Nutritional profile, phytochemical characterization, and biological activities of Tunisian cultivar Ficus carica zidi leaves

In keeping with Hippocrates' philosophy 'let thy food be thy medicine and thy medicine be thy food', we focused on the nutraceutical potential of an agriculture by-product: Ficus carica cultivar Zidi leaves. The nutritional profiling of dried fig leaf at post-harvest stage was investigated, showing that it is a good source of carbohydrates (39.66 +/- 0.50%), proteins (25.49 +/- 0.27%), crude fiber (13.3 +/- 0.01%), iron (14.63 +/- 0.01 mg/100 g DW), manganese (52.55 +/- 0.14 mg/100 g DW), zinc (0.57 +/- 0.01 mg/100 g DW), and copper (0.34 +/- 0.0047 mg/100 g DW). GC-MS fatty acid analysis revealed that linolenic acid (48.76%) is the major component, followed by palmitic, stearic, and linoleic acids, resulting in a good oil quality according to lipid quality indices. Among the different extraction procedures applied to recover phenolic compounds from leaves collected at pre-ripening (S1) and post-harvest (S2) stages, ethanol-water sonication stage 1 has the best total phenols, flavonoids, and condensed tannins contents values (53.95 +/- 0.17 mg gallic acid equivalent/g dry weight (DW), 17.64 +/- 0.48 mg catechin equivalent/g DW, and 28.42 +/- 2.17 mg catechin equivalent/g DW, respectively). Aqueous extracts of stage 1 have the strongest 2,2 '-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity (IC50 = 0.47 mg/mL); and ethanol-water sonication stage 1 and ethanol-water maceration stage 2 extracts exhibited the highest antioxidant activities against DNA strand breaks. The assessment of the antibacterial activity by disc diffusion method showed that ethanol-water maceration extract of stage 2 exhibits the best bacteria inhibition activity. The highest inhibition diameter was 17 mm, against L. monocytogenes ATCC 15313 and B. cereus ATCC 11778.