Comparative Study of the Chemical Composition and Antioxidant Capacity of Leaves, Stems and Roots of Alchornea cordifolia (Schumach. & Thonn.) Müll. Arg.

Abstract

Aims: This work aims to compare the chemical composition and the antioxidant capacity of the leaves, stems and roots of Alchornea cordifolia. Study design: The leaves, stems and roots of Alchornea cordifolia were harvested during the month of August 2020 in the botanical garden of the University Jean Lorougnon Guede in Daloa. After that, they were dried in the shade for 17 days. Subsequently, they were crushed and kept in jars in order to be sent to the Laboratory of Industrial Processes, Synthesis, Environment and New Energies (LAPISEN) of Yamoussoukro (Côte d'Ivoire), for analyzes. Place and duration of study: This study was carried out during september to december 2020 in Laboratory of Industrial Processes, Synthesis, Environment and New Energies (LAPISEN) of Yamoussoukro (Côte d'Ivoire) Methodology: Physicochemical parameters (pH, ° Brix, MS) and the mineral contents of leave, stem and root aqueous extracts were determined by classic methods. Then, phytochemical screening are carried out by TLC analysis followed by spectrophotometric assay of total polyphenols, total flavonoids and antioxidant activity. Results: The results showed that the aqueous extract from A. cordifolia leaves, stems and roots are all acidic (pH ≤ 5.33). However, these extracts contain a low level of dry matter. The measured minerals (Na, Ca, Mg, Mn, K, Fe; Cu and Zn) are present in these extracts at varying concentrations. The leaf extract is richer in Fe (8.28 ppm), Ca (1.71 ppm), Mn (1.17 ppm) and K (0.55 ppm). In contrast, the root extract contains more Na (18.38 ppm), Cu (0.75 ppm) and Mg (0.34 ppm). As for the phytochemical screening revealed the presence of coumarins, flavonoids, sterols and terpenes, in the aqueous extract of all organs, except tannins, absent in the roots. However, the leaves have the highest content of polyphenols (256.67 mg.g-1 GAE) and flavonoids (92.75 mg.g-1 QE), as well as the best antioxidant capacity (204.23 µmol.L -1 TE). Conclusion: The leaves, stems and roots of A. cordifolia contain practically the same chemical compounds with a few exceptions. However, the difference lies in the concentration of these compounds in the different extracts.