Rhodanine-benzamides as potential hits for α-amylase enzyme inhibitors and radical (DPPH and ABTS) scavengers.

A series of 3-substituted and 3,5-disubstituted rhodanine-based derivatives were synthesized from 3-aminorhodanine and examined for α-amylase inhibitory, DPPH (1,1-diphenyl-2-picrylhydrazyl) and ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging activities in vitro. These derivatives displayed significant α-amylase inhibitory potential with IC50 values of 11.01-56.04 µM in comparison to standard acarbose (IC50 = 9.08 ± 0.07 µM). Especially, compounds 7 (IC50 = 11.01 ± 0.07 µM) and 8 (IC50 = 12.01 ± 0.07 µM) showed highest α-amylase inhibitory activities among the whole series. In addition to α-amylase inhibitory activity, all compounds also demonstrated significant scavenging activities against DPPH and ABTS radicals, with IC50 values ranging from 12.24 to 57.33 and 13.29-59.09 µM, respectively, as compared to the standard ascorbic acid (IC50 = 15.08 ± 0.03 µM for DPPH; IC50 = 16.09 ± 0.17 µM for ABTS). These findings reveal that the nature and position of the substituents on the phenyl ring(s) are crucial for variation in the activities. The structure-activity relationship (SAR) revealed that the compounds bearing an electron-withdrawing group (EWG) at para substitution possessed the highest activity. In kinetic studies, only the km value was changed, with no observed changes in Vmax, indicating a competitive inhibition. Molecular docking studies revealed important interactions between compounds and the α-amylase active pocket. Further advanced research needs to perform on the identified compounds in order to obtain potential antidiabetic agents.

Syntheses, in vitro, and in silico studies of rhodanine-based schiff bases as potential α-amylase inhibitors and radicals (DPPH and ABTS) scavengers.

A two-step reaction method was used to synthesize a series of rhodanine-based Schiff bases (2-33) that were characterized using spectroscopic techniques. All compounds were assessed for α-amylase inhibitory and radical scavenging (DPPH and ABTS) activities. In comparison to the standard acarbose (IC50 = 9.08 ± 0.07 µM), all compounds demonstrated good to moderate α-amylase inhibitory activity (IC50 = 10.91 ± 0.08-61.89 ± 0.102 µM). Compounds also demonstrated significantly higher DPPH (IC50 = 10.33 ± 0.02-96.65 ± 0.03 µM) and ABTS (IC50 = 12.01 ± 0.12-97.47 ± 0.13 µM) radical scavenging activities than ascorbic acid (DPPH, IC50 = 15.08 ± 0.03 µM; ABTS, IC50 = 16.09 ± 0.17 µM). The limited structure-activity relationship (SAR) suggests that the position and nature of the substituted groups on the phenyl ring have a vital role in varying inhibitory potential. Among the series, compounds with an electron-withdrawing group at the para position showed the highest potency. Kinetic studies revealed that the compounds followed a competitive mode of inhibition. Molecular docking results are found to agree with experimental findings, showing that compounds reside in the active pocket due to the main rhodanine moiety.

Effects of nitric oxide modulators and antioxidants on endocrine and cellular markers of acute stress in rats.

The effects of nitric oxide modulators (NO-modulators) and antioxidants on acute (RSx1) restraint stress induced endocrine, cellular and oxidative/nitrosative stress markers was studied in Wistar rats. The results of our study revealed that exposure to RS(x1) enhanced malondialdehyde (MDA), heat shock protein (HSP-70), corticosterone, nuclear factor kappa B (NF-κB) levels and suppressed glutathione (GSH), superoxide dismutase (SOD) and total nitrites and nitrates (NOx) levels. NO precursor and NO synthase inhibitors were found to differentially modulate stress mechanisms, by altering NF-κB, HSP-70 and corticosterone levels. l-Ascorbic acid significantly suppressed acute stress induced elevation of NF-κB and HSP-70 levels depicting protective effects, as also evidenced by reversal of elevated plasma corticosterone levels. Therefore, modulation of oxidative and nitrosative pathways, offers an approach in modulating stress induced changes associated with various disorders.

In Vitro Phytochemical Screening, Cytotoxicity Studies of Curcuma longa Extracts with Isolation and Characterisation of Their Isolated Compounds.

The Curcuma longa plant is endowed with multiple traditional and therapeutic utilities and is here explored for its phytochemical constituents and cytotoxic potential. Turmeric rhizomes were extracted from three different solvents and screened for the presence of different phytochemical constituents, observation of which indicated that the polar solvents favoured extraction of greater versatile phytochemical constituents. These extracts were investigated for their cytotoxic potential by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay on three different of cell lines including SCC-29B (oral cancer cell line), DU-145 (prostate cancer cell line) and the Vero cell line (healthy cell line/non-cancerous cell line). This assay was performed by taking three extracts from isolated curcuminoids and a pure bioactive compound bisdemethoxycurcumin (BD). Bisdemethoxycurcumin was isolated from curcuminoids and purified by column and thin-layer chromatography, and its structural characterisation was performed with different spectroscopic techniques such as FTIR, NMR (1H Proton and 13C Carbon-NMR) and LC-MS. Amongst the extracts, the ethanolic extracts exhibited stronger cytotoxic potential against the oral cancer cell line (SCC-29B) with an IC50value of 11.27 µg/mL, and that this was too low of a cytotoxicity against the Vero cell line. Although, curcuminoids have also shown a comparable cytotoxic potential against SCC-29B (IC50 value 16.79 µg/mL), it was not as potent against the ethanolic extract, and it was even found to be cytotoxic against healthy cell lines at a very low dose. While considering the isolated compound, bisdemethoxycurcumin, it also possessed a cytotoxic potential against the prostate cancer cell line (DU-145) (IC50 value of 93.28 µg/mL), but was quite safe for the healthy cell line in comparison to doxorubicin.

Quantification of Luteolin, Apigenin and Chrysoeriol in Tecoma stans by RP-HPLC Method.

Tecoma stans (Fam. Bignoniaceae) is also popularly known as yellow bells and yellow trumpet bush in vernacular terminology. Limited and variable data are available from the literature regarding the quantification of luteolin, apigenin and chrysoeriol, which are considered as the most active pharmacological active constituents. High-performance liquid chromatography-photodiode array detection has been developed for the determination of the bioactive flavonoids, luteolin, apigenin and chrysoeriol, from the methanolic extract of the leaves of T. stans. A column packed with a pentafluorophenyl-based stationary phase was used for the separation of the analytes under gradient elution. The detection wavelength was 345 nm. The validation of the method as per the International Council on Harmonisation (ICH) guidelines (ICH 2005) for linearity, accuracy and precision was investigated and found within limits specified by the ICH guidelines. The method was linear over with a good regression coefficient of more than 0.99. The limit of detection of the method was 0.68, 2.97 and 1.76 µg/mL for luteolin, apigenin and chrysoeriol, respectively. In conclusion, a reliable and reproducible method was devised that can be used for the estimation of the said components from T. stans.

New pyrrolopyridine-based thiazolotriazoles as diabetics inhibitors: enzymatic kinetics and in silico study.

Aim: To synthesize pyrrolopyridine-based thiazolotriazoles as a novel class of α-amylase and α-glucosidase inhibitors and to determine their enzymatic kinetics. Methodology: Pyrrolopyridine-based thiazolotriazole analogs (1-24) were synthesized and characterized through proton nuclear magnetic resonance, carbon-13 nuclear magnetic resonance and high-resolution electron ionization mass spectrometry. Results: All synthesized analogs displayed good inhibitory potential of α-amylase and α-glucosidase ranging 17.65-70.7 µM and 18.15-71.97 µM, respectively, compared with the reference drug, acarbose (11.98 µM and 12.79 µM). Analog 3 was the most potent among the synthesized analogs, having α-amylase and α-glucosidase inhibitory activity at 17.65 and 18.15 µM, respectively. The structure-activity relationship and binding modes of interactions between selected analogs were confirmed via docking and enzymatic kinetics studies. The compounds (1-24) were tested for cytotoxicity against the 3T3 mouse fibroblast cell line and were observed to be nontoxic.

Synthetic benzofuran-linked chalcones with dual actions: a potential therapeutic approach to manage diabetes mellitus.

Background: Identification of molecules having dual capabilities to reduce postprandial hyperglycemia and oxidative stress is one of the therapeutic approaches to treat diabetes mellitus. In this connection, a library of benzofuran-linked chalcone derivatives were evaluated for their dual action. Methods: A series of substituted benzofuran-linked chalcones (2-33) were synthesized and tested for α-amylase inhibitory as well as 2,2-diphenylpicrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging activities. Results: All compounds showed α-amylase inhibitory activity ranging from IC50 = 12.81 ± 0.03 to 87.17 ± 0.15 µM, compared with the standard acarbose (IC50 = 13.98 ± 0.03 µM). Compounds also demonstrated radical scavenging potential against DPPH and ABTS radicals. Conclusion: The identified compounds may serve as potential leads for further advanced research.

Design, synthesis and bio-evaluation of indolin-2-ones as potential antidiabetic agents.

Background: Diabetes mellitus is a serious global health concern, and this is expected to impact more than 300 million people by 2025. The current study focuses on identifying substituted indolin-2-one-based inhibitors for two indispensable drug targets, α-amylase and α-glucosidase. Methods: The structures of synthetic compounds were confirmed by spectroscopic techniques and evaluated for enzyme inhibition activities. Kinetic and in silico studies were also performed. Results: All compounds exhibited good-to-moderate inhibitory potential. Most importantly, compounds 1, 2, 6, 16 and 17 were identified as potent α-glucosidase inhibitors (IC50 = 9.15 ± 0.12-13.74 ± 0.12 µM). Conclusion: This study identified that these synthetic compounds might serve as potential lead molecules for antidiabetic agents.

Target-based virtual screening and molecular interaction studies for lead identification of natural olive compounds against glioblastoma multiforme.

Glioblastoma multiforme, a rare traumatic brain disorder, is at the research climax for its uncontrolled growth leading to a catastrophic outcome. Throwing light on the target-based virtual screening of drugs using natural phytocompounds is a striking cornerstone in glioblastoma-based drug discovery, accelerating with leaps and bounds. This project aims to develop promising lead compounds against glioblastoma brain cancer using OliveNet™, an open-source database. In this pursuit, our rationale for selecting molecules was based on their capability to pass through the blood-brain barrier. Out of 51 derivative molecules from flavonoids and polyphenols, 17 molecules were screened out bearing the best ADMET (absorption, distribution, metabolism, excretion, and toxicity) properties, alongside fulfilling our rationale of lead selection. Two polyphenols, 3,4,5-trimethoxybenzoic acid and 4-ethyl guaiacol, have binding affinity for the antioxidant flavonoid luteolin of -5.1 and -4.3 kcal/mol, respectively. According to docking studies, the residues ASN1960, ASN1966, ASN1960, PHE1984, TYR1896, VAL1911, and LYS1966 make both polar and nonpolar interactions with 3,4,5-trimethoxybenzoic acid and 4-ethylguanidine, respectively. LD50 values of toxicity screening using TOX Pro brought to limelight the excellent safety profile of polyphenols and flavonoids. Furthermore, studies using in silico cytotoxicity prediction and molecular modelling have decisively shown that these polyphenols are likely to be effective brain cancer inhibitors and promising future lead candidates against glioblastoma multiforme.

"Cutting the Mustard" with Induced Pluripotent Stem Cells: An Overview and Applications in Healthcare Paradigm.

Treatment of numerous ailments has been made accessible by the advent of genetic engineering, where the self-renewal property has unfolded the mysteries of regeneration, i.e., stem cells. This is narrowed down to pluripotency, the cell property of differentiating into other adult cells. The generation of induced pluripotent stem cells (iPSCs) was a major breakthrough in 2006, which was generated by a cocktail of 4 Yamanaka Factors, following which significant advancements have been reported in medical science and therapeutics. The iPSCs are reprogrammed from somatic cells, and the fascinating results focused on developing authentic techniques for their generation via molecular reprogramming mechanisms, with a plethora of molecules, like NANOG, miRNAs, and DNA modifying agents, etc. The iPSCs have exhibited reliable results in assessing the etiology and molecular mechanisms of diseases, followed by the development of possible treatments and the elimination of risks of immune rejection. The authors formulate a comprehensive review to develop a clear understanding of iPSC generation, their advantages and limitations, with potential challenges associated with their medical utility. In addition, a wide compendium of applications of iPSCs in regenerative medicine and disease modeling has been discussed, alongside bioengineering technologies for iPSC reprogramming, expansion, isolation, and differentiation. The manuscript aims to provide a holistic picture of the booming advancement of iPSC therapy, to attract the attention of global researchers, to investigate this versatile approach in treatment of multiple disorders, subsequently overcoming the challenges, in order to effectively expand its therapeutic window.

"Aducanumab" making a comeback in Alzheimer's disease: An old wine in a new bottle.

Despite presence of substantial evidence suggesting the pivotal role of amyloid (Aß) in Alzheimer's disease (AD), very few therapeutic agents have been able to ameliorate the disease. This paved the way for the discovery of antibody-based immunotherapy to ace Aß clearance and curb neuronal toxicity, resulting in revival of aducanumab, which following its entry into the brain, interacts with the parenchymal amyloid and decreases Aß concentration, in a dose-dependent manner. However, the surprising approval from the FDA has created a controversy among healthcare professionals, due to Alzheimer's related imaging abnormality (ARIA) and hypersensitivity, serving as backlogs in its acceptance. Therefore, aducanumab is recognised as being "risen from the grave", accompanied with contrasting statements within the healthcare paradigm. The manuscript provides a collection of data, aiming to elucidate, both the commendable and critical faces, simultaneously intending to gain the attention of the global researchers towards the possibility of disease-modifying therapy in AD. The manuscript discusses the failure of anti-amyloid therapies in AD, that have accelerated the need to find a suitable therapeutic approach, followed by the discussion of timeline and impact of aducanumab in AD models, alongside the controversial judgement raising significant question. Besides, the authors throw some light on the onco-therapeutic implications of the drug approval, which is identified as a significant consequence of the event. The text provides a holistic picture of the drug action, and enlists the considerations for the future, that might be beneficial to both the acceptance of the drug, and the treatment of the disease.