Rajeev K Singla

Vasorelaxant and antihypertensive effect of Cocos nucifera Linn. endocarp on isolated rat thoracic aorta and DOCA salt-induced hypertensive rats

ETHNOPHARMACOLOGICAL RELEVANCE The fruits of Cocos nucifera Linn. (Arecaceae) have long been used in traditional medicine for the treatment of cardio-metabolic disorders. AIM OF THE STUDY To evaluate the ethanolic extract of Cocos nucifera Linn. endocarp (CNE) for its vasorelaxant activity on isolated rat aortic rings and antihypertensive effects in deoxycorticosterone acetate (DOCA) salt-induced hypertensive rats. MATERIALS AND METHODS Cocos nucifera Linn. endocarp was extracted with ethanol and characterized by HPLC. CNE was examined for its in vitro vascular relaxant effects in isolated norepinephrine, phenylephrine or potassium chloride pre-contracted aortic rings (both intact endothelium and denuded). In vivo anti-hypertensive studies were conducted in DOCA salt-induced uninephrectomized male Wistar rats. RESULTS Removal of endothelium or pretreatment of aortic rings (intact endothelium) with l-NNA (10μM) or ODQ (10 μM) followed by addition of contractile agonists prior to CNE significantly blocked the CNE-induced relaxation. Indomethacin (10μM) and atropine (1 μM) partially blocked the relaxation, whereas glibenclamide (10 μM) did not alter it. CNE significantly reduced the mean systolic blood pressure in DOCA salt-induced hypertensive rats (from 185.3 ± 4.7 mmHg to 145.6±6.1 mmHg). The activities observed were supported by the polyphenols, viz. chlorogenic acid, vanillic acid and ferulic acid identified in the extract. CONCLUSIONS These findings reveal that the vasorelaxant and antihypertensive effects of CNE, through nitric oxide production in a concentration and endothelium-dependent manner, is due to direct activation of nitric oxide/guanylate cyclase pathway, stimulation of muscarinic receptors and/or via cyclooxygenase pathway.

Current Updates on Oxazolidinone and Its Significance

Oxazolidinone is a five-member heterocyclic ring exhibiting potential medicinal properties with preferential antibacterial activity. Scientists reported various synthetic procedures for this heterocyclic structure. Current review articles tried to cover each and every potential aspect of oxazolidinone like synthetic routes, pharmacological mechanism of action, medicinal properties, and current research activities.

QSAR model for predicting the fungicidal action of 1,2,4-triazole derivatives against Candida albicans

QSAR analysis of a series of previously synthesised 1-(1H-1,2,4-triazole-1-yl)-2-(2,4-difluorophenyl)-3-substituted-2-propanols(TDFPP) as analogues of fluconazole were tested for growth inhibitory activity against Candida albicans using computer assisted multiple regression analysis. This was in order to explore the selectivity requirements for fungicidal activity against C. albicans among these congeners. A training set comprising 40 analogues and a test set comprising ten analogues of 1-(1H-1, 2, 4-triazole-1-yl)-2-(2,4-difluorophenyl)-3-substituted-2-propanols were selected for the present investigation by using the sphere exclusion method embedded in the Vlife MDS 3.5 software. With respect to the modelling of the growth inhibitory activity of the reported compounds, the regression analysis shows that even in the mono-parametric correlations the topological and physicochemical parameters give significant regression coefficients. The validation of the QSAR models was performed by cross-validation and external test set prediction. The model is not only able to predict the activity of new compounds but also explains the important region in the molecules in a quantitative manner.

Antihyperlipidemic potential of Albizia amara (Roxb) Boiv. bark against Triton X-100 induced hyperlipidemic condition in rats

Background: The plant Albizia amara (Roxb.) Boiv. bark was used in traditional medical practices of India to treat cardiovascular diseases. Hyperlipidemia is the greatest risk factor of coronary heart disease. Objective: The objective of this study was to screen the potential of A. amara against the condition of hyperlipidemia in rats. Materials and Methods: The antihyperlipidemic activity of A. amara ethanolic extract (AAEE) was studied on Triton X-100 induced model of hyperlipidemia in rats. Hyperlipidemia in experimental rats was evidenced by an enhancement in the levels of serum cholesterol, triglycerides (TGs), low density lipoprotein (LDL), very LDL (VLDL) and decrease in high density lipoprotein (HDL). Results: AAEE showed significant antihyperlipidemic effect by lowering the serum levels of biochemical parameters such as a significant reduction in the level of serum cholesterol, TG (104.1 ± 3.39), LDL (48.2 ± 2.19), VLDL (20.81 ± 0.67) and increase in HDL (47.25 ± 2.05) level with an increase in a dose of AAEE (41.39 ± 1.24) < (47.25 ± 2.05), which was similar to the standard drug atorvastatin. The results of serum glutamate oxaloacetate transaminase and serum glutamate pyruvate transaminase also revealed that the plant extract was found to be safe on liver. Histopathological evaluation also revealed the positive effect of the plant extract. Preliminary phytochemical analysis revealed the presence of phytoconstituents such as saponins, glycosides and tannins. The preliminary chemical constituents stood as a strong evidence for the study. Conclusion: Summing up the evidences of the pragmatic study, we can conclude that the extract of A. amara (Roxb.) Boiv. Bark aids in declining the condition of hyperlipidemia in rats.

Antitrypanosomal Activity & Docking Studies of Isolated Constituents from the Lichen Cetraria islandica: Possibly Multifunctional Scaffolds

Chemical investigation of the lichen Cetraria islandica has led to the isolation of four compounds identified as protolichesterinic acid, lichesterinic acid, protocetraric acid and fumarprotocetraric acid. Their structures were characterized using their physical and spectroscopic data. Using an Alamarblue™ 96 well microplate assay, these compounds were tested to evaluate their trypanocidal activity against Trypanosoma brucei brucei. Protolichesterinic acid (MIC = 6.30 µM) and lichesterinic acid (MIC = 12.5 µM) showed very significant activity against the test organism. Docking studies (GRIP technique) of these molecules revealed their strong affinity towards possible targets of Trypanosoma brucei such as riboflavin kinase, sterol-14α-demethylase (CYP51), rohedsain and glutathione synthetase. Hydrophobicity played a significant role in their antitrypanosomal activity.

Exploration of natural enzyme inhibitors with hypoglycemic potentials amongst Eucalyptus Spp. by in vitro assays.

AIM To investigate the presence and potency of natural enzyme inhibitors with hypoglycemic potentials amongst Eucalyptus Spp. by in vitro assays. METHODS The leaf extracts of the three different Eucalyptus species [E. globulus (EG), E. citriodora (EC), E. camaldulensis (ECA)] were subjected to in vitro assay procedures to explore the prevalence of natural enzyme inhibitors (NEIs) after preliminary qualitative and quantitative phytochemical evaluations, to study their inhibitory actions against the enzymes like α-amylase, α-glucosidase, aldose reductase, angiotensin converting enzyme and dipeptidyl peptidase 4 playing pathogenic roles in type 2 diabetes. The antioxidant potential and total antioxidant capacity of the species were also evaluated. RESULTS Major bioactive compounds like polyphenols (341.75 ± 3.63 to 496.85 ± 3.98) and flavonoids (4.89 ± 0.01 to 7.15 ± 0.02) were found in appreciable quantity in three species. Based on the IC50 values of the extracts under investigation, in all assays the effectivity was in the order of EG > ECA > EC. The results of the ferric reducing antioxidant power assay showed that the reducing ability of the species was also in the order of EG > ECA > EC. A strong correlation (R(2) = 0.81-0.99) was found between the phenolic contents and the inhibitory potentials of the extracts against the targeted enzymes. CONCLUSION These results show immense hypoglycemic potentiality of the Eucalyptus Spp. and a remarkable source of NEIs for a future phytotherapeutic approach in Type 2 diabetes.

Antitrypanosomal Activity & Docking Studies of Components of Crateva adansonii DC Leaves: Novel Multifunctional Scaffolds

Chemical investigation of Crateva adansonii DC has led to the isolation of aurantiamide acetate, a novel ethyl pyropheophorbide A, purpurin-18 ethyl ester and pyropheophorbide A. Their structures were elucidated using extensive spectral data. These metabolites were then evaluated for their in vitro bioactivity against the African trypanosome Trypanosoma brucei brucei (S427) blood stream forms. Anti-trypanosomal activity decreased with aurantiamide acetate (MIC 25µM), while it increased with the pheopytins (MIC 6.25µM), when compared to the standard drug Suramin. Using the Vlife MDS 4.3 - GRIP docking, these phytoconstituents were then tested to identify the proteins targeted and the mode of activity employed. Their affinity towards the receptor sites of trypanothione reductase, riboflavin kinase, rohedsain, glutathione synthetase & sterol-14α-demethylase (CYP51) of Trypanosoma brucei were evaluated according to the resulting docking energies.

Isolation and Characterization of Phytoconstituents from the Stems of Ichnocarpus frutescens

Abstract Aim To study the chemical constituents of the stem part of Ichnocarpus frutescens . Methods The ethanolic extract of Ichnocarpus frutescens was used for the isolation of chemical constituents with the help of silica gel G and Sephadex column chromatography and their structures were elucidated on the basis of spectral data and chemical methods. Results Five compounds were isolated and identified as n -butyl oleate ( 1 ), n -octyl tetracontane ( 2 ), tetratriacontadiene ( 3 ), n -nonadecanyl benzoate ( 4 ), and benzocosanyl arachidate ( 5 ). Conclusion Compound 5 is new; and compounds 1 – 4 are isolated from genus Ichnocarpus frutescens for the first time.

Analytical Methods for the Assessment of Maillard Reactions in Foods

The aim of this chapter is to give a reliable overview of analytical methods for the quantitative and qualitative evaluation of Maillard reaction products in foods during processing and storage steps. At present, the importance of Maillard reactions in food processing is correlated with the appearance of sensorial alterations in foods: colours, flavours, and odours can be seriously compromised. Maillard reaction-related modifications may be a distinctive advantage in certain foods. On the other side, the attention of researchers in the area of public health is often focused on safety aspects of selected molecules or classes of substances such as furfurals, furosine, 3-deoxyglucosone, and other chemicals such as acrylamide. This chapter describes the Maillard reaction in detail. Moreover, many problems concerning the real comprehension of this group of chemical reactions depend on the peculiarity of analysed food products and analyte features. As a result, the choice of the ‘right’ analytical procedure should take into account these aspects related to peculiar analytes: a brief introduction to the problem is presented here.

Insights on the Antioxidant Potential of 1, 2, 4-Triazoles: Synthesis, Screening & QSAR Studies

The aligned manuscript reports synthesis, screening and QSAR analysis of twenty six 1, 2, 4-triazole analogues from their respective aromatic carboxylic acids. The structures of synthesized analogues were characterized using physical and spectral analysis. 1, 2, 4-Triazole analogs antioxidant capacity was determined using DPPH radical scavenging assay. Results revealed that out of L, T & VRT series, VRT series of 1, 2, 4-triazoles have significant antioxidant activities when compared with standard ascorbic acid. To obtain structural insights for development of new antioxidants a 2D-QSAR analysis of this dataset of 26 molecules was performed. The 2D-QSAR models correlate with the in vitro results and explain the salient structural features predominant in the molecules responsible for antioxidant activity.