Encapsulation of Marjoram Phenolic Compounds Using Chitosan to Improve Its Colon Delivery

Design of chitosan colon delivery micro/nano particles for an Achillea millefolium extract with antiproliferative activity against colorectal cancer cells

In this study, chitosan low molecular weight (LCH) and chitosan medium molecular weight (MCH) were employed to encapsulate a yarrow extract rich in chlorogenic acid and dicaffeoylquinic acids (DCQAs) that showed antiproliferative activity against colon adenocarcinoma cells. The design of CH micro/nanoparticles to increase the extract colon delivery was carried out by using two different techniques: ionic gelation and spray drying. Ionic gelation nanoparticles obtained were smaller and presented higher yields values than spray-drying microparticles, but spray-drying microparticles showed the best performance in terms of encapsulation efficiency (EE) (> 94%), also allowing the inclusion of a higher quantity of extract. Spray-drying microparticles designed using LCH with an LCH:extract ratio of 6:1 (1.25 mg/mL) showed a mean diameter of 1.31 ± 0.21 µm and EE values > 93%, for all phenolic compounds studied. The release profile of phenolic compounds included in this formulation, at gastrointestinal pHs (2 and 7.4), showed for most of them a small initial release, followed by an increase at 1 h, with a constant release up to 3 h. Chlorogenic acid presented the higher release values at 3 h (56.91% at pH 2; 44.45% at pH 7.4). DCQAs release at 3 h ranged between 9.01- 40.73%, being higher for 1,5- and 3,4-DCQAs. After gastrointestinal digestion, 67.65% of chlorogenic and most DCQAs remained encapsulated. Therefore, spray-drying microparticles can be proposed as a promising vehicle to increase the colon delivery of yarrow phenolics compounds (mainly chlorogenic acid and DCQAs) previously described as potential agents against colorectal cancer.

Development of Pectin Particles as a Colon-Targeted Marjoram Phenolic Compound Delivery System

Marjoram is a culinary herb that has been widely employed in folk medicine and presents a high content in phenolics. Thus, the aim of this project was to design formulations to encapsulate phenolic compounds from marjoram to allow their release in the colon. For this purpose, pectin was used as an encapsulating agent, applying two different encapsulation techniques (ionic gelation and spray-drying), followed by a CaCl2 bath. The ionic gelation technique showed a higher yield (77%) compared to spray-drying (31%), and the particles obtained were smaller (267 nm). However, the microparticles obtained by spray-drying presented a higher encapsulation efficiency (93%). Moreover, spray-dried microparticles protected a higher percentage of the encapsulated phenolics from the action of gastrointestinal pHs and enzymes. Hence, the results showed that spray-drying was a more appropriate technique than ionic gelation for the encapsulation of marjoram phenolics in order to protect them during the gastrointestinal step, facilitating their arrival in the colon. These microparticles would also be suitable for inclusion in food matrices for the development of phenolic colon delivery systems.

Phytosome Supplements for Delivering Gymnema inodorum Phytonutrients to Prevent Inflammation in Macrophages and Insulin Resistance in Adipocytes

Gymnema inodorum (GI) is a leafy green vegetable found in the northern region of Thailand. A GI leaf extract has been developed as a dietary supplement for metabolic diabetic control. However, the active compounds in the GI leaf extract are relatively nonpolar. This study aimed to develop phytosome formulations of the GI extract to improve the efficiencies of their phytonutrients in terms of anti-inflammatory and anti-insulin-resistant activities in macrophages and adipocytes, respectively. Our results showed that the phytosomes assisted the GI extract's dispersion in an aqueous solution. The GI phytocompounds were assembled into a phospholipid bilayer membrane as spherical nanoparticles about 160-180 nm in diameter. The structure of the phytosomes allowed phenolic acids, flavonoids and triterpene derivatives to be embedded in the phospholipid membrane. The existence of GI phytochemicals in phytosomes significantly changed the particle's surface charge from neutral to negative within the range of -35 mV to -45 mV. The phytosome delivery system significantly exhibited the anti-inflammatory activity of the GI extract, indicated by the lower production of nitric oxide from inflamed macrophages compared to the non-encapsulated extract. However, the phospholipid component of phytosomes slightly interfered with the anti-insulin-resistant effects of the GI extract by decreasing the glucose uptake activity and increasing the lipid degradation of adipocytes. Altogether, the nano-phytosome is a potent carrier for transporting GI phytochemicals to prevent an early stage of T2DM.