Improving the production of unsaturated fatty acid esters and flavonoids from date palm pollen and their effects as anti-breast-cancer and antiviral agents: An in-vitro study

Background/aim Pollens from different plants contain unsaturated fatty acid esters (USFAEs) and flavonoids that play a very important role as bioactive compounds. Therefore, the present study was designed to improve the production of volatile USFAEs and flavonoids from date palm pollen (DPP) in a culture of Trichoderma koningii and test its activities as an anti-breast-cancer and antiviral agent. Materials and methods The volatile esters of fermented and nonfermented date palm pollens (FDPPs) were identified using gas chromatographic-mass spectrometric (GC-MS) analysis. Antioxidant activities were determined using three different methods: the 2,2′-diphenyl-1-picrylhydrazyl (DPPH) assay, the ferric reducing antioxidant power assay, and the 2,2-azinobis(3-ethyl-benzothiazoline-6-sulfonic acid) (ABTS) assay. Polyphenols (phenolics and flavonoids) were also determined. Anti-breast-cancer and antiviral activities were determined using the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay. Results GC-MS analysis showed an improvement in the level of USFAE in FDPP (47.99%) almost double that of the DPP results (24.11%) extract concentration. Flavonoids content of the FDPP extract (93.4 ± 6.3 mg/ml) was higher than that obtained by the DPP extract (45.4 ± 2.1 mg/ml), which was more than double the value. Antioxidant activity of the FDPP extract increased 3.16, 3.42, and 2.14 times that of the DPP extract as determined by the ABTS, ferric reducing antioxidant power (FRAP), and DPPH assays, respectively. The extract of FDPP showed strong anticancer activity against the MCF-7 cell line (IC 50 : 9.52 μg/ml) compared with the DPP extract (IC 50 : 96.22 μg/ml). Also, the FDPP extract had strong antiviral activity (CC 50 : 16.5 μg/ml) compared with DPP (CC 50 : 38.8 μg/ml). This is the first report in which the FDPP extract is used in biological studies as anti-breast-cancer and antiviral agents. Conclusion Fermentation of DPP by T. koningii improves many bioactive volatile USFAE and flavonoid contents; these have anti-breast-cancer and antiviral activity.