PHYTOCHEMICAL AND ANTIMALARIAL STUDIES OF THE LEAVES OF UVARIA CHAMAE P.BEAUV. (ANNONACEAE)

PHYTOCHEMICAL AND ANTIMALARIAL STUDIES OF THE LEAVES OF UVARIA CHAMAE P.BEAUV. (ANNONACEAE), A RESEARCH PROJECT TOPIC ON BIOCHEMISTRY

ABSTRACT

Uvaria chamae P.Beauv. belong to the Annonaceae family of flowering plants. It is distributed in the savannah and secondary forest. The plant is used in ethnomedicine for the treatment of malaria, inflammation, gonorrhea, dysentery; pile and fever. The ethyl alcohol leaves extract of the plant was subjected to phytochemical as well as antimalarial studies. Phytochemical studies were carried out using techniques including preliminary phytochemical tests, thin layer chromatographic analysis (TLC), column chromatography and gel filtration. The antimalarial activity of the crude ethyl alcohol leaves extract was evaluated using two models, suppressive and curative tests. The result of the preliminary phytochemical screening revealed the presence of saponins, flavonoids, carbohydrates, tannins, alkaloids and terpenoids. A flavonoids was isolated from the extract. The structure of the compound isolated was elucidated using UV, IR, 1D NMR and ESI-MS. The compound was found to be an epicatechin (3, 3, 4, 5, 7-pentahydroxyflavan). The leaf extract caused no lethality in mice at oral LD₅₀ value of greater than 5000 mg/kg body weight. This indicated that the extract is safe for oral use. In the suppressive test the extract exhibited good antimalarial property that was dose dependent. At doses of 25, 50 and 100 mg/kgbody weight the extract produced a significant (P< 0.05) chemosuppression of 48, 53.3 and 65% respectively. Chloroquine the positive control drug produced the highest parasite chemosuppression at 79%. In the curative test the extract at doses of 25, 50 and 100 mg/kg body weight produced significant (P< 0.05) chemosuppression at 68, 70 and 73% respectively. Chloroquine the positive control drug produced the highest parasite chemosuppression of 98%. The result of this studies has established the rationale for the use of this plant in ethnomedicine. The isolated compound might be responsible for the observed biological activity.

CHAPTER ONE

1.0 INTRODUCTION

1.1            Natural Product

A natural product is a chemical compound or substance produced by a living organism. In the broadest sense, natural products include any substance produced by life (Samuelson, 1999). Natural products can also be prepared by chemical synthesis and have played a central role in the development of the field of organic chemistry by providing challenging synthetic targets (Natural Products Foundation, 2013). Within the field of organic chemistry, the definition of natural products is usually restricted to mean purified organic compounds isolated from natural sources (Hanson, 2003).

PHYTOCHEMICAL AND ANTIMALARIAL STUDIES OF THE LEAVES OF UVARIA CHAMAE P.BEAUV. (ANNONACEAE), A RESEARCH PROJECT TOPIC ON BIOCHEMISTRY