Stress response due to sodium azide treatment inside Nigella sativa L. plant and its effect on antioxidative property

Nigella sativa is a potent medicinal plant having remarkable antioxidant property. More than hundred phytochemicals known for this plant, thymoquinone is one of the major active and strong antioxidative phyto-constituent found in it. Thymoquinone being a cyclicdione, reacts with sodium azide to synthesize its analogs α-azido ketones that are versatile with wide variety of reactions. The stress produced due to sodium azide, modulates the antioxidant system (antioxidative property) of the plant. The present study was aimed to observe the effect of sodium azide on antioxidative property and thymoquinone content within Nigella sativa plant. The results revealed the effect of sodium azide with strong positive correlation between percent yield and percent composition of thymoquinone in Ajmer Nigella 1(AN1) and UP Nigella 1 (UP1) in a concentration dependent manner. Minimum percent yield and percent composition of thymoquinone (analyzed by RP-HPLC) were observed (0.823 ± 0.035% for AN1 and 0.530 ± 0.020% for UP1) and (0.022 ± 0.002% for AN1 and 0.012 ± 0.002% for UP1), respectively at 100 μM concentration of sodium azide used. However, a strong negative correlation was observed with the decrease in thymoquinone content, with the increase in antioxidant property (−0.9369 and −0.9526) for AN1 and UP1, respectively. The findings clearly indicate the effect of sodium azide on thymoquinone content and their antioxidant property. The elevated antioxidant property might be due to the elicitation in production of other antioxidants or by the formation of analogs of thymoquinone that are more powerful antioxidants. Therefore, further research is also needed to further explore the interaction of sodium azide with thymoquinone that produce more potent antioxidant analogs and thus may be useful in various therapeutic applications.