Research Journal of Pharmacy and Technology

Leucaena leucocephala traditionally utilized in folk treatment for its antimicrobial and anti-inflammatory properties. Despite its widespread availability, its phytochemical richness and associated biological activities remain underexplored. Qualitative & quantitative evaluation of phytochemical composition of chloroform extract of Leucaena leucocephala (CELL), ethyl acetate extract of Leucaena leucocephala (EAELL) and ethanolic extract of Leucaena leucocephala (EELL), and also assess the in vitro antioxidant and antibacterial activity of CELL, EAELL and EELL with a focus on identifying the most bioactive extract. The collected leaves were dried under shade, pulverized into a coarse powder, extracted serially by using different solvents according to polarity. Phytochemical constituents were identified through standard methods. Total phenolic and flavonoid contents were quantified using the Folin–Ciocalteu and aluminum chloride methods, respectively. Antioxidant activity was assessed via 2,2-Diphenyl-1-Picrylhydrazyl (DPPH), Hydrogen Peroxide (H₂O₂) and Nitric Oxide (NO) assays. Antibacterial potential was assessed by the disk diffusion technique against selected Gram-positive strains (Staphylococcus aureus and Streptococcus pneumoniae) and Gram-negative strains (Salmonella typhi and Escherichia coli). The ethanolic extract exhibited the richest phytochemical profile, with the highest total phenolic (189.34 ± 0.982 μg GAE/mg) and flavonoid (46.50 ± 0.078 μg QE/mg) contents. It showed potent antioxidant activity in H₂O₂ (IC₅₀ 55.59 μg/mL), medium activity in NO (IC₅₀ 67.53 μg/mL) while lowest activity found in DPPH (IC₅₀ 75.68 μg/mL) method. Furthermore, the ethanolic extract demonstrated the greatest antibacterial activity, with inhibition zones ranging from 11.23 to 18.54 mm. In contrast, the chloroform and ethyl acetate extracts showed comparatively lower phytochemical and biological activities. The study concluded that ethanolic extract of Leucaena leucocephala leaves as a promising source of antioxidants and antibacterial, credited may be to its high content of phenolic and flavonoid. Results support its potential application in the development of phototherapeutic products, warranting further investigation into its bioactive constituents and mechanisms of action.