Phytochemical screening, in vitro antioxidant and antibacterial activities of methanolic extracts of Capparis Spionsa L. different parts from Tunisia

The present work consisted in preparing methanolic extracts from the leaves, flowers, fruits and roots of Capparis spinosa L by maceration, in order to study certain biological activities. Antioxidant activities were assessed against radicals DPPH and total antioxidant capacity (TAC). Moreover, we have determined the contents of phenolic compounds (total phenols, flavonoids, tannins and anthocyanins). The total polyphenols contents are variable according to the organ of the plant studied the results obtained, reveal that the leaf extract of Capparis spinosa L is the richest in total phenols 77.7 ± 1.1 mg EAG / g DW. The contents of flavonoids, tannins and anthocyanins recorded equal to 39.6 ± 0.6 mg EQ / g DW,11.4 ± 0.9 mg EC / g DW and0.33±0.01 mg cyanidin-3-glucoside equivalent / kg dry mass) respectively. Then, we evaluated the antioxidant activity by the method of the total antioxidant capacity (TAC) which shows that all the extracts have different antioxidant activities. The analysis of GC/MS of the methanolic extract of C.spinosa L. fruits has identified 19 organic compounds, three of which are the majority, namely: β-sitosterol (28.70%), Hexadecanoic acid (26.25%) and 9,12,15- Octadecatrienoic acid, (Z, Z,Z) (7.61%) are the major compounds of the extract fruits. The FTIR analysis of the fruit methanol extract confirms these three products. The analysis of the results of the antiradical activity of the organic extracts of Capparis spinosa L. The DPPH radical shows that extract of the leaves has the most important activity (70.10 ± 0.94 mg / L). Furthermore, we evaluated the antimicrobial activity of the methanolic extracts of different parts of C. spinosa by the radial diffusion method (RDA), this activity was revealed on five reference bacterial strains (Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Salmonella and Enterococcus).