An Update on Recent Advances for the Treatment of Cerebral Malaria.

Among all the parasitic diseases in humans, malaria is the most significant and malicious one. The widespread species are Plasmodium falciparum and Plasmodium vivax, but the infection caused by the former is the deadliest. According to the November 2018 report of the World Health Organization (WHO), a total of 219 million cases of malaria were reported globally in 2017, which led to an estimated 435,000 deaths. Mortality due to malaria is estimated at 1.5 - 2.7 million deaths each year. Among all the complications associated with Plasmodium falciparum infection, cerebral malaria (CM) is the most fretful, accounting for almost 13% of all malaria-related deaths. CM is a medical emergency that requires immediate clinical testing and treatment. A compromised microcirculation, with sequestration of parasitized erythrocytes, is central in the disease pathology. No effective therapeutic agents are available yet for the treatment of CM, and therefore, potential interventions are needed to be developed urgently. The currently available anti-malarial drugs lack lipophilicity and are thus not able to reach the brain tissues. Therefore, safe, cost-effective agents with improved lipophilicity possessing the potential to target brain tissues are needed to be searched in order to fight CM worldwide. The aim of present review is to systematically revise the published research work available concerning the development and evaluation of some potential drug targets in the management of CM.

3D QSAR studies on 1, 3, 4-thiadiazole derivatives: an approach to design novel anticonvulsants.

A three-dimensional quantitative structure-activity relationship (3D-QSAR) study was performed on a series of 1, 3, 4-thiadiazole derivatives reported as anticonvulsant employing self-organizing molecular field analysis (SOMFA) techniques to investigate the structural requirements for the design of novel anticonvulsant. The training set composed of twenty two 1, 3, 4-thiadiazole derivatives that exhibit a potent activity in MMS test while predictive power was evaluated using a test set of 7 molecules. Physicochemical determinants of binding, such as steric and electrostatic properties, were mapped onto the molecular structures of 1, 3, 4-thiadiazole in order to interpret graphically the SOMFA results in terms of master grids showing various field contributions. The present 3D-QSAR studies yielded stable and statistically robust models indicated by the moderate cross correlation coefficients which may prove to be a guideline for design of novel anticonvulsants.

Sulphonamides as inhibitors of protein tyrosine phosphatase 1B: a three-dimensional quantitative structure-activity relationship study using self-organizing molecular field analysis approach.

Protein tyrosine phosphatase 1B (PTP 1B), a cytosolic PTP involved in down-regulation of receptor tyrosine kinase activity following stimulation of the insulin or leptin receptors. Thus, PTP 1B inhibitors could potentially ameliorate insulin resistance and normalize plasma glucose and insulin levels without inducing hypoglycemia, and could therefore be a major advancement in the treatment of type 2 diabetes. A three-dimensional quantitative structure-activity relationship (3D-QSAR) study has been performed on a novel class of sulphonamides using self-organizing molecular field analysis (SOMFA) to correlate their chemical structures with their observed PTP 1B inhibitory activities. The master grid obtained for the various SOMFA models indicates electrostatic and shape potential contributions that can be mapped back onto structural features relating to the trends in inhibitory activities. On the basis of the spatial arrangement, steric and electrostatic factors should appropriately be taken into account for development of new potent inhibitors of PTP 1B for the management of type 2 diabetes.

Saxagliptin: a new drug for the treatment of type 2 diabetes.

Saxagliptin (BMS-477118) has been recently FDA approved drug for the management of T2DM developed by Bristol-Myers Squibb and AstraZeneca under the trade name Onglyza. Saxagliptin is a nitrile-containing selective, potent, reversible and durable DPP IV inhibitor developed as an alternative second-line adds on to Metformin in place of a sulphonylurea. Saxagliptin increases and prolongs the action of incretin hormones by inhibiting the DPP IV enzyme that inactivates incretins usually within minutes. Saxagliptin is well absorbed and has low plasma protein binding and displays slow-binding properties to DPP IV. Saxagliptin is metabolized in vivo to form an active metabolite (BMS-510849), which is twofold less potent than the parent molecule. The X-ray crystallography revealed that Saxagliptin is covalently bound to the DPP IV active site. In drug-native patients with T2DM and inadequate glycemic control, once-daily Saxagliptin monotherapy for 24 wks demonstrated clinically meaningful with no weight gain and generally well tolerated.

3D-QSAR studies on a series of 5-arylidine-2, 4-thiazolidinediones as aldose reductase inhibitors: a self-organizing molecular field analysis approach.

Aldose Reductase (AR), the key enzyme of the polyol pathway catalyzes the reduction of glucose to sorbitol using nicotinamide adenine dinucleotide phosphate as an essential cofactor, has been demonstrated to play an important role in the pathogenesis of diabetic complications. Self Organizing Molecular Field Analysis (SOMFA), a novel three-dimensional quantitative structure activity relationship (3D-QSAR) method has been used in present case to study the correlation between the molecular properties and the aldose reductase inhibitory activities on a series of 5-arylidine-2, 4-thiazolidinedione. SOMFA calculations for both shape and electrostatic potentials were carried out. The master grid maps derived from the best model has been used to display the contribution of electrostatic potential and shape molecular field. The statistical results showed good cross-validated r(2)(CV), non cross-validated r(2), F-test set and significant predictive ability indicated by r(2)(pred). All analysis of SOMFA model may provide useful information in the design of new aldose reductase inhibitors with improved spectrum of activity for management of diabetic complications.

Hypolipidemic effect of ethanolic extract from the leaves of Hibiscus sabdariffa L. in hyperlipidemic rats.

The present study is designed to investigate the hypolipidemic effect of ethanolic extract from the leaves of Hibiscus sabdariffa L. (HSEE) in hyperlipidemic rats. In the present work, HSEE was evaluated at three doses (i.e. 100, 200 and 300 mg/kg, orally) in cholesterol-induced (2 g/kg, orally) hyperlipidemic Wistar rats. Atorvastatin (10 mg/kg, orally) was used as the standard drug. Administration of HSEE (200 mg/kg and 300 mg/kg) together with continuous cholesterol feeding for four weeks showed significant reduction in serum cholesterol level by 18.5% and 22%, respectively (p < 0.05); serum triglyceride level by 15.6% and 20.6%, respectively (p < 0.05); serum LDL level by 24% and 30%, respectively (p < 0.05), and serum VLDL level by 15.5% and 20.5%, respectively (p < 0.05), as compared to cholesterol group. However, no significant change in HDL level was observed. HSEE 300 mg/kg was more effective than HSEE 200 mg/kg dose but less effective than the standard drug, atorvastatin. HSEE 100 mg/kg did not show any significant reduction in lipid levels. These results indicate that HSEE exhibit the hypolipidemic effect and among all HSEE groups investigated, HSEE 300 mg/kg has the best hypolipidemic effect.

3D-QSAR Studies on a Series of 5-Arylidine-2, 4-Thiazolidinediones as Aldose Reductase Inhibitors: A Self-Organizing Molecular Field Analysis Approach.

Aldose Reductase (AR), the key enzyme of the polyol pathway catalyzes the reduction of glucose to sorbitol using nicotinamide adenine dinucleotide phosphate as an essential cofactor, has been demonstrated to play an important role in the pathogenesis of diabetic complications. Self Organizing Molecular Field Analysis (SOMFA), a novel three-dimensional quantitative structure activity relationship (3D-QSAR) method has been used in present case to study the correlation between the molecular properties and the aldose reductase inhibitory activities on a series of 5-arylidine-2, 4-thiazolidinedione. SOMFA calculations for both shape and electrostatic potentials were carried out. The master grid maps derived from the best model has been used to display the contribution of electrostatic potential and shape molecular field. The statistical results showed good cross-validated r(2)(CV), non cross-validated r(2), F-test set and significant predictive ability indicated by r(2)(pred). All analysis of SOMFA model may provide useful information in the design of new aldose reductase inhibitors with improved spectrum of activity for management of diabetic complications.

Self-organizing molecular field analysis on pregnane derivatives as human steroidal 5alpha-reductase inhibitors.

Normal growth and development of human prostate is regulated by the androgens which balances cell proliferation and apoptosis. Testosterone (T) and dihydrotestosterone (DHT) are the two key androgens that stimulate most of the androgen action in prostate. Testosterone is converted to DHT by the membrane bound NADPH-dependent 5alpha-reductase enzyme. As a consequence of the important observation that progesterone and deoxycortisone inhibits the synthesis of DHT by competing with 4-en-3-one function of the testosterone for the 5alpha-reductase enzyme a number of pregnane derivatives were synthesized and have been reported as inhibitors of human 5alpha-reductase enzyme. Due to lack of information on the crystal structure of human 5alpha-reductase, ligand-based 3D-QSAR study has been performed on pregnane derivatives using self-organizing molecular field analysis (SOMFA) for rationalizing the molecular properties and human 5alpha-reductase inhibitory activities. The statistical results having good cross-validated r(cv)(2) (0.881), non-cross-validated r(2) (0.893) and F-test value (175.527), showed satisfied predictive ability r(pred)(2) (0.777). Analysis of SOMFA models through electrostatic and shape grids provide useful information for the design and optimization of steroidal structure as novel human 5alpha-reductase inhibitors.

An overview on 5alpha-reductase inhibitors.

Benign prostatic hyperplasia (BPH) is the noncancerous proliferation of the prostate gland associated with benign prostatic obstruction and lower urinary tract symptoms (LUTS) such as frequency, hesitancy, urgency, etc. Its prevalence increases with age affecting around 70% by the age of 70 years. High activity of 5alpha-reductase enzyme in humans results in excessive dihydrotestosterone levels in peripheral tissues and hence suppression of androgen action by 5alpha-reductase inhibitors is a logical treatment for BPH as they inhibit the conversion of testosterone to dihydrotestosterone. Finasteride (13) was the first steroidal 5alpha-reductase inhibitor approved by U.S. Food and Drug Administration (USFDA). In human it decreases the prostatic DHT level by 70-90% and reduces the prostatic size. Dutasteride (27) another related analogue has been approved in 2002. Unlike Finasteride, Dutasteride is a competitive inhibitor of both 5alpha-reductase type I and type II isozymes, reduced DHT levels >90% following 1 year of oral administration. A number of classes of non-steroidal inhibitors of 5alpha-reductase have also been synthesized generally by removing one or more rings from the azasteroidal structure or by an early non-steroidal lead (ONO-3805) (261). In this review all categories of inhibitors of 5alpha-reductase have been covered.