Design and Development of Nanovehicle-Based Delivery Systems for Preventive or Therapeutic Supplementation with Flavonoids

Abstract

To date more than 4000 compounds are recognized to belong to the class of flavonoids. These natural phenolic drugs are poorly soluble in water and are rapidly degraded and metabolized in the human body, but nevertheless are very promising for their potential contribution to the prevention and therapy of major chronic diseases, including cardiovascular and neurodegenerative diseases and cancer. In recent years a number of flavanols (e.g. catechins), flavonols (e.g. quercetin, myricetin) and isoflavones (e.g. genistein, daidzein) have been confirmed to possess strong antioxidant, anti-inflammatory, anti-proliferative and anti-aging activities. Incorporation into lipidic or polymer-based nanoparticles appears to markedly help the oral delivery of flavonoids, as these particles can protect the drug from degradation in the gastrointestinal tract and, by virtue of their unique absorption mechanism through the lymphatic system, also from first-pass metabolism in the liver. In addition, both oral and parenteral administration of flavonoids exploits a pharmacologic delivery route that guarantees sustained release of the active principle at the desired site of action. A comprehensive review of studies currently available on the in vitro and in vivo experimental administration of flavonoids by means of nanovectors may be of use as a foundation for the development of advanced delivery systems for these powerful compounds, in view of their adoption in primary and secondary disease prevention.

Natural product-based nanomedicine: recent advances and issues

“…The nanospheres are porous and the drug is uniformly distributed among the pores. 19 Phospholipids comprise liposomes and some micelles ( Figure 1A). Liposomes are composed of phospholipid bilayers similar to cell membranes, whereas micelles composed of phospholipids only have one layer in which the head group faces the outside and the hydrophobic tails form the micelle core in a hydrophilic environment, such as the blood.…”

“…SLNs are more stable than liposomes and, in some cases, are less toxic than polymeric nanoparticles. 19 To overcome some limitations in the old-generation SLNs, liquid lipid has been incorporated into the solid structure, resulting in nanostructured lipid carriers ( Figure 1D). Three types of lipid nanoparticles have been described: an imperfect type, an amorphous type, and a multiple type.…”

“…To our knowledge, only a few reviews with limited scopes have been published on natural product-centered nanotechnology. Past reviews have focused on the use of nanoparticles with curcumin, 22,24,25 flavonoids, 19 traditional Chinese medicine, 26 and the synthesis and characterization of nanoparticles with natural products. 5 In our review, we will address key aspects of natural product-based nanomedicine, including natural compounds, bioavailability, targeting, controlled release, and related challenges.…”

Effects of polymer molecular weight on relative oral bioavailability of curcumin

“…2 However, the beneficial effects of many polyphenols on human health are limited due to their low oral bioavailability. This is because the polyphenols, including curcumin, 3 resveratrol, 4 quercetin, 5 daidzein, 6 silymarin, 7 and other polyphenols 2 are poorly absorbed in the gut and undergo fast metabolism by the liver.…”

“…2,8 The mechanism by which these nanoformulations enhance the oral bioavailability of polyphenols involves increasing the surface area and interaction of the compounds, thereby raising the dissolution rate to improve their absorption. 9 Nevertheless, previous studies have shown that polyester nanoparticle-based formulations are suitable for oral ingestion because they are more stable than other formulations in the gastrointestinal tract.…”