The positive health effects of phenolic compounds (PCs) have been extensively reported in the literature. An understanding of their bioaccessibility and bioavailability is essential for the elucidation of their health benefits. Before reaching circulation and exerting bioactions in target tissues, numerous interactions take place before and during digestion with either the plant or host's macromolecules that directly impact the organism and modulate their own bioaccessibility and bioavailability. The present work is focused on the gastrointestinal (GI) interactions that are relevant to the absorption and metabolism of PCs and how these interactions impact their pharmacokinetic profiles. Non-digestible cell wall components (fiber) interact intimately with PCs and delay their absorption in the small intestine, instead carrying them to the large intestine. PCs not bound to fiber interact with digestible nutrients in the bolus where they interfere with the digestion and absorption of proteins, carbohydrates, lipids, cholesterol, bile salts and micronutrients through the inhibition of digestive enzymes and enterocyte transporters and the disruption of micelle formation. PCs internalized by enterocytes may reach circulation (through transcellular or paracellular transport), be effluxed back into the lumen (P-glycoprotein, P-gp) or be metabolized by phase I and phase II enzymes. Some PCs can inhibit P-gp or phase I/II enzymes, which can potentially lead to drug-nutrient interactions. The absorption and pharmacokinetic parameters are modified by all of the interactions within the digestive tract and by the presence of other PCs. Undesirable interactions have promoted the development of nanotechnological approaches to promote the bioaccessibility, bioavailability, and bioefficacy of PCs.

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The search for foods with biological potential for the prevention of chronic diseases has highlighted sorghum, and numerous studies have been conducted to determine the best processing conditions without compromising the nutritional, functional or sensory qualities. We conducted a review of the scientific literature on the techniques used in sorghum and their effects on phenolic compounds and antioxidant capacity. This review allowed us to conclude that the type and content of phenolic compounds in the different varieties of sorghum must be considered for the selection of adequate technologies that allow the retention of phenolic compounds with improved bioaccessibility and biological potential. The available information has been mostly focused on the content of total phenols and the antioxidant activity of sorghum, while the digestibility, absorption, utilization and excretion of phenolic compounds have been poorly studied. On this regard, there is a clear need for further studies on sorghum with the aim of including sorghum as part of a healthy diet.

Obesity is considered to be a low-grade chronic inflammatory process, which is associated with cardiovascular and metabolic diseases. An integral evaluation of the effects of ferulic acid on biomarkers of glucose dysregulation, dyslipidemia, inflammation, and antioxidant potential induced by a high-fat diet (HFD) in rats was carried out. Three groups of male Wistar rats (six per group) consumed a basal diet (BD), which was supplemented with either lard at 310 g/kg (HFD) or lard and ferulic acid at 2 g/kg (HFD + FA), ad libitum for eight weeks. Body weight gain, hyperplasia, and hypertrophy in abdominal fat tissues were higher in the HFD group than in the HFD+FA group. The rats fed a HFD + FA significantly inhibited the increase in plasma lipids and glucose, compared with the HFD group. Biomarkers associated with inflammation were found at higher concentrations in the serum of rats fed a HFD than the HFD + FA group. Plasma antioxidant levels were lower in HFD rats compared to rats fed the HFD + FA. These results suggest that ferulic acid improves the obesogenic status induced by HFD, and we elucidated the integral effects of ferulic acid on a biological system.

The ability of phenolic compounds to cross the blood–brain barrier and reach the central nervous system is discussed. There are knowledge gaps that require additional experimentation, such as inconclusive transport mechanisms and lack of human data.

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Sorghum is a source of hydroxycinnamic acids (HCA), which have shown antioxidant, anti-inflammatory and anti-proliferative capacities. However, a high proportion of them have low bioaccessibility due the complex structural disposition of the plant's cell wall. The effects of boiling and extrusion processes on sorghum bran and their effects on the antioxidant capacity and bioaccessibility of HCA during simulated in vitro gastrointestinal digestion were investigated. The bioaccessibility of phenolic compounds was significantly higher in extruded sorghum bran (38.4%) than that obtained by boiling (29.5%). This is consistent with the increase of the antioxidant capacity after in vitro digestion. In contrast, a low bioaccessibility of pure monomeric HCA was observed when they were exposed to in vitro gastrointestinal digestion. There were significant bioaccessibility reductions of 36.8, 19.5, 13.5, 62.1% for caffeic, ρ-coumaric, ferulic and sinapic acids, respectively, when unproccessed sorghum bran was added. Although the bioaccessibility of monomeric HCA was low, the total phenolic compounds and antioxidant capacity increased during the digestion simulation due to the thermal processes of extrusion and boiling. Extrusion and boiling could be utilized to produce food based on sorghum bran with biological potential.

An imbalance between free radicals and antioxidants is known as oxidative stress, and it promotes cellular aging and the development of chronic noncommunicable diseases. The bioactive compounds present in food play an important role in preventing oxidative stress. The aim of this study was to determine the contributions and interactions of the hydroxycinnamic acids found in the bran and whole grain of sorghum and to evaluate their effects on the antioxidant capacity and inhibition of the hemolysis of human erythrocytes. Results showed that the caffeic acid, p-coumaric acid, and ferulic acid found in sorghum contributed to the scavenging of DPPH and ABTS radicals in various proportions. Ferulic acid, which was present in bound form in the bran and wholegrain sorghum, significantly inhibited the AAPH radical-induced oxidation of the erythrocyte membranes by 78.0 and 4.3%, respectively. Combinations of two, three, or four hydroxycinnamic acids may interact in an antagonistic or synergistic manner, thereby altering each other's bioactivities. The various interactions between the different sorghum bioactives can have a significant impact on their potential bioactivities. These results can be useful in the design of functional foods that aim to deliver bioactives to mitigate cellular aging or noncommunicable diseases.