Phaseolus vulgaris, Common Bean is a herbaceous annual plant grown worldwide for its edible dry seed (known as just "beans") or unripe fruit (green beans) and a member of the legume family Fabaceae.  They are quite popular amongst the natives because of its high protein, minerals and vitamins content (Gentry et al., 1999).

The use of a wide range of chemicals to destroy pests and weeds is an important aspect of agricultural practice in both developed and developing countries but there is a widespread concern over the potential adverse effects of these chemicals on both human health and plants. Today, synthetic chemical contamination is pervasive and global with pesticides that have a highly acute toxicity but are readily metabolized and eliminated. With some rapidly eliminated but induce persistent biological effect such as oxidative stress. (Pimental, 1995), with larger proportion being lost via spray drift, off-target deposition, run off, photodegradation and so on.

Oxidative stress is associated with increased production of oxidizing species or a significant decrease in the effectiveness of antioxidant defenses, such as glutathione (Schafer et al., 2001) The effects of oxidative stress depend upon the size of these changes, with a cell being able to overcome small perturbations and regain its original state. However, more severe oxidative stress can cause cell death, and even moderate oxidation can trigger apoptosis, while more intense stresses may cause necrosis (Halliwell, 1994). Antioxidants are molecules that inhibit or quench free radical reactions and delay or inhibit cellular damage (Young et al., 2001). Antioxidants can be categorized in multiple ways. Based on their activity, they can be categorized as enzymatic and nonenzymatic antioxidants. Enzymatic antioxidants work by breaking down and removing free radicals (Shashidi et al., 2010).