Antioxidant Activity and Cytotoxicity of the Leaf and Bark Extracts of &lt;i&gt;Tarchonanthus camphorates&lt;/i&gt;

Ao Oyedeji,Ar Opoku,Fb Lewu,M Singh,Oo Oyedeji,Sk Nanyonga

doi:10.4314/tjpr.v12i3.16

Abstract

Purpose: To investigate the antioxidant potential and cytotoxicity of the leaf and bark extracts of Tarchonanathus campharatus..Methods: The antioxidant activity of the aqueous leaf extract (Aq LF), methanol leaf extract (MET LF), dichloromethane leaf extract (DCM LF), methanol bark extract (MET BK), dichloromethane bark extract (DCM BK), and ethyl acetate bark extract (Et Ac BK) were examined by 1,1-Diphenyl-2-picryl-hydrazil (DPPH), 2f-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS.+), nitric oxide radical scavenging, reducing power and iron chelating activity methods. Brine shrimp lethality and MTT cytotoxicity testswere used to investigate the cytotoxicity of the extracts.Results: The Aq LF, DCM LF, MET LF and MET BK showed good DPPH, ABTS radical scavenging and total reducing power activities. Total reducing power was high and in the rank order of DCM LF > Aq LF > MET LF > MET BK. All the extracts, however, showed weak nitric oxide scavenging activity aswell as weak iron chelating ability. Flavonoids, phenols, tannins and saponins were present in some of the extracts, but alkaloids, terpenoids, cardenolides and cardiac glycosides were absent in all the extracts. All the extracts did not show significant cytotoxic properties (p . 0.05) with 50% inhibitory concentration IC50 values > 30 ƒÊg/ml in both cytotoxicity assays.Conclusion: The antioxidant activity and low cytotoxicity of Tarchonanthus camphoratus probably justify its use in folk medicine.Keywords: Tarchonanthus camphoratus, Antioxidant activity, Cytotoxicity

Highlights

In the living system, free radicals are constantly generated and can cause extensive damage to tissues and biomolecules, creating various degenerative diseases [1]
Tarchonanathus campharatus L,.(family Asteraceae) has many medicinal applications in traditional healing where infusions and tinctures of the leaves are used for stomach trouble, abdominal pain, headache, toothache, asthma, bronchitis and inflammation; smoke generated by burning the fresh or dried plant is inhaled for rheumatism [3]
DPPH radical and ABTS+ radical cation are reactive towards most antioxidants and their decolourization reflects the capacity of an antioxidant species to donate electrons or hydrogen atoms to inactivate the radical species [8,16]

Summary

Introduction

Free radicals are constantly generated and can cause extensive damage to tissues and biomolecules, creating various degenerative diseases [1]. Due to the adverse side effects of synthetic drugs, natural antioxidants from plant origin have drawn much attention in recent years. Plants are known to possess potent bioactive compounds capable of preventing and treating most oxidative-related diseases and these compounds might act as leads in drug development [2]. Tarchonanathus campharatus L,.(family Asteraceae) has many medicinal applications in traditional healing where infusions and tinctures of the leaves are used for stomach trouble, abdominal pain, headache, toothache, asthma, bronchitis and inflammation; smoke generated by burning the fresh or dried plant is inhaled for rheumatism [3]. The medicinal activity of plants may be attributed to the presence of antioxidants [5]

Results

Discussion

Conclusion