The solubility and stability of amino acids in biocompatible ionic liquids.

In recent years, ionic liquids (ILs) represent a new class of biocompatible co-solvents for biomolecules. In this work, we report the apparent transfer free energies (ΔG'tr) for six amino acids (AA) from water to aqueous solutions of six ammonium based ILs (diethylammonium acetate (DEAA), diethylammonium sulfate (DEAS), triethyl ammonium acetate (TEAA), triethylammonium sulfate (TEAS), triethylammonium dihydrogen phosphate (TEAP), and trimethylammonium acetate (TMAA)) through solubility measurements, as a function of IL concentration at 298.15 K under atmospheric pressure. Salting-out effect was found for AA in aqueous IL solutions with increasing IL concentrations. In addition, we observed positive values of ΔG'tr for AA from water to ILs, indicating that the interactions between ILs and AA are unfavorable. From the obtained results, we found that the selected ammonium based ILs act as stabilizers for the structure of AA.

Structural basis for the enhanced stability of protein model compounds and peptide backbone unit in ammonium ionic liquids.

Protein folding/unfolding is a fascinating study in the presence of cosolvents, which protect/disrupt the native structure of protein, respectively. The structure and stability of proteins and their functional groups may be modulated by the addition of cosolvents. Ionic liquids (ILs) are finding a vast array of applications as novel cosolvents for a wide variety of biochemical processes that include protein folding. Here, the systematic and quantitative apparent transfer free energies (ΔG'(tr)) of protein model compounds from water to ILs through solubility measurements as a function of IL concentration at 25 °C have been exploited to quantify and interpret biomolecular interactions between model compounds of glycine peptides (GPs) with ammonium based ILs. The investigated aqueous systems consist of zwitterionic glycine peptides: glycine (Gly), diglycine (Gly(2)), triglycine (Gly(3)), tetraglycine (Gly(4)), and cyclic glycylglycine (c(GG)) in the presence of six ILs such as diethylammonium acetate (DEAA), diethylammonium hydrogen sulfate (DEAS), triethylammonium acetate (TEAA), triethylammonium hydrogen sulfate (TEAS), triethylammonium dihydrogen phosphate (TEAP), and trimethylammonium acetate (TMAA). We have observed positive values of ΔG'(tr) for GPs from water to ILs, indicating that interactions between ILs and GPs are unfavorable, which leads to stabilization of the structure of model protein compounds. Moreover, our experimental data ΔG'(tr) is used to obtain transfer free energies (Δg'(tr)) of the peptide backbone unit (or glycyl unit) (-CH(2)C═ONH-), which is the most numerous group in globular proteins, from water to IL solutions. To obtain the mechanism events of the ILs' role in enhancing the stability of the model compounds, we have further obtained m-values for GPs from solubility limits. These results explicitly elucidate that all alkyl ammonium ILs act as stabilizers for model compounds through the exclusion of ILs from model compounds of proteins and also reflect the effect of alkyl chain on the stability of protein model compounds.

Influence of alkyl chain length and temperature on thermophysical properties of ammonium-based ionic liquids with molecular solvent.

Mixing of ionic liquids (ILs) with molecular solvent can expand the range of structural properties and the scope of molecular interactions between the molecules of the solvents. Exploiting of these phenomena essentially require a basic fundamental understanding of mixing behavior of ILs with molecular solvents. In this context, a series of protic ILs possessing tetra-alkyl ammonium cation [R(4)N](+) with commonly used anion hydroxide [OH](-) were synthesized and characterized by temperature dependent thermophysical properties. The ILs [R(4)N](+)[OH](-) are varying only in the length of alkyl chain (R is methyl, ethyl, propyl, or butyl) of tetra-alkyl ammonium on the cationic part. The ILs used for the present study included tetramethyl ammonium hydroxide [(CH(3))(4)N](+)[OH](-) (TMAH), tetraethyl ammonium hydroxide [(C(2)H(5))(4)N](+)[OH](-) (TEAH), tetrapropyl ammonium hydroxide [(C(3)H(7))(4)N](+)[OH](-) (TPAH) and tetrabutyl ammonium hydroxide [(C(4)H(9))(4)N](+)[OH](-) (TBAH). The alkyl chain length effect has been analyzed by precise measurements such as densities (ρ), ultrasonic sound velocity (u), and viscosity (η) of these ILs with polar solvent, N-methyl-2-pyrrolidone (NMP), over the full composition range as a function of temperature. The excess molar volume (V(E)), the deviation in isentropic compressibility (Δκ(s)) and deviation in viscosity (Δη) were predicted using these properties as a function of the concentration of ILs. Redlich-Kister polynomial was used to correlate the results. A qualitative analysis of the results is discussed in terms of the ion-dipole, ion-pair interactions, and hydrogen bonding between ILs and NMP molecules. Later, the hydrogen bonding features between ILs and NMP were also analyzed using a molecular modeling program with the help of HyperChem 7.

Role of Pterocarpus santalinus against mitochondrial dysfunction and membrane lipid changes induced by ulcerogens in rat gastric mucosa.

Free radicals produced by ulcerogenic agents affect the TCA cycle enzymes located in the outer membrane of the mitochondria. Upon induction with ulcerogens, peroxidation of membrane lipids bring about alterations in the mitochondrial enzyme activity. This indicates an increase in the permeability levels of the mitochondrial membrane. The ability of PSE to scavenge the reactive oxygen species results in restoration of activities of TCA cycle enzymes. NSAIDs interfere with the mitochondrial beta-oxidation of fatty acids in vitro and in vivo, resulting in uncoupling of mitochondrial oxidative phosphorylation process. This usually results in diminished cellular ATP production. The recovery of gastric mucosal barrier function through maintenance of energy metabolism results in maintenance of ATP levels, as observed in this study upon treatment with PSE. Membrane integrity altered by peroxidation is known to have a modified fatty acid composition, a disruption of permeability, a decrease in electrical resistance, and increase in flip-flopping between monolayers and inactivated cross-linked proteins. The severe depletion of arachidonic acid in ulcer induced groups was prevented upon treatment with PSE. The acid inhibitory property of the herbal extract enables the maintenance of GL activity upon treatment with PSE. The ability to prevent membrane peroxidation has been traced to the presence of active constituents in the PSE. In essence, PSE has been found to prevent mitochondrial dysfunction, provide mitochondrial cell integrity, through the maintenance of lipid bilayer by its ability to provide a hydrophobic character to the gastric mucosa, further indicating its ability to reverse the action of NSAIDs and mast cell degranulators in gastric mucosa.

Ulcer protective effect of Terminalia arjuna on gastric mucosal defensive mechanism in experimental rats.

The methanol extract of the bark of Terminalia arjuna (Combretaceae) (TAE) showed marked antiulcer and ulcer healing activity against 80% ethanol (ETH), diclofenac sodium (DIC) and dexamethasone (DEX) induced ulcer models dose dependently at doses of 100, 400 and 200 mg/kg body weight respectively. Pre-, post and co-administration of TAE offered 100% protection to the gastric mucosa against ETH, DIC and DEX induced ulcers as observed from the ulcer score. Gastric mucosal analysis of DEX induced rats were associated with changes in the levels of protein, protein bound carbohydrate complexes, lipid peroxides (LPO), glutathione (GSH) and activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) compared with control rats. Co-administration with TAE in DEX rats (DEX + TAE) favorably altered the levels of LPO, GSH and also the activities of SOD and CAT in gastric mucosa, whereas the activities of GPx remained unaltered in all groups. In DEX + TAE rats, the levels of protein and protein bound carbohydrate complexes were increased when compared with DEX rats. The results indicate that the gastroprotective effect of TAE is probably related to its ability to maintain the membrane integrity by its antilipid peroxidative activity that protects the gastric mucosa against oxidative damage and its ability to strengthen the mucosal barrier, the first line of defense against exogenous and endogenous ulcerogenic agents.

Pterocarpus santalinus: a traditional herbal drug as a protectant against ibuprofen induced gastric ulcers.

The ethanol extract of Pterocarpus santalinus (PS) was evaluated for gastroprotection in rats using ibuprofen as the induction model. Rats treated with PS (100-400 mg/kg) showed a significant reduction in gastric lesions. PS at a dose of 200 mg/kg was found to be the minimum effective dose and hence further studies with that dose were carried out. PS treatment increased the LDH activity and decreased the lipid peroxidation levels. The extract had the ability to increase the antioxidant enzymes SOD, CAT and GPx when compared with the untreated but induced rats. The membrane bound ATPases - H(+)K(+)ATPase, Na(+)K(+)ATPase and Ca(2+)ATPases were increased upon the induction with ulcerogen. The treated group showed a decrease in the activities of these enzymes and also had the ability to restore the sodium and potassium ion concentrations to near normal levels, which were altered by ibuprofen mediated acid stimulation. The results suggest that the antiulcer properties of PS could traced to its acid inhibiting potential, antioxidant activity and the ability to maintain functional integrity of the cell membranes.

A short-term diabetes induced changes of catecholamines and p38-MAPK in discrete areas of rat brain.

Chronic diabetes is associated with the alteration of second messengers and CNS disorders. We have recently identified that protein kinases (CaMKII and PKC-alpha) and brain neurotransmitters are altered during diabetes as well as in hyperglycemic and acidotic conditions. In this study, we investigated the effects of acute diabetes on the levels of dopamine (DA), norepinephrine (NE), epinephrine (E) and p38-Mitogen-Activated Protein Kinase (p38-MAPK) in striatum (ST), hippocampus (HC), hypothalamus (HT), midbrain (MB), pons medulla (PM), cerebellum (CB) and cerebral cortex (CCX). Alloxan (45 mg/kg) diabetic untreated rats that showed hyperglycemia (>260 mg%), revealed significant increases of DA level in ST (1.5 fold), HC (2.2 fold) and PM (2.0 fold) and the E level also found to be increased significantly in HT (2.4 fold), whereas the NE level was decreased in CB (0.5 fold), after 7 days of diabetes. Immunoblotting study of p38-MAPK expression under identical conditions showed significant alterations in ST, HC, HT and PM (p<0.05) correlated with the changes of catecholamines (DA and E). On the other hand, the above changes were reversed in insulin-treated diabetic rats maintained under normal glucose level (80 -110 mg %). These results suggest that p38-MAPK may regulate the rate of either the synthesis or release of DA and E in corresponding brain areas, but not NE, under these conditions.

T lymphocyte subsets and immunoglobulins in intracranial tumor patients before and after treatment, and based on histological type of tumors.

It has been reported that nervous system and peripheral immune system communicate with each other and the peripheral immune status is depressed in some intracranial tumor (ICT) patients pre operatively. Little is known about the immune status of intracranial tumor patients during the post operative survival period. We thus investigated total T cells (CD 11+), helper/inducer (CD4+) T cells, suppressor/cytotoxic (CD8+) T cells, B cells (CD19+) and serum immunoglobulins in peripheral blood in certain ICT patients before and after treatment, and based on the histological type of the tumors. Post treatment analysis were conducted 30 days after surgical removal of tumor tissue in benign brain tumor patients and 30 days after chemo therapy (CT)/radiotherapy (RT) following surgical removal of tumor tissue in malignant brain tumor patients. Decreased CD11+, CD4+ and increased CD8+ T cell counts were observed in both benign and malignant tumor cases before treatment compared with control subjects. After treatment, CD4+ T cell count increased and CD8+ T cell count decreased than their pre treatment levels. Serum IgA and IgG levels were decreased in both benign and malignant brain tumor patients before treatment than in control subjects. Serum IgM level has been increased in both benign and malignant tumor patients before and after treatment than in control subjects. Anaplastic malignant astrocytoma, medulloblastoma and glioblastoma multiforme patients showed higher IgM level than astrocytoma, meningioma and ependymoma patients. In conclusions, the depressed host cellular immunity in benign and malignant tumor patients before treatment may be due to the changes in CD4+ and CD8+ counts in addition to tumour specific immunosuppressive factors. Treatment procedures such as surgery, CT and RT may play certain role in the post operative depressed immunosuppression in malignant tumor patients. Humoral immune mechanism (CD19+) in the ICT patients was less markedly affected.

Effect of a polyherbal formulation, Ambrex, on butylated hydroxy toluene (BHT) induced toxicity in rats.

Effect of polyherbal formulation Ambrex was evaluated in butylated hydroxytoluene (BHT) induced toxicity of lungs and liver in rats. Toxicity was produced by administering BHT (500 mg/kg/day) for 3 days. Lung damage was evidenced by elevated levels of broncho alveolar lavage fluid (BAL) parameters such as protein, lactate, lactate dehydrogenase (LDH), alkaline phosphatase (ALP), acid phosphatase (ACP) and glucose-6-phosphate dehydrogenase (G6PDH). Liver damage was proved by elevated levels of serum protein and markers such as LDH, ALP, aspartate amino transferase (AST), alanine amino transferase (ALT), decreased level of lipid peroxides (LPO) in serum and glutathione (GSH) in liver. Administration of aqueous suspension of Ambrex (50 mg/kg orally) retained these elevated levels of BAL-protein, lactate, LDH, ALP, ACP, G6PDH and serum-protein, LDH, ALP, AST and ALT at near normal values. Decreased level of liver GSH was retained at near normalcy in Ambrex pretreated BHT-administered animals. There was no change in liver LPO in all the four groups.

Neuro-immunomodulation by dorsolateral hippocampus--role of macrophages,T and B cells.

In dorsolateral hippocampal lesioned, Sham and control animals, the total number of splenocytes was determined and macrophages, B cells and T cells were isolated and their percentage distribution in total splenocytes were determined. The leukocyte migration inhibition was studied in these groups using different fractions of splenocytes namely whole splenocytes, macrophage removed fraction, and nylon wool eluted T cell population. The same groups were also studied after an antigenic challenge. The results indicate alterations in the macrophages, adherent cell population as well as T cell population in lesioned and Sham animals and also in their immunized groups. These altered cell sub-populations may be responsible for the altered migration.

Carcinoma gall bladder presenting as hemobilia.

A 60-year-old man presented with recurrent bouts of melena, requiring multiple transfusions. Upper GI endoscopic evaluation demonstrated fresh bleeding from the ampulla of Vater. Ultrasonography and CT scan suggested a gall bladder mass without evidence of metastases. Laparotomy confirmed a mass confined to the lumen of the gall bladder. The patient underwent cholecystectomy. Histological examination showed papillary adenocarcinoma of the gall bladder extending up to the muscularis propria.

Glycoprotein components in the serum of patients with cancer breast.

The levels of total sialic acid, lipid bound sialic acid and fucose were estimated in the sera of patients with benign and malignant tumours of breast. An increase was noted in all the three parameters, with a more marked increase in malignancy, when compared with benign and controls. Consequent to surgery, there was an elevation in the serum levels of the above parameters than the values prior to surgery and a decline was noted two months after surgery although none of the values reached the normal range. These results suggest a close association of the glycoproteins with the tumour burden and further signify their role in early detection and staging of cancer breast.

Regional specificity seen within hypothalamus in neuroimmunomodulation.

Wistar strain male albino rats lesioned and sham lesioned at Ventromedial hypothalamus (VMH) were used to study the neuroimmunomodulation by this brain region. Except the decrease in thymus weight/body weight ratio (P < 0.01), and its cellularity (P < 0.02) in immunized VMH lesion animals, the rest of the parameters like plaque forming cells (PFC), antibody titre, leukocyte migration inhibition index, foot pad thickness in the lesioned as well as the lesion immunized animals never deviated from their respective sham and immunized sham animals. Sham operated belongs to VMH when compared to control rats, showed marked decrease in spleen weight (P < 0.001), thymus weight (P < 0.02) and decrease in popliteal lymph node weight (P < 0.001) ratios. After immunization, the immunized sham animals showed a marked decrease in antibody titre (P < 0.05), PFC (P < 0.05), spleen (P < 0.05) and thymus (P < 0.001) weight ratios with the significant increase in splenic cell count (P < 0.01) compared to immunized control rats. VMH may be one of the information receiving center. However, from these results, it is inferred that VMH could not be a modulating center for the many of the parameters studied as far as neuroimmunomodulation is concerned.

Peripheral immune response in albino rats following cerebroventricular and intraperitoneal antigen challenge.

Success in neural tissue transplants at central nervous system suggest that the site may be immunologically privileged. However, this experimental study in which an antigen (Sheep Red Blood Cells) was administered into the third ventricle does not support the above concept. The antibody titre and soluble immune complex levels seen in these animals are similar to the levels seen in animals immunized with the same amount of antigen through the intraperitoneal route. Intraventricular immunization is rather a more potent modulator in decreasing the total WBC count (P < 0.05) and neutrophils (P < 0.001). Further a marked increase in lymphocytes (P < 0.01) in peripheral blood was observed in these animals. Intraventricular immunization also increased the killing power (NBT reduction) of the neutrophils (P < 0.05).

Activated charcoal--an antidote to methyl alcohol poisoning.

Every year a considerable number of people die due to methly alcohol poisoning, in which most of them die even before they are given proper treatment. This report gives a simple and cheap first aid measure to those affected by methanol poisoning by the administration of activated charcoal. This study has shown that the mortality of methanol recipient rats have significantly reduced by the administration of activated charcoal.

Cyclea peltata diels - a possible substitute for cissampelos pareira linn.

Chromatographic studies have been carried out on cyclea peltata Diels and Cissampelos pareira Linn. The results substantiate that cyclea peltata Diels can be substituted for cissampelos pareira in ayurvedic formulations.

Modulation of non-specific immunity by hippocampal stimulation.

Rats subjected to electrical stimulation of hippocampus (30 min/day for 4 days) showed an increase in the neutrophils in the peripheral blood when compared to sham (P < 0.01) and controls (P < 0.001). They also showed a significant decrease in lymphocytes, when compared to control rats (P < 0.001). Both sham and stimulated animals showed a significant decrease in total white blood cell count when compared to controls (P < 0.001). The phagocytic index of stimulated animals showed a significant increase from control (P < 0.001) and sham (P < 0.001). In addition, the stimulated animals showed a significant (P < 0.001) decrease in plasma corticosterone level when compared to sham and controls.

Modulation of specific immunity by ventral hippocampal formation in albino rats.

Rats with bilateral electrolytic ventral hippocampal formation (VHF) lesion show a significantly (p less than 0.001) enhanced migration of leucocytes in the presence of antigen. Immunization in these animals enhances (p less than 0.001) the leucocyte migration and presents a significant decrease in footpad thickness. Antibody titre (p less than 0.001) and plaque-forming cells (p less than 0.02) also show a significant decrease when compared with sham-lesion-immunized animals and control-immunized animals. These data indicate the influence of VHF in modulating the specific immunity.

Neuro immuno modulation by ventral hippocampus.

Bilateral electrical lesion at ventral hippocampal formation (VHF) did not affect some aspects of nonspecific immunity like total W.B.C. count, percentage of cells in differential count, their absolute count (lymphocyte and neutrophils) and neutrophil functions. The changes observed are due to non-specific craniocerebral trauma as the sham operated animals also showed a similar pattern of response. However the lesion at VHF increases the spleen cell count significantly whereas immunization in these animals decreases the spleen cell count. The thymus weight/body weight ratio also decreases in these animals. Our study confirms the neuroimmuno modulation and the influence of VHF on certain nonspecific immune parameters.