Optimization of fungal fermentation for the extraction of polyphenols from Flourensia cernua and its effect on cellular metabolism

This study aimed to maximize the potential of Flourensia cernua as a source of phenolic compounds through solid-state fermentation with Aspergillus niger, focusing on evaluating the antioxidant activity of the extracted compounds and their effects on modulating the metabolism of animal, cancerous, and plant cells. Initially, a comparison of the phytochemical profiles between macerated and fermented extracts was conducted. Different culture conditions were then assessed using a Plackett-Burman design (including salt concentration, inoculum concentration, moisture, and pH) to identify the most significant factors. This was followed by a response surface methodology to optimize the concentration of hydrolyzable phenolic compounds. Moisture and KH₂PO₄ concentration were identified as critical parameters for enhancing phenolic content, resulting in a final concentration of 43.440 mg GAE/g. The chemical composition of these extracts was analyzed using infrared spectroscopy and X-ray diffraction, confirming the presence of characteristic polyphenol functional groups, along with inorganic compounds such as MgO, SiO₂, and CaO. In vitro metabolic evaluations of animal and plant cells exposed to the extracts revealed a marked stimulation of 3T3 fibroblast and bone cell metabolism with the fermented extract. Moreover, the phenolic compounds in the extract exhibited cytotoxic effects on HeLa and colon cancer cells at 48 hours. Regarding plant cells derived from red and green tomato, cantaloupe, and watermelon seeds, the fermented extract significantly stimulated metabolic activity after 48 hours of exposure. These findings suggest that fermented extracts of Flourensia cernua with Aspergillus niger hold promise for various biotechnological applications.