Rosmarinus Officinalis: Phytochemical analysis and biological activities

Abstract

Rosemary (Rosmarinus officinalis), a very abundant species in Algeria, is a medicinal plant belonging to the Lamiaceae family, used for its various therapeutic effects. The present study was conducted to determine the bioactive compounds and biological activities (antioxidant and antibacterial activities) of the aqueous extract of the plant (EQRO). The sensitivity of the tested bacterial strains varies according to dilutions and bacterial nature (Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli), which was determined using the agar diffusion method. Meanwhile, the in vitro antioxidant activity was assessed using DPPH radical scavenging. EQRO showed high levels of polyphenols and flavonoid contents (455.10 µg EAG/mg extract; 7.33 µg EAQ / mg extract, respectively) with a yield of 14.47%. In addition, the plant extract revealed a significant antioxidant activity as evidenced by the DPPH (IC50=0.128 mg/ml), which is close to that obtained by BHT. Results showed a remarked antimicrobial effect against gram-positive bacteria (Staphylococcus aureus). At the same time, there was no significant effect on gram-negative bacteria (Pseudomonas aeruginosa and Escherichia coli), which explains the difference in susceptibility of the tested bacterial strains. Rosmarinus officinalis is suggested as an effective therapeutic medicinal plant because of its antioxidant and antibacterial properties. Keywords: Antibacterial activity, Antioxidant activity, Aqueous extract, bioactive compounds, Rosmarinus officinalis.