Natural cyclic polypeptides as vital phytochemical constituents from seeds of selected medicinal plants

Cyclopolypeptides are among the most predominant biomolecules in nature, especially those derived from plant seeds. This category of compounds has gained extraordinary attention due to remarkable variety of structures and valuable biofunctions. These congeners display enormous variation in terms of both structure and function and are the most significant biomolecules due to their widespread bioproperties. The estrogenic activity, immunosuppressive activity, cytotoxicity, vasorelaxant activity, and other properties possessed by cyclic peptides from seeds of plants make these congeners attractive leads for the drug discovery process. The current study covers the important structural features, structure-activity relationship, synthesis methods, and bioproperties of plant seeds-originated bioactive peptides from Vaccaria segetalis, Linum usitatissimum, and Goniothalamus leiocarpus, which may prove vital for the development of novel therapeutics based on a peptide skeleton.

IMPACT OF MOLECULAR METHOD FOR THE DIAGNOSIS OF ACUTE BACTERIAL MENINGITIS IN A TERTIARY HEALTH CARE CENTRE IN NORTH INDIA

Background. Acute bacterial meningitis is one of the significant infectious diseases that add an immense burden to the health system. Proper management of meningitis is an invincible need to overcome the severe consequences. Objectives. The aim of the study is detection of the etiological agents of acute bacterial meningitis by PCR. Methods. Total 267 CSF samples collected from suspected bacterial meningitis cases were processed for the detection of S. pneumoniae, H. influenzae, N. meningitidis, E. coli and Group B streptococci by conventional and molecular diagnosis method. CSF was inoculated on Blood, chocolate and MacConkey agar plates and incubated at 37 °C for 24-48 hrs. Bacteria grown were identified by Matrix assisted laser desorption/ionization time of flight (MALDI-TOF). Multiplex PCR of the enlisted bacteria was performed using DNA extracted from CSF by DNA extraction kit (Qiagen, USA). Results. 5 (1.87%) out of the total 267 CSF samples were culture positive (3 S. pneumoniae and 2 E. coli) and 28 (10.49%) had detectable DNA by conventional PCR. Out of these 28 samples, 20 (71.43%) were S. pneumoniae and 8 (28.57%) were E. coli. 15 (53.57%) out of total S. pneumoniae were present in children below 5 years of age. Similarly, E. coli was predominant in neonates. Sensitivity and specificity of the PCR was 100% and 95-98% respectively. Conclusions. Streptococcus pneumoniae is the commonest cause of community acquired bacterial meningitis in children below five years of age. Hence, for the promising outcome, PCR should be implemented for the diagnosis of acute bacterial meningitis.

Natural Bioactive Thiazole-Based Peptides from Marine Resources: Structural and Pharmacological Aspects

Peptides are distinctive biomacromolecules that demonstrate potential cytotoxicity and diversified bioactivities against a variety of microorganisms including bacteria, mycobacteria, and fungi via their unique mechanisms of action. Among broad-ranging pharmacologically active peptides, natural marine-originated thiazole-based oligopeptides possess peculiar structural features along with a wide spectrum of exceptional and potent bioproperties. Because of their complex nature and size divergence, thiazole-based peptides (TBPs) bestow a pivotal chemical platform in drug discovery processes to generate competent scaffolds for regulating allosteric binding sites and peptide–peptide interactions. The present study dissertates on the natural reservoirs and exclusive structural components of marine-originated TBPs, with a special focus on their most pertinent pharmacological profiles, which may impart vital resources for the development of novel peptide-based therapeutic agents.

Exploring novel colon-targeting antihistaminic prodrug for colitis

Present work was inspired by an interesting finding of Raithel et al. (11) about remission of steroid-dependent, chronically active ulcerative colitis (UC) in a patient, after treatment with a combination of fexofenadine, disodium cromoglycate and an amino acid-based formula. Literature reports involvement of mast cells activation and increased histamine secretion in the pathogenesis of colitis. The purpose of present work was to evaluate the potential of a novel prodrug of fexofenadine in 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis in rats. A colon-specific mutual amide prodrug of fexofenadine with D-glucosamine was synthesized. Release was studied in tissue homogenates and rat fecal matter by HPLC. It was further screened in TNBS-induced colitis in rats and also for adverse effects on rat liver, stomach and pancreas. The spectral analysis confirmed the structure of the prodrug. Highly hydrophilic prodrug enabled efficient delivery of fexofenadine to colon. Prodrug furnished negligible release of fexofenadine in upper gastrointestinal tract (GIT) homogenates. About 82% release of fexofenadine was observed in rat fecal matter at the end of 12 hours. The prodrug was twice as effective in lowering the quantifying parameters of colonic inflammation in TNBS- induced colitis than fexofenadine, D-glucosamine, their physical mixture and interestingly oral 5-amino salicylic acid while 2.7 times less effective than sulfasalazine. The prodrug restored disrupted colonic architecture to normal without adversely affecting stomach, liver and pancreas. In conclusion, the results support histamine involvement in the pathogenesis of UC. This novel, dual acting colon-specific prodrug of fexofenadine is promising as combination maintenance therapy with sulfasalazine for UC.

Drug susceptibility of Mycobacterium tuberculosis in patients with AIDS at a tertiary care hospital in northern India

The study was done to determine the anti-tuberculosis drug resistance patterns of Mycobacterium tuberculosis (MTB) in AIDS patients. Fifty antiretroviral drug naïve new AIDS patients with clinical evidence of pulmonary tuberculosis and no previous history of tuberculosis were recruited. Baseline CD4 counts and plasma viral loads (PVL) were measured by flow cytometry and RT-PCR, respectively. Sputum samples were obtained from each patient and subjected to Ziehl-Neelsen staining and cultured on Lowenstein-Jensen medium and using the BACTEC 460 system (B460). Antimicrobial susceptibilities were tested in all isolates using the B460 gystem. The occurrence of MTB was found to be more common with a PVL>4 log10 copies/ml (odds ratio: 4.6). Of 15 MTB isolates, 8 (53.3%) had single drug resistance, 4 (26.7%) had multidrug resistance (MDR) and 1 (6.7%) had resistance to three drugs (non-MDR). Two isolates (13.3%) were sensitive to all the four drugs. Resistance to first line anti-tuberculosis drugs was found to be higher among AIDS patients with MTB.

Correlation between baseline CD4 + T-Lymphocyte count and plasma viral load in AIDS patients and their early clinical and immunological response to HAART: a preliminary study

The aim of this study was to determine the clinical, immunological and virological status of newly diagnosed AIDS cases and to monitor their clinical and immunological response to HAART after a minimum period of three months. Forty three drug naive AIDS patients were enrolled. The most common presenting complaints were weight loss (74.4%), cough (72.1%) and diarrhoea (67.4%). Mean baseline CD4 cell count was 112 +/- 60 cells/microL and mean baseline plasma viral load of 31 patients studied was 192,686 copies/mL. Baseline plasma viral load was higher among patients with lower baseline CD4 cell count. During follow-up, 80.8% patients showed clinical improvement, while a CD4 cell count increased by > or =50 cells/microL in 84.6% cases. Mean CD4 cell count increased from 126 +/- 16.6 cells/microL at baseline to 278 +/- 196.7 cells/microL.

Vegetative tissue lectins of peanut (A. hypogaea)

Lectin activities in roots, nodules, stems and leaves of 1-6 week old peanut plant (A. hypogaea) were checked by erythrocyte (human and rabbit) agglutination and sugar inhibition assays. Human and rabbit erythrocyte agglutinating activities were specifically inhibited by lactose/cellobiose (SLII) and methyl alpha-mannoside (SLI) respectively. Seeds, embryos and cotyledons agglutinated neuraminidase treated human erythrocytes and that activity was inhibited by T-disaccharide. In the roots of field grown plants SLI was the major activity, while nodules showed both activities (SLI and SLII). Specific activities of SLI and SLII were maximal in stem tissue and hypocotyl exhibited minimal levels. Actively growing tissues like newly emerging young leaves and elongating stem contained more SLII activity in comparison to the mature tissues. Immunological test indicated that all the vegetative tissue lectins are serologically related.