Polyphenols are natural organic compounds produced by plants, acting as antioxidants by reacting with ROS. These compounds are widely consumed in daily diet and many studies report several benefits to human health thanks to their bioavailability in humans. However, the digestion process of phenolic compounds is still not completely clear. Moreover, bioavailability is dependent on the metabolic phase of these compounds. The LogP value can be managed as a simplified measure of the lipophilicity of a substance ingested within the human body, which affects resultant absorption. The biopharmaceutical classification system (BCS), a method used to classify drugs intended for gastrointestinal absorption, correlates the solubility and permeability of the drug with both the rate and extent of oral absorption. BCS may be helpful to measure the bioactive constituents of foods, such as polyphenols, in order to understand their nutraceutical potential. There are many literature studies that focus on permeability, absorption, and bioavailability of polyphenols and their resultant metabolic byproducts, but there is still confusion about their respective LogP values and BCS classification. This review will provide an overview of the information regarding 10 dietarypolyphenols (ferulic acid, chlorogenic acid, rutin, quercetin, apigenin, cirsimaritin, daidzein, resveratrol, ellagic acid, and curcumin) and their association with the BCS classification.

Whole wheat flour possesses many nutritional properties because of its abundant bioactive components which are affected by cultivar, but little attention is paid to its relationship with storage conditions. In this study, phenolic extracts of whole wheat flour from four cultivars stored under different conditions (aerated and under vacuum) and different times (0, 2, 4, 8 weeks) were obtained. The total polyphenol (TPC) and flavonoid (TFC) contents, composition of phenolic acids, and antioxidant activities (AA) of phenolic extracts were evaluated. The results showed that Verna exhibited the highest levels of TPC, TFC, and AA for both storage conditions among the four cultivars. Moisture content, TFC, and AA fluctuated during storage. After 8 weeks, the TPC, TFC, and AA decreased with respect to Week 0 in all the cultivars. The TPC losses ranged between 16.39% and 20.88% and TFC losses from 14.08% to 31.18%. The AA losses were approximately 30% from the DPPH assay, but no significant losses were shown in the FRAP assay. However, these parameters were not distinctive between the two storage conditions. The wheat phenolic acid profiles were influenced more by storage time than storage conditions in all cultivars. Overall, the results validate the effect of the storage time on wheat polyphenol.

Increases in non-communicable and auto-immune diseases, with a shared etiology of defective autophagy and chronic inflammation, have motivated research both on natural products in drug discovery fields and on the interrelationship between autophagy and inflammation. Within this framework, the tolerability and protective effects of a wheat-germ spermidine (SPD) and clove eugenol (EUG) combination supplement (SUPPL) were investigated on inflammation status (after the administration of lipopolysaccharide (LPS)) and on autophagy using human Caco-2 and NCM460 cell lines. In comparison to the LPS treatment alone, the SUPPL + LPS significantly attenuated ROS levels and midkine expression in monocultures, as well as occludin expression and mucus production in reconstituted intestinal equivalents. Over a timeline of 2–4 h, the SUPPL and SUPPL + LPS treatments stimulated autophagy LC3-11 steady state expression and turnover, as well as P62 turnover. After completely blocking autophagy with dorsomorphin, inflammatory midkine was significantly reduced in the SUPPL + LPS treatment in a non-autophagy-dependent manner. After a 24 h timeline, preliminary results showed that mitophagy receptor BNIP3L expression was significantly downregulated in the SUPPL + LPS treatment compared to the LPS alone, whereas conventional autophagy protein expression was significantly higher. The SUPPL shows promise in reducing inflammation and increasing autophagy to improve intestinal health.

Impaired autophagy, responsible for increased inflammation, constitutes a risk factor for the more severe COVID-19 outcomes. Spermidine (SPD) is a known autophagy modulator and supplementation for COVID-19 risk groups (including the elderly) is recommended. However, information on the modulatory effects of eugenol (EUG) is scarce. Therefore, the effects of SPD and EUG, both singularly and in combination, on autophagy were investigated using different cell lines (HBEpiC, SHSY5Y, HUVEC, Caco-2, L929 and U937). SPD (0.3 mM), EUG (0.2 mM) and 0.3 mM SPD + 0.2 mM EUG, significantly increased autophagy using the hallmark measure of LC3-II protein accumulation in the cell lines without cytotoxic effects. Using Caco-2 cells as a model, several crucial autophagy proteins were upregulated at all stages of autophagic flux in response to the treatments. This effect was verified by the activation/differentiation and migration of U937 monocytes in a three-dimensional reconstituted intestinal model (Caco-2, L929 and U937 cells). Comparable benefits of SPD, EUG and SPD + EUG in inducing autophagy were shown by the protection of Caco-2 and L929 cells against lipopolysaccharide-induced inflammation. SPD + EUG is an innovative dual therapy capable of stimulating autophagy and reducing inflammation in vitro and could show promise for COVID-19 risk groups.

The anti-cancer potential of eugenol (EUG) is well recognized, whereas that of spermidine (SPD) is subject to dispute and requires further research. The anti-tumorigenic potential of wheat germ SPD (150 µM) and clove EUG (100 µM), alone, in combination as SPD+EUG (50 µM + 100 µM) and, as a supplement (SUPPL; 0.6 µM SPD + 50 µM EUG), was investigated on both metastatic SW620 and primary Caco-2 colorectal cancer (CRC) spheroids. Compared to untreated controls, all treatments significantly reduced the vitality and spheroid area, increased the necrotic area, and induced apoptosis on both cell-type spheroids after 96 h, with a reduced migration evident in 2D (two-dimensional) cultures after 48 h. The comparable anti-CRC effects of the SPD+EUG and the SUPPL reflected a wide-range dose efficacy of SPD and EUG. It is of note that SPD+EUG induced a synergistic effect on the increased caspase-3 expression and reduced the migration percentage in SW620. In more physiologically relevant intestinal equivalents (healthy enterocytes [NCM460], fibroblasts [L929], and monocytes [U937]) containing embedded SW620/Caco-2 spheroids, SPD+EUG administration significantly reduced the spheroid CEA marker and proliferation, whilst simultaneously increasing occludin, autophagy LC3-II expression, and monocyte differentiation, compared to the control models. Exogenous SPD, alone and in combination with EUG, displayed an anti-CRC potential on tumor growth and metastasis, and warrants further investigation.

Natural wound healing products are in increased demand. The potential for unexplored Sedum species in wound healing was discovered based on benefits of the genus reported in traditional medicine. The objectives were to screen ten Sedum species for wound healing, to ascertain the optimal harvest period using the five best, and finally to investigate effects of extraction protocols on wound healing using the most promising species. Different protocols were used to extract leaf polyphenol and mucilage content. Wound healing was assessed from L929 fibroblast migration. April was the optimal harvest month for wound healing efficacy, whereas the highest polyphenol content and antioxidant activity were evident in September and November. S. album Murales (ALBU), the best candidate, was then compared with S. telephium (TELE), which is well recognized in skin care. The mucilage-containing aqueous extract of ALBU was shown for the first time to induce the highest fibroblast migration after 24 h, not evident in TELE. Moreover, functional constituents contained within the absolute acetone- and isopropanol-containing polyphenol pools from ALBU induced significantly higher migration compared to TELE. A prototype cream, containing the water- and solvent-extracted bioactive compounds was effective at inducing fibroblast migration at 24 h in ALBU. The potential of ALBU in wound healing was evidenced and warrants further investigation.