Ethanolic extract of sweet basil callus cultures as a source of antioxidant and sun-protective agents

Background Basil (Ocimum basilicum L.) is a medicinal plant largely used in medicine, cosmetics, and cooking. Objective The current work aimed to improve the production of both phenolic and flavonoid compounds in the callus cultures of sweet basil (O. basilicum L.), which can be used in cosmetics as antioxidant and sun-protection agents. Materials and methods Different combinations of growth regulators have been used to induce calli. Phenylalanine and salicylic acid have been used to enhance phenolics and flavonoids production. Quantitative analyses including total phenolics (TPC), total flavonoids, 2,2'-diphenyl 1-Picryl-hydrazyl radical scavenging activity, half maximal inhibitory concentration (IC50), correlation coefficient (R2) between antioxidant activity and both TPC and TFC, and sun-protective factor have been performed for both treatments and control. Results and conclusions Results reported that 1-naphthaleneacetic acid (NAA)+6-benzylaminopurine (BAP) was the best combination to induce calli tissue with good texture. The addition of 1.0 g/l phenylalanine for 2 weeks and 0.5 mm salicylic acid for 4 weeks were the best treatments to increase the production of phenolic and flavonoid components, and it showed the maximum % radical scavenging capacity. Higher correlation coefficient was found between % radical scavenging capacity and TPC compounds (0.83). The treatment of 1.0 g/l phenylalanine for 2 weeks indicated the lowest and best IC50, and it showed the maximum sun-protective factor value (36.50 +/- 0.003).