Chemo-profiling and bioactivities of Taif rose (Rosa damascena Mill.) industrial by-products after hydrodistillation

This study investigated the chemical composition of Rosa damascena Mill. (grown in the Taif region of Saudi Arabia), in relation to their potential as antioxidants and anticancer agents. The rose flowers are used to produce essential oils and hydrosol, but the process generates a significant amount of —solid and liquid. They contain biologically active compounds and can be treated as by-products. This study aimed to characterize these materials and analyze their extracts for biological activity. The total phenolic, flavonol, and flavonoid contents were quantified, and their chemical compositions were determined using liquid chromatography-mass spectrometry analysis. The antioxidant properties were estimated in vitro using three methods [1,1-diphenyl picrylhydrazyl (DPPH) radical, phosphomolybdenum, and ferric reducing power assays], while an anticancer test was carried out using the liver carcinoma cell line (HepG2). The findings showed that the texture’s n -butanol ( n -BuOH) fraction had the highest overall phenolic, flavonoid, and flavonol contents (230.69 ± 10.50 mg gallic acid equivalents /g ext., 71.66 ± 3.15 mg RE/g ext., and 51.70 ± 0.61 mg QE/g ext., respectively). The liquid chromatography-electrospray ionization-mass spectrometry analysis of the by-product extracts led to identifying 55 polyphenolic compounds, including organic acids, flavonoids, phenolic acids, and tannins, of which some constituents were described in Rosa extracts for the first time. In addition, the n -BuOH fraction of the texture and wastewater had a significant DPPH radical scavenging activity with SC 50s values of 7.57 ± 0.01 and 12.78 ± 0.13 µg/ml, respectively. Furthermore, the cytotoxic activity of the n -BuOH fraction of texture showed the highest activity on HepG2 (IC 50 = 12.1 ± 0.85 μg/ml) followed by wastewater n -BuOH fr. (IC 50 = 14.00 ± 1.05 μg/ml) and the methanolic extract of texture (IC 50 = 20.5 ± 1.41 μg/ml). Our findings indicated that rose industrial by-products are enriched with polyphenolic compounds with promising antioxidants and anticancer activities. Thus, they could be used as a food supplement.