Antioxidant Activity, Phytochemical Content and Antibacterial Activity of Extracts of Aloiampelos ciliaris
| dc.contributor.author | Mayau, John Kirimi | |
| dc.date.accessioned | 2026-03-11T13:14:26Z | |
| dc.date.available | 2026-03-11T13:14:26Z | |
| dc.date.issued | 2025-11 | |
| dc.description | A Thesis Submitted in Partial Fulfillment of the Requirements for the Award of the Degree of Master of Science (Chemistry) in the School of Pure and Applied Sciences of Kenyatta University, November, 2025 Supervisor: 1.Wilson Njue 2.Henry Mwangi 3.John Maingi | |
| dc.description.abstract | Extensive research on medicinal plants has revealed their antibacterial, antifungal, and antioxidant properties. However, the increasing prevalence of bacterial resistance to conventional antibiotics highlights the need to identify new bioactive compounds from medicinal plants. Currently, natural products account for over 50 % of drugs used in the treatment of different infections. Within this context, the Aloe genus (family Asphodelaceae), comprising approximately 500 Aloe species globally and about 50 species in Kenya, has a long-standing history of medicinal use. Notably, Aloe arborescence, Aloe ferox, and Aloe perryli have been extensively documented for their therapeutic potential. Traditionally, Aloe extracts have been employed for anti-malarial, anti-diabetic, anti-inflammatory, ornamental, and green manure purposes. Despite this established knowledge, inadequate information exists regarding the phytochemical composition, therapeutic evaluation, antioxidant activity, and antibacterial properties of Aloiampelos ciliaris (A. ciliaris). The present study, therefore, aimed to screen for phytochemicals (tannins, phenols, flavonoids, cardiac glycosides), evaluate antioxidant and antibacterial activities, and determine the total phenolic and flavonoid content of A. ciliaris. Plant samples were collected from Meru County and macerated in 80 % methanol for 48 hours, followed by solvent partitioning (n-hexane, dichloromethane, EtOAc and water). Antioxidant activity was assessed using the 2,2- diphenyl-1-picrylhydrazyl radical (DPPH) radical scavenging assay, with results ranging from 15.67 % (IC50 > 0.0300) to 74.74 % (IC50 > 0.0300) at 0.3mg/mL, using ascorbic acid as a standard reference. Total phenolic content ranged from 105.89 ± 0.07 mg GAE/g in the flower crude extract to 1.46 ± 0.04 mg GAE/g in flower DCM extract, with gallic acid as a reference standard. Similarly, total flavonoid content ranged from 182.69 ± 1.64 mg QE/g in root crude extract to 3.59 ± 0.41 mg QE/g in the flower n-hexane extract, with quercetin as the reference standard. The antibacterial potential of the extracts was tested against pathogenic Gram-positive (E. faecalis, B. subtilis) and Gram-negative bacteria (E. coli, S. typhi) using gentamicin and ciprofloxacin as positive controls and 10 % dimethyl sulfoxide (DMSO) as the negative control. Activity ranged from inhibition of E. coli by the EtOAc extract (12.0 ± 0.500) to inhibition of B. subtilis by the root DCM extract (7.0 ± 0.000). Phytochemical screening revealed the presence of flavonoids, tannins, alkaloids, terpenoids, cardiac glycosides, phenols, and saponins. Furthermore, GC-MS analysis facilitated the separation, identification, and quantification of compounds such as methyl-cyclohexane and dodecane. Overall, the findings demonstrate that A. ciliaris possesses considerable therapeutic potential, attributable to its diverse secondary metabolites, antioxidant activity, antibacterial effects, and total phenolic and flavonoid contents. | |
| dc.description.sponsorship | Kenyatta University | |
| dc.identifier.uri | https://ir-library.ku.ac.ke/handle/123456789/32710 | |
| dc.language.iso | en | |
| dc.publisher | Kenyatta University | |
| dc.title | Antioxidant Activity, Phytochemical Content and Antibacterial Activity of Extracts of Aloiampelos ciliaris | |
| dc.type | Thesis |