Preliminary phytochemical analysis, determination of phenolic contents and evaluation of antioxidant activity of propolis collected in Koumra (Southern Chad)

Propolis is a resinous substance manufactured by bees to protect their hive. It is used in folk medicine in Chad for the treatment of many microbial and inflammatory pathologies. The objective of this study was to determine the chemical composition and the antioxidant activity of different extracts of propolis from Koumra (Southern Chad) obtained by the Soxhlet extractor using solvents with increasing polarity. Phytochemical screening revealed the presence of alkaloids, coumarins, flavonoids, polyphenols, saponins, tannins and triterpenes. The total polyphenol content was evaluated using Folin-Ciocalteu reagent and gallic acid as standard. The total flavonoid content was assessed by ferric chloride and quercetin standard. The methanolic extract had a higher amount of polyphenolics (6.150±0.008 gEAG/100gMB) and flavonoids (2.143±0.006 gEQc/100gMB). The DPPH free radical assay showed that the methanolic extract exhibited antiradical activity with the lowest IC50 value of 0.0379 g/mL. All extracts revealed a chelating power to iron with a maximum effect at 71.53% for the methanol extract. Significant amounts of antioxidants could justify the use of propolis in the traditional medicine for the treatment of many diseases.