**6. Conclusion**

Malaysian plant extracts are a potential source of natural antioxidants. The chapter focuses on the identification of selected Malaysian plants that exhibit high antioxidant capability. We provide information concerning the complete profile of selected Malaysian plants on their antioxidant/pro-oxidant activity, cytotoxicity, heavy metal content and method of standardisation. In conclusion, it was established that *Nephelium lappaceum* rind and *Mangifera indica* leaf extract have great potential to be developed into an antioxidant nutraceutical. In future study, studies of membrane interaction and the regulation of antioxidant gene expression in the presence of extracts and their pure compounds in the cells will provide better understanding of the mode of actions of the antioxidant activity exhibited. *In vivo* subacute and chronic toxicity studies will need to be carried out to determine the effect of long term intake of *Nephelium lappaceum* rind extract and geraniin in the animals.
