Abstract:
Background: Calpurnia aurea (Ait.) Benth. leaves are used to treat different diseases like
ectoparasite infestation, diarrhea, sores, anthrax, fevers, pain, and snake venom. The leaves
of Calpurnia aurea were first extracted by methanol and further fractionated with the help of
n-hexane, dichloromethane and ethyl acetate with increasing polarity.
Methods: The antibacterial activities of the fractions were evaluated against disease causing
bacteria using agar well diffusion. The minimum inhibitory concentrations (MIC) of the
fractions were determined by the micro-broth dilution method using tetrazolium salt colorimetric
assay. The antioxidant activities of the solvent fractions were determined by phosphomolbedum
reduction assay, reducing power assay and hydroxyl radical scavenging activity.
Results: The average MIC value of C. aurea fractions ranged from 1.95mg/mL to 31.25mg/
mL, 7.81mg/mL to 31.25mg/mL and 13.02mg/mL to 62.5mg/mL, for ethyl acetate, dichloromethane
and n-hexane fractions, respectively. The leaf extracts have a higher antioxidant
effect, as shown in the phospho-molbedum reduction assay, reducing power and hydroxyl
radical scavenging assay.
Conclusion: The ethyl acetate and dichloromethane fractions revealed significant antibacterial
effects against the growth of pathogenic bacteria. However, the n-hexane fraction
showed the least antibacterial effect against all of the test bacteria. Furthermore, the nhexane
fractions of C. aurea showed higher antioxidant activity.
Keywords: antimicrobial, antioxidant, Calpurnia aurea, in vitro, solvent fractions
