GC-MS analysis and antibacterial activities of some plants belonging to the genus Euphorbia on selected bacterial isolates

Plant extracts have always been used as an alternative source of antimicrobial compounds. The recent spread of multi-drug-resistant bacteria and their increased treatment costs necessitated the study of alternative, cheap sources. The family Euphorbiaceae has over 300 genera and is widely used in traditional medicine. Euphorbia triaculeata, E. fractiflexa, and E. inarticulata were selected to study the antibacterial activity of the methanolic extract against 13 Gram-positive Staphylococcus aureus strains (including methicillin-resistant S. aureus) and 2 Gram-negative isolates, Escherichia coli and Klebsiella pneumoniae, by the Kirby Bauer Disc diffusion test. Paper discs with different concentrations of the extracts (100, 50, and 25 µg mL−1) were prepared, along with the methanol control and standard antibiotic control. A gas chromatography-mass spectrometry (GC/MS) analysis was done to study the phytochemical components present in the plant methanolic extracts. A total of 50 different phytochemical compounds with antibacterial activity were detected by GC/MS analysis of the plants. Twenty-five compounds were detected in E. inarticulata, 24 in E. triaculeata, and 21 in E. fractiflexa. Out of 37 compounds found in E. inarticulata and E. triaculeata, 12 (32.43%) were common to both. Eleven (22%) compounds were unique to E. inarticulata, while 9 (18%) compounds were unique to E. triaculeata, and 13 (26%) compounds were unique to E. fractiflexa. E. fractiflexa showed the best antibacterial activity against MRSA and Gram-negative bacteria. It also showed higher unique compounds with antibacterial activity (26%), followed by E. inarticulata (11, 22%). This is the first GC/MS analysis and antimicrobial activity report of E. triaculeata and E. fractiflexa

Antibiofilm Potential of Coelomic Fluid and Paste of Earthworm <i>Pheretima posthuma</i> (Clitellata, Megascolecidae) against Pathogenic Bacteria

Antibiotic drug resistance is a global public health issue that demands new and novel therapeutic molecules. To develop new agents, animal secretions or products are used as an alternative agent to overcome this problem. In this study, earthworm (Pheretima posthuma) coelomic fluid (PCF), and body paste (PBP) were used to analyze their effects as antibiofilm agents against four bacterial isolates MH1 (Pseudomonas aeruginosa MT448672), MH2 (Escherichia coli MT448673), MH3 (Staphylococcus aureus MT448675), and MH4 (Klebsiella pneumoniae MT448676). Coelomic fluid extraction and body paste formation were followed by minimum inhibitory concentrations (MICs), biofilm formation time kinetics, and an antibiofilm assay, using heat and cold shock, sunlight exposure auto-digestion, and test tube methods. The results showed that the MIC values of PCF and PBP against S. aureus, P. aeruginosa, K. pneumoniae, and E. coli bacterial isolates ranged from 50 to 100 μg/mL, while, the results related to biofilm formation for P. aeruginosa, S. aureus, and K. pneumoniae strains were observed to be highly significantly increased (p E. coli produced a significant (p p > 0.05) antibiofilm activity against all the selected strains (MH1-MH4). At 50 μg/mL concentration, both PCF and PBP showed significant (p p p < 0.001) biofilm inhibition at 150 and 200 μg/mL concentrations. Moreover, more than 90% biofilm inhibition was observed at 200 μg/mL of PCF, while in the case of the PBP, <96% biofilm reduction (i.e., 100%) was also observed by all selected strains at 200 μg/mL. In conclusion, earthworm body fluid and paste have biologically active components that inhibit biofilm formation by various pathogenic bacterial strains. For future investigations, there is a need for further study to explore the potential bioactive components and investigate in depth their molecular mechanisms from a pharmaceutical perspective for effective clinical utilization

Screening of Bioactive Compounds from Endophytic Marine-Derived Fungi in Saudi Arabia: Antimicrobial and Anticancer Potential

Nowadays, endophytic fungi represent a rich source of biological active compounds. In the current study, twelve endophytic fungal species were isolated from Avicennia marina leaves. From the isolates, Aspergillus niger, Penicillium rubens and Alternaria alternata recorded the highest isolation frequency (80%), relative density (12.5%) and antimicrobial activity. The antimicrobial and anticancer activities of P. rubens were more effective than those of A. niger and A. alternata; therefore, its identification was confirmed via the ITS rRNA gene. Filtrate extracts of P. rubens, A. alternata and A. niger were analyzed using GC-MS and showed different detected constituents, such as acetic acid ethyl ester, N-(4,6-Dimethyl-2-pyrimidinyl)-4-(4-nitrobenzylideneamino) benzenesulfonamide, 1,2-benzenedicarboxylic acid, hexadecanoic acid and octadecanoic acid. Filtrate extract of P. rubens exhibited the presence of more compounds than A. alternata and A. niger. Bacillus subtilis, Staphylococcus&nbsp;aureus, Escherichia coli, Pseudomonas aeruginosa, Candida albicans and Aspergillus fumigatus were more inhibited by P. rubens extract than A. alternata or A. niger, with inhibition zones of 27.2 mm, 22.21 mm, 26.26 mm, 27.33 mm, 28.25 mm and 8.5 mm, respectively. We observed negligible cytotoxicity of P. rubens extract against normal cells of human lung fibroblasts (WI-38 cell line), unlike A. alternata and A. niger extracts. Proliferation of prostate cancer (PC-3) was inhibited using P. rubens extract, exhibiting mortality levels of 75.91% and 76.2% at 200 &micro;g/mL and 400 &micro;g/mL of the extract. Molecular docking studies against the crystal structures of C. albicans (6TZ6) and the cryo-EM structure of B. subtilis (7CKQ) showed significant interactions with benzenedicarboxylic acid and N-(4,6-dimethyl-2-pyrimidinyl)-4-(4-nitrobenzylideneamino) benzenesulfonamide as a constituent of P. rubens extract. N-(4,6-dimethyl-2-pyrimidinyl)-4-(4-nitrobenzylideneamino) benzenesulfonamide had the highest scores of &minus;6.04905 kcal/mol and &minus;6.590 kcal/mol towards (6tz6) and (7CKQ), respectively