Edited by Vladimir SkulachevKeywords: Aldo-keto reductase ALR2 AKR1B10 Curcumin Sorbitol a b s t r a c t Accumulation of intracellular sorbitol due to increased aldose reductase (ALR2) activity has been implicated in the development of various secondary complications of diabetes. In this study we show that curcumin inhibits ALR2 with an IC 50 of 10 lM in a non-competitive manner, but is a poor inhibitor of closely-related members of the aldo-keto reductase superfamily, particularly aldehyde reductase. Results from molecular docking studies are consistent with the pattern of inhibition of ALR2 by curcumin and its specificity. Moreover, curcumin is able to suppress sorbitol accumulation in human erythrocytes under high glucose conditions, demonstrating an in vivo potential of curcumin to prevent sorbitol accumulation. These results suggest that curcumin holds promise as an agent to prevent or treat diabetic complications.

In the present study, a series of novel pyrazole‐thiazole hybrids (4a‐l) were designed, synthesized and assessed for their in vitro antimicrobial activity against both Gram‐positive and Gram‐negative pathogenic bacterial and fungal strains. Compounds derived from p‐CH3 phenyl (4b), p‐Br phenyl (4g), 8‐bromocoumarinyl (4k), and 6,8‐dibromocoumarinyl (4l) exhibited promising inhibitory activity against the tested bacterial strains with minimum inhibitory concentration (MIC)/minimum bactericidal concentration (MBC) spectrum of 1.9/7.8 μg/mL to 3.9/7.8 μg/mL. The compounds with p‐CH3 phenyl (4b), p‐OCH3 phenyl (4c), benzo[f]coumarinyl (4j), 8‐bromocoumarinyl (4k) substitutions showed their inhibitory potency against various Candida strains with MIC/minimum fungicidal concentration (MFC) values of 3.9/7.8 μg/mL. Also, anti‐biofilm and toxicity profile of the compounds was also tested. The biofilm inhibition results revealed that the compound 4 j exhibited promising activity with an IC50 value of 11.8 μM against S. aureus MTCC 96, while 4 k showed significant activity against S. aureus MLS16 MTCC 2940, K. planticola MTCC 530 and C. albicans MTCC 3017 with IC50 values of 12, 14 and 16 μM, respectively. The present study has emphasized that thiazole‐pyrazole hybrids with benzothiazole and coumarin scaffolds can be a novel and potent class of molecules with potential biological activities.

Staphylococcus aureus is a serious causative agent of infectious disease. Multidrug-resistant strains like methicillin-resistant S. aureus compromise treatment efficacy, causing significant morbidity and mortality. Active efflux represents a major antimicrobial resistance mechanism. The proton-driven multidrug efflux pump, LmrS, actively exports structurally distinct antimicrobials. To circumvent resistance and restore clinical efficacy of antibiotics, efflux pump inhibitors are necessary, and natural edible spices like cumin are potential candidates. The mode of cumin antibacterial action and underlying mechanisms behind drug resistance inhibition, however, are unclear. We tested the hypothesis that cumin inhibits LmrS drug transport. We found that cumin inhibited bacterial growth and LmrS ethidium transport in a dosage-dependent manner. We demonstrate that cumin is antibacterial toward a multidrug-resistant host and that resistance modulation involves multidrug efflux inhibition.

Study DesignDevelopment of an in vitro model for assessing the anti-inflammatory efficacies of naringin (Nar) and naringenin (NG).PurposeTo evaluate the efficacy of natural flavonoids as therapeutic drugs against anti-inflammatory processes in the nucleus pulposus (NP) cells using in-vitro and in-silico methods.Overview of LiteratureIntervertebral disc (IVD) disease is a common cause of low back pain. Chronic inflammation and degeneration play a significant role in its etiopathology. Thus, a better understanding of anti-inflammatory agents and their role in IVD degeneration and pro-inflammatory cytokines expression is necessary for pain management and regeneration in IVD.MethodsWe performed primary cell culture of NP cells; immunocytochemistry; gene expression studies of cytokines, metalloproteases, extracellular proteins, and apoptotic markers using quantitative polymerase chain reaction and reverse transcription-polymerase chain reaction (RT-PCR); cytotoxicity assay (MTT); and molecular docking studies using AutoDock 4.2 software (Molecular Graphics Laboratory, La Jolla, CA, USA) to confirm the binding mode of proteins and synthesized complexes. We calculated the mean±standard deviation values and performed analysis of variance and t-test using SPSS ver. 17.0 (SPSS, Inc., Chicago, IL, USA).ResultsMolecular docking showed that both Nar and NG bind to the selected genes of interest. Semi-quantitative RT-PCR analysis reveals differential gene expression of collagen (COL)9A1, COL9A2, COL9A3, COL11A2, COMT (catechol-O-methyltransferase), and THBS2 (thrombospondin 2); up regulation of ACAN (aggrecan), COL1A1, COL11A1, interleukin (IL)6, IL10, IL18R1, IL18RAP, metalloprotease (MMP)2, MMP3, MMP9, ADAMTS5 (a disintegrin and metalloproteinase with thrombospondin motifs 5), IGF1R (insulin-like growth factor type 1 receptor), SPARC (secreted protein acidic and cysteine rich), PARK2 (parkin), VDR (vitamin D receptor), and BCL2 (B-cell lymphoma 2); down regulation of IL1A, CASP3 (caspase 3), and nine genes with predetermined concentrations of Nar and NG.ConclusionsThe present study evaluated the anti-inflammatory and regenerative efficiencies of Nar and NG in degenerated human NP cells. Altered gene expressions of cytokines, metalloproteases, extracellular proteins, apoptotic genes were dose responsive. The molecular docking (in silico) studies showed effective binding of these native ligands (Nar and NG) with genes identified as potent inhibitors of inflammation. Thus, these natural flavonoids could serve as anti-inflammatory agents in the treatment of low back pain and sciatica.

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