Effect of Increasing the Polarity of Solvent on Total Phenol and Flavonoid Contents and Antioxidant Activity of Myrtle (Myrtus communis L.)

Background and Medicinal plants are the main source of very potent antioxidants. Myrtus communis L. (Myrtle, Myrtaceae) is a medicinal plant used worldwide in traditional medicine. It is a well-known plant with distinctive antioxidant activity. This study aimed at investigating the effect of solvents extraction on total phenolics and antioxidant activity of extracts from Myrtle (Myrtus communis L.) leaf. The shade-dried leaf was extracted separately or successively with 6 solvets with different polarity: n-hexane, chloroform, ethyl acetate, n-butanol, methanol, and water. Twelve extracts were prepared. Antioxidant capacity was assessed using DPPH and nitric oxide (NO), free radicals scavenging, reducing power and iron chelating activity. The total phenolic and flavonoid contents were also determined. The highest yield of extraction was achieved by the most polar solvent, water. It also showed highest amount of phenolics but the extract did not contain the highest amount of flavonoids. Polar solvent extracts showed the best antioxidant capacities in DPPH and NO free radicals scavenging and reducing power. Nonpolar solvents, such as Chloroform, n-butanol and ethyl acetate had the highest amount of flavonoids and were also detected with the best iron chelating activity. The results clearly showed that utilization of polar solvent results in extraction of significant amounts of phenolics. Those components were the most potent antioxidants present in these extracts. Nonpolar solvents are more suitable for extraction of favonoids.