**7. Conclusion**

Obvious deleterious effects of free radicals as regards man's heath cannot be over emphasized. Oxidative stress due to overwhelming levels of free radicals has promoted the progression of diseases such as diabetes, cancer, cardiovascular diseases, atherosclerosis etc. and even aging. Plants phytochemicals and some vitamins have shown to possess antioxidant properties capable of scavenging free radicals, preventing cellular damages and related diseases via several mechanisms. As such, plants phytochemicals are now being considered as the most sustainable alternative source of antioxidants to supplement the endogenous oxidative stress defense system in humans. Continuous efforts are needed to characterize plants phytochemicals for their antioxidant potentials and mode of action for various therapeutic uses against oxidative stress-related diseases while regular consumption of fruits and vegetables are encouraged for the prevention of these diseases.
