scholarly journals ANTI-METHICILLIN RESISTANT STAPHYLOCOCCUS AUREUS POTENTIAL OF PHYTOCHEMICALS IN TERMINALIA CATAPPA AND THEIR PROPOSED IN SILICO MECHANISM OF ACTION

Author(s):  
LOKESH RAVI ◽  
DIVYA JINDAM ◽  
SUGANYA KUMARESAN ◽  
VENKATESH SELVARAJ ◽  
JAYARAMA REDDY

Objective: The objective of this study was to investigate the antibacterial potential of leaves of this Terminalia catappa and identify the mechanism of action for those phytochemicals present in this leaves. Methods: Phytochemicals were extracted using maceration and the extracts were analyzed using gas chromatography–mass spectrometry (GC-MS) to identify the chemical structure. Antibacterial potential was evaluated using agar well diffusion. The phytochemicals were subjected to in silico protein–ligand docking study to identify the mechanism of action. Results: In vitro antibacterial study demonstrated that the ethanol extract of the leaves has significant antibacterial activity against Staphylococcus aureus (SA) and methicillin-resistant SA (MRSA) with a zone of inhibition of 16 mm and 18 mm, respectively, at a concentration of 2 mg/ml. The chloroform and hexane extracts of the leaves did not demonstrate any significant activity. Based on GC-MS analysis and literature review, 12 phytochemicals were identified to be present in the ethanol extract of the T. catappa leaves. These molecules were subjected to in silico protein–ligand docking study against common drug target proteins of SA and MRSA. Among the studied ligands, granatin A demonstrated the highest significance to inhibit topoisomerase IV with a binding energy of −11.3 kcal/mol and produced 7 hydrogen bonds, followed by punicalin with −10.7 kcal/mol binding energy toward penicillin-binding protein 2a with 6 hydrogen bonds. Conclusion: Phytochemicals of T. catappa demonstrates significant drug ability potential against drug-resistant MRSA pathogen and demands further investigation on their individual activity and mechanism.

Author(s):  
RACHAEL EVANGELINE ◽  
NIHAL AHMED

Objective: The aim of this study is to investigate the potential of Persea americana extracts for their Anti-Parkinson application through an in-silico docking study. Methods: PubChem and protein data bank databases were used to retrieve 3D structures. AutoDock4 was used to perform protein-ligand docking analysis. PyMOL was used to visualize the docking results. Results: Among the 30 ligand, the highest affinity was demonstrated by Hesperidin with a free binding energy of −6.8 kcal/mol and formation of five hydrogen bonds. The second highest significance was demonstrated by Biphenyl 4-(4-diethylaminobenzylidenamino) with a free binding energy of −5.9 kcal/mol with the formation of 2 hydrogen bonds. Among the three sets of phytochemicals from different solvent extracts, water extract demonstrated the highest potential as Anti-Parkinson active. Conclusion: P. americana extracts were analyzed for their Anti-Parkinson potential, and among the three extracts, the aqueous extract was predicted to have significant Anti-Parkinson potential, based on in silico docking analysis, due to the presence of active phytochemicals such as Hesperidin and others.


Author(s):  
RAMESH BS ◽  
LOKESH RAVI

Objective: Aim of this study is to evaluate theanti-diabetic activity of Pseuderanthemum bicolor commonly called limang-sugat by inhibiting alpha-amylase protein. Methods: Leaves of P. bicolor were extracted with methanol, chloroform, and ethyl acetate. The extracts were subjected for alpha-amylase inhibition assay and gas chromatography–mass spectrometry (GC–MS) analysis. Phytochemical compounds identified by GC-MS were subjected for protein-ligand docking study against alpha-amylase protein. Acarbose was used as a positive standard drug. Results: The major bioactive compounds obtained from methanol, chloroform, and ethyl acetate extracts were 1,6;2,3-Dianhydro-4-Deoxy-Beta-D-Ribo-Hexopyranose, Pseduosarsasapogenin-5,20-Dien, methyl ether/Hexatriacontane, Di-N-decylsulfone/Octadecanal, and squalene, respectively. A total of 19 secondary metabolites were subjected for protein–ligand docking study against the alpha-amylase protein. The reference drug acarbose demonstrated binding energy of −7.8 Kcal/mol and formed 20 hydrogen bonds with the enzyme. Acarbose signified high polar interaction with the amylase enzyme. Among the 19 test ligands, “2,2-Dibromocholestanone” from ethyl acetate extract exemplified the highest binding energy of −9.3 Kcal/mol. The next highest remarkable inhibition was showed by “Pseduosarsasapogenin-5,20-Dien Methyl Ether” present in the methanol extract, with a binding energy of -9.3 Kcal/mol with the formation of 2 hydrogen bonds. Conclusion: From the result, it could be concluded that the P. bicolor leaves contain various bioactive compounds which are considered as a good anti-diabetic drug.


2021 ◽  
Vol 12 (2) ◽  
pp. 180
Author(s):  
Fuji Astuti Febria ◽  
Yossi Rahmadeni ◽  
Amri Bachtiar

The excessive use of antibiotics in the treatment of infections or diseases caused by Staphylococcus aureus is the main cause of antibiotic resistance. Methicillin-resistant S. aureus (MRSA) strains are a serious problem because of their wide distribution in the clinical environment and the living community, so it is necessary to search for antibacterial sources from natural products and traditional medicines such as Kayu racun leaves (Rhinacanthus nasutus). Information regarding the content of the active ingredient and the antibacterial potential of the ethanol extract of Kayu racun leaves is still limited. This study aims to test the phytochemical and antibacterial activity of the ethanol extract of Kayu racun leaves against S. aureus and MRSA bacteria by invitro. The research used an experimental method and was divided into two stages, namely; Phytochemical test of the ethanol extract of Kayu racun leaves using the Thin Layer Chromatography (TLC) method and the antibacterial activity test of the ethanol extract of Kayu racun leaves against S. aureus and MRSA using the paper disc diffusion method. Based on the research results, it can be concluded that the ethanol extract of Kayu racun leaves contains alkaloids, phenols, and flavonoids. The best antibacterial activity was found at a concentration of 100 mg/ml with an inhibition zone diameter of 26.20 mm against S. aureus and 17.90 mm against MRSA.


2021 ◽  
Vol 11 (7) ◽  
pp. 3206
Author(s):  
Lorina I. Badger-Emeka ◽  
Promise Madu Emeka ◽  
Hairul Islam M. Ibrahim

Methicillin-resistant Staphylococcus aureus (MRSA) infection is detrimental to hospitalized patients. With diminishing choices of antibiotics and the worry about resistance to colistin in synergistic combined therapy, there are suggestions for the use of herbal derivatives. This investigation evaluated the synergistic effects of Nigella sativa (NS) in combination with beta-lactam (β-lactam) antibiotics on extreme drug-resistant (XDR) MRSA isolates. NS concentrations of 10, 7.5, 5.0, 2.5, 1.0, and 0.1 µg/mL, alone and in combination with β-lactam antibiotics, were used to determine the antimicrobial susceptibility of MRSA isolates by the well diffusion method. Time–kill assays were performed using a spectrophotometer, with time–kill curves plotted and synergism ascertained by the fractional inhibitory concentration (FIC). Scanning and transmission electron microscopy were used to gain insight into the mechanism of action of treated groups. Isolates were inhibited by the NS concentrations, with differences in the zones of inhibition being statistically insignificant at p < 0.05. There were statistically significant differences in the time–kill assay for the MRSA isolates. In addition, NS combined with augmentin showed better killing than oxacillin and cefuroxime. The mechanism of action shown by the SEM and TEM results revealed cell wall disruption, which probably created interference that led to bacterial lysis.


2021 ◽  
Vol 14 (5) ◽  
pp. 420
Author(s):  
Tanveer Ali ◽  
Abdul Basit ◽  
Asad Mustafa Karim ◽  
Jung-Hun Lee ◽  
Jeong-Ho Jeon ◽  
...  

β-Lactam antibiotics target penicillin-binding proteins and inhibit the synthesis of peptidoglycan, a crucial step in cell wall biosynthesis. Staphylococcus aureus acquires resistance against β-lactam antibiotics by producing a penicillin-binding protein 2a (PBP2a), encoded by the mecA gene. PBP2a participates in peptidoglycan biosynthesis and exhibits a poor affinity towards β-lactam antibiotics. The current study was performed to determine the diversity and the role of missense mutations of PBP2a in the antibiotic resistance mechanism. The methicillin-resistant Staphylococcus aureus (MRSA) isolates from clinical samples were identified using phenotypic and genotypic techniques. The highest frequency (60%, 18 out of 30) of MRSA was observed in wound specimens. Sequence variation analysis of the mecA gene showed four amino acid substitutions (i.e., E239K, E239R, G246E, and E447K). The E239R mutation was found to be novel. The protein-ligand docking results showed that the E239R mutation in the allosteric site of PBP2a induces conformational changes in the active site and, thus, hinders its interaction with cefoxitin. Therefore, the present report indicates that mutation in the allosteric site of PBP2a provides a more closed active site conformation than wide-type PBP2a and then causes the high-level resistance to cefoxitin.


Jurnal Kimia ◽  
2019 ◽  
pp. 221
Author(s):  
N. M. P. Susanti ◽  
N. P. L. Laksmiani ◽  
N. K. M. Noviyanti ◽  
K. M. Arianti ◽  
I K. Duantara

Atherosclerosis is a chronic inflammatory disease that begins with endothelial dysfunction, it caused fat accumulation and plaque growth in the inner arteries walls. Endothelial dysfunction will activate the Mitogen Activated Protein Kinase (MAPK) pathway involving ERK1, ERK2, JNK1, JNK2, and p38MAPK proteins, as well as the Nuclear Factor Kappa B (NF-kB) pathway involving IKK proteins. Terpinen-4-ol is constituent found in the bangle rhizome. The purpose of this study were to determine the affinity and mechanisms of terpinen-4-ol against ERK1, ERK2, JNK1, JNK2, and p38MAPK proteins as anti-inflammatory in atherosclerosis performed using molecular docking method. The study was conducted exploratively with several steps such as preparation and optimization of terpinen-4-ol structure, preparation of 3D ERK1, ERK2, JNK1, JNK2, and p38MAPK proteins, validation method of molecular docking, and docking terpinen-4-ol in these proteins. The docking result are assessed from the binding energy and hydrogen bonds formed between terpinen-4-ol and proteins. The smaller value of binding energy terpinen-4-ol with target proteins showed the complex that form more stable. The result showed that terpinen-4-ol and has activity in inhibiting the inflammatory process because it is able to disturb ERK1, ERK2, JNK1, JNK2, and p38MAPK proteins with respective bond energy values -5,12; -5,24; -5,08; -5,88; and -4,99 Kcal/mol. The molecular mechanism in inhibiting the activity of ERK1, ERK2, JNK1, JNK2, and p38MAPK proteins is through the formation of hydrogen bonds in these proteins. These results show that terpinen-4-ol have the potential to inhibit inflammatory process and the formation of atherosclerotic plaque can be obstructed. Keywords : atherosclerosis, terpinen-4-ol, molecular docking, in silico


Molecules ◽  
2014 ◽  
Vol 19 (4) ◽  
pp. 4491-4509 ◽  
Author(s):  
Claudia Avitia-Domínguez ◽  
Erick Sierra-Campos ◽  
José Salas-Pacheco ◽  
Hugo Nájera ◽  
Arturo Rojo-Domínguez ◽  
...  

2022 ◽  
Author(s):  
Mariah Ndilimeke Muhongo ◽  
Mourine Kangogo ◽  
Christine Bii

The complete halt in the synthesis of new effective antimicrobial compounds is a global concern. Pathogenic microorganisms' virulence mechanisms seem to have a significant impact on their pathogenesis. The purpose of this study was to examine the antimicrobial activity of the ethanol and methanol fractions of Pechuel-Loeschea leubnitziae leaf extract, as well as its effect on the expression level of virulence-associated genes.The extract's fractions were evaluated for antimicrobial activity against Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, Klebsiella pneumoniae (clinical), Methicillin-resistant Staphylococcus aureus, and Candida albicans ATCC 90029. The test organism's antibiogram pattern was determined. The extracts' attenuation effect on the target genes of the susceptible organisms was investigated employing relative quantification using RT-qPCR. The test organism's antibiogram pattern revealed that it was drug-resistant, intermediate, and sensitive. The extracts tested positive for antimicrobial activity against Methicillin-resistant Staphylococcus aureus and Candida albicans ATCC 90029, with zones of inhibition varying from 20.33 to 29 mm. The lowest recorded MIC value was 4.688 mg/ml, while the highest was 37.5 mg/ml. In contrast to the methanol extract, the ethanol extract had a cidal action at a lower dose. The ethanol extract's Sub-MIC (18.25 mg/ml) merely reduced the expression of the hly gene in MRSA. The MRSA virulence genes were not suppressed by the sub-MIC of methanol extract (18.25 mg/ml). Notably, the expression of als1, pbl1, and sap1 in Candida albicans ATCC 90029 was significantly attenuated when exposed to sub-MICs of ethanol extract (2,344 mg/ml) and methanol extract (9.375 mg/ml). Per the findings of this research, the leaves of P. leubnitziae could be a source of an effective antimicrobial agent in the therapy of MRSA/Candida-related disorders.


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