Pyrrole-based inhibitors of RND-type efflux pumps reverse antibiotic resistance and display anti-virulence potential.

Efflux pumps of the resistance-nodulation-cell division (RND) superfamily, particularly the AcrAB-TolC, and MexAB-OprM, besides mediating intrinsic and acquired resistance, also intervene in bacterial pathogenicity. Inhibitors of such pumps could restore the activities of antibiotics and curb bacterial virulence. Here, we identify pyrrole-based compounds that boost antibiotic activity in Escherichia coli and Pseudomonas aeruginosa by inhibiting their archetype RND transporters. Molecular docking and biophysical studies revealed that the EPIs bind to AcrB. The identified efflux pump inhibitors (EPIs) inhibit the efflux of fluorescent probes, attenuate persister formation, extend post-antibiotic effect, and diminish resistant mutant development. The bacterial membranes remained intact upon exposure to the EPIs. EPIs also possess an anti-pathogenic potential and attenuate P. aeruginosa virulence in vivo. The intracellular invasion of E. coli and P. aeruginosa inside the macrophages was hampered upon treatment with the lead EPI. The excellent efficacy of the EPI-antibiotic combination was evidenced in animal lung infection and sepsis protection models. These findings indicate that EPIs discovered herein with negligible toxicity are potential antibiotic adjuvants to address life-threatening Gram-negative bacterial infections.

Synthesis, biological evaluation and computational studies of acrylohydrazide derivatives as potential Staphylococcus aureus NorA efflux pump inhibitors.

The NorA efflux pump decreases the intracellular concentration of fluoroquinolones (ciprofloxacin, norfloxacin) by effluxing them from Staphylococcus aureus cells. The synthesis of novel acrylohydrazide derivatives was achieved using well-known reactions and were characterized by various spectroscopy techniques. The synthesized 50 compounds were evaluated for the NorA efflux pump inhibition activity against S. aureus SA-1199B (norA++) and K1758 (norA-) strains. The study provided two most active compounds viz. 19 and 52. Compound 19 was found to be most active in potentiating effect of norfloxacin and also it showed enhanced uptake, efflux inhibition in ethidium bromide assay. Further compound 19 also enhanced post antibiotic effect and reduced mutation prevention concentration of norfloxacin. The homology modeling study was performed to elucidate three-dimensional structure of NorA. Docking studies of potent molecules were done to find the binding affinity and interaction with active site residues. Further, all the tested compounds exhibited good ADME and drug-likeness properties in- silico. Based on the in-silico studies and detailed in vitro studies, acrylohydrazides derivatives may be considered as potential NorA EPI candidates.

MsrA Efflux Pump Inhibitory Activity of Piper cubeba L.f. and its Phytoconstituents against Staphylococcus aureus RN4220.

MsrA, an efflux pump belonging to ATP-binding cassette (ABC) transporter family that conferred resistance to macrolides, was detected in Staphylococcus aureus strains. Herein, we report the isolation of phytoconstituents from Piper cubeba fruit methanol extract and investigated their efflux pump inhibitory potential against S. aureus MsrA pump. Four isolated compounds, viz. pellitorine, sesamin, piperic acid and tetrahydropiperine studied in combination with erythromycin in S. aureus RN4220, exhibited 2-8-fold reduction in minimum inhibitory concentration (MIC) of erythromycin. Pellitorine and sesamin decreased MIC of erythromycin by 8-fold. The real-time fluorometry-based efflux and accumulation studies of ethidium bromide (EtBr) on S. aureus RN4220 in the presence of these compounds showed reduced efflux and enhanced uptake, thus indicating inhibition of the efflux pump. Pellitorine showed significant post-antibiotic effect of erythromycin. The results revealed that the primary mechanism of action of these compounds involves steady ATP production impairment.

Pyrazole-coumarin and pyrazole-quinoline chalcones as potential antitubercular agents.

Pyrazole, coumarin, and quinoline are medicinally important moieties. In this study, two series of novel pyrazole-coumarin chalcones and pyrazole-quinoline chalcones were synthesized using multiple-step reactions. All the synthesized compounds were well characterized using different spectroscopic techniques including 1 H and 13 C nuclear magnetic resonance, high-resolution mass spectroscopy, and electrospray ionization-mass spectrometry. The compounds were evaluated for their antitubercular activity against the Mycobacterium tuberculosis H37Rv strain using the microplate Alamar Blue assay, and the minimal inhibitory concentrations (MIC) of the compounds were determined. Among the 32 tested compounds, compounds 3e, 3u, and 7h showed an MIC value of 3.125 µg/ml, and they were found to be nontoxic. Molecular docking studies of the compounds with the enzyme DprE1 revealed the probable mechanism of action. The chalcone derivatives exhibited binding affinity values between -7.047 and -9.353 kcal/mol. ADME parameters were predicted using the QikProp module of the Schrödinger software, and these compounds exhibited good pharmacological and oral absorption properties.

Is Cinnamon Efficacious for Glycaemic Control in Type-2 Diabetes Mellitus?

Diabetes is on the rise, and has become a major public health issue. In view of limitations of available glucose lowering therapy, there is a need to explore and develop natural remedies with anti-diabetic properties. Spices such as cinnamon, cloves, bay leaves, and turmeric display insulin-enhancing activity in vitro. Cinnamon or Dalchini is popularly use as a spice for its fragrance and flavour in wide variety of traditional foods. Among various types of cinnamon, C. zeylanicum is well known as effective substitute for diabetes. Cinnamaldehyde is one of the major constituents (65-80%) of bark oil extracted from C. Zeylonicum which seems to reduce plasma blood glucose concentration more effectively when it is compared with metformin. It enhances the expression of proteins involved in glucose transport, insulin signalling, and regulates dyslipidaemia. This review describes the basic and clinical pharmacology of cinnamon.

Nanoparticle formulation of 11-keto-ß-boswellic acid (KBA): anti-inflammatory activity and in vivo pharmacokinetics.

CONTEXT: The oleo-gum-resin of Boswellia serrata Roxb. (Burseraceae) is widely used for the treatment of inflammatory diseases such as osteoarthritis, rheumatoid arthritis and cancer. Anti-inflammatory activity of 11-keto-ß-boswellic acid (KBA) is impeded by poor oral bioavailability due to its high lipid solubility, rapid phase-1 metabolism and poor intestinal permeability. OBJECTIVE: This study developed a poly-dl-lactide-co-glycolide-based nanoparticle formulation of KBA to improve its oral bioavailability and in vivo anti-inflammatory activity. MATERIALS AND METHODS: KBA was isolated from the oleo-gum resin of B. serrata, and its nanoparticle formulation (KBA-NPs) was prepared by the emulsion-diffusion-evaporation method. Oral bioavailability of KBA and KBA-NPs was studied at 50 mg/kg p.o. dose in Sprague-Dawley rats, and further evaluated for in vivo anti-inflammatory activity in carrageenan-induced rat paw oedema assay at the same dose level. RESULTS: The prepared KBA-NPs had a particle size of 152.6 nm with polydispersity index of 0.194, 79.7% entrapment efficiency and a cumulative 61.5% release of KBA from KBA-NPs, at 72 h. KBA-NPs showed 60.8% inhibition of rat paw oedema at 5 h as compared to 34.9% as that of KBA. The results of oral bioavailability study and in vivo anti-inflammatory activity showed 7- and 1.7-fold increase in bioavailability and anti-inflammatory activity, respectively, of KBA in KBA-NPs as compared to KBA alone. CONCLUSION: The results of improved oral bioavailability and in vivo anti-inflammatory activity of KBA-NPs suggested successful development of KBA nanoparticle formulation.

2'-Hydroxy flavanone derivatives as an inhibitors of pro-inflammatory mediators: Experimental and molecular docking studies.

2'-Hydroxy flavanone (1) was previously isolated from Mimosa pudica (L.) whole plant and was found to exhibit anti-inflammatory effects in vitro. There are also reports on anti-inflammatory properties of compounds bearing flavanone/chromone nucleus. Taking this into account, fourteen derivatives of 2'-hydroxy flavanone (1) were synthesized and evaluated against pro-inflammatory mediators (TNF-α, IL-1ß and NO) in in vitro and in vivo models. Results directed that among the synthesized compounds, four derivatives (11-14) showed profound inhibition of pro-inflammatory mediators as compared to the lead molecule. Further, 11-14 demonstrated comparable anti-inflammatory activity with ibuprofen in carrageenan-induced rat paw edema assay and appreciable inhibition of lipopolysaccharide (LPS) induced pro-inflammatory mediators (TNF-α and IL-1ß) in Sprague Dawley (SD) rats. The synthesized compounds were further subjected to molecular docking analysis and in silico prediction of pharmacokinetic properties.

Anti-inflammatory potential of a lipid-based formulation of a rotenoid-rich fraction prepared from Boerhavia diffusa.

CONTEXT: Boerhavia diffusa L. (Nyctaginaceae) roots are used in Ayurveda for treating inflammatory diseases. Generally poor oral bioavailability is a major problem associated with herbal drugs. OBJECTIVE: To develop a phospholipid complex of rotenoid-rich fraction (RRF) and evaluate its in vivo anti-inflammatory activity and pharmacokinetic study. MATERIALS AND METHODS: RRF was prepared from a 70% ethanol extract of B. diffusa roots. This RRF was complexed with phosphatidylcholine by refluxing in 70% ethanol. In vivo anti-inflammatory activity of RRF-PC and RRF was determined using the carrageenan-induced rat paw edema method, at a dose equivalent to 100 mg/kg p.o. of RRF. Edema volume was calculated at 3 and 5 h. The plasma concentration of boeravinone B was estimated in rats at a same dose level. Blood samples were collected at 1, 2, 4, 6, 8, 10, 12, 24, and 36 h. RESULTS: (1)H and (31)P NMR spectra of RRF-PC showed up-field shift of protons of the (+)N(CH3)3 group (3.37 → 3.23) and the phosphorus atom (-1.26 → -1.57 ppm), respectively, which confirmed phospholipid complex formation between phosphatidylcholine [PO4 and (+)N(CH3)3 groups] and phytoconstituents by hydrogen bonding. The RRF-PC showed significantly enhanced in vivo anti-inflammatory activity (64%) as compared with RRF (48%) and ibuprofen (50%) at 5 h (p < 0.001). Furthermore, detected plasma concentration of boeravinone B was two times higher in RRF-PC (75 ng/mL) as compared with RRF (40 ng/mL). CONCLUSION: The present study demonstrated an increased anti-inflammatory potential and higher plasma level of boeravinone B in lipid-based formulation (RRF-PC) as compared with RRF.

Synthesis, biological evaluation and docking analysis of 3-methyl-1-phenylchromeno[4,3-c]pyrazol-4(1H)-ones as potential cyclooxygenase-2 (COX-2) inhibitors.

As a part of our continued efforts to discover new COX inhibitors, a series of 3-methyl-1-phenylchromeno[4,3-c]pyrazol-4(1H)-ones were synthesized and evaluated for in vitro COX inhibitory potential. Within this series, seven compounds (3a-d, 3h, 3k and 3q) were identified as potential and selective COX-2 inhibitors (COX-2 IC50's in 1.79-4.35µM range; COX-2 selectivity index (SI)=6.8-16.7 range). Compound 3b emerged as most potent (COX-2 IC50=1.79µM; COX-1 IC50 >30µM) and selective COX-2 inhibitor (SI >16.7). Further, compound 3b displayed superior anti-inflammatory activity (59.86% inhibition of edema at 5h) in comparison to celecoxib (51.44% inhibition of edema at 5h) in carrageenan-induced rat paw edema assay. Structure-activity relationship studies suggested that N-phenyl ring substituted with p-CF3 substituent (3b, 3k and 3q) leads to more selective inhibition of COX-2. To corroborate obtained experimental biological data, molecular docking study was carried out which revealed that compound 3b showed stronger binding interaction with COX-2 as compared to COX-1.

Quantitative analysis of boeravinones in the roots of Boerhaavia Diffusa by UPLC/PDA.

INTRODUCTION: Boerhaavia diffusa is a perennial herb belonging to Nyctaginaceae. Various classes of chemical constituents such as phenolics (boeravinones), terpenoids and organic acids have been reported in B. diffusa roots. As boeravinones have been proposed as putative active constituents for the anti-cancer, spasmolytic and anti-inflammatory activities exhibited by B. diffusa extracts, it is worthwhile developing and validating an ultra-performance liquid chromatography (UPLC) method for analysis of boeravinones in B. diffusa roots. OBJECTIVE: To develop and validate a simple, accurate, robust and rapid UPLC analytical method for quality control of B. diffusa roots. METHODS: Samples for analysis were prepared by refluxing powdered root material with methanol for 2 h. The extracts were concentrated, dried and stored at -20°C until their use. A UPLC with photodiode array (PDA) method was developed and validated for the quantification of boeravinones in the roots of B. diffusa. The separation of boeravinones was achieved using a BEH Shield C18 -column (2.1 × 100 mm, 1.7 µm) with gradient elution of methanol and water (0.1% acetic acid), at a flow rate of 0.4 mL/min and detection was carried out at λmax 273 nm. RESULTS: The UPLC method developed showed good linearity (r(2) ≥ 0.9999), accuracy and precision. CONCLUSION: The UPLC method developed provided a selective, sensitive and rapid analytical method for the quantification of boeravinones in B. diffusa roots. All the validation parameters were found to be within the permissible limits as per International Conference on Harmonisation guidelines.

Murraya koenigii (L.) Spreng. as a Natural Intervention for Diabesity: A Review.

BACKGROUND: Murraya koenigii (L.) Spreng. (family: Rutaceae), commonly known as curry leaf or sweet neem, is a tropical plant native to India and Southeast Asia. It is highly valued in Ayurveda for its medicinal properties. Almost every part (fresh leaves, fruits, bark, and roots) of this plant is used to treat various ailments. Its fresh leaves are considered to have numerous medicinal properties for various diseases, including piles, inflammation, itching, fresh cuts, dysentery, and edema. A combination of curry leaf and buttermilk is used to treat diseases, such as amoebiasis, diabetes, and hepatitis. Its leaves are also believed to possess antioxidant, anti-inflammatory, and antimicrobial properties. The bark has been traditionally used for treating snakebites. Its roots are utilized in Ayurveda for the treatment of body aches. Being a storehouse of carbazole alkaloids, M. koenigii has been reported to show anti-obesity and anti-diabetic activity in in vitro and in vivo studies. The review aimed to appraise the role of M. koenigii leaf in the prevention of diabesity. METHODS: We performed a literature search with the keywords "diabesity", "obesity", "diabetes", "adipose tissue", and "carbazole alkaloids" on Google Scholar, PubMed, and ScienceDirect databases. Several in vitro and in vivo studies conducted on cell lines and animals for anti-diabetic/anti-hyperglycemic and antihyperlipidemic activities have been included and appraised in the article, providing supporting evidence for the ethnomedicinal claims. RESULTS AND CONCLUSION: This review has been an attempt to summarize comprehensively the overall research done on M. koenigii with regard to obesity and diabetes. The studies on anti-diabetic/anti-hyperglycemic and anti-hyperlipidemic activities of the plant have ranged from studies on crude extracts to isolated compounds. However, some of the studies require further in-depth analysis and validation of obtained results.

An alkaloid enriched fraction from Murraya koenigii (L.) Spreng. Leaves ameliorate HFD-induced obesity and metabolic complexities in C57BL/6J mice.

ETHNOPHARMACOLOGICAL RELEVANCE: Murraya koenigii commonly known as curry leaf, is traditionally used in India to manage various ailments including diabetes mellitus. Curry leaves are well documented in Indian Ayurvedic system of medicine for beneficial effects in skin eruptions, dysentery, emesis, poisonous bites and bruises. The anti-hyperglycemic and anti-hyperlipidemic effects of curry leaf extracts have been demonstrated through several in vitro and in vivo experiments previously. AIM OF THE STUDY: To prepare an alkaloid enriched fraction (AEF) from M. koenigii and its evaluation on i) in vitro adipogenesis process and ii) in vivo high fat diet-induced obesity in C57BL/6J mice. MATERIALS AND METHODS: MKME and AEF were prepared from M. koenigii leaves. The four carbazole alkaloids (bioactive markers) isolated from AEF were quantitatively determined in the leaves by RP-HPLC method. MKME and AEF were studied for anti-obesogenic activity in adipocytes in vitro and in HFD-induced C57BL/6J obese mice in vivo. At the termination of the in vivo study, lipid profile, hepatic and renal injury and glucose levels were analyzed in the blood samples. Animal tissues were examined histopathologically to determine any signs of damage. Repeated dose oral toxicity study for 28 days on Sprague-Dawley rats was also performed to determine the safety profile of AEF. RESULTS: Both MKME and AEF displayed anti-obesogenic activity at 25 µg/ml concentration in vitro and showed 54.06 ± 3.86% and 37.46 ± 3.17% lipid accumulation, respectively compared to control. Further, supplementation of AEF and MKME in HFD-fed C57BL/6J mice helped in controlling weight gain, improved dyslipidemia and glucose intolerance significantly. AEF showed better anti-obesity activity than MKME both in vitro and in vivo study. Repeated administration of AEF up to 1 g/kg dose for 28 days showed no pathological tissue damage. Both MKME and AEF were standardized using a simple and validated RP-HPLC method. CONCLUSION: Present study was aimed at preparation of a novel alkaloid-enriched fraction from methanolic extract of M. koenigii leaf and its evaluation for anti-diabesity effect. Our results demonstrated AEF to be a promising plant-based therapy for ameliorating obesity and related metabolic complications in HFD-fed C57BL/6J mice.

Exploring the efficacy of ethnomedicinal plants of Himalayan region against the malaria parasite.

ETHNOPHARMACOLOGICAL RELEVANCE: Plasmodium falciparum multi-drug resistant (MDR) strains are a great challenge to global health care. This predicament implies the urgent need to discover novel antimalarial drugs candidate from alternative natural sources. The Himalaya constitute a rich repository of medicinal plants which have been used traditionally in the folklore medicine since ages and having no scientific evidence for their activity. Crambe kotschyana Boiss. and Eremurus himalaicus Baker are used for their antipyretic and hepatoprotective properties in Kinnaur district of Himachal Pradesh, India. AIM OF THE STUDY: This study would investigate the antiplasmodial efficacy of C. kotschyana and E. himalaicus extracts, their fractions and active components using in vitro, in vivo and in silico approaches to provide a scientific insight into their activity. METHODS: The methanol extracts of C. kotschyana (CKME) and E. himalaicus (EHME) were prepared by maceration followed by fractionation using ethyl acetate. The isolation of flavonoid glycosides isorhamnetin-3, 7-di-O-glucoside from C. kotschyana and luteolin-6-C-glucoside (isoorientin) from E. himalaicus was carried out by antiplasmodial activity-guided isolation. In vitro antimalarial activity was assessed by WHO method while in vitro cytotoxicity was ascertained employing the MTT assay. Molecular docking and molecular dynamics simulation were performed using the Glide module of Schrödinger Software and Gromacs-2022 software package respectively. In vivo curative activity was assessed by Ryley and Peters method. RESULTS: The methanol extracts of both the plants illustrated the best antiplasmodial activity followed by the ethyl acetate fractions. Iso-orientin (IC50 6.49 µg/ml) and Isorhamnetin-3,7-di-O-glucoside (IC50 9.22 µg/ml) illustrated considerable in vitro activity even against P. falciparum resistant strain. Extracts/fractions as well as the isolated compounds were found to be non-toxic with CC50 > 640 µg/ml. Molecular docking studies were performed with these 2 O-glucosides against four malaria targets to understand the binding pose of these molecules and the results suggested that these molecules have selectivity for lactate dehydrogenase enzyme. CKME and EHME exhibited curative activity in vivo along with increase in Mean Survival Time of mice. CONCLUSION: The research delineated the scientific evidence that both the therapeutic herbs possessed antimalarial activity and notably, bioactive compounds responsible to exhibit the antimalarial activity have been isolated, identified and characterized. Further studies are underway to assess the antiplasmodial efficacy of isolated compounds alone and in combination with standard antimalarials.

Wound-healing effect of topical nanoemulsion-loaded cream and gel formulations of Hippophae rhamnoides L. (sea buckthorn) fruit oil and their acute dermal toxicity study on female SD rats.

OBJECTIVE: The objective of this study was to evaluate the efficacy and safety of topical nanoemulsion (NE)-loaded cream and gel formulations of Hippophae rhamnoides L. (sea buckthorn [SBT]) fruit oil for wound healing. MATERIALS AND METHODS: The NE-loaded cream and gel formulations of H. rhamnoides L. (SBT) fruit oil (IPHRFH) were prepared and evaluated for their wound-healing activity on female Sprague-Dawley (SD) rats. They were further divided into groups (seven) and the wound-healing activity was determined by measuring the area of the wound on the wounding day and on the 0th, 4th, 8th, and 10th days. The acute dermal toxicity of the formulations was assessed by observing the erythema, edema, and body weight (BW) of the rats. RESULTS: The topical NE cream and gel formulations of H. rhamnoides L. (SBT) fruit oil showed significant wound-healing activity in female SD rats. The cream formulation of IPHRFH showed 78.96%, the gel showed 72.59% wound contraction on the 8th day, whereas the positive control soframycin (1% w/w framycetin) had 62.29% wound contraction on the 8th day. The formulations also showed a good acute dermal toxicity profile with no changes significantly affecting BW and dermal alterations. CONCLUSIONS: The results of this study indicate that topical NE-loaded cream and gel formulation of H. rhamnoides L. (SBT) fruit oil are safe and effective for wound healing. The formulations showed no signs of acute dermal toxicity in female SD rats.

Synthesis of novel celecoxib analogues by bioisosteric replacement of sulfonamide as potent anti-inflammatory agents and cyclooxygenase inhibitors.

Two series of celecoxib analogues having 1,5-diaryl relationship were synthesized. The key strategy of the molecular design was oriented towards exploring bioisosteric modifications of the sulfonamide moiety of celecoxib. First series (2a-2i) of celecoxib analogues bearing cyano functionality in place of sulfonamide moiety was synthesized by the reaction of appropriate trifluoromethyl-ß-diketones (5a-5i) with 4-hydrazinylbenzonitrile hydrochloride (4) in ethanol. Cyano moiety of pyrazoles 2 was then converted into corresponding carbothioamides 3 by bubbling H2S gas in the presence of triethylamine. All the synthesized compounds (2a-2i and 3a-3i) were screened for their in vivo anti-inflammatory (AI) activity using carrageenan-induced rat paw edema assay. COX-1 and COX-2 inhibitory potency was evaluated through in vitro cyclooxygenase (COX) assays. Compounds 2a, 2b, 2c, 2e and 3c showed promising AI activity at 3-4h after the carrageenan injection that was comparable to that of the standard drug indomethacin. Although compounds 3d, 3e and 3f exhibited more pronounced COX-2 inhibition but they also inhibit COX-1 effectively thus being less selective against COX-2. Three compounds 2a, 2f and 3a were found to have a COX profile comparable to the reference drug indomethacin. However 2e, 3b, 3c and 3i compounds were the most potent selective COX-2 inhibitors of this study with 3b showing the best COX-2 profile. In order to better rationalize the action and the binding mode of these compounds, docking studies were carried out. These studies were in agreement with the biological data.

Rotenoids from Boerhaavia diffusa as potential anti-inflammatory agents.

Five new (2, 3, 5, 7, and 9) and four known rotenoids (1, 4, 6, and 8) were isolated from a methanol extract of Boerhaavia diffusa roots. The structures of the new rotenoids were elucidated by spectroscopic data interpretation. The 70% ethanol extract, a rotenoid-rich fraction, and all isolated rotenoids were evaluated for their COX-1 and COX-2 inhibitory activities. Among the rotenoids tested, compound 7 showed the most potent COX-1 and COX-2 inhibition, with IC50 values of 21.7 ± 0.5 and 25.5 ± 0.6 µM, respectively. Boeravinone B (6) exhibited significant anti-inflammatory activity (56.6% at 50 mg/kg) when evaluated in an in vivo carrageenan-induced rat paw model.

Efflux pump inhibitory potential of indole derivatives as an arsenal against norA over-expressing Staphylococcus aureus.

NorA, an extensively studied efflux pump in Staphylococcus aureus, has been connected to fluoroquinolone, antiseptic, and disinfection resistance. Several studies have also emphasized how efflux pumps, including NorA, function as the first line of defense of S. aureus against antibiotics. In this study, we have screened some chemically synthesized indole derivatives for their activity as efflux pump inhibitors (EPIs). The derivative SMJ-5 was found to be a potent NorA efflux pump inhibitor among the screened indole derivatives, owing to increased ethidium bromide and norfloxacin accumulation in norA over-expressing S. aureus. The combination of SMJ-5 and ciprofloxacin demonstrated the eradication of S. aureus biofilm and prolonged the post-antibiotic effect more than ciprofloxacin alone. SMJ-5 was able to inhibit staphyloxanthin virulence. In in vitro time-kill trials and in vivo efficacy investigations, the combination enhanced the bactericidal activity of ciprofloxacin against S. aureus. Additionally, reverse transcription PCR results revealed that SMJ-5 also inhibits the NorA efflux pump indirectly at the transcriptional level. IMPORTANCE The NorA efflux pump is the most effective resistance mechanism in S. aureus. The clinical importance of NorA efflux pumps is demonstrated by the expression of pump genes in S. aureus strains in response to fluoroquinolones and biocides. Along with the repercussions of decreased fluoroquinolone sensitivity, increasing expression of efflux pump genes by their substrate necessitates the importance of efflux pump inhibitors. Reserpine and verapamil are clinically used to treat ailments and have proven NorA inhibitors, but, unfortunately, the concentration needed for these drugs to inhibit the pump is not safe in clinical settings. In the current study, we have screened some indole derivatives, and among them, SMJ-5 was reported to potentiate norfloxacin and ciprofloxacin at their sub-inhibitory concentration by inhibiting the norA gene transcriptionally. Here we highlight the promising points of this study, which could serve as a model to design a therapeutic EPI candidate against norA over-expressing S. aureus.

Efficacy of Young Cinnamomum zeylanicum Blume Bark on Hyperglycemia and PTPase Activity in Type 2 Diabetes.

Diabetes is a major public health concern and natural easy-going remedies are being searched. Since Cinnamomum zeylanicum Blume has a low coumarin concentration and possible insulin-enhancing properties, it is preferred over all other cinnamon species. Although similar research has been done on humans, there have been very few studies on this particular species, and none among South Asians. Moreover, no human trial that properly described their intervening agent (C. zeylanicum) and checked its efficacy at the molecular level along with clinical variables was conducted. Therefore, the current research aimed to explore the effects of C. zeylanicum on the glycemic index, lipid profile, and expression of the protein tyrosine phosphatase 1 B (PTP1B) enzyme in the peripheral blood mononuclear cells (PBMC) in type 2 diabetes. We examined the presence of bioactive compounds in young C. zeylanicum bark (Alba grade) from native Sri Lanka using gas chromatography-mass spectrometry, high-performance thin-layer chromatography, and thin-layer chromatography before introducing it in the clinical study where trans-Cinnamaldehyde was found to be a major chemical constituent (>60%). Then, from January 2020 to March 2022, a randomized double-blinded placebo-controlled trial was carried out in the Diabetic Clinic at AIIMS Rishikesh. A total of 154 diabetic patients were enrolled and were taken either cinnamon or placebo capsules (1.5 g/day) for 120 days on an empty stomach with warm water along with their conventional treatment. Reduction in fasting blood glucose levels in the cinnamon group was found -35.50% (95% CI, -173 to 58.4), whereas in the placebo group change was 5.00% (95% CI, -165 to 224). For glycosylated hemoglobin, it differed -0.85% (95% CI, -8.2 to 1.6) in the cinnamon group compared to the placebo where it was found 0.15% (95% CI, -6.1 to 5.5). PTP1B expression in PBMC was determined from pre- and post-trial blood samples using the Western Blot, and significant inhibition was also observed (p=0.039). The study result depicts, C. zeylanicum is emerging as a beneficial plant for type 2 diabetes in Northern India and could be used as an adjunctive treatment rather than as a standalone managerial remedy.

Antidiabetic Activity of Gnidia glauca and Dioscorea bulbifera: Potent Amylase and Glucosidase Inhibitors.

Diabetes is a metabolic disorder affecting about 220 million people worldwide. One of the most critical complications of diabetes is post-prandial hyper-glycemia (PPHG). Glucosidase inhibitor and α-amylase inhibitors are class of compounds that help in managing PPHG. Low-cost herbal treatment is recommended due to their lesser side effect for treatment of diabetes. Two plants with significant traditional therapeutic potential, namely, Gnidia glauca and Dioscorea bulbifera, were tested for their efficiency to inhibit α-amylase and α-glucosidase. Stem, leaf, and flower of G. glauca and bulb of D. bulbifera were sequentially extracted with petroleum ether, ethyl acetate, and methanol as well as separately with 70% ethanol. Petroleum ether extract of flower of G. glauca was found to inhibit α-amylase significantly (78.56%). Extracts were further tested against crude murine pancreatic, small intestinal, and liver glucosidase enzyme which revealed excellent inhibitory properties. α-glucosidase inhibition provided a strong in vitro evidence for confirmation of both G. glauca and D. bulbifera as excellent antidiabetic remedy. This is the first report of its kind that provides a strong biochemical basis for management of type II diabetes using G. glauca and D. bulbifera. These results provide intense rationale for further in vivo and clinical study.

Quantitative analysis of tiliroside and other flavonoid glycosides in Hippophae salicifolia D. Don leaves by HPLC-PDA.

A new HPLC-PDA method was developed and validated for simultaneous determination of five phenolic compounds (trans-and cis- isomers of tiliroside, quercetin-3-O-ß-D-glucoside, ellagic acid, kaempferol-3-O-ß-D-glucoside and isorhamnetin-3-O-glucoside) in the leaves of Hippophae salicifolia D. Don. Of the five compounds, three (tiliroside, quercetin-3-O-ß-D-glucoside and ellagic acid) were isolated and characterised by spectroscopy techniques. The developed HPLC method provided a selective, sensitive and rapid analysis with good linearity (r2> 0.999), accuracy and precision. Also, the leaves of H. salicifolia were extracted by three different extraction techniques viz. reflux, microwave and ultrasound. Methanolic extracts prepared by reflux method showed the highest content of all the five compounds.