ANTIMICROBIAL ACTIVITY

Artemisia annua (Asteraceae), commonly known as sweet wormwood, has been widely used in traditional medicine for treating fevers, malaria, and various infections. While it’s active component, artemisinin, is well known for its antimalarial properties, recent studies have suggested that other bioactive compounds in A. annua may also exhibit significant antimicrobial activity. However, the antimicrobial potential of A. annua leaf extract, particularly against multidrug-resistant bacteria, remains underexplored. This study was therefore designed to evaluate the antimicrobial potential of A. annua leaves and identify constituents with potential antimicrobial activity. The research involved the collection and authentication of A. annua leaves, extraction and fractionation using organic solvents of varying polarity (n-hexane, dichloromethane, ethyl acetate, and methanol), acute toxicity screening and antimicrobial testing against selected bacterial strains. Gas Chromatography-Mass Spectrometry (GC-MS) and High-Performance Liquid Chromatography (HPLC) were employed to identify bioactive compounds in the most active fractions. The results showed that the ethyl acetate fraction exhibited the highest antimicrobial activity, with significant inhibitory effects on a broad spectrum of bacteria. Key bioactive compounds
identified include scopoletin, deoxyqinghaosu, naringenin, kaempferol, and sapogenin. Acute toxicity studies revealed a high safety margin for A. annua extract. These findings highlight A. annua’s potential as a natural antimicrobial agent, offering a sustainable and cost-effective alternative to synthetic antibiotics, particularly in resource-limited settings.

Antimicrobial resistance (AMR) poses a growing global health threat, necessitating the development of alternative therapeutic agents. Cymbopogon citratus (lemongrass), a perennial herb rich in bioactive compounds such as citral, geraniol, and flavonoids, has demonstrated significant antimicrobial, antioxidant, and anti-inflammatory properties. This study investigates the antimicrobial efficacy of soap formulated with Cymbopogon citratus extract obtained via n- hexane solvent extraction. Fresh Cymbopogon citratus leaves were collected from Obagie community, Edo State, Nigeria, shade-dried, and pulverized. A total of 500 g of powdered leaves was macerated in 2.5 L of analytical-grade n-hexane for seven days at room temperature. The extract was filtered and concentrated using a rotary evaporator at 40 °C. Phytochemical screening of the n-hexane extract confirmed the presence of alkaloids, flavonoids, saponins, terpenoids, and phenolic compounds. Soap was prepared via cold saponification method using palm and coconut oils. Antimicrobial assays were conducted on the extract and soap using concentrations of 100 mg/ml, 200 mg/ml, and 400 mg/ml against bacterial and fungal strains. The n-hexane extract showed the highest zones of inhibition against Staphylococcus aureus (28 mm) and Klebsiella pneumoniae (26 mm) at 400 mg/ml. The formulated soap demonstrated notable activity against Pseudomonas aeruginosa (20 mm), Klebsiella pneumoniae (17.5 mm), and Penicillium spp. (22.5 mm) These findings support the potential of Cymbopogon citratus-based soap as a natural, safe, and effective topical antimicrobial agent, particularly in resource-limited settings.