Phytochemical Screening and Antioxidant Activities of Some Selected Medicinal Plants Used for Malaria Therapy in Southwestern Nigeria

Sa Adesegun,Ec Ezennia,K Obaweya,Ha Coker,Aa Adepoju-Bello,To Atangbayila,Ga Ayoola

doi:10.4314/tjpr.v7i3.14686

Abstract

Purpose: Oxidative stress has been shown to play an important role in the development of anaemia in malaria. Indeed, increase in total antioxidant status has been shown to be important in recovery from malaria. The antioxidant activities of four medicinal plants traditionally used in the treatment of malaria in southwestern Nigeria were determined. Methods: The ethanolic extracts of the leaves of Carica papaya Linn. [Caricaceae] , stem bark of Magnifera indica Linn. [Anacardiaceae], leaves of Psidium guajava Linn. [Myrtaceae] and the leaves of Vernonia amygdalina Del. [Compositae], were used in the present study. The plant parts commonly used in the locality in malaria therapy were employed in this study. The plants were screened for the presence of phytochemicals and, their effect on 2,2-Diphenyl-1-picryl-hydrazyl radical (DPPH) was used to determine their free radical scavenging activity. Results: Phytochemical screening of the plants showed the presence of flavonoids, terpenoids, saponins, tannins and reducing sugars. M. indica did not contain cardiac glycosides and alkaloids while, P. guajava also showed the absence of alkaloids and anthraquinones. Anthraquinones was similarly absent from V. amygdalina. Concentrations of the plant extracts required for 50% inhibition of DPPH radical scavenging effect (IC50) were recorded as 0.04 mg/ml, 0.313 mg/ml, 0.58 mg/ml, 2.30 mg/ml and 0.054 mg/ml for P. guajava, M. Indica, C. papaya, V. amygdalina and Vitamin C, respectively. Conclusion: All the plants showed potent inhibition of DPPH radical scavenging activity, P. guajava being the most potent. The free radical scavenging (antioxidant) activities of these plants probably contribute to the effectiveness of the above plants in malaria therapy. Keywords: Carica papaya, Magnifera indica, Psidium guajava, Vernonia amygdalina, Antioxidants, Malaria, DPPH, Oxidative stress. Tropical Journal of Pharmaceutical Research Vol. 7 (3) 2008: pp. 1019-1024

Highlights

Malaria is a global disease prevalent in the tropics caused by Plasmodium species
The phytochemical screening of the plants studied showed the presence of flavonoids terpenoids, saponins and tannins (Table 1), M. indica, V. amygdalina and P. guajava showed the absence of anthraquinones
M. indica and P. guajava tested negative for the presence of alkaloids and only M. indica tested negative for the presence of cardiac glycosides (Table 1)

Summary

Introduction

Malaria is a global disease prevalent in the tropics caused by Plasmodium species. It is one of the oldest and greatest health challenges affecting 40% of the world’s population. High mortality rate is reported in children and pregnant women, the disease has a negative impact on the economy of prevalent countries[2]. The immune system of the body is activated by infections, including malaria, thereby causing the release of reactive oxygen species. Increased resistance of malaria parasites to the commonly used antimalarial drugs have been reported, and the need to intensify research in the area of development of new antimalarial drugs especially from medicinal plants.

Methods

Results

Discussion

Conclusion