Optimizing Antioxidant and Biological Activities of Quercus Fructus: Synergistic Role of Inner Shell and Extraction...

Area of Science:

• Natural Product Chemistry
• Pharmacology
• Food Science

Background:

• Quercus Fructus (QF) is a potential source of natural antioxidants.
• Optimizing extraction methods is crucial for maximizing the bioactivity of plant-derived compounds.

Purpose of the Study:

• To evaluate the impact of including the inner shell and different extraction methods on the antioxidant activity of QF.
• To identify the optimal extraction strategy for enhancing QF's functional properties.

Main Methods:

• Eight QF extracts were prepared with/without the inner shell using stirring and ultrasonication (80% ethanol), boiling, and autoclaving (distilled water).
• Antioxidant activities were assessed using DPPH radical scavenging, ABTS assay, reducing power, and SOD-like activity assays.
• HPLC-UV profiling was performed to identify major phenolic compounds.
• In vitro assays using LPS-stimulated Raw 264.7 cells and in vivo assays using zebrafish embryos were conducted to evaluate anti-inflammatory and antioxidant effects.

Main Results:

• The ultrasonication extract with the inner shell (IU) demonstrated the highest antioxidant capacity across all tested assays.
• IU exhibited significant DPPH radical scavenging (228.8 mg TEAC/g), ABTS activity (162.9 mg TEAC/g), reducing power (380.9 mg TERP/g), and SOD-like activity (38.1%).
• IU significantly suppressed nitric oxide production and iNOS expression in LPS-stimulated cells and reduced ROS accumulation in zebrafish embryos without cytotoxicity.

Conclusions:

• Including the inner shell and employing ultrasonication extraction synergistically enhances the antioxidant efficacy of Quercus Fructus.
• This optimized extraction strategy offers a practical approach to maximize the functional potential of QF for natural antioxidant development.