Biological and pharmacological activities of essential oils of Ocimum basilicum L. grown with Zn-salicylic acid nano-complex

Abstract

A greenhouse study was conducted to investigate the impact of different rates of application of Zn-EDTA, salicylic acid (SA) and zinc-salicylic acid nano-complex (n[Zn(SA)2]) on the antioxidant and antimicrobial activities of essential oil (EO) of sweet basil (Ocimum basilicum L.). Sixty-one compounds were detected in the EOs after Zn and SA sources were applied to the plants. GC-MS analysis showed that the main components of the EOs after the treatment were epi-α-Cadinol and trans-α-Bergamotene. The highest amount of epi-α-Cadinol (29.06±1.31%) and trans-α-Bergamotene (11.90±1.1%) in the EO were observed at 0.2% n[Zn(SA)2] treatment. In general, the application of 0.2% n[Zn(SA)2] significantly increased percentages of phenolic and flavonoid compounds of extract. HPLC analysis showed that the predominant phenolic compound after treatments with different Zn and SA sources were rosmarinic acid and quercetin, respectively. The lowest IC50 values for RNS, ROS, TBARS and H2O2, scavenging activities were obtained in EOs of basils which were treated with 0.2% n[Zn(SA)2]. Zinc-salicylic nano-complex was the most effective treatment to inhibit fungal and bacterial growth. Our results are quite encouraging since the Eos of n[Zn(SA)2] treated basil exhibited potent antioxidant effect, antimicrobial activities comparable with synthetic drugs.