@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 {1213, title = {Chemical Composition and Some Biological Activities of the Methanolic Encephalartos ferox Fruit Extract}, journal = {Pharmacognosy Journal}, volume = {12}, year = {2020}, month = {August 2020}, pages = {1190-1197}, type = {Review Article}, chapter = {1190}, abstract = {

Background: Although literature reports the therapeutic properties of Encephalartos ferox, there are limited pharmacological studies of its fruit. Objective: This study sought to evaluate the antibacterial, antioxidant, anti-quorum sensing and in vitro cytotoxic activities of the methanolic E. ferox fruit extract. Methods: The chemical constituent of the methanolic fruit extract was analysed using gas chromatography-mass spectrometry. Antibacterial activity of the extract was investigated against Staphylococcus aureus (ATCC 25923), Bacillus cereus (ATCC 10102), Escherichia coli (ATCC 25922) and Pseudomonas aeruginosa (ATCC 27853) using the broth dilution method. The standard 2.2-diphenyl-1-picrylhydrazyl (DPPH) and 2.2-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) methods were used to evaluate the scavenging activities of the extract. Anti-quorum sensing activity was assessed against biosensor strain- Chromobacterium violaceum (ATCC 12472). Cytotoxicity in HepG2 cells was investigated using the tetrazolium-based colorimetric (MTT) assay. Results: The extract revealed eight volatile compounds with cis-Vaccenic acid (87.06\%) and 9-Octadecenoic acid, 1,2,3-propanetriyl ester (5.21\%) as the major components. Antibacterial activity against all tested strains with minimum inhibitory concentration range of 1.56 - 12.5 mg/mL was observed. The DPPH and ABTS assays demonstrated scavenging activities with the median inhibitory concentration (IC50) values of 0.09 mg/mL and 0.003 mg/mL, respectively. The extract also displayed strong anti-quorum sensing activity with 93\% inhibition of violacein production at 25 mg/mL. A half maximum inhibitory concentration (IC50) of 5370 μg/mL was computed in HepG2 cells. Conclusion: The extract has potential to be used as a source of therapeutic compounds in pharmaceutical applications.

}, keywords = {Anti-quorum sensing, Antibacterial, Antioxidant, Cytotoxicity}, doi = {10.5530/pj.2020.12.167}, author = {Phakamani Hopewell Tsilo and Sidney Tsolanku Maliehe and Jabulani Siyabonga Shandu and Rene Khan} } @article {1253, title = {Computational Evaluation of ADMET Properties and Bioactive Score of Compounds from Encephalartos ferox}, journal = {Pharmacognosy Journal}, volume = {12}, year = {2020}, month = {September 2020}, pages = {1357-1362}, type = {Research Article}, chapter = {1357}, abstract = {

Background: Plant based products are recognised as sources of drugs for treatment of diseases. Objective: The study aimed at predicting the physicochemical, pharmacokinetics, drug-likeness and toxicity of the compounds identified from the methanolic Encephalartos ferox fruit extract. Methods: The physicochemical, pharmacokinetics properties and bioactive scores of the compounds were predicted using SwissADME and Molinspiration computational tools. Drug-likeness of the compounds was evaluated based on the Lipinski rule of five (Ro5). In silico mutagenicity, carcinogenicity and inhibition of human ether-a-go-go-related (hERG) gene were also investigated using PreADMET web tool. Results: The physicochemical properties showed the compounds, except 9-Octadecenoic acid, 1, 2, 3-propanetriyl ester to adhere to Ro5. The evaluation of their inhibitory effects profile in several cytochrome P450 isoforms indicate that all the compounds are not the inhibitors of CYP2C19 and CYP3A4 whereas some inhibited CYP1A2, CYP2C9 and CYP2D6. The drug-likeness evaluation employed Ro5 as a filter and all compounds complied with it except for 9-Octadecenoic acid, 1, 2, 3-propanetriyl ester. About 50\% of the tested compound were found to be safe as they did not exhibit antimutagenic and carcinogenic effects. Moreover, the risk of inhibition of hERG gene revealed to be low to medium risk depending on the compound. Conclusion: The calculated physicochemical and pharmacokinetic properties suggest that most of the compounds are safe and have promising oral bioavailability.

}, keywords = {Bioactive score, Compounds, Pharmacokinetic; Drug-likeness, Toxicity}, doi = {10.5530/pj.2020.12.187}, author = {Tsolanku Sidney Maliehe and Phakamani Hopewell Tsilo and Jabulani Siyabonga Shandu} } @article {1215, title = {In vitro Antibacterial and In silico Toxicity Properties of Phytocompounds from Ricinus communis Leaf Extract}, journal = {Pharmacognosy Journal}, volume = {12}, year = {2020}, month = {August 2020}, pages = {977-983}, type = {Original Article}, chapter = {977}, abstract = {

Background: The rapid occurrence of multiple drug resistance and adverse side effects of aliphatic medicine threatens human health. Medicinal plants are known to possess phytocompounds with antibacterial activity and less toxic effects. Objective: This study aimed at determining the chemical composition of the methanolic Ricinus communis{\textquoteleft} leaf extract and evaluate their antibacterial and toxic effects. Methods: R. communis leaves were extracted by acetone, chloroform, ethanol and methanol. The extracts were assessed for antibacterial activity against Bacillus cereus (ATCC 10102), Escherichia coli (25922), Staphylococcus aureus (25923) and Pseudomonas aeruginosa (ATCC 27853) using agar-well diffusion and microwell dilution methods. The extracts were screened for alkaloids, flavonoids, saponins, steroids, tannins and terpenoids. The chemical constituents of the methanolic extract were analysed by gas chromatography {\textendash} mass spectrophotometry (GC-MS). In silico toxicity of the phytocompounds were investigated using PreADMET tool. Results: The methanol extract showed the antibacterial activity against the bacterial strains, with the MIC values of 1.56 mg/mL against B. cereus, 3.13 mg/mL and 6.25 mg/mL against P. aeruginosa and E. coli. The extracts revealed the presence of alkaloids, flavonoids, glycosides, steroids, tannins, terpenoids and saponins. The GC-MS showed phytocompounds namely hexadecanoic acid, methyl ester (0.62\%), tridecanoic acid (0.76\%), pentafluoropropionic acid, nonyl ester (0.85\%), 10-octadecanoic acid, methyl ester (2.93\%) and cis-vaccenic acid (94.84\%). Hexadecanoic acid, methyl ester was predicted not to have mutagenic and carcinogenic effects. Moreover, all compounds exhibited low inhibitory risks against hERG gene. Conclusion: R. communis leaf extract has potential to be used as a safe source of therapeutic compounds.

}, keywords = {Antibacterial activity, Chemical compounds, Ricinus communis, Toxicity}, doi = {10.5530/pj.2020.12.138}, author = {Sandile Nduduzo Mboyazi and Mduduzi Innocent Nqotheni and Tsolanku Sidney Maliehe and Jabulani Siyabonga Shandu} }