V. M. L. Srivastava

Modulation of inflammatory mediators by ibuprofen and curcumin treatment during chronic inflammation in rat.

Inflammation is a protective tissue response occurring in three distinct phases, acute, subacute and a chronic proliferative phase. We undertook the present study to understand the overall immune response of the body during adjuvant induced chronic inflammation in rat and the effect of ibuprofen and curcumin on this response. Inflammatory mediators were estimated on day 21 and day 35 after adjuvant injection. The level of C-reactive protein increased to 200% on day 21 and then reduced to 50% on day 35 compared to control. Curcumin and ibuprofen further reduced the increased levels at both the time intervals. Haptoglobin level decreased to 42% on day 21 but increased to 5 times of control on day 35.Curcumin and ibuprofen reduced the increased levels at day 35. No significant change was observed in Prostaglandin-E2 and Leukotriene-B4 levels and in Lymphocyte proliferation. The level of Tumor Necrosis Factor-α increased by three folds on day 21, but came down to 88% on day 35. Ibuprofen treatment decreased the raised level on day 21 and increased the reduced level on day 35. Interleukin-1β increased to 2 folds on day 21 and 10 folds on day 35 which were significantly brought down by curcumin and ibuprofen. Nitric oxide level was reduced at both the time intervals, which were increased by drug treatment.

Chondroid Expression by Lapine Articular Chondrocytes in Spinner Culture Following Monolayer Growth

When articular chondrocytes from rabbits 2 to 3 months old were transferred from confluent monolayer to spinner culture, they ceased to proliferate but deposited large quantities of metachromatic extracellular material. Return of the suspended cells to monolayer conditions resulted in renewal of DNA and marked depression of sulfated glycosaminoglycan (GAG) synthesis. The GAG of rabbit articular cartilage were heterogeneous and included 4.9% hyaluronate, 11.6% unsulfated chondroitin, 18.7%, disulfated chondroitin and 2.4% dermatan sulfate in addition to chondroitin sulfates 4 and 6. Monolayer cultured chondrocytes produced higher levels of sulfated GAG but much smaller quantities of hyaluronate than did dermal fibrocytes. The GAG synthesized by chondrocytes in spinner culture closely resembled those of whole cartilage or synthesized by whole cartilage in organ culture.

A novel pentasaccharide from immunostimulant oligosaccharide fraction of buffalo milk.

A processed oligosaccharide mixture of buffalo milk induced significant stimulation of antibody, delayed-type hypersensitivity response to sheep red blood cells in BALB/c mice. This also stimulated non-specific immune response of the animals measured in terms of macrophage migration index. A novel pentasaccharide has been isolated from the oligosaccharide containing fraction having immunostimulant activity of buffalo milk. This compound was isolated by a combination of gel filtration chromatography, silica gel column chromatography of derivatised oligosaccharides while the homogeneity was confirmed by high performance liquid chromatography. The results of structural analyses, i.e. proton nuclear magnetic resonance, fast atom bombardment mass spectrometry, chemical transformations and degradations are consistent with the following structure: GlcNAcbeta(1-->3)Galbeta(1-->4)GlcNAcbeta(1-->3)Gal beta(1-->4)Glc

Oxidation and reduction of cytochrome c by mitochondrial enzymes of Setaria cervi

A mitochondria-rich fraction isolated from the cuticle-hypodermis-muscle system of Setaria cervi, a bovine filarial parasite, possessed substrate-coupled cytochrome c reductases and cytochrome c oxidase in appreciable activities. All these activities were located predominantly in the membranes. NADH-coupled cytochrome c reductase was more prominent than NADPH- and succinate-coupled reductases. All the three reductases exhibited marked sensitivity to rotenone and antimycin A. Salicylhydroxamic acid strongly inhibited succinate requiring reductase and cytochrome c oxidase, but the other two reductases only mildly. Sodium azide activated the reductases but substantially inhibited the oxidase activity. Potassium cyanide activated the succinate requiring reductase but did not cause any noticeable change in the activities of pyridine nucleotide linked reductases. Anthelmintics also influenced these activities but no definite correlation could be drawn regarding their mode of action.

Syntheses and antifilarial profile of 5-amino and 5,8-diamino-isoquinoline derivatives: A new class of antifilarial agents

Abstract The syntheses of 5-amino (4–12,15) and 5,8-diamino(16–17) isoquinoline derivatives. their antifilarial activity and their effect on metabolic activities of filariids are delineated. Some of the screened compounds have shown promising filaricidal response against Acanthocheilonema viteae in rodents.

Role of reactive oxygen species in expulsion of Nippostrongylus brasiliensis from rats

To understand the mechanism for the expulsion of Nippostrongylus brasiliensis from rats, age-dependent variations in the metabolism of reactive oxygen species in the parasite and the host intestines were examined. N. brasiliensis showed an age-dependent increase in its susceptibility to xanthine-xanthine oxidase and t-butyl hydroperoxide generated oxidants as well as to H2O2. Protection obtained with several scavengers suggested that the worms were damaged by the combined action of oxidants generated by the in vitro systems employed. The level of superoxide dismutase in the nematode and its release into the surroundings exhibited a marked depression with advancement of age. No such alteration was, however, recorded for catalase and glutathione peroxidase. An appreciable decrease in the level of reduced glutathione in older N. brasiliensis appears to render them prone to oxidant attack. The rat intestines, on the other hand, exhibited an appreciable depression in catalase and a reduced glutathione content with progress of the infection. Vitamin E levels were elevated. The release of O2-. and H2O2 by the intestines was also found to be greater during later stages of the infection. The combined effect of the changes observed in N. brasiliensis and in the rat intestines may be at least partly responsible for expulsion of the nematode from the rats after day 10.

Macrophages in the development of protective immunity against experimental Brugia malayi infection

The present report compares the macrophage function in rodent hosts susceptible and resistant to the human lymphatic filariid Brugia malayi. Macrophages from both mastomys (resistant) and gerbil (susceptible) infected intraperitoneally (i.p.) with the infective larvae (L3) of B. malayi were isolated from peritoneal lavage at different time-intervals and formation rate of NO, H2O2, O2-, TNF-alpha, glutathione peroxidase and reductase was assayed. NO release was found to be significantly increased in resistant mastomys as compared to gerbils and the release was markedly suppressed by i.p. administration of the NOS inhibitor aminoguanidine (AG). The AG-treated mastomys also demonstrated significantly greater establishment of larvae which correlated well with suppressed formation of NO. Nitric oxide synergizes with superoxide to form peroxynitrite radical (potent oxidant), which is known to be more toxic per se than NO. Results indicate the possible involvement of peroxynitrite in the rapid killing of larvae in the peritoneal cavity of mastomys. In contrast, the production of H2O2 was found to be enhanced in both species indicating that B. malayi L3 could withstand the toxic effects of H2O2. The higher level of glutathione peroxidase and reductase, as observed in mastomys compared with the gerbil after larval introduction, possibly protects the cell against the injurious effect of H2O2. The TNF-alpha level remained virtually unchanged in both the hosts, suggesting an insignificant role for this cytokine in parasite establishment.

Reactive oxygen intermediates metabolizing enzymes in Ancylostoma ceylanicum and Nippostrongylus brasiliensis

Adult worms of Ancylostoma ceylanicum and Nippostronglyus brasiliensis were found to possess an active system for the detoxification of reactive oxygen intermediates. Xanthine oxidase, which is known to produce superoxide anion, was detected in both the nematode parasites in significant activities. Superoxide anion, thus produced, may quickly be eliminated by superoxide dismutase. Both parasites also exhibited the presence of catalase, peroxidase, and glutathione peroxidase for efficient removal of hydrogen peroxide. Glutathione reductase and glucose-6-phosphate dehydrogenase were, however, detected in low levels of activities. Endowment of A. ceylanicum and N. brasiliensis with these antioxidant enzymes, therefore, enables them to evade the hosts effector mechanism for their survival. Superoxide dismutase of both these nematodes showed marked inhibition by KCN and, hence, the enzyme appears to be of copper-zinc type.

STUDIES ON THE PROFILE OF IMMUNOSTIMULANT ACTIVITIES OF MODIFIED IRIDOID GLYCOSIDES

Immunostimulant activity profile of modified iridoid glycosides prepared from loganin (1), ketologanin (2) and arbortristoside A (3) have been studied and some structure–activity relationships have been obtained.

Energy metabolism in Cotugnia digonopora and the effect of anthelmintics

Incorporation of 32Pi into organic phosphate by mitochondria of Cotugnia digonopora was supported maximally by malate. Fumarate and succinate induced lower but significant production of ATP. Pyruvate, alpha-ketoglutarate and oxalacetate proved to be poor substrates and citrate and isocitrate had no effect. A net phosphorylation of approximately 2 mol of ADP was observed for each mol of CO2 liberated from malate or succinate. In contrast, with pyruvate, in spite of a high rate of decarboxylation, the production of ATP was extremely low. 2,4-Dinitrophenol inhibited phosphorylation. All anthelmintics examined interfered with the mitochondrial phosphorylation of ADP, with maximum inhibition by salicylanilide compounds. The anticestodal activity of the latter group of compounds, niclosamide for example, may, therefore, be attributed to their ability to inhibit mitochondrial phosphorylation.