Psiguanol, a novel α-pyrone derivative from Psidium guajava leaves and vasorelaxant activity in rat aorta cells through intracellular cGMP-dependent opening of calcium-activated potassium channels.

The phytochemical investigation of Psidium guajava leaves led to the isolation of total nineteen compounds which belongs to meroterpenoids, flavonoid, phenolics, and triterpenoids. The compounds were isolated using extensive chromatography techniques and identified as psiguanol (4), as new compound along with guajadial (1), psidial A (2), ß-caryophyllene (3), quercetin (5), avicularin (6), guaijaverin (7), hyperin (8), rutin (9), ursolic acid (10), corosolic acid (11), asiatic acid (12), ß-sitosterol (13), ß-sitosterol-D-glucoside (14), ellagic acid (15), 3,3',4'-trimethylellagic acid 4-O-glucoside (16), protocatechuic acid (17), gallic acid (18), and tricosanoic acid (19) as known molecules. The compound 16 was isolated for the first time from this plant. The isolated compounds were evaluated for vasorelaxation activity in rat aorta cells and it was observed that compound 4 exhibited the most potent vasorelaxation response in the ex-vivo model in isolated rat aorta cells. Mechanistically, the vasorelaxation activity of 4 was mediated through cGMP-dependent BKCa channel opening.

Dual targeted 2-Benzylideneindanone pendant hydroxamic acid group exhibits selective HDAC6 inhibition along with tubulin stabilization effect.

Abnormal epigenetics has been recognised as an early event in tumour progression and aberrant acetylation of lysine in particular has been understood in tumorigenesis. Therefore, it has become an attractive target for anticancer drug development. However, HDAC inhibitors have limited success due to toxicity and drug resistance concerns. Present study deals with design and synthesis of bivalent indanone based HDAC6 and antitubulin ligands as anticancer agents. Two of the analogues 9 and 21 exhibited potent antiproliferative activities (IC50, 0.36-3.27 µM) and high potency against HDAC 6 enzyme. Compound 21 showed high selectivity against HDAC 6 while 9 exhibited low selectivity. Both the compounds also showed microtubule stabilization effects and moderate anti-inflammatory effect. Dual targeted anticancer agents with concomitant anti-inflammatory effects will be more attractive clinical candidates in future.

Vasorelaxant property of 2-phenyl ethyl alcohol isolated from the spent floral distillate of damask rose (Rosa damascena Mill.) and its possible mechanism.

ETHNOBOTANICAL RELEVANCE: Rosa damascena Mill. (Rosaceae), commonly known as damask rose, is an ancient medicinal and perfumery plant used in Traditional Unani Medicine due to various therapeutic effects, including cardiovascular benefits. AIM OF THE STUDY: This study aimed to evaluate the vasorelaxant effect of the 2-phenyl ethyl alcohol (PEA) isolated from the spent flowers of R. damascena which remain after the extraction of essential oil. MATERIALS AND METHODS: The freshly collected flowers of R. damascena were hydro-distilled in a Clevenger's type apparatus to extract the rose essential oil (REO). After removing the REO, the spent-flower hydro-distillate was collected and extracted with organic solvents to yield a spent-flower hydro-distillate extract (SFHE), which was further purified by column chromatography. The SFHE and its isolate were characterized by gas chromatography (GC-FID), gas chromatography-mass spectrometry (GC-MS), and nuclear magnetic resonance (NMR) techniques. The PEA, isolated from SFHE, was evaluated for vasorelaxation response in conduit blood vessels like rat aorta and resistant vessels like mesenteric artery. The preliminary screening of PEA was done in aortic preparation pre-constricted with phenylephrine/U46619. Further, a concentration-dependent relaxation response to PEA has been elicited in both endothelium-intact and endothelium-denuded arterial rings, and the mode of action was explored. RESULTS: The SFHE revealed the presence of PEA as the main constituent (89.36%), which was further purified by column chromatography to a purity of 95.0%. The PEA exhibited potent vasorelaxation response both in conduit vessels like the rat aorta and resistance vessels like the mesenteric artery. The relaxation response is mediated without any involvement of vascular endothelium. Further, TEA sensitive BKCa channel was found to be the major target for PEA-induced relaxation response in these blood vessels. CONCLUSIONS: The spent flowers of R. damascena, which remain after the extraction of REO, could be used to extract PEA. The PEA possessed marked vasorelaxation properties in both aorta and mesenteric artery and showed promise for development into an herbal product against hypertension.

Chitotriosidase, a biomarker of amyotrophic lateral sclerosis, accentuates neurodegeneration in spinal motor neurons through neuroinflammation.

BACKGROUND: Cerebrospinal fluid from amyotrophic lateral sclerosis patients (ALS-CSF) induces neurodegenerative changes in motor neurons and gliosis in sporadic ALS models. Search for identification of toxic factor(s) in CSF revealed an enhancement in the level and enzyme activity of chitotriosidase (CHIT-1). Here, we have investigated its upregulation in a large cohort of samples and more importantly its role in ALS pathogenesis in a rat model. METHODS: CHIT-1 level in CSF samples from ALS (n = 158), non-ALS (n = 12) and normal (n = 48) subjects were measured using ELISA. Enzyme activity was also assessed (ALS, n = 56; non-ALS, n = 10 and normal-CSF, n = 45). Recombinant CHIT-1 was intrathecally injected into Wistar rat neonates. Lumbar spinal cord sections were stained for Iba1, glial fibrillary acidic protein and choline acetyl transferase to identify microglia, astrocytes and motor neurons respectively after 48 h of injection. Levels of tumour necrosis factor-α and interleukin-6 were measured by ELISA. FINDINGS: CHIT-1 level in ALS-CSF samples was increased by 20-fold and it can distinguish ALS patients with a sensitivity of 87% and specificity of 83.3% at a cut off level of 1405.43 pg/ml. Enzyme activity of CHIT-1 was also 15-fold higher in ALS-CSF and has a sensitivity of 80.4% and specificity of 80% at cut off value of 0.1077989 µmol/µl/min. Combining CHIT-1 level and activity together gave a positive predictive value of 97.78% and negative predictive value of 100%. Administration of CHIT-1 increased microglial numbers and astrogliosis in the ventral horn with a concomitant increase in the levels of pro-inflammatory cytokines. Amoeboid-shaped microglial and astroglial cells were also present around the central canal. CHIT-1 administration also resulted in the reduction of motor neurons. CONCLUSIONS: CHIT-1, an early diagnostic biomarker of sporadic ALS, activates glia priming them to attain a toxic phenotype resulting in neuroinflammation leading to motor neuronal death.

Structural insight into conformational dynamics of non-active site mutations in KasA: A Mycobacterium tuberculosis target protein.

The enzyme ß-Ketoacyl ACP synthase I (KasA) is a potent drug target in mycolic acid pathway of Mycobacterium tuberculosis (Mtb). In the present study, we investigated the structural dynamics of wild-type (WT) and mutants KasA (D66N, G269S, G312S, and F413L) in both monomer and dimer form to provide insight into protein structural stability. To gain better understanding of structural flexibility of KasA, combined molecular dynamics and essential dynamics were employed to analyze the conformational changes induced by non-active site mutations. The results confirm that non-active site mutations lower the structural stability in dimer KasA as compared to WT. The protein network topology and close residue interactions of WT and mutant residues of KasA have been predicted through residue interaction network analysis (RIN). Non-active site mutations distort RIN architecture and subsequently affect the drug binding landscape. T-pad associated with mode vector analysis comprehensively pronounces the structural impact caused by non-active site mutations. It also identified the critical fluctuating residues present in the gate segment (GS) region (115-147). The non-active site mutations altered the structural stability of the mutant protein structures, and these mutations may be a cause for the resistance mechanism of KasA against anti-tuberculosis drugs. Further, it is observed that dimer mutant KasA proteins display much more structural flexibility than WT at the ligand binding site which is evident from the binding site analysis and hydrogen bond interaction patterns. This study provides a better understanding of the structural dynamic behaviour of KasA mutants, thereby facilitating the need to find a novel and potent inhibitor against Mtb.

Gastrointestinal histoplasmosis: a case series from a non-endemic region in North India

No abstract available.

Purification and characterization of fibrinolytic protease from Bacillus amyloliquefaciens MCC2606 and analysis of fibrin degradation product by MS/MS.

A serine protease with preference for fibrin protein was purified and characterized from Bacillus amyloliquefaciens MCC2606, isolated from dosa batter. The protease was purified using ammonium sulfate precipitation, ion-exchange, and gel filtration chromatography. The degradation activity of the protease toward the fibrin was significantly higher compared with other protein substrates in the study. The molecular weight of the CFR15-protease was estimated to be 32 kDa based on SDS-PAGE. The purified enzyme exhibited both fibrinolytic and fibrinogenolytic activity. The optimum pH and temperature for the activity of the enzyme was found to be 10.5 and 45°C. A significant inhibition was seen with the protease inhibitors phenyl methyl sulphonyl fluoride and ethylene diamine tetra acetic acid and the activity of the enzyme was enhanced in presence of Mn2+. There was an observed increase in vitro activated partial thromboplastin time and prothrombin time of both time and dose dependent study. Among the four chains of fibrin, the ß-chain of fibrin appears to be the primary component and site susceptible for CFR15-protease in early action as indicated by MS/MS analysis of initial degradation products. These results indicated that the CFR15-protease have the potential to be an effective fibrinolytic agent.