Effect of salicylic acid on antioxidant properties of In vitro proliferated shoots of Melissa officinalisL.

Melissa officinalis is a medicinal plant belong to  lamiacea family.  This plant has been cultivated in many parts of the world due to its therapeutic effects. This study was conducted to improve antioxidant activities of proliferated shoots from tissue culture. The seeds of plant   were cultured in MS hormone free medium in order to obtain   seedlings. Then the  shoots were transfer to MS medium supplemented with 2 mg/ L  BAP.After 45 days salicylic acid (SA) was added to the medium at concentrations of 0, 50, 100 and 200 µM. The antioxidant activity and phenolics, flavonoids and rosmarinic acid content in proliferated shoots were evaluated 4,7,10 and 14 days after treatment. As a result the highest free radical scavenging and reducing power activity, as well as the highest value of total phenolic   and rosmarinic acid were observed in shoots   after 14 days of treatment with 100 µM salicylic acid. The elevated level of superoxide anion scavenging activity      and total flavonoids        were obtained from the shoots treated with 50 µM salicylic acid for 14 days. Over all treatment with100 µM salicylic acid for 14 days was better in order to antioxidant activity and compounds with recognized antioxidant activity.