@article {1992, title = {Antibacterial and Anti-quorum Sensing Activities of Erianthemum dregei{\textquoteleft}s Leaf Extract and Molecular Docking}, journal = {Pharmacognosy Journal}, volume = {15}, year = {2023}, month = {April 2023}, pages = {279-285}, type = {Original Article }, chapter = {279}, abstract = {

Background: The increasing incidence of multi-drug resistance among pathogens has propelled researchers to search for novel antimicrobial and anti-quorum sensing agents characterised by different mechanisms and high potency. Objective: The study aimed at investigating the antibacterial and antiquorum sensing properties of compounds from Erianthemum dregei and their molecular interactions with the target proteins. Methods: The methanolic leaf extract from E. dregei was evaluated for its chemical composition and antibacterial activity using gas chromatography-mass spectrophotometry (GC-MS) and micro-dilution method, respectively. The inhibition of violacein production in Chromobacterium violaceum (ATCC 07) was assayed as anti-quorum sensing activity using micro-dilution method. The molecular docking of the GC-MS ligands and penicillin-binding protein 2x (PDP2) and CviR was executed using AutoDock Vina. Results: The two volatile compounds namely phytol (93.58\%) and 3-tetradecyn-1-ol (6.42\%) were shown by GC-MS. The extract exhibited antibacterial activity against the selected bacterial strains with minimum inhibitory concentration (MIC) values ranging from 1.56 to 3.125 mg/mL. The maximum inhibition of violacein production of 53.93\% was observed at 1.56 mg/mL. Both compounds had docking scores of more than -6.0 kcal/mol against the target proteins. Conclusion: The results revealed that the extract is a potential source of antibacterial and anti-quorum sensing compounds and thus can have pharmacological applicability.

}, keywords = {Anti-quorum sensing activity, Antibacterial activity, Erianthemum dregei, Molecular docking}, doi = {10.5530/pj.2023.15.39}, author = {Tsolanku Sidney Maliehe and Tlou Nelson Selepe and Nokuthula Nomusa Mthembu and Jabulani Siyabonga Shandu} } @article {1367, title = {Antioxidant, Anti-quorum Sensing and Cytotoxic Properties of the Endophytic Pseudomonas aeruginosa CP043328.1 {\textquoteright}s Extract}, journal = {Pharmacognosy Journal}, volume = {13}, year = {2021}, month = {March 2021}, pages = {332-340}, type = {Original Article}, chapter = {332}, abstract = {

Background: Novel bioactive compounds are in high demand to combat challenges of microbial resistance. In recent years, secondary metabolites from endophytic bacteria have drawn attention from researchers due to their novel structures and significant biological activities. Objective: This study aimed at extracting secondary metabolites from endophytic Pseudomonas aeruginosa CP043328.1 from Anredera cordifolia leaves for their biological activities. Methods: The anti-SMASH was used to predict the biosynthetic gene clusters of P. aeruginosa CP043328.1. The bacteria was resuscitated on Nutrient agar. Ethyl acetate was used to extract the secondary metabolites. Chemical composition of the secondary metabolites was evaluated using gas chromatography-mass spectrometry (GC-MS) and 2, 2-diphenyl-1-picrylhydrazyl (DPPH), and 2, 2-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) methods were used to analyze the scavenging activity. Anti-quorum sensing activity was investigated using Chromobacterium violacuem ATCC 12472 as the biological indicator. Cytotoxicity assay was performed using a tetrozolium-based columetric (MTT) assay. Results: The bacterium has 12 gene clusters that encode for secondary metabolites. The extract revealed 15 volatile constituents with diisooctyl phthalate (50.51\%) and [1, 2, 4] oxadiazole, 5-benzyl-3 (10.44\%) being the major compounds. The extract revealed scavenging capabilities with IC50 of 0.625 mg/ml for DPPH and 0.15 mg/ml for ABTS. It displayed anti-quorum sensing activity with 88\% violacein inhibition at 3.31 mg/ml. According to MTT assay, the extract was found to be safe for use up to 2000 μg/mL. Conclusion: P. aeruginosa CP043328.1 shows a potential use as a source of pharmacologically important metabolites.

}, keywords = {Anti-quorum sensing activity, antioxidant activity, Chemical composition, Cytotoxicity assay, Pseudomonas aeruginosa CP043328.1}, doi = {10.5530/pj.2021.13.43}, author = {L S Ngidi and C I Nxumalo and J S Shandu and T S Maliehe and K Rene} }