Plant secondary metabolites and gut health: the case for phenolic acids

Abstract

Plant-based diets contain a plethora of secondary metabolites that may impact on health and disease prevention. Much attention has been focused on the potential bioactivity and nutritional relevance of several classes of phytochemicals such as flavonoids, carotenoids, phyto-oestrogens and glucosinolates. Less attention has been paid to simple phenolic acids that are widely found in fruit, vegetables, herbs, spices and beverages. Daily intakes may exceed 100 mg. In addition, bacteria in the gut can perform reactions that transform more complex plant phenolics such as anthocyanins, procyanidins, flavanones, flavonols, tannins and isoflavones into simple phenolic metabolites. The colon is thus a rich source of potentially active phenolic acids that may impact both locally and systemically on gut health. Both the small and large intestine (colon) contain absorption sites for phenolic acids but low post-prandial concentrations in plasma indicate minimal absorption early in the gastrointestinal tract and/or rapid hepatic metabolism and excretion. Therefore, any bioactivity that contributes to gut health may predominantly occur in the colon. Several phenolic acids affect the expression and activity of enzymes involved in the production of inflammatory mediators of pathways thought to be important in the development of gut disorders including colon cancer. However, at present, we remain largely ignorant as to which of these compounds are beneficial to gut health. Until we can elucidate which pro-inflammatory and potentially carcinogenetic changes in gene expression can be moderated by simple phenolic acids, it is not possible to recommend specific plant-based foods rich in particular phenolics to optimise gut health.

Isolation and purification of plant secondary metabolites using column-chromatographic technique

“…Plants are healthy and natural resource of life (Russell and Duthie, 2011). In particular, medicinal plants are of great importance with endless therapeutic properties useful for curing various diseases with an advantage of being natural (El-Shemy et al, 2007).…”

“…At present, there are un-countable products in market, with adverse side effects on once heath. Therefore, the use of secondary metabolites from plant origin could be an advantage and best solution to narrow down the use of unhealthy products (Russell and Duthie, 2011).…”

“…Moreover, plants have always been a source of a wide array of secondary metabolites with potential pharmacological properties (Russell and Duthie, 2011). Polyphenolic (flavonoids) compounds occur ubiquitously in foods of plant origin have many beneficial health effects due to their potential antioxidant, anti-inflammatory and cancer-preventive activities (Li et al, 2014).…”

Antibiofilm activity of trans-cinnamaldehyde, p-coumaric, and ferulic acids on uropathogenic Escherichia coli

“…Plants have many chemical strategies to protect them from microbial infections and different products of plant origin are well known for their antimicrobial activities (8). Phenolic products are common plant secondary metabolites and can exhibit a wide range of biological effects, including antimicrobial, antiinflammatory, and anticarcinogenic action (9). Therefore, they are considered potential therapeutic agents against inflammatory and infectious diseases.…”

The influence of phase II conjugation on the biological activity of flavonoids

“…It should be noted that polyphenols are not the sole source of phenolic acids that can be detected in plasma and urine after ingestion of polyphenol rich foods, as certain foods contain phenolic compounds alongside polyphenols [159][160][161]. While only a limited amount of research has been performed on the health effects of phenolic acids, there are indications that certain phenolic acids, e.g.…”