Phytochemical Composition, Antidiarrheal Activity and Antibacterial Effect of Aqueous Leaf Extract of Plectranthus Barbatus (Andrews)
| dc.contributor.author | Ajwang, Emmah Clarice | |
| dc.date.accessioned | 2024-09-30T12:42:27Z | |
| dc.date.available | 2024-09-30T12:42:27Z | |
| dc.date.issued | 2024-05 | |
| dc.description | A Thesis Submitted in Partial Fulfilment of the Requirements for the Award of the Degree of Master of Science (Biochemistry) in the School of Pure and Applied Sciences of Kenyatta University May, 2024 Supervisors: 1. Mathew Piero Ngugi 2. George Omwenga | |
| dc.description.abstract | Diarrhea is defined as the movement of unformed or watery stool more than three times a day. Globally, diarrheal infections remain a public health problem, especially in children. With nearly 1.7 billion episodes and 1.3 million fatalities reported annually. Developing countries bear 78% of diarrhea burden worldwide. A range of viral, bacterial, and parasitic species induce diarrhea in humans, including rotavirus and Escherichia coli. The mainstays of pharmacological therapy for infectious diarrhea include probiotics, antibacterials, antiviral drugs, and intestinal adsorbents. However, these clinical treatments are not devoid of shortcomings, including prohibitive costs, drug-drug interactions, and adverse effects such as lethargy, constipation, respiratory depression, and coma. Medicinal plants, including Plectranthus barbatus have folkloric remedies against diarrhea. However, there is a paucity of knowledge to scientifically validate the efficacy of the leaves of P. barbatus on diarrheal infections. The study, therefore, was undertaken to ascertain the antidiarrheal efficacy, antibacterial activity, bioactive composition, and toxicity profiles of P. barbatus aqueous leaf extracts. Antidiarrheal activity and acute toxicity were carried out on mice. Using Swiss albino mice, castor oil-induced diarrhea, charcoal meal-based gastrointestinal motility, and castor oil-induced secretion models were employed to assess antidiarrheal activity. In all of the test models, animals were randomly assigned into six groups consisting of six animals in each. Group I received distilled water, group II received 10 ml/kgbw of the vehicle (distilled water), while group III was treated with standard drug (3 mg/kgbw loperamide) in the respective models, whereas groups IV to VI received 100, 200, and 400 mg/kgbw of the aqueous leaf extracts of Plectranthus barbatus. Antibacterial activity was carried out on selected bacterial pathogens. Quantitative phytocompound analysis was evaluated using liquid chromatography mass spectrometry. Data were analysed using one-way analysis of variance followed by Tukey’s test, and p< 0.05 was considered statistically significant at 95% confidence of interval.The study results indicated that P. barbatus extract has antidiarrheal activity. The plant extract prolonged the onset of diarrhea, caused a significant decline in the occurrence of wet feces and intestinal transit. Additionally, the extract elicited a reduction in the accumulation of intraluminal fluid, resulting in a decrease in distension, intestinal overload, and water content in the fecal drops. Loperamide showed a statistically similar antidiarrheal effect with the extract at a dosage of 200mg/kgbw suggesting a probable effective dosage of the extract. This study demonstrated that the aqueous leaf extracts of P. barbatus exhibited diarrheal inhibition activity. The percentage inhibition was dose dependent with 100, 200 and 400mg/kgbw showing 49.98±1.61, 66.12±2.17 and 75.80±2.16% inhibition of diarrheal output respectively (p<0.05). Further, P. barbatus demonstrated antibacterial activity against pathogens associated with diarrheal diseases. The extract had varying Mean Zones of Inhibition (MZI), 7.33±0.33 to 17.17±0.73mm, against the bacterial pathogens, with higher effects observed against P. aeruginosa and B. subtilis. Acute toxicity assays on mice showed that P. barbatus extract was non-toxic at the dosage level of 2000mg/kgbw. LC-MS analysis detected the presence of phytocompounds associated with antidiarrheal and antibacterial effects. Findings from this study offer scientific validation for the folkloric utilization of P. barbatus in the management of diarrhea. However, further studies should be conducted to explore the mechanistic approach to the reduction of diarrhea and the comprehensive chronic toxicological effects on biochemical and hematological parameters. | |
| dc.description.sponsorship | Kenyatta University | |
| dc.identifier.uri | https://ir-library.ku.ac.ke/handle/123456789/28990 | |
| dc.language.iso | en | |
| dc.publisher | Kenyatta University | |
| dc.title | Phytochemical Composition, Antidiarrheal Activity and Antibacterial Effect of Aqueous Leaf Extract of Plectranthus Barbatus (Andrews) | |
| dc.type | Thesis |