Indicine N-oxide binds to tubulin at a distinct site and inhibits the assembly of microtubules: A mechanism for its cytotoxic activity

Indicine N-oxide, a pyrrolizidine alkaloid present in the plant Heliotropium indicum had shown promising cytotoxic activity in various tumor models. The compound exhibited severe toxicity to hepatocytes and bone marrow cells. The present work was aimed to evaluate the molecular mechanism of the toxicity of indicine N-oxide. We found that indicine N-oxide inhibited the proliferation of various cancer cell lines in a concentration dependent manner with IC₅₀ ranging from 46 to 100 μM. At the half maximal inhibitory concentration it blocked the cell cycle progression at mitosis without significantly altering the organization of the spindle and interphase microtubules. The toxicities of the compound at higher concentrations are attributed to its severe depolymerizing effect on both the interphase and spindle microtubules. Binding studies using purified goat brain tubulin indicated that indicine N-oxide binds to tubulin at a distinct site not shared by colchicine or taxol. It decreased the polymer mass of both purified tubulin and MAP-rich tubulin. It was found to induce cleavage of DNA using pUC18 plasmid. The interactions of indicine N-oxide on DNA were also confirmed by computational analysis; which predicted its binding site at the minor groove of DNA. These studies bring to light that the toxicities of indicine N-oxide were due to its DNA damaging effects and depolymerization of microtubules.     

Anti-Fatigue and Exercise Performance Improvement Effect of Glossogyne tenuifolia Extract in Mice

Glossogyne tenuifolia (GT) is a native perennial plant growing across the coastline areas in Taiwan. The current study aimed to examine the efficacy of GT extract in ameliorating physical fatigue during exercise and increasing exercise performance. Fifty male Institute of Cancer Research (ICR) mice were randomly segregated into five groups (n = 10) to GT extract orally for 4 weeks, at different concentrations (50, 100, 250, and 500 mg/kg BW/day): LGT 1X, MGT 2X, HGT 5X, and HGT 10X groups. Forelimb grip strength, endurance swimming time, serum biochemical marker levels, blood lipid profile and histological analysis of various organs were performed to assess the anti-fatigue effect and exercise performance of GT extract. The forelimb-grips strength and endurance-swimming time of GT-administered mice were increased significantly in a dose-dependent manner when compared to the control. Serum glucose, creatine kinase, and lactate levels were increased significantly in the HGT 10X group. Liver marker serum glutamic-oxaloacetic transaminase (GOT) was increased in the HGT 5X and HGT 10X groups, whereas Serum Glutamic Pyruvic Transaminase (GPT) was not altered. Renal markers, creatinine and uric acid levels, were not altered. Muscle and hepatic glycogen levels, which are essential for energy sources during exercise, were also significantly increased in a dose-dependent manner in all GT extract groups. No visible histological aberrations were observed in the vital organs after GT extract administration. The supplementation with GT extract could have beneficial effects on exercise performance and anti-fatigue function without toxicity at a higher dose.     

Initial upregulation of growth factors and inflammatory mediators during nerve regeneration in the presence of cell adhesive peptide-incorporated collagen tubes

Neurotrophic factors play an important modulatory role in axonal sprouting during nerve regeneration involving the proliferation of hematogenous and Schwann cells in damaged tissue. We have exposed lesioned sciatic nerves to a collagen prosthesis with covalently bonded small cell adhesive peptides Arg-Gly-Asp-Ser (RGDS), Lys-Arg-Asp-Ser (KRDS), and Gly-His-Lys (GHK) to study local production of growth factors and cytokines in the regenerating tissues. Western/enzyme-linked immunosorbent assay (ELISA) studies were performed after 10 days of regeneration, when the tubular prosthesis is filled with fibrous matrix infiltrated by hematogenous cells and proliferating Schwann cells with growth factors produced locally. Regeneration was also analyzed by morphometrical methods after 30 days. The quantification of growth factors and proteins by ELISA revealed that there was an enhanced expression of the neurotrophic factors nerve growth factor (NGF) and neurotrophins (NT-3 and NT-4) in the regenerating tissues. This was further established by Western blot to qualitatively analyze the presence of the antigens in the regenerating tissues. Schwann cells were localized in the regenerating tissues using antibodies against S-100 protein. Other growth factors including growth-associated protein 43 (GAP-43), apolipoprotein E (Apo E), and pro-inflammatory cytokine like interleukin-1alpha (IL-1alpha) expression in the peptide groups were evaluated by ELISA and confirmed by Western blotting. Cell adhesive integrins in the proliferating cells were localized using integrin-alpha V. The combined results suggest that the early phase of regeneration of peripheral nerves in the presence of peptide-incorporated collagen tubes results in the enhanced production of trophic factors by the recruited hematogenous cells and Schwann cells, which in turn help in the secretion of certain vital trophic and tropic factors essential for early regeneration. Furthermore, hematogenous cells recruited within the first 10 days of regeneration help in the production of inflammatory mediators like interleukins that in turn stimulate Schwann cells to produce NGF for axonal growth.     

Antioxidant property of α-asarone against noise-stress-induced changes in different regions of rat brain

Free radicals and other reactive species are considered to be an important causative factor in the development of neurodegenerative diseases. Recent reports have indicated that exposure to loud noise generates excess oxygen free radicals (OFR) in the brain. Antioxidant properties of medicinal plants are attracting more and more research in medicine, to counteract OFR and to minimize the neurodegenerative processes. The drug alpha-asarone (3, 6 and 9 mg kg(-1) body weight, i.p., for 30 days), one of the active principle components of Acorus calamus Linn., was administered intraperitoneally 1/2 h before the animals were exposed to noise-stress (100 dB for 4 h d(-1), for 30 days). We investigated whether 30 days exposure of noise can produce an oxidative stress. Further, if yes then, could alpha-asarone counteract the stress. This was verified by measuring the activity of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), levels of reduced glutathione (GSH), Vitamin C, Vitamin E, protein thiols and lipid peroxidation (LPO) in different regions of the rat brain. All the three doses of alpha-asarone had an effectively protective role by normalizing the increased SOD and LPO, decreased CAT, GPx, GSH, Vitamins C and E and protein thiols due to noise exposure. Thus, action of alpha-asarone against noise-stress may be due its antioxidant property. Our data proved that antioxidant property of alpha-asarone against noise-stress induced changes in the rat brain. Further, more clinical studies are required to investigate effectiveness of the alpha-asarone in noisy environment in human subjects.     

Impact of ivermectin drug combinations on Pediculus humanus capitis infestation in primary schoolchildren of south Indian rural villages

Background  Antifilarial drug combinations including ivermectin provide antifilarial activity with ancillary benefits on intestinal helminths and ectoparasites, such as chiggers and lice. The impact of single oral dose of antifilarial drugs, viz; (1) diethylcarbamazine (DEC) alone, (ii) DEC + albendazole (ALB), (iii) ivermectin (IVR) + DEC and (iv) IVR + ALB, was determined, on the head louse ( Pediculus humanus capitis ) in primary school children in a rural community in south India.
Methods  Primary school children ( n  = 534) of age 6–10 years from four villages of South India were examined for the presence of head lice before and after single dose of DEC + ivermectin drug combination. The effectiveness and the duration of cure sustained by these drugs were quantified. The head louse was examined by "combing method" during post-treatment periods at 15, 45, 60 and 75 days interval.
Results  The antifilarial drug consumption rate was similar (96–98%) in all treatment arms. In pre-treatment survey the prevalence of head lice in children administered with DEC, DEC + ALB, IVR + DEC and IVR + ALB arm was 86%, 80%, 87% and 80%, respectively, with the latter two arms demonstrating significant reduction in louse infestation ( P  < 0.05) for 60 days.
Conclusion  Single dose with IVR combination demonstrates a greater impact in reducing head louse infestation in the endemic rural communities for nearly 60 days. Therefore, in regions such as Africa where ivermectin is part of the antifilariasis campaign, this drug will have an additional benefit in reducing head lice infestation.     

Prevalence of intestinal parasitic infestation in HIV/AIDS patients with diarrhea in Madurai City, South India

The prevalence and pattern of parasitic infestation among 80 HIV/AIDS patients with diarrhea in Madurai, south India, was studied by microscopy. Eighty HIV-negative patients were used as controls. Intestinal parasites were detected in 31 HIV/AIDS patients (38.7%) and in 14 (17.5%) HIV-negative patients, a difference that was statistically significant (P < 0.05). In HIV/AIDS patients with diarrhea, protozoa accounted for the majority of diarrhea cases (Entamoeba spp. 37.5%, Cryptosporidium parvum 28.7%). It is therefore suggested that enteric infections are more common in HIV-infected patients than in HIV-negative persons in south India, and this may be due to differences in immunological profile, susceptibility as well as factors related to sanitation and the environment.     

Hypolipidemic effect of triphala in experimentally induced hypercholesteremic rats

Hypercholesteremia is one of the risk factors for coronary artery disease. The present study highlights the efficacy of Ayurvedic herbal formulation Triphala (Terminalia chebula, Terminalia belerica, and Emblica officinalis) on total cholesterol, Low density lipoprotein (LDL), Very low density lipoprotein (VLDL), High density lipoprotein (HDL) and free fatty acid in experimentally induced hypercholesteremic rats. Four groups of rats were employed namely control, Triphala treated, hypercholesterolemia rats (4% Cholesterol + 1% cholic acid + egg yolk) and Triphala pre-treatment in hypercholesteremic rats. Results showed significant increase in the total cholesterol, LDL, VLDL, and free fatty acid in hypercholesteremic rats were significantly reduced in Triphala treated hypercholesteremic rats. The data demonstrated that Triphala formulation was associated with hypolipidemic effects on the experimentally induced hypercholesteremic rats.     

Transcatheter closure of large pulmonary arteriovenous fistula including pulmonary artery to left atrial fistula with Amplatzer septal occluder.

OBJECTIVES: We sought to evaluate the safety and efficacy of Amplatzer septal occluder (ASO) to close very large pulmonary arteriovenous fistula (PAVF). BACKGROUND: Transcatheter coil embolization, the standard treatment for PAVF, has potential complications particularly in patients with very large fistulas. Several recently available devices have been tried effectively, however, they too have limitations. METHODS: During 2004, three patients (aged 17-56 years), diagnosed with large PAVF including one with pulmonary artery (PA) to left atrial (LA) fistula, had interventional closure prospectively using ASO. Following hemodynamic evaluation and angiographic localization of PAVF, the feeding artery (FA) was selectively cannulated with Amplatzer delivery sheath. ASO, with the right atrial (RA) disc diameter equal to or up to 4 mm larger than the maximum diameter of FA, was delivered through it in such a way that the left atrial disc assumed an oblong shape and the right atrial disc retained its designed flat configuration for better anchorage and thrombogenicity. RESULTS: All patients had very large PAVF fed by a single FA (size 12-24 mm), which was closed completely, without complications, using ASO (size 7-16 mm; RA disc diameter 15-26 mm). Their arterial saturation rose from mean 72.3% to 97.3%. Follow up (1.5-3 years) showed disappearance of the radiological shadows and stable arterial saturations (mean 97.7%). CONCLUSIONS: We conclude that, using the new criteria for device size selection and modified technique of implantation, very large PAVFs including PA to LA fistula can be closed safely, effectively and nonsurgically with ASO.     

Therapeutic response to single intravenous bolus administration of formate dehydrogenase in methanol-intoxicated rats

Methanol remains to be a major public and environmental health hazard. Formic acid is the toxic metabolite responsible for the metabolic acidosis observed in methanol poisoning in humans, in non-human primates and in folate-depleted rodents. Cytochrome oxidase inhibition by formate leads to lactic acid accumulation, which contributes significantly to metabolic acidosis. Toxic effects in human beings are characterized by formic acidemia, metabolic acidosis, ocular toxicity, nervous system depression, blindness, coma and death. Elimination of formate is one of the principles of management in methanol poisoning. Hemodialysis facility is not readily available in all the places, in developing countries like India. Formate dehydrogenase (EC 1.2.1.2) acts directly over formate and converts formate into CO(2) in the presence of NAD. Effect of single intravenous bolus infusion of formate dehydrogenase, obtained from Candida boidinii; in methanol-intoxicated folate deficient rat model was evaluated. Folate depletion induced by methotrexate (MTX) treatment. Carbicarb (Carb) (equimolar solution of sodium carbonate and sodium bicarbonate) was used to treat metabolic acidosis. Experimental design consists of seven groups, namely Saline control, methanol control, MTX control, Enzyme control, MTX-methanol control, MTX-methanol-Carb and MTX-methanol-Carb-Enz group. Male wistar rats treated with MTX (0.3mg/kg) for a week, were injected (i.p.) with methanol (4 gm/kg), 12h latter, Carbicarb solution was infused, following this enzyme was infused (i.v.) in bolus. Blood samples were collected every 15 min for an hour from the cannulated left jugular vein and blood methanol, formate were estimated, respectively, with HPLC and fluorimetric assay. Blood pH, blood gases pO(2), pCO(2) and bicarbonate were monitored with blood gas analyzer in order to evaluate acid base status of the animal. Results obtained show that there is significant elimination of formate within 15 min. It may be concluded that single bolus infusion of formate dehydrogenase facilitates fast removal of formate, a highly toxic metabolite in methanol poisoning.     

Immunomodulatory activity of triphala on neutrophil functions

Immune activation is an effective as well as protective approach against emerging infectious diseases. The immunomodulatory activities of Triphala (Terminalia chebula, Terminalia belerica and Emblica officinalis) were assessed by testing the various neutrophil functions like adherence, phagocytosis (phagocytic index (P.I) and avidity index (A.I)) and nitro blue tetrazolium (NBT) reduction in albino rats. In recent years much attention is being focused on the immunological changes occur during stress. Noise (100 dB) stress for 4 h/d for 15 d, was employed to alter the neutrophil functions. The neutrophil function tests and corticosterone levels were carried out in eight different groups of animals, namely control, Triphala, noise-stress, Triphala noise-stress, and corresponding immunized groups were used. Sheep red blood cells (SRBC 5 x 10(9) cells per ml) were used for immunizing the animals that belongs to immunized groups. In Triphala administration (1 g/kg/d for 48 d), A.I was found to be significantly enhanced in the Triphala group, while the remaining neutrophil functions and steroid levels were not altered significantly. However the neutrophil functions were significantly enhanced in the Triphala immunized group with a significant decrease in corticosterone level was observed. Upon exposure to the noise-stress, the neutrophil functions were significantly suppressed and followed by a significant increase in the corticosterone levels were observed in both the noise-stress and the noise-stress immunized groups. These noise-stress-induced changes were significantly prevented by Triphala administration in both the Triphala noise-stress and the Triphala noise-stress immunized groups. Hence our study has divulged that oral administration of Triphala appears to stimulate the neutrophil functions in the immunized rats and stress induced suppression in the neutrophil functions were significantly prevented by Triphala.