PHYTOCHEMICAL SCREENING GC-MS ANALYSIS AND ANTIOXIDANT ACTIVITIY OF LEMON BALM (MELISSA OFFICINALIS) LEAF

ABSTRACT This work evaluates some chemical constituents and antioxidant activities of Melissa officinalis plant leaf. The analyses were carried out using standard methods. Fresh leaves of Melissa officinalis were collected from Okuruke in Cross River State and were identified, screened and processed for analysis. Samples were screened for phytochemical, antioxidant potentials using standard method of analysis while the bioactive compound present in the sample were analyzed using GC-MS technique. The result of the phytochemical screening revealed the presence of phenolics, tannin and glycoside in abundance while flavonoids, alkaloids, saponnin and terpenoids were moderately present and the test recorded the absence of steroids. GC-MS chemical analysis of the methanolic plant extract revealed the presence of thirty five bioactive constituents. Some of the identified compounds and their percentage yield include 9-Octadecenoic acid (Z)-, 2-hydroxy-1-(hydroxymethyl)ethyl ester (91%), Tridecanal and oxirane, tetradecyl (89%), 1-Tricosene (86%), octadecenal (83%), and 9-Octadecenoic acid (Z)-, 2-hydroxyethyl ester (70%) which account for the numerous medicinal properties exhibited by this plant such as antimicrobial, antiiflammatory, anti-hypertensive etc. The result of the antioxidant activity evaluated with DPPH (2,2-diphenyl-1-picryl hydrazyl) radical scavenging activities and FRAP inhibition activities at different concentration revealed that the DPPH assay percentage scavenging activity decreased with increase in plant extracts concentration with the highest scavenging activity observed at 10mg/ml (79.03±0.36%) which was lower compared to the scavenging activities of BHT (98.50%) the standard. The FRAP result on the other hand showed that percentage (%) inhibition of Melissa officinalis increased with increase in the concentration of the plant extract. The range is from 64.10±0.36% to 82.53±0.12. These results showcase the therapeutic potential of the plant as a rich source of natural antioxidants and bioactive compounds. The study highlights the therapeutic significance of Melissa officinalis as a promising candidate for the development of natural antioxidant agents and as well can be harnessed in the formulation of therapeutics, in ajurvedic and orthodox medicine.