Antimicrobial, Antioxidant Activities and Phytochemical Screening of Extracts and Essential Oil of Cymbopogon schoenanthus Flowers

Introduction: Antibiotic resistance represents one of the major worldwide health problems. Though many medicinal plants are traditionally used to treat microbial infections. The antimicrobial potential of Cymbopogon schoenanthus flowers has not been investigated yet. Furthermore, exploring novel antioxidants has been a major goal for the management of various human health problems.

Objectives: To evaluate in vitro antimicrobial and antioxidant activities as well as a phytochemical screening of Cymbopogon schoenanthus flowers extracts and essential oil.

Materials and Methods: The methanol, aqueous extracts and essential oil of Cymbopogon schoenanthus were tested for antimicrobial activity against standard gram positives bacteria (Staphylococcus aureus and Bacillus subtilis), gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa) and fungus of Candida albicans. Antioxidant activity was determined by using DPPH radical scavenging assay, and then extracts were subjected to qualitative phytochemical screening for the major secondary metabolites.

Results: Extracts and volatile oils showed promising activities against standard microorganisms with inhibition zone values 20-14 mm/20µL and minimum inhibitory concertation values 3.12 to 12.5 mg/ml. The highest activity was associated with methanol extract and volatile oil. Antioxidant activity found in order; methanol extract > aqueous extract > essential oil with DPPH radical scavenging activity (%) 77.0 ± 0.06, 64.0 ± 0.03, 40.0 ± 0.04 respectively. Phytochemical screening indicates the presence of, alkaloids, tannins, flavonoids, saponins, steroids, and triterpenes.

Conclusion: Cymbopogon schoenanthus flowers extract and volatile oils showed promising antimicrobial and antioxidant activities. However, a detailed phytochemical study of these extracts and the essential oil is essential to standardize the extract and isolate the active principle(s) responsible for their activities.