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Introduction: Hymenosporum flavum (Hook.) F. Muell. is the sole species within the genus Hymenosporum is known for its antimicrobial activity. The current study aims to examine the prospective activity of H. flavum as a safe supporter of sorafenib (as a reference standard) against hepatocellular carcinoma (HCC). Methods: Isolation and identification of compounds were made by chromatographic and spectroscopic methods. A fingerprint for the plant extract was done using HPLC-MS/MS spectrometric analysis. The total plant extract was examined in vitro for HCC activity. The isolated flavonoids were examined for their cytotoxic activities using molecular docking studies against both RAF-1 and ERK-2, and the promising compounds were further examined in vitro using quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Results: Two new flavonols were isolated from the leaf extract of H. flavum (Hook.) F. Muell., quercetin-3-O-(glucopyranosyl 1→2 ribopyranoside) (1) and kaempferol-3-O-(glucopyranosyl 1→2 ribopyranoside) (2), accompanying other six known flavonoids (3-8), and identified via spectroscopic analysis. Moreover, HPLC- PDA/MS/MS spectrometric analysis revealed the presence of seventy phenolic metabolites. The cytotoxic activity of the plant extract confirmed its potential action on HepG2 cells indicated by the production level of lactate dehydrogenase (LDH) upon treatment compared with the normal cells. The isolated flavonoids were examined for their cytotoxic activity using molecular docking studies against both RAF-1 and ERK-2 as proposed mechanisms of their anticancer activities. Furthermore, compounds 1 and 3, which showed the best in silico results, were further examined in vitro using qRT-PCR. They exhibited promising inhibitory activities against both RAF-1 and ERK-2 gene expression. Moreover, they showed promising cytotoxic activities indicated by the MTT assay. Also, both of them improved the efficiency of sorafenib in targeting both RAF-1 and ERK-2 pathways suggesting synergistic combinations. Conclusion: Our findings showed the potential cytotoxic activity of H. flavum extract on HepG2 cells. Some isolated compounds (1 & 3) exhibited promising inhibitory activities against both RAF-1 and ERK-2 gene expression giving a lead future study for these compounds to be used in pharmaceutical preparations either alone or in combination with sorafenib.

Wounds and burn injury are major causes of death and disability worldwide. Myricetin is a common bioactive flavonoid isolated naturally from the plant kingdom. Herein, a topical application of naturally isolated myricetin from the shoots of Tecomaria capensis v. aurea on excisional wound healing that was performed in albino rats. The wounded rats were treated every day with 10 and 20% myricetin for 14 days. During the experiment, the wound closure percentage was estimated at days 0, 7, and 14. Effects of myricetin on the inflammatory cytokines (tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and cluster of differentiation 68 (CD68) in the serum were evaluated using immunosorbent assay kits. The percentage of wound closure and contraction was delayed in wounded rats (67.35%) and was remarkably increased after treatment of wounded rats with myricetin; the treatment with 20% myricetin was the most potent (98.76%). Histological findings exhibited that 10% myricetin caused the formation of a large area of scarring at the wound enclosure and stratified squamous epithelium without the formation of papillae as in the control group. Treatment with 20% myricetin exhibited less area of scarring at the wound enclosure as well as re-epithelialization with a high density of fibroblasts and blood capillaries in the wound. Level elevations of serum pro-inflammatory cytokines, IL-1β, and TNF-α and macrophage CD68 were decreased in wounded rats treated with myricetin. Thus, it can be suggested that the enhancements in inflammatory cytokines as well as systemic reorganization after myricetin treatment may be recommended to play a crucial part in the promotion of wound healing. The findings suggest that treatment with a higher dose of myricetin was better in improving wound curing in rats. It could serve as a potent anti-inflammatory agent and can be used as an adjunctive or alternative agent in the future.

Objectives: This study focused on the identification and characterization of secondary metabolites tentatively from aqueous ethanolic leaf extract of Livistona chinensis by HPLC-PDA-ESI-MS/MS and evaluation of its cytotoxic activity. Methods: The aqueous ethanolic extract was analyzed by high performance liquid chromatography (HPLC) coupled to photodiode array detection of mass spectroscopy (PDA-MS/MS), to detect the secondary metabolites in L. chinensis leaves extract. It was also estimated for its cytotoxicity against human prostate carcinoma (PC3) and hepatocellular liver carcinoma (HepG2) cancer cell lines using SRB (3-(4, 5-dimethyl thiazol-2-yl)-2, 5-diphenyltetrazolium bromide) assay. Results: Fortytwo secondary metabolites were tentatively identified; the most major compounds were C-glycoside derivatives of apigenin, luteolin and tricin together with phenolic acids. The 70% alcoholic extract of L. chinensis leaves exhibit more antitumor activity against PC3 than against HepG2. Conclusion: L. chinensis is a privileged source of C-flavonoids that revealed the efficiency of HPLC-MS metabolomics in natural products drug discovery.