Phytochemical Profiling of Ethanolic Extracts from the Bark and Tuber of Colocasia Esculenta (L) Schott, Identification and Quantification of Compounds Present in Kenya

Abstract

Bacterial infections are the major cause of morbidity and mortality, with high financial impacts among human beings globally. Antibiotics are used in the treatment of bacterial infections. They eliminate or prevent bacteria from reproducing and spreading. Since they do so at different rates, some bacteria may mutate with an under-dose and resist antibiotic treatment through natural selection. The bacteria develop acquired antimicrobial resistance to several drugs due to increased use and misuse of antibiotics. This has resulted in increased interest in the use of medicinal plants in the treatment of bacterial infections. The plants serve as resistance modifying agents from the metabolites that they produce. Previous studies show that metabolites such as tannins, alkaloids and polyphenols may have antimicrobial and resistance-modifying properties. They destroy the microorganisms and interfere with the crucial events in the pathogenic process, reducing the bacteria's ability to develop resistance to botanicals.

Colocasia esculenta (L) Schott leaves were previously tested against Pseudomonas aeruginosa and the extracts showed higher activity against bacterial infections compared to the use of the antibiotic drug Clarithromycin. Leaves of aqueous and ethanolic extracts of Colocasia esculenta in previous studies were found to contain steroids, Flavonoids, saponins, terpenoids, Anthroquinones and Alkaloids. The extracts were found to have anti-diabetic activity and anti-helminthic activity compared to the standard drug, Piperazine citrate. This study determined phytochemicals present in ethanolic extracts of the bark and tuber of Colocasia esculenta (L) Schott in Kenya. A qualitative research design was adopted in this study. Colocasia esculenta plant samples used in this study were purposely obtained from Kaimosi Friends University farm in Vihiga County. They were taken to the laboratory of Botany at Maseno University, where they were washed with sterile distilled water, separated into bark and tuber, dried, crushed into powder, packed separately in airtight plastic containers, labelled and stored for later use. Plant ethanolic extracts were prepared separately (from powders) in triplicate for use in experiments. Screening for the presence of phytochemicals was done using standard methods. Qualitative analysis of the plant samples was used to check for the presence of flavonoids, saponins, steroids, tannins, alkaloids, glycosides, phenolic compounds and anthraquinones. Data were collected and then analyzed. Results were presented in the form of a table as the presence or absence of the specific phytochemicals. Results showed that Saponins, steroids, tannins, alkaloids, glycosides and phenolic compounds were present in both the tuber and bark ethanolic extracts of Colocasia esculenta. Interestingly, the bark extract had more saponins and tannins than the tuber extract. The results of this study can be used to further determine the antibacterial activity of the extracts on selected sidearm bacteria. The findings could be of commercial interest to both the Kenya Ministry of Health and pharmaceutical companies in the world in the production of new antibacterial drugs. Policymakers may help reduce the increasing mortality due to bacterial infections by using results from this study. The results can also support Kenya's Vision 2030 of ensuring adequate health care for all by integrating traditional healthcare practices into the national healthcare system for the realization of universal health coverage.