br Materials and methods br Results and discussions br

Materials and methods
Results and discussions
Conclusion The capability of the CTs extracts to scavenge free radicals in different systems, indicating that they may be useful therapeutic agents for treating various chronic diseases which are more related to oxidative stress associated diseases. The CTs extract showed significant antimicrobial activity, against different pathogens and inhibited cell proliferation and induced apoptosis in MCF-7, Hep G2 and HT29 cancer cells. These preliminary investigations have suggested that the CTs extracted from L. leucocephala hybrid-Rendang can be used to discover the bioactive natural product that may serve as a leads in the development of new pharmaceuticals in food and as potent antimicrobial and cytotoxic agent. Further studies will be designed to investigate its biomedical applications with a detailed mechanism through appropriate experimental model.
Conflict of interests
Acknowledgements This study was financially supported by the Universiti Putra Malaysia (RUGS:9199879). Special thanks to one of the author; the late Dr Sieo Chin Chin.
Introduction The reactive oxygen species (ROS) and reactive nitrogen species (RNS) are known to cause damage to lipids, proteins, enzymes, and nucleic acids leading to cell or tissue injury and are implicated in the processes of aging as well as in wide range of degenerative diseases viz. cancer, atherosclerosis, diabetes, liver injury, Alzheimer, Parkinson, and coronary heart pathologies, etc.[1,2]. Antioxidant based drugs and formulations have appeared during last three decades [3]. Currently available synthetic antioxidants like butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), tertiary butylated hydroquinon and gallic kainic acid esters have been suspected to cause or prompt negative health effects. Hence, strong restrictions have been imposed on their application and there is a trend to substitute them with naturally occurring antioxidants. Moreover, these synthetic antioxidants also show low solubility and moderate antioxidant activity [4]. The search for natural antioxidants as alternatives is therefore of great interest. Recent studies have shown that a number of plant products including polyphenols, terpenes and various plant extracts exert an antioxidant action [5,6]. Our present study focuses on one of the most potent Indian medicinal herb Acorus calamus (vacha or sweet flag or buch plant) for its antioxidant property. It belongs to Acoraceae family and has been used in the Indian and Chinese system of medicine for several decades to treat diseases, especially the central nervous system (CNS) abnormalities [7,8]. The rhizome of this plant is widely used in the treatment of several ailments like epilepsy, mental ailments, chronic diarrhea, dysentery, bronchial catarrh, intermittent fevers glandular, abdominal tumors, kidney and liver troubles, rheumatism, sinusitis and eczema [9]. However, there is scanty information on antioxidant properties of A. calamus and it is not known whether it has DNA protective activity. Hence, the aim of this study was to determine the antioxidant potential of A. calamus using different solvent extracts of rhizome using in vitro assays including DNA protection. Stress leads to hyper secretion of glucocorticoids [10] and an increased secretion of glucocorticoids (GCs) results in overproduction of reactive oxygen species [11] and leads to oxidative damage [12]. Hence there is a need to prevent stress induced oxidative damage. Several studies demonstrate suppression of long term stress-induced oxidative damage following administration of herbal extracts [13,14]. Thus far there is no information as to whether the altered antioxidant status due to short term stress exposure is prevented by herbal extracts. Earlier we have reported that acute stress i.e. 1h exposure of adult male rats to restraint followed by forced swimming for 15min after a gap of 4h alters the antioxidant status [15]. Hence this is a good model for speedy assessment of total antioxidant activity in vivo. The present study using this model investigates whether benzene extract of rhizome prevents stress induced changes in antioxidant status using total antioxidant assay.