Molecular docking and inhibition studies on the interactions of Bacopa monnieri's potent phytochemicals against pathogenic Staphylococcus aureus

In vitro, in vivo and in silico antiplasmodial profiling of the aqueous extract of Hibiscus asper HOOK F. Leaf (Malvaceae)

ETHNOPHARMACOLOGICAL RELEVANCE

Plasmodium resistance to antimalarial drugs raises the urgent need to seek for alternative treatments. Aqueous extract of Hibiscus asper leaves is currently used in malaria management but remains less documented.

AIM OF THE STUDY

The study aims to evaluate antimalarial effects of the aqueous extract of Hibiscus asper. UHPLC/MS, was used to identify some likely compounds present in the plant that were thereafter docked to some malaria parasite proteins.

STUDY DESIGN

In vitro anti-plasmodium and antioxidant, UHPLC/Ms analysis, in vivo antimalarial of the plant extract, and in silico molecular docking prediction of some identified compounds were performed to investigate the pharmacological effects of H. asper.

MATERIAL AND METHODS

The in vitro antiplasmodial activity of the extract was carried out on Plasmodium falciparum strains using SYBR-green dye; then, the curative antimalarial activity was conducted on Plasmodium berghei NK65-infected male Wistar rats. The UHPLC/MS analysis was used to identify plant compounds, followed by interactions (docking affinity) between some compounds and parasitic enzymes such as P. falciparum purine nucleoside phosphorylase (2BSX) and 6-phosphogluconate dehydrogenase (6FQY) to explore potential mechanisms of action at the molecular level.

RESULTS

No hemolysis effect of the extract was observed at concentrations up to 100 mg/mL. In vitro test of the aqueous leaves extract of H. asper showed inhibitory activity against P. falciparum Dd2 and 3D7 strains with IC50 values of 19.75 and 21.97 μg/mL, respectively. The curative antimalarial test of the H. asper extract in infected rats exhibited significant inhibition of the parasite growth (p < 0.001) with inhibition percentage of 95.11%, 97.68% and 95.59% at all the doses (50, 100 and 200 mg/kg) respectively. The extract corrected major physiological alterations such as liver and kidney impairments, oxidative stress and architectural disorganization in liver, spleen and kidneys tissues. The UHPLC/MS analysis identified 7 compounds, namely chlorogenic acid, azulene, quercetin, rhodine, 1-ethyl-2,4-dimethyl benzene and phthalan. Out of seven compounds identified in the extract quercetin and phthalan showed higher in silico inhibitory activity against P. falciparum purine nucleoside phosphorylase and Plasmodium falciparum 6-phosphosgluconate dehydrogenase parasite enzymes.

CONCLUSION

These findings indicate that H. asper could be a promising complementary medicine to manage malaria. Meanwhile, the affinity of annoted compounds with these enzymes should be further confirmed.

Phytochemical determination and mechanistic investigation of Polygala tenuifolia root (Yuanzhi) extract for bronchitis: UPLC-MS/MS analysis, network pharmacology and in vitro/in vivo evaluation

ETHNOPHARMACOLOGICAL RELEVANCE

Bronchitis is a respiratory disease characterized by a productive cough. Polygala tenuifolia Willd., commonly known as Yuan zhi, is a traditional Chinese herbal medicine used for relieving cough and removing phlegm. Despite its historical use, studies are lacking on the effectiveness of P. tenuifolia in treating bronchitis. Furthermore, the molecular mechanisms underlying the action of its bioactive compounds remain unknown.

AIM OF THE STUDY

This study aims to identify the main bioactive compounds responsible for the effects of P. tenuifolia liquid extract (PLE) in treating bronchitis and to elucidate the associated molecular mechanisms.

MATERIALS AND METHODS

The main chemical compounds in PLE were identified and determined using ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS). The antitussive, expectorant and anti-inflammatory activities of PLE were evaluated in an ammonia-induced mouse cough model, a tracheal phenol red excretion mouse model, and a xylene-induced ear swelling mouse model, respectively. A network pharmacology analysis was conducted to investigate the associated gene targets, gene ontology, and KEGG pathways related to the main bioactives in PLE targeting bronchitis. PLE and its five bioactive compounds were assessed for their potential anti-inflammatory activities in lipopolysaccharide (LPS)-stimulated RAW264.7 cells. Western blot analysis was conducted to elucidate the associated molecular mechanisms.

RESULTS

Thirty-seven compounds in PLE were identified, and twelve main compounds were further quantified in PLE using UPLC-MS/MS. PLE oral gavage administrations (0.6 and 0.12 mg/kg) for 7 days markedly reduced cough frequency, prolonged latency period of cough, reduced phlegm and inflammation in mice. The network pharmacology analysis identified 57 gene targets of PLE against bronchitis. The PI3K/AKT and MAPK signalling pathways were the top two modulated pathways. In RAW264.7 cells, PLE (12.5-50 μg/mL) significantly reduced cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), interleukin (IL)-1β, IL-6 and tumor necrosis factor (TNF)-α. PLE downregulated LPS-elevated protein targets in both PI3K/AKT and MAPK signaling pathways. In PLE, tenuifolin, polygalaxanthone ⅠⅠⅠ, polygalasaponin ⅩⅩⅤⅢ, tenuifoliside B, and 3,6'-Disinapoyl sucrose, were identified as the top five core components responsible for treating bronchitis. These compounds were also found to modulate the protein targets in the PI3K/AKT and MAPK signalling pathways.

CONCLUSIONS

This study demonstrated the potential therapeutic effects of PLE on bronchitis by reducing cough, phlegm and inflammation. The anti-inflammatory action and molecular mechanisms of the 5 main bioactive compounds in PLE were partly validated through the in vitro assays. The findings provide valuable insights into the mechanisms underlying the traditional use of PLE for bronchitis.

New combined Inverse-QSAR and molecular docking method for scaffold-based drug discovery

Computer-aided drug discovery plays a vital role in developing novel medications for various diseases. The COVID-19 pandemic has heightened the need for innovative approaches to design lead compounds with the potential to become effective drugs. Specifically, designing promising inhibitors of the SARS-CoV-2 main protease (Mpro) is crucial, as it plays a key role in viral replication. Phytochemicals, primarily flavonoids and flavonols from medicinal plants, were screened. Fifty small molecules were selected for molecular docking analysis against SARS-CoV-2 Mpro (PDB ID: 6LU7). Binding energies and interactions were analyzed and compared to those of the anti-SARS-CoV-2 inhibitor Nirmatrelvir. Using these 50 structures as a training set, a QSAR model was built employing simple, reversible topological descriptors. An inverse-QSAR analysis was then performed on 2⁹ = 512 hydroxyl combinations at nine possible positions on the flavone and flavonol scaffold. The model predicted three novel, promising compounds exhibiting the most favorable binding energies (-8.5 kcal/mol) among the 512 possible hydroxyl combinations: 3,6,7,2',4'-pentahydroxyflavone (PF9), 6,7,2',4'-tetrahydroxyflavone (PF11), and 3,6,7,4'-tetrahydroxyflavone (PF15). Molecular dynamics (MD) simulations demonstrated the stability of the PF9/Mpro complex over 300 ns of simulation. These predicted structures, reported here for the first time, warrant synthesis and further evaluation of their biological activity through in vitro and in vivo studies.

Molecular Dynamics Simulation Studies of Beta-Glucogallin and Dihydro Dehydro Coniferyl Alcohol from Syzygium cumini for its Antimicrobial Activity on Staphylococcus aureus

With the escalating threat of antimicrobial resistance (AMR), discovering novel therapeutic agents against resistant pathogens like Staphylococcus aureus is crucial. This study explores phytochemicals from Syzygium cumini for their potential efficacy against AMR S. aureus infections, elucidating their mechanisms through in silico methods. We investigated 83 compounds from S. cumini, sourced from PubMed, using rigorous docking analysis against the ATP binding domain AgrC of S. aureus with AMdock with Autodock Vina v1.5.2. Drug-likeness predictions were assessed using SwissADME v2023 and Pass online v2.0. Molecular dynamics (MD) simulations identified promising compounds, focusing on stability and interaction dynamics. Beta-Glucogallin (BEG) and Dihydro Dehydro Coniferyl alcohol (DIH) emerged as significant hits. MD simulations with GROMACS v2020.6 revealed stable BEG and DIH complexes with AgrC, forming six hydrogen bonds with six key amino acids (Arg-303, Asp-338, Glu-342, Glu-384, Lys-389, Gly-396), indicating strong and stable bonding. The binding affinities for DIH and BEG are -73.474 ± 11.104 kJ/mol and -6.319 ± 18.823 kJ/mol with 4BXI, respectively. Our findings highlight BEG and DIH as promising candidates against AMR S. aureus infections, showing favourable binding affinities and stable interactions with AgrC. This study underscores the importance of natural products in combating AMR and demonstrates the utility of computational methodologies in drug discovery. Further experimental validation is warranted to fully exploit these phytochemicals' therapeutic potential.

Isolation, structural elucidation of bioactive compounds and their wound-healing ability, antibacterial and In silico molecular docking applications

Andrographis echioides has been extensively utilized in traditional Indian folk medicines for several skin disorders and other biological actions such as diuretic, antimicrobial, anthelmintic, anti-ulcer, and hepatoprotective properties. Different crude extracts were extracted from A. echioides leaves using various solvents such as methanol and water. The prepared crude extracts were utilized to formulate different herbal ointments. Further, the prepared ointments were examined against wounds and bacterial pathogens. The wound healing ability of the prepared formulations was observed for F1, F2, and F3, to be (89.84%, 95.11%, and 95.75%) respectively. Moreover, wound healing capabilities were compared with standard Betadine which exhibits 98.12%, those results indicating that the prepared herbal ointment also has a promising wound healing ability. The F2 formulations outperform the other two formulations (F1 and F2) in terms of their antibacterial ability to combat Staphylococcus aureus, Klebsiella pneumoniae Bacillus subtilis, and Escherichia coli. Moreover, there are two compounds were successfully isolated and identified from methanolic extract, which are 2-(3,4-dihydroxyphenyl)-3,4-dihydro-2H-chromene-3,5,7-triol and 3-(3,4-Dihydroxyphenyl)-2-propenoic acid. Meanwhile, the molecular docking investigation exposed high binding energy Staphylococcus aureus TyrRS (-8.9 kcal/mol), Isoleucyl-tRNA synthetase (-7.5 kcal/mol), Penicillin-binding protein 2a (-8.0 kcal/mol), S. aureus DNA Gyrase (-7.2 kcal/mol), GSK-3beta (Glycogen synthase kinase-3 beta) (-8.3 kcal/mol) and TGF - Beta Receptor Type 1 Kinase Domain (-8.7 kcal/mol) indicating high degree of interaction between Compound-1 2-(3,4-dihydroxyphenyl)-3,4-dihydro-2H-chromene-3,5,7-triol (DHPDHC) and 7 clinically important skin infective pathogen Staphylococcus aureus proteins at the active sites. Additionally, the standard drug Povidone iodine, Sulphothiazole, and Nitrofurazone (<-8 kcal/mol), displayed low binding affinity on targeted proteins. A molecular dynamics simulation research with high free energy showed stable interaction between the ligand and protein. Which endorses the capabilities of A. echioides derived compounds as a potential wound healer and antibacterial therapeutic candidate for drug development in the future.

Catechin-Induced changes in PODXL, DNMTs, and miRNA expression in Nalm6 cells: an integrated in silico and in vitro approach

BACKGROUND

This study explored the impact of predicted miRNAs on DNA methyltransferases (DNMTs) and the PODXL gene in Nalm6 cells, revealing the significance of these miRNAs in acute lymphocytic leukemia (ALL).

METHODS

A comprehensive approach was adopted, integrating bioinformatic analyses encompassing protein structure prediction, molecular docking, dynamics, and ADMET profiling, in conjunction with evaluations of gene and miRNA expression patterns. This methodology was employed to elucidate the therapeutic potential of catechin compounds in modulating the activity of DNA methyltransferases (DNMTs) and the PODXL gene.

RESULTS

The findings from our investigation indicate that catechins possess the capability to inhibit DNMT enzymes. This inhibitory effect is associated with the upregulation of microRNAs miR-200c and miR-548 and a concurrent downregulation of PODXL gene expression. These molecular interactions culminate in an augmented apoptotic response within ALL (Nalm6) cells.

CONCLUSION

The study posits that catechins may represent a viable therapeutic avenue for inducing apoptosis in ALL cells. This is achieved through the modulation of epigenetic mechanisms and alterations in gene expression profiles, highlighting the potential of catechins as agents for cancer therapy.

Phytochemicals as Antimicrobials: Prospecting Himalayan Medicinal Plants as Source of Alternate Medicine to Combat Antimicrobial Resistance

Among all available antimicrobials, antibiotics hold a prime position in the treatment of infectious diseases. However, the emergence of antimicrobial resistance (AMR) has posed a serious threat to the effectiveness of antibiotics, resulting in increased morbidity, mortality, and escalation in healthcare costs causing a global health crisis. The overuse and misuse of antibiotics in global healthcare setups have accelerated the development and spread of AMR, leading to the emergence of multidrug-resistant (MDR) pathogens, which further limits treatment options. This creates a critical need to explore alternative approaches to combat bacterial infections. Phytochemicals have gained attention as a potential source of alternative medicine to address the challenge of AMR. Phytochemicals are structurally and functionally diverse and have multitarget antimicrobial effects, disrupting essential cellular activities. Given the promising results of plant-based antimicrobials, coupled with the slow discovery of novel antibiotics, it has become highly imperative to explore the vast repository of phytocompounds to overcome the looming catastrophe of AMR. This review summarizes the emergence of AMR towards existing antibiotics and potent phytochemicals having antimicrobial activities, along with a comprehensive overview of 123 Himalayan medicinal plants reported to possess antimicrobial phytocompounds, thus compiling the existing information that will help researchers in the exploration of phytochemicals to combat AMR.

Targeting Shikimate Kinase Pathway of Acinetobacter baumannii: A Structure-Based Computational Approach to Identify Antibacterial Compounds

Acinetobacter baumannii (A. baumannii) is an opportunistic bacterium that has developed multidrug resistance (MDR) to most of today’s antibiotics, posing a significant risk to human health. Considering the fact that developing novel drugs is a time-consuming and expensive procedure, this research focuses on utilizing computational resources for repurposing antibacterial agents for A. baumannii. We targeted shikimate kinase, an essential enzyme in A. baumannii, that plays a significant role in the metabolic process. The basis for generating new therapeutic compounds is to inhibit the shikimate kinase and thereby targeting the shikimate pathway. Herein, 1941 drug-like compounds were investigated in different in silico techniques for assessing drug-likeness properties, ADMET (absorption, distribution, metabolism, excretion, and toxicity) profiling, binding affinity, and conformation analysis utilizing Autodock-vina and SwissDock. CHEMBL1237, CHEMBL1237119, CHEMBL2018096, and CHEMBL39167178 were determined as potential drug candidates for suppressing shikimate kinase protein. Molecular Dynamics Simulation (MDS) results for root mean square deviation, root mean square fluctuation, hydrogen bond, and gyration radius confirm the drug candidates’ molecular stability with the target protein. According to this study, CHEMBL1237 (Lisinopril) could be the most suitable candidate for A. baumannii. Our investigation suggests that the inhibitors of shikimate kinase could represent promising treatment options for A. baumannii. However, further in vitro and in vivo studies are necessary to validate the therapeutic potential of the suggested drug candidates.

Breynia cernua: Chemical Profiling of Volatile Compounds in the Stem Extract and Its Antioxidant, Antibacterial, Antiplasmodial and Anticancer Activity In Vitro and In Silico

Breynia cernua has been used as an alternative medicine for wounds, smallpox, cervical cancer, and breast cancer. This plant is a potential source of new plant-derived drugs to cure numerous diseases for its multiple therapeutic functions. An in vitro study revealed that the methanol extract of B. cernua (stem) exhibits antioxidant activity according to DPPH and SOD methods, with IC₅₀ values of 33 and 8.13 ppm, respectively. The extract also exerts antibacterial activity against Staphylococcus aureus with minimum bactericidal concentration of 1875 ppm. Further analysis revealed that the extract with a concentration of 1-2 ppm protects erythrocytes from the ring formation stage of Plasmodium falciparum, while the extract with a concentration of 1600 ppm induced apoptosis in the MCF-7 breast cancer cell line. GC-MS analysis showed 45 bioactive compounds consisting of cyclic, alkyl halide, organosulfur, and organoarsenic compounds. Virtual screening via a blind docking approach was conducted to analyze the binding affinity of each metabolite against various target proteins. The results unveiled that two compounds, namely, N-[β-hydroxy-β-[4-[1-adamantyl-6,8-dichloro]quinolyl]ethyl]piperidine and 1,3-phenylene, bis(3-phenylpropenoate), demonstrated the best binding score toward four tested proteins with a binding affinity varying from -8.3 to -10.8 kcal/mol. Site-specific docking analysis showed that the two compounds showed similar binding energy with native ligands. This finding indicated that the two phenolic compounds could be novel antioxidant, antibacterial, antiplasmodial, and anticancer drugs. A thorough analysis by monitoring drug likeness and pharmacokinetics revealed that almost all the identified compounds can be considered as drugs, and they have good solubility, oral bioavailability, and synthetic accessibility. Altogether, the in vitro and in silico analysis suggested that the extract of B. cernua (stem) contains various compounds that might be correlated with its bioactivities.

Antibacterial Potential of Bacopa monnieri (L.) Wettst. and Its Bioactive Molecules against Uropathogens-An In Silico Study to Identify Potential Lead Molecule(s) for the Development of New Drugs to Treat Urinary Tract Infections

Urinary tract infections (UTIs) are becoming more common, requiring extensive protection from antimicrobials. The global expansion of multi-drug resistance uropathogens in the past decade emphasizes the necessity of newer antibiotic treatments and prevention strategies for UTIs. Medicinal plants have wide therapeutic applications in both the prevention and management of many ailments. Bacopa monnieri is a medicinal plant that is found in the warmer and wetlands regions of the world. It has been used in Ayurvedic systems for centuries. The present study aimed to investigate the antibacterial potential of the extract of B. monnieri leaves and its bioactive molecules against UTIs that are caused by Klebsiella pneumoniae and Proteus mirabilis. This in vitro experimental study was conducted by an agar well diffusion method to evaluate the antimicrobial effect of 80% methanol, 96% ethanol, and aqueous extracts of B. monnieri leaves on uropathogens. Then, further screening of their phytochemicals was carried out using standard methods. To validate the bioactive molecules and the microbe interactions, AutoDock Vina software was used for molecular docking with the Klebsiella pneumoniae fosfomycin resistance protein (5WEW) and the Zn-dependent receptor-binding domain of Proteus mirabilis MR/P fimbrial adhesin MrpH (6Y4F). Toxicity prediction and drug likeness were predicted using ProTox-II and Molinspiration, respectively. A molecular dynamics (MD) simulation was carried out to study the protein ligand complexes. The methanolic leaves extract of B. monnieri revealed a 22.3 mm ± 0.6 mm to 25.0 mm ± 0.5 mm inhibition zone, while ethanolic extract seemed to produce 19.3 mm ± 0.8 mm to 23.0 mm ± 0.4 mm inhibition zones against K. pneumoniae with the use of increasing concentrations. In the case of P. mirabilis activity, the methanolic extracts showed a 21.0 mm ± 0.8 mm to 24.0 mm ± 0.6 mm zone of inhibition and the ethanol extract produced a 17.0 mm ± 0.9 mm to 23.0 mm ± 0.7 mm inhibition zone with increasing concentrations. Carbohydrates, flavonoids, saponin, phenolic, and terpenoid were common phytoconstituents identified in B. monnieri extracts. Oroxindin showed the best interactions with the binding energies with 5WEW and 6Y4F, -7.5 kcal/mol and -7.4 kcal/mol, respectively. Oroxindin, a bioactive molecule, followed Lipinski's rule of five and exhibited stability in the MD simulation. The overall results suggest that Oroxindin from B. monnieri can be a potent inhibitor for the effective killing of K. pneumoniae and P. mirabilis. Additionally, its safety has been established, indicating its potential for future drug discovery and development in the treatment for UTIs.

An imperical analysis of various extracts of Bacopa Monnieri towards antibacterial and antifungal activities

Bacopa monnieri was also known as “Brahmi.” Theses plant has been considered as medicinal plants in Ayurvedic systems for centuries. This present study was carried out to evaluate the antibacterial and antifungal properties of ethanolic, diethyl ether, ethyl acetate, and aqueous extracts of B. monnieri. Agar disc diffusion tests were carried out to determine the antimicrobial effects of ethanolic, diethyl ether, ethyl acetate and aqueous extracts of B. monnieri against Gram-positive (Staphylococcus aureus), Gram-negative (Escherichia coli) bacterial strains and antifungal strains (Aspergillus flavus, and Candida albicans). Among the various extracts, diethyl ether extracts of B. monnieri has an antibacterial potency against Staphylococcus aureus (gram positive), and ethyl acetate extract showed effects on E. coli (gram negative) at higher concentrations of 300 μg mL-1. The ethanolic extract has potent antifungal activity against the fungus (Aspergillus flavus, and Candida albicans) compared to diethyl ether and ethyl acetate-ether. Both extracts (diethyl ether and ethyl acetate) has a minimum antifungal effect while these extracts showed more inhibitory effects on tested bacteria. 

Molecular docking and pharmacokinetic prediction of phytochemicals from Syzygium cumini in interaction with penicillin-binding protein 2a and erythromycin ribosomal methylase of Staphylococcus aureus

Background

MRSA and MLSB resistant S. aureus are known as important pathogens, which are responsible for many cases of both hospital and community-acquired infections worldwide. Studying drug discovery from plant sources is regarded as an important prevention strategy regarding these types of infections.

Material and methods

Agar well diffusion method was performed for antimicrobial evaluation, LCMS technique used for identification of different compounds, molecular docking performed by application of i GEMDOCK for PBP2a and ERM to plant compounds, and its pharmacokinetic evaluation of ADMET through use of AdmetSAR.

Results

Water extract was the most effective against resistant strains of Staphylococcus aureus. Twenty compounds belonging to phenols, flavonoids, organic acids, terpenoids groups were reported. Eighteen plant compounds passed in Lipinski's rule of five. i GEMDOCK revealed diferulic acid has the least binding energy -102.37 kcal/mole to penicillin-binding protein 2a and taxifolin has the least binding energy of -103.12 kcal/mole to erythromycin ribosomal methylase in comparison to control linezolid. These compounds raise the potential for developing potent inhibitors of penicillin-binding protein 2a and erythromycin ribosomal methylase for drug development. ADMET properties revealed that eighteen studied compounds were found in category III and IV with non-toxic properties except two butin and taxifolin found in category II with toxic properties.

Conclusions

It can be concluded that diferulic acid and taxifolin compounds provide the best inhibitor effect to PBP2a and ERM protein for inhibition of MRSA and MLSB resistant strains of S. aureus through the application of molecular docking, leading to a lead drug candidate for the treatment of diseases.

The impact of curcumin derived polyphenols on the structure and flexibility COVID-19 main protease binding pocket: a molecular dynamics simulation study

The newly occurred SARS-CoV-2 caused a leading pandemic of coronavirus disease (COVID-19). Up to now it has infected more than one hundred sixty million and killed more than three million people according to 14 May 2021 World Health Organization report. So far, different types of studies have been conducted to develop an anti-viral drug for COVID-19 with no success yet. As part of this, silico were studied to discover and introduce COVID-19 antiviral drugs and results showed that protease inhibitors could be very effective in controlling. This study aims to investigate the binding affinity of three curcumin derived polyphenols against COVID-19 the main protease (Mpro), binding pocket, and identification of important residues for interaction. In this study, molecular modeling, auto-dock coupled with molecular dynamics simulations were performed to analyze the conformational, and stability of COVID-19 binding pocket with diferuloylmethane, demethoxycurcumin, and bisdemethoxycurcumin. All three compounds have shown binding affinity −39, −89 and −169.7, respectively. Demethoxycurcumin and bisdemethoxycurcumin showed an optimum binding affinity with target molecule and these could be one of potential ligands for COVID-19 therapy. And also, COVID-19 main protease binding pocket binds with the interface region by one hydrogen bond. Moreover, the MD simulation parameters indicated that demethoxycurcumin and bisdemethoxycurcumin were stable during the simulation run. These findings can be used as a baseline to develop therapeutics with curcumin derived polyphenols against COVID-19.

Ethnomedicinal Value of Antidiabetic Plants in Bangladesh: A Comprehensive Review

The use of conventional drugs to treat metabolic disorders and the pathological consequences of diabetes further increases the complications because of the side effects, and is sometimes burdensome due to relatively higher costs and occasionally painful route of administration of these drugs. Therefore, shifting to herbal medicine may be more effective, economical, have fewer side effects and might have minimal toxicity. The present review amasses a list of ethnomedicinal plants of 143 species belonging to 61 families, from distinctive domestic survey literature, reported to have been used to treat diabetes by the ethnic and local people of Bangladesh. Leaves of the medicinal plants were found leading in terms of their use, followed by fruits, whole plants, roots, seeds, bark, stems, flowers, and rhizomes. This review provides starting information leading to the search for and use of indigenous botanical resources to discover bioactive compounds for novel hypoglycemic drug development.

Bromelain a Potential Bioactive Compound: A Comprehensive Overview from a Pharmacological Perspective

Bromelain is an effective chemoresponsive proteolytic enzyme derived from pineapple stems. It contains several thiol endopeptidases and is extracted and purified via several methods. It is most commonly used as an anti-inflammatory agent, though scientists have also discovered its potential as an anticancer and antimicrobial agent. It has been reported as having positive effects on the respiratory, digestive, and circulatory systems, and potentially on the immune system. It is a natural remedy for easing arthritis symptoms, including joint pain and stiffness. This review details bromelain's varied uses in healthcare, its low toxicity, and its relationship to nanoparticles. The door of infinite possibilities will be opened up if further extensive research is carried out on this pineapple-derived enzyme.

Pharmacoinformatics approaches in the discovery of drug-like antimicrobials of plant origin

Medicinal plants have served as an important source for addressing the ailments of humans and animals alike. The emergence of advanced technologies in the field of drug discovery and development has helped in isolating various bioactive phytochemicals and developing them as drugs. Owing to their significant pharmacological benefits and minimum adverse effects, they not only serve as good candidates for therapeutics themselves but also help in the identification and development of related drug like molecules against various metabolic and infectious diseases. The ever-increasing diversity, severity and incidence of infectious diseases has resulted in an exaggerated mortality and morbidity levels. Geno-proteomic mutations in microbes, irrational prescribing of antibiotics, antimicrobial resistance and human population explosion, all call for continuous efforts to discover and develop alternated therapeutic options against the microbes. This review article describes the pharmacoinformatics tools and methods which are currently used in the discovery of bioactive phytochemicals, thus making the process more efficient and effective. The pharmacological aspects of the drug discovery and development process have also been reviewed with reference to the in silico activities. Communicated by Ramaswamy H. Sarma.

Insightful Valorization of the Biological Activities of Pani Heloch Leaves through Experimental and Computer-Aided Mechanisms

Pani heloch (Antidesma montanum) is traditionally used to treat innumerable diseases and is a source of wild vegetables for the management of different pathological conditions. The present study explored the qualitative phytochemicals; quantitative phenol and flavonoid contents; in vitro antioxidant, anti-inflammatory, and thrombolytic effects; and in vivo antipyretic and analgesic properties of the methanol extract of A. montanum leaves in different experimental models. The extract exhibited secondary metabolites including alkaloids, flavonoids, flavanols, phytosterols, cholesterols, phenols, terpenoids, glycosides, fixed oils, emodines, coumarins, resins, and tannins. Besides, Pani heloch showed strong antioxidant activity (IC50 = 99.00 µg/mL), while a moderate percentage of clot lysis (31.56%) in human blood and significant anti-inflammatory activity (p < 0.001) was achieved with the standard. Moreover, the analgesic and antipyretic properties appeared to trigger a significant response (p < 0.001) relative to in the control group. Besides, an in silico study of carpusin revealed favorable protein-binding affinities. Furthermore, the absorption, distribution, metabolism, excretion, and toxicity analysis and toxicological properties of all isolated compounds adopted Lipinski's rule of five for drug-like potential and level of toxicity. Our research unveiled that the methanol extract of A. montanum leaves exhibited secondary metabolites that are a good source for managing inflammation, pyrexia, pain, and cellular toxicity. Computational approaches and further studies are required to identify the possible mechanism which responsible for the biological effects.

GC-MS Phytochemical Profiling, Pharmacological Properties, and In Silico Studies of Chukrasia velutina Leaves: A Novel Source for Bioactive Agents

Chukrasia velutina is a local medicinal plant commonly known as chikrassy in Bangladesh, India, China, and other South Asian countries. The leaves, bark, and seeds are vastly used as herbal medicine for fever and diarrhea, and its leaves essential oils are used for antimicrobial purposes. In this study, we discuss the neuropsychiatric properties of C. velutina leaves through several animal models, quantitative and qualitative phytochemical analysis, and computational approaches. Neuropsychiatric effects were performed in rodents on the methanolic extract of C. velutina leaves (MECVL). Antidepressant, anxiolytic, and sedative effects experimented through these rodent models were used such as the force swimming test (FST), tail suspension test (TST), hole board test (HBT), elevated plus maze test (EPMT), light/dark box test (LDBT), open field test (OFT), and hole cross test (HCT). In these rodent models, 200 and 400 mg/kg doses were used which exhibited a significant result in the force swimming and tail suspension test (p < 0.001) for the antidepressant effect. In the anxiolytic study, the results were significant in the hole board, elevated plus maze, and light/dark box test (p < 0.001) for doses of 200 and 400 mg/kg. The result was also significant in the open field and hole cross test (p < 0.001) for sedative action in the sake of similar doses. Moreover, qualitative and quantitative studies were also performed through phytochemical screening and GC-MS analysis, and fifty-seven phytochemical compounds were found. These compounds were analyzed for pharmacokinetics properties using the SwissADME tool and from them, thirty-five compounds were considered for the molecular docking analysis. These phytoconstituents were docking against the human serotonin receptor, potassium channel receptor, and crystal structure of human beta-receptor, where eight of the compounds showed a good binding affinity towards the respective receptors considered to the reference standard drugs. After all of these analyses, it can be said that the secondary metabolite of C. velutina leaves (MECVL) could be a good source for inhibiting the neuropsychiatric disorders which were found on animal models as well as in computational studies.

Calpurnia aurea (Aiton) Benth Extracts Reduce Quorum Sensing Controlled Virulence Factors in Pseudomonas aeruginosa

Pseudomonas aeruginosa is the causative agent of several life-threatening human infections. Like many other pathogens, P. aeruginosa exhibits quorum sensing (QS) controlled virulence factors such as biofilm during disease progression, complicating treatment with conventional antibiotics. Thus, impeding the pathogen's QS circuit appears as a promising alternative strategy to overcome pseudomonas infections. In the present study, Calpurnia aurea were evaluated for their antibacterial (minimum inhibitory concentrations (MIC)), anti-quorum sensing/antivirulence (AQS), and antibiofilm potential against P. aeruginosa. AQS and antivirulence (biofilm formation, swimming, and swarming motility) activities of plant extracts were evaluated against Chromobacterium violaceum and P. aeruginosa, respectively. The in vitro AQS potential of the individual compounds were validated using in silico molecular docking. Acetone and ethanolic extracts of C. aurea showed MIC at 1.56 mg/mL. The quantitative violacein inhibition (AQS) assay showed ethyl acetate extracts as the most potent at a concentration of 1 mg/mL. GCMS analysis of C. aurea revealed 17 compounds; four (pentadecanol, dimethyl terephthalate, terephthalic acid, and methyl mannose) showed potential AQS through molecular docking against the CviR protein of C. violaceum. Biofilm of P. aeruginosa was significantly inhibited by ≥60% using 1-mg/mL extract of C. aurea. Confocal laser scanning microscopy correlated the findings of crystal violet assay with the extracts significantly altering the swimming motility. C. aurea extracts reduced the virulence of pseudomonas, albeit in a strain- and extract-specific manner, showing their suitability for the identification of lead compounds with QS inhibitory potential for the control of P. aeruginosa infections.

Identification and Molecular Docking Studies of Bioactive Principles from Alphonsea madraspatana Bedd. against Uropathogens

AIMS

The present study aims to determine the antimicrobial efficacy of Alphonsea madraspatana leaves extract against selected uropathogens.

BACKGROUND

The plant Alphonsea madraspatana is an endangered species, reported to exhibit high antimicrobial activity due to the presence of phenolic compounds. Prevalence of high UTI infection and increased cases of bacterial resistance directed for alternative approach to meet the challenge of drug resistance.

OBJECTIVE

Our objective is to determine antimicrobial efficacy of Alphonsea madraspatana leaves extract against selected uropathogens and subsequent in-silico analysis to predict the underlying mechanism.

METHODS

Phytochemicals extraction from the dried leaves of Alphonsea madraspatana was performed using solvent gradient technique. All the extracts were subjected to preliminary phytochemical screening using liquid chromatography-mass spectrometry. Antimicrobial activity of the prepared extract was determined against the selected uropathogens using agar diffusion method. Finally, molecular docking study of the selected bio-actives was performed against a representative bacterial resistance enzyme ''DNA Gyrase".

RESULTS

Methanolic extract exhibits relatively higher antimicrobial activity against the selected strains with Minimum Inhibitory Concentration (MIC) and minimum bactericidal concentration (MBC) of 1.56 ± 1 ug/mL and 6.25 ± 2 ug/mL, respectively. Phytochemical screening showed the presence of 3 flavonoids compounds such as Luteolin-7-O-glucoside, Kaempferol-3-O- rotinoside-7-O-rhamnoside and Genestein-7-O-glucoside. The results of molecular docking shows Luteolin-7-O-glucoside has best docking scores of -8.5 kcal/mol than other ligand molecules. Experimental simulation in presence of DNA Gyrase inhibitors showed lowest MIC and MBC value for E. Coli, which was found to be 1.56 ±1 ug/mL and 6.25±2 ug/mL respectively, support the docking outcomes.

CONCLUSION

Outcomes of this study suggested that the methanolic extract of this plant shows good anti-microbial potential against resistant uropathogens.

Chalcone derivatives and their antibacterial activities: Current development

The increase in antibiotic resistance due to various factors has encouraged the look for novel compounds which are active against multidrug-resistant pathogens. In this framework, chalcone-based compounds showed a diversity of pharmacological properties, and its derivatives possess a high degree of structural diversity, and it is helpful for the discovery of new therapeutic agents. The growing resistance to antibiotics worldwide has endangered their efficacy. This has led to a surging interest in the discovery of new antibacterial agents. Thus, there is an urgent need for new antibacterial drug candidates with increased strength, new targets, low cost, superior pharmacokinetic properties, and minimum side effects. The present review concluded and focuses on the recent developments in the area of medicinal chemistry to explore the diverse chemical structures of potent antibacterial agents and also describes its structure-activity relationships studies. The various synthetic structures leading to this class of neutral protective compound is common and additional structural optimization is promising for potential drug discovery and development.

Molecular docking and dynamics of Nickel-Schiff base complexes for inhibiting β-lactamase of Mycobacterium tuberculosis

In recent years, multidrug-resistance has become a primary concern in the treatment and management of tuberculosis, an infectious disease caused by Mycobacterium tuberculosis. In this context, searching new anti-tuberculosis agents particularly targeting the β-lactamase (BlaC) is reported to be promising as this enzyme is one of the key player in the development of multidrug resistance. This study reports the design of some Nickel (Ni) based tetradentate N₂O₂ Schiff bases, employing density functional theory. All analogs are optimized at B3LYP/SDD level of theory. Dipole moment, electronic energy, enthalpy, Gibbs free energy, HOMO-LUMO gap, and softness of these modified drugs are also investigated. Molecular interactions between designed ligands and BlaC have been analyzed by molecular docking approach, followed by molecular dynamics (MD) simulation. All designed compounds show low HOMO-LUMO gap, while addition of halogen increases the dipole moment of the compounds. Docking and MD simulation investigations reveal that the designed compounds are more potent than standard inhibitor, where Ile117, Pro290, Arg236 and Thr253 residues of BlaC are found to play important role in the ligand binding. Through MD simulation study, the best binding compound is also observed to form stable complex by increasing the protein rigidness. The ADME/T analysis suggests that modified drugs are less toxic and shows an improved pharmacokinetic properties than that of the standard drug. These results further confirm the ability of Ni-directed Schiff bases to bind simultaneously to the active site of BlaC and support them as potential candidates for the future treatment of tuberculosis disease.

Antioxidant properties and anti-mutagenic potential of Piper Cubeba fruit extract and molecular docking of certain bioactive compounds

Spices and herbs are recognized as sources of natural antioxidants and thus play an important role in the chemoprevention of diseases and aging. Piper cubeba is one among them and known for its medicinal properties for decades. Various biological activities are associated with its extract and phytocompounds. However, the anti-mutagenic activity of antioxidant rich extract is less explored. In this study, we performed the fraction-based antioxidant activity of P. cubeba using four different assays and evaluated the anti-mutagenic activity of most potent antioxidant fraction using Salmonella typhimurium tester strains against four mutagens (methyl methanesulfonate [MMS], sodium azide [SA], benzo(a)pyrene, and 2-aminoflourene) respectively. Among all tested fractions at 25-200 µg/ml, ethanolic extract revealed highest antioxidant activity and significant anti-mutagenicity against both direct and indirect acting mutagens at least one tester strain. Phytochemical analysis by gas chromatography-mass spectrometry (GC/MS) revealed the presence of various phytocompounds including copaene, isocaryophyllene, α-cubebene, etc. Molecular docking studies on DNA binding interactions of GC/MS detected phytocompounds highlight the possible mode of binding. In summary, these in vitro studies have provided the scientific basis for validation of using this plant in the traditional system of medicine and highlighted the need for exploring the role of various compounds for therapeutic efficacy. On the other hand, synergistic interaction among phytocompounds is to be explored to optimize or standardize the extracts for the exploitation in modern phytomedicine.

Novel T-C@AgNPs mediated biocidal mechanism against biofilm associated methicillin-resistant Staphylococcus aureus (Bap-MRSA) 090, cytotoxicity and its molecular docking studies

Staphylococcus aureus is a commonly found pathogen that can cause food-spoilage and life threatening infections. However, the potential molecular effects of natural active thymol molecules and chitosan silver nanoparticles (C@AgNPs) in bacteria remain unclear. This gap in the literature has prompted us to study the effects of thymol loaded chitosan silver nanoparticles (T-C@AgNPs) against biofilm associated proteins in methicillin-resistant S. aureus (Bap-MRSA) 090 and also their toxicity, anti-cancer activity, and validation of their in silico molecular docking. The results showed excellent antibacterial activity of T-C@AgNPs against Bap-MRSA 090, having a minimum inhibitory concentration of 100 μg mL-1 and a 10.08 ± 0.06 mm zone of inhibition (ZOI). The cyclic voltammogram (CV) analysis clearly showed pore forming of T-C@AgNPs at 300 μg mL-1 concentration, and evidence of the interruption of the electron transport chain was clearly seen. The 200 μg mL-1 concentration exhibited a 52.60 ± 0.25% anti-biofilm property by T-C@AgNPs against Bap-MRSA 090. The T-C@AgNPs showed no toxicity to peripheral blood mononuclear cells (PBMC) (IC50 = 221 ± 0.71 μg mL-1) compared to the control, and anti-cancer activity against human triple negative breast cancer cell line (MDA-MB-231) (IC50 110 ± 1.0 μg mL-1) compared to the standard drug Doxorubicin (IC50 = 19 ± 1.0). The excellent properties of T-C@AgNPs were validated by in silico molecular docking studies and showed best match scoring to target proteins compared to standards. These excellent properties of T-C@AgNPs highlight for the first time its pharmacology and potential in medicinal drug development applications for future research.

Effect of Bacoside A on growth and biofilm formation by Staphylococcus aureus and Pseudomonas aeruginosa

The goal of this study was to evaluate the antibiofilm and antimicrobial activities of Bacoside A, a formulation of phytochemicals from Bacopa monnieri, against Staphylococcus aureus and Pseudomonas aeruginosa, which are known to form biofilms as one of their virulence traits. The antimicrobial effects of Bacoside A were tested using the minimum inhibitory concentration and minimum bactericidal concentration assays. A cell membrane disruption assay was performed to find its possible target site. MTT assay, crystal violet assay, and microscopic studies were performed to assess the antibiofilm activity. Bacoside A showed antimicrobial activity against both test organisms in their planktonic and biofilm states. At a subminimum inhibitory concentration of 200 μg·mL^-1, Bacoside A significantly removed ∼88%-93% of bacterial biofilm developed on microtiter plates. Biochemical and microscopic studies suggested that the eradication of biofilm might be due to the loss of extracellular polymeric substances and to a change in cell membrane integrity of the selected bacterial strains treated with Bacoside A. These results indicate that Bacoside A might be considered as an antimicrobial having the ability to disrupt biofilms. Thus, either alone or in combination with other therapeutics, Bacoside A could be useful to treat biofilm-related infections caused by opportunistic bacterial pathogens.

Identification and characterization of antibacterial compound(s) of cockroaches (Periplaneta americana)

Infectious diseases remain a significant threat to human health, contributing to more than 17 million deaths, annually. With the worsening trends of drug resistance, there is a need for newer and more powerful antimicrobial agents. We hypothesized that animals living in polluted environments are potential sources of antimicrobials. Under polluted milieus, organisms such as cockroaches encounter different types of microbes, including superbugs. Such creatures survive the onslaught of superbugs and are able to ward off disease by producing antimicrobial substances. Here, we characterized antibacterial properties in extracts of various body organs of cockroaches (Periplaneta americana) and showed potent antibacterial activity in crude brain extract against methicillin-resistant Staphylococcus aureus and neuropathogenic Escherichia coli K1. The size-exclusion spin columns revealed that the active compound(s) are less than 10 kDa in molecular mass. Using cytotoxicity assays, it was observed that pre-treatment of bacteria with lysates inhibited bacteria-mediated host cell cytotoxicity. Using spectra obtained with LC-MS on Agilent 1290 infinity liquid chromatograph, coupled with an Agilent 6460 triple quadruple mass spectrometer, tissues lysates were analysed. Among hundreds of compounds, only a few homologous compounds were identified that contained the isoquinoline group, chromene derivatives, thiazine groups, imidazoles, pyrrole-containing analogs, sulfonamides, furanones, and flavanones and known to possess broad-spectrum antimicrobial properties and anti-inflammatory, anti-tumour, and analgesic properties. Further identification, characterization, and functional studies using individual compounds can act as a breakthrough in developing novel therapeutics against various pathogens including superbugs.

New Is Old, and Old Is New: Recent Advances in Antibiotic-Based, Antibiotic-Free and Ethnomedical Treatments against Methicillin-Resistant Staphylococcus aureus Wound Infections

Staphylococcus aureus is the most common pathogen of wound infections. Thus far, methicillin-resistant S. aureus (MRSA) has become the major causative agent in wound infections, especially for nosocomial infections. MRSA infections are seldom eradicated by routine antimicrobial therapies. More concerning, some strains have become resistant to the newest antibiotics of last resort. Furthermore, horizontal transfer of a polymyxin resistance gene, mcr-1, has been identified in Enterobacteriaceae, by which resistance to the last group of antibiotics will likely spread rapidly. The worst-case scenario, "a return to the pre-antibiotic era", is likely in sight. A perpetual goal for antibiotic research is the discovery of an antibiotic that lacks resistance potential, such as the recent discovery of teixobactin. However, when considering the issue from an ecological and evolutionary standpoint, it is evident that it is insufficient to solve the antibiotic dilemma through the use of antibiotics themselves. In this review, we summarized recent advances in antibiotic-based, antibiotic-free and ethnomedical treatments against MRSA wound infections to identify new clues to solve the antibiotic dilemma. One potential solution is to use ethnomedical drugs topically. Some ethnomedical drugs have been demonstrated to be effective antimicrobials against MRSA. A decline in antibiotic resistance can therefore be expected, as has been demonstrated when antibiotic-free treatments were used to limit the use of antibiotics. It is also anticipated that these drugs will have low resistance potential, although there is only minimal evidence to support this claim to date. More clinical trials and animal tests should be conducted on this topic.