Sterols and flavonoids in strawberry calyx with free radical scavenging, anti-inflammatory, and molecular dynamic study

Abstract

Abstract Background The phytochemical constitution and biological capabilities of Fragaria ananassa's calyx have not been extensively investigated before. Consequently, the research study pointed for characterization, isolation, and identification of the sterols and flavonoids as the major active constituents in the calyx of F. ananassa and evaluation for their impacts as free radicals scavenger and anti-inflammatory agent. Results GC/MS investigation for the lipoidal constitutions of F. ananassa's calyx was performed to identify twenty-six compounds signifying 83.08%, as well as isolation of campesterol, stigmast-4-en-3-one, and β-sitosterol-d-glucoside by column chromatography technique. Additionally, quantification and identification of the flavonoids in the ethyl acetate extract was carried out by HPLC/DAD technique beside to isolation and structure elucidation of 5-hydroxy-7, 4′-dimethoxy flavone and Chrysin. The free radicals scavenging and anti-inflammatory activities of both non-polar and polar extracts have been tested against (DPPH and ABTS radicals) and (COX-1, COX-2, and 5-LOX enzymes), correspondingly. The results illustrated significant effects of the polar extract of F. ananassa calyx greater than non-polar one. The dynamic natures, binding interactions, and protein–ligand stabilities have also been investigated using the molecular dynamics (MD) simulation research. The MD simulation revealed that Chrysin's chromen ring was extended to catalytic position of COX-1 receptor, producing Pi-Pi T-shaped contact with Tyr 354 and Trp 356. In addition, Chrysin's chromen ring has formed a Pi-alkyl bond with Val 318 and Leu 321. However, due to the huge size of ꞵ-sitosterol-d-glucoside, the glycoside ring can form a hydrogen bond with Tyr 317. The cyclopentyl phenanthrene ring also possesses Pi-alkyl interactions with Ile 58, Leu 62, Val 85, Val 318, Tyr 324, Leu 326, Ala 496, and Leu 500. Conclusions The findings of our study are crucial in establishing the molecular bases for Chrysin and ꞵ-sitosterol-d-glucoside action against anti-inflammatory targets and for developing more effective selective inhibitors. The discovery of the binding location for ATP can pave the door for development unique, structure-based approach for natural anti-inflammatory medications.

Keywords

• Fragaria ananassa calyx
• Phytoconstituents
• Antioxidant
• Anti-inflammatory
• Molecular docking