Thesis Abstract

Abstract
Chloris gayana Kunth, commonly known as Rhodes grass, is a widely distributed grass species in Africa and Australia, known for its nutritional value and potential medicinal properties. This study aimed to evaluate the antimicrobial activity of Chloris gayana Kunth extract against a panel of pathogenic microorganisms. The extraction of bioactive compounds from Chloris gayana Kunth was carried out using various solvents including ethanol, methanol, and water. The antimicrobial activity was assessed using well-diffusion and microdilution methods to determine the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the extract. The pathogens tested included both Gram-positive (Staphylococcus aureus, Bacillus subtilis) and Gram-negative bacteria (Escherichia coli, Pseudomonas aeruginosa), as well as the yeast Candida albicans. The results demonstrated significant antimicrobial activity of Chloris gayana Kunth extract against all tested microorganisms. The ethanol extract exhibited the highest antimicrobial activity, followed by the methanol and water extracts. The well-diffusion assay showed clear zones of inhibition around the wells containing the Chloris gayana Kunth extract, indicating the presence of bioactive compounds with antimicrobial properties. The MIC and MBC values further confirmed the potency of the extract, with low concentrations being effective against the pathogens tested. Furthermore, the phytochemical analysis of the Chloris gayana Kunth extract revealed the presence of various bioactive compounds such as alkaloids, flavonoids, tannins, and saponins, which are known for their antimicrobial properties. These findings suggest that the antimicrobial activity of Chloris gayana Kunth extract may be attributed to the synergistic effects of these bioactive compounds. Overall, this study provides valuable insights into the antimicrobial potential of Chloris gayana Kunth, highlighting its possible application as a natural antimicrobial agent. Further research is warranted to elucidate the specific mechanisms of action of the bioactive compounds present in the extract and to explore its potential use in the development of novel antimicrobial agents for clinical applications.

Thesis Overview

1.0 INTRODUCTION1.1 BACKGROUND OF STUDYPlants have formed the basis of traditional medicine system which has been used for thousands of years. Traditional medicine refers to health practices, approaches, knowledge and beliefs incorporating plant, animal and mineral-based medicines, spiritual therapies, manual techniques and exercises, applied singularly or in combination to treat or to diagnose and prevent illnesses or maintain well being (World Health Organization, 2003). In developing countries where orthodox medicines are quite expensive, traditional medicine is widely practiced thus, screening for antimicrobial active compounds from ethno medicinal plants is vital so as to ascertain genuine active plants and active compounds. Ultimately, these phytochemicals will find their way into the arsenal of antimicrobial drugs prescribed by physicians (Cowan, 1999). Plants have been one of the main sources of medicaments either in the form of traditional preparations or pure active principles since the dawn of the human civilization. The utilization of plant based drugs in the world is flourishing and ever increasing. India has a wealthy ancestry of science on plant based drugs both for use in remedial and preventive medicine. Charaka S amhita reports the use of nearly 2000 vegetable remedies against various diseases. Nearly 60% of all pharmaceuticals are plant based. 300000 plants have already been explored for their medicinal properties. Every culture, including western culture has evolved indigenous system of traditional healing. Traditional healing in different cultures has a long history of ancestors creating primitive medicine during their struggle against natural calamities and diseases. Equally while searching for food; the ancient humans discovered that some foods have specific properties of relieving or eliminating certain diseases and maintaining good health. In recent years, secondary plant metabolites have been extensively investigated as a source of medicinal agents. It is anticipated that phytochemicals with good antibacterial activity will be used for the treatment of bacterial, fungal and viral infections. During the last two decades, there has been a considerable increase in the study and use of medicinal plants all over the world, especially in advanced countries. There was also a tremendous increase in the international trade and commercial exploitation of herbal medicines over the counter labeled products. In some countries, herbal medicines are still a central part of the medical system e.g. China, Ethiopia, Argentina and Papua New GuineaChloris gayana kunth of the family of poaceae and is commonly known as Rhode grass and it is mainly use for grazing of animals and most people use it as vegetable when cooking, As literature survey revealed that not much work had been reported on Choris gayana kunth, in the present study, the leaf portion of the plant was investigated for its pharmacognostical properties. Preliminary photochemical out followed by the isolation and characterization screening has been carried of chemical constituents and the antibacterial and antifungal activity of the various extracts as well as the isolated compounds were examined against microbes. In the present study, an endeavour has been made to find out the antibacterial and antifungal activity of various extracts obtained from the plant. 1.2 AIMS OF STUDY1. To extract and characterize compounds responsible for this claim.2. This research is aimed at evaluating the antimicrobial activity of Chloris gayana kunth used for the treatment of some illness caused by microorganism.3. To analyze whether the plant extract has capability to control the growth of the microorganism.1.3 OBJECTIVES OF THE STUDYThe objectives of this study include the following:Antimicrobial investigation of the plant extracts.Collection and precise botanical identification of the plant.Determination of phytochemical ingredient contained in the plant.1.4 SCOPE AND LIMITATION OF THIS RESEARCHThe scope of this research work is aimed at evaluating Chloris gayana kunth found in Agbarho in Ughelli North local government area of Delta State, Nigeria. This will be done by evaluating the 3 systematical screening of Chloris gayana kunth through phytochemical screening, antimicrobial (antibacterial/antifungal screening), so as to better understand their properties, safety and efficiency.1.4 JUSTIFICATION OF STUDYThe choice of Chloris gayana kunth for phytochemical and antimicrobial analysis is based on the plant’s specialty and diverse use in the treatment of various illness amongst the Agbarho people of Delta State and its environs. This study will also aid with discovering other possible sources of producing anti- microbial drugs.1.5 LITERATURE REVIEWPhytochemical are non-nutritive plant chemicals that have protective or disease preventive properties. There is growing interest in correlating the phytochemical constituents of a medicinal plant with its pharmacological activity. Phytochemicals are primary and secondary compounds. Chlorophyll, proteins and common sugars are included in primary constituents and secondary compounds have terpenoid, alkaloids and phenolic compounds. The secondary metabolites of plants were found to be source of various phytochemicals that could be directly used as intermediates for the production of new drugs.The currently available screening methods for the detection of antimicrobial activity of natural products fall into three groups, including bio autographic, diffusion, and dilution methods.1.6 DESCRIPTION OF THE PLANTChloris gayana kunth is a species of grass known by the common name Rhodes grass. It is native to Africa but it can be found throughout the tropical and subtropical world as a naturalized species.It can grow in many types of habitat. It is also cultivated in some areas as a palatable graze for animals and a ground cover to reduce erosion and quickly re-vegetate denuded soil. It is tolerant of moderately saline and alkaline soils and irrigation.This is a perennial grass which can reach one half to nearly three meters in height and spreads via stolon’s. It forms tufts and can spread into wide monotypic stands. The inflorescence is a single or double whorl of finger-like racemes up to 15 centimeters long. Each spike let in the raceme is a few millimeters long and contains one or two fertile florets and up to four sterile florets.