Phytochemical, antioxidant and antimicrobial studies of partitioned fractions of Lannea kerstingii Engl. and K. Krause (Anarcadiaceae)

Background: Antimicrobial resistance is a serious threat to global public health and requires actions like the development of new antimicrobial with significant activities over existing drugs.

Objectives: This study aims at investigating the phytochemical, antioxidant and antimicrobial potentials of partitioned fractions of Lannea kerstingii.

Methods: A quantitative phytochemistry of chloroform, ethyl acetate, acetone and methanol fractions of L. kerstingii for total flavonoid, phenol and alkaloid were done using standard method; antioxidant and antimicrobial activity were determined using 1,1-Diphenyl-2-picrylhydrazyl and agar diffusion method respectively.

Results: The chloroform fraction contained only alkaloid (11%) and steroids while all the other fractions contained phenolic compounds in the range 0.43 to 0.67 mg/g garlic acid. The total flavonoid content ranged from 0.43 to 0.67 mg/g of quercetin. The total flavonoid in the ethyl acetate was significantly different from that of the methanol fraction but not with the acetone fraction. The acetone fraction showed highest antioxidant activity (60.4%) at 0.05 mg/mL though not as comparable to vitamin C. The ethyl acetate showed high antimicrobial activity as it was active against most of the organisms tested upon and zone of inhibition ranged from 13±0.02 to 29±0.1 mm. The acetone fraction was active only against T. mentagrophytes while the methanol fraction showed no activity.

Conclusion: The antioxidant and antimicrobial activities may be due to the presence of flavonoids, as well as the presence of tannins and terpenoids present in the different fractions. This makes the ethyl acetate fraction a good source of antioxidant and antimicrobial agent.