was significant decrease in hepatic reduced glutathione level. The propolis extract (100 and 200 mg/kg, po) exhibited recoupment in both pre- and post-treatment (prophylactic and curative studies) of biochemical changes induced by CCl 4 . The post treatment of 200 mg/kg, po extract showed most significant hepatoprotective effect. Histopathological studies showed damage in hepatocytes and disturbed chord arrangement after toxicant administration. Propolis extract (200 mg/kg, po) was found to be more effective in restoring CCl 4 induced histopathological alterations.

Cholinergic-NO-cGMP mediation of sildenafil-induced antinociception.

Abstract: Acetylcholine and cholinomimetic agents with predominant muscarinic action are known to increase the concentration of cGMP by activation of nitric oxide signaling pathway in the nociceptive conditions. The present study was aimed to investigate the NO-cGMP-PDE5 pathway in nociceptive conditions in the experimental animals. Nociceptive threshold was assessed by acetic acid-induced writhing assay (chemonociception) or carrageenan-induced hyperalgesia. Sildenafil [1-5 mg/kg, ip, 50-200 microg/paw, intraplantar (ipl)] produced dose dependent antinociception in both the tested models. Coadministration of acetylcholine (50 mcg/paw, ipl) or cholinomimetic agent, neostigmine (0.1 mcg/kg, ip and 25 ng/paw, ipl) augmented the peripheral antinociceptive effect of sildenafil. This effect was sensitive to blockade by L-NAME (20 mg/kg, ip, 100 microg/paw, ipl), a non-selective NOS inhibitor and methylene blue (1 mg/kg, ip), a guanylate cyclase inhibitor, which per se had little or no effect in both the models of nociception. Further, the per se analgesic effect of acetylcholine and neostigmine was blocked by both L-NAME and methylene blue in the models of nociception, suggesting the activation of NO-cGMP pathway. Also, both L-NAME and methylene blue blocked the per se analgesic effect of sildenafil. These results indicate the peripheral accumulation of cGMP may be responsible for antinociceptive effect, and a possible interaction between cholinergic agents and PDE5 system in models of nociception.

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

Abstract: 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. anacardium at dose of I mg/100g 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 IC 5 0 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.

Evaluation of protective potentials of a potentized homeopathic drug, Chelidonium majus, during azo dye induced hepatocarcinogenesis in mice.

Abstract: Several cytogenetical and enzymatic protocols were used to test if two microdoses of Chelidonium majus, namely Chelidonium-30 (Ch-30) and Chelidonium-200 (Ch-200), used as homeopathic drugs, showed anti-tumor activity and also favorably modulated genotoxic damages produced by an azo dye in mice at several intervals of fixation. Different sets of healthy mice were fed: (i) hepatocarcinogen, p-dimethylaminoazobenzene (p-DAB, initiator) + phenobarbital (PB, promoter), (ii) only p-DAB, (iii) only PB, and (iv) neither p-DAB nor PB (normal control). Mice fed with p-DAB + PB were divided into different sets that were also fed either Ch-30 (v) or Ch-200 (vi) or diluted alcohol (vii), the "vehicle" of the microdoses of Chelidonium. All mice of group (i), a few of group (ii) and group (vii) and none of groups (iii) and (iv) developed tumors in liver at the longer intervals of fixation. The frequencies of chromosome aberrations (CA), micronucleated erythrocytes (MN), mitotic index (MI) and sperm head abnormality (SHA) were much higher in groups (i) and (vii) mice than in groups (ii), (iii) and (iv) mice at all fixation intervals. However, in mice of both groups (v) and (vi), the frequencies of CA, MN, SHA were strikingly less than those of groups (i) and (vii), and moderately less than those of groups (ii) and (iii). Both Ch-30 and Ch-200 also modulated favourably some toxicity marker enzymes like acid and alkaline phosphatases, peroxidases, glutamate oxaloacetate and glutamate pyruvate transaminases in liver, kidney and spleen tissues of the carcinogen fed mice. The microdoses of Chelidonium having no visible ill effects of their own, may be strong candidates for use in delaying/protecting liver cancer.

Effect of bamboo shoot, Bambusa arundinacea (Retz.) Willd. on thyroid status under conditions of varying iodine intake in rats.

Abstract: Young shoots or sprouts of common bamboos are used as food in third world countries. Evidences suggest the presence of cyanogenic glucoside like anti-thyroidal substance in bamboo shoots (BS) but effect of prolonged BS consumption on thyroid status under conditions of varying iodine nutriture remains unexplored. The study was undertaken to evaluate goitrogenic content, in vitro anti thyroid peroxidase (TPO) activity and in vivo anti thyroid potential of BS with and without extra iodide. Fresh BS contains high cyanogenic glucoside (551 mg/kg), followed by thiocyanate (24mg/kg) and glucosinolate (9.57mg/kg). In vitro inhibition in TPO activity was found with raw, raw boiled and cooked extracts. Inhibition constant (IC50) and PTU equivalence of fresh BS were 27.5+/-0.77 microg and 3.27 respectively. Extra iodide in the incubation media reduced TPO inhibition induced by BS but could not cancel it. Thyroid weight, TPO activity and total serum thyroid hormone levels of BS fed animals for 45 and 90 days respectively were determined and compared with controls. Significant increase in thyroid weight as well as higher excretion of thiocyanate and iodine along with marked decrease in thyroid peroxidase activity, T4 and T3 levels were observed in BS fed group. Chronic BS consumption gradually developed a state of hypothyroidism. Extra iodide had reduced the anti-thyroidal effect of BS to an extent but could not cancel it because of excessive cyanogenic glucoside, glucosinolate and thiocyanate present in it.