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Abstract
Introduction: Emilia praetermissa is used traditionally for the treatment of infections, wound healing, and gastrointestinal complaints. Despite ethnomedicinal use, systematic chemical characterisation
and laboratory evaluation of the ethanolic aerial fraction remain limited. This study profiles its phytochemicals, antibacterial and antioxidant activities. Method: The aerial parts were extracted with 70% ethanol from which the ethanolic fraction were obtained and analyzed by HPLC and GC-MS to identify non-volatile and volatile constituents. Antibacterial activity against six clinical isolates (Escherichia coli, Staphylococcus aureus, Enterobacter cloacae, Bacillus subtilis, Pseudomonas aeruginosa, Bacillus cereus) was assessed by agar well diffusion method, Minimum Inhibitory Concentration (MIC) (agar dilution) and Minimum Bactericidal Concentration (MBC) determinations were carried out. Antioxidant
The capacity was measured using 1,1-diphenyl-2-picrylhydrazyl (DPPH), Ferric reducing antioxidant power (FRAP), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) and Total Antioxidant Capacity (TAC) assays; ascorbic acid served as the standard.
Result: HPLC detected varying non-volatile constituents of which flavonoids (notably Flavanol, epicathecin, narigenin) were present with Cumulative Flavonoid concentration of 66.083 μg/mL (21.15%) while GC-MS identified 27 volatile/semi-volatile compounds dominated by fatty acid methyl esters and terpenoids. The extract produced moderate inhibition zones (15–18 mm) against the six clinical isolates. MIC testing showed complete growth inhibition at 40 mg/mL for all organisms; at 20 mg/mL only S. aureus, P. aeruginosa and B. cereus remained inhibited. MBC at 40 mg/mL was bactericidal for S. aureus, E. cloacae, P. aeruginosa and B. cereus. Staphylococcus aureus, Enterobacter cloacae, Pseudomonas aeruginosa and Bacillus cereus all have MBC/MIC ratios ≤ 4 and are therefore classified as bactericidal. In antioxidant assays the extract demonstrated strong radical scavenging (high DPPH and ABTS at increasing concentrations), modest FRAP activity, and a concentration dependent increase in TAC. Conclusion: The ethanolic aerial fraction of Emilia praetermissa contains a complex mixture of
alkaloids, phenolics, flavonoids, saponins and lipidic constituents that together confer measurable antibacterial and antioxidant activities in vitro.
and laboratory evaluation of the ethanolic aerial fraction remain limited. This study profiles its phytochemicals, antibacterial and antioxidant activities. Method: The aerial parts were extracted with 70% ethanol from which the ethanolic fraction were obtained and analyzed by HPLC and GC-MS to identify non-volatile and volatile constituents. Antibacterial activity against six clinical isolates (Escherichia coli, Staphylococcus aureus, Enterobacter cloacae, Bacillus subtilis, Pseudomonas aeruginosa, Bacillus cereus) was assessed by agar well diffusion method, Minimum Inhibitory Concentration (MIC) (agar dilution) and Minimum Bactericidal Concentration (MBC) determinations were carried out. Antioxidant
The capacity was measured using 1,1-diphenyl-2-picrylhydrazyl (DPPH), Ferric reducing antioxidant power (FRAP), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) and Total Antioxidant Capacity (TAC) assays; ascorbic acid served as the standard.
Result: HPLC detected varying non-volatile constituents of which flavonoids (notably Flavanol, epicathecin, narigenin) were present with Cumulative Flavonoid concentration of 66.083 μg/mL (21.15%) while GC-MS identified 27 volatile/semi-volatile compounds dominated by fatty acid methyl esters and terpenoids. The extract produced moderate inhibition zones (15–18 mm) against the six clinical isolates. MIC testing showed complete growth inhibition at 40 mg/mL for all organisms; at 20 mg/mL only S. aureus, P. aeruginosa and B. cereus remained inhibited. MBC at 40 mg/mL was bactericidal for S. aureus, E. cloacae, P. aeruginosa and B. cereus. Staphylococcus aureus, Enterobacter cloacae, Pseudomonas aeruginosa and Bacillus cereus all have MBC/MIC ratios ≤ 4 and are therefore classified as bactericidal. In antioxidant assays the extract demonstrated strong radical scavenging (high DPPH and ABTS at increasing concentrations), modest FRAP activity, and a concentration dependent increase in TAC. Conclusion: The ethanolic aerial fraction of Emilia praetermissa contains a complex mixture of
alkaloids, phenolics, flavonoids, saponins and lipidic constituents that together confer measurable antibacterial and antioxidant activities in vitro.
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