In Vitro Intestinal Bioaccessibility of Alkylglycerols Versus Triacylglycerols as Vehicles of Butyric Acid

Abstract

Butyric acid has been the subject of much attention last years due to its bioactivity. However, the potential advantages of butyrate are limited by the problem to reach enough plasma concentrations; therefore, pro-drugs have been proposed as an alternative to natural butyrate. A comparative study on in vitro intestinal digestion of 2,3-dibutyroil-1-O-octadecyl glycerol (D-SCAKG) and tributyrin (TB), as potential pro-drugs of butyric acid, was performed. Aliquots were taken at different times of digestion for studying the extent and rate of hydrolysis of both substrates. The micellar phase (MP) and oily phase (OP) formed in the digestion media were separated and their composition in lipid products was analyzed. Initially, it was confirmed that the in vitro model reproduced physiological results by testing against olive oil as a standard lipid. The progress of in vitro intestinal digestion of D-SCAKG was slower than that of TB. TB hydrolyzed completely to butyric acid, whereas D-SCAKG mainly yielded 2-butyroil-1-O-octadecyl glycerol (M-SCAKG), followed by butyric acid and 1-O-octadecyl glycerol (AKG). The MP from both substrates mainly consisted of butyric acid. Minor levels of M-SCAKG and AKG were also found in the MP after hydrolysis of D-SCAKG, the M-SCAKG being mainly distributed in the OP. Therefore, D-SCAKG produced a stable form of esterified butyric acid as M-SCAKG after in vitro intestinal digestion, unlike TB. Additionally, such a product would integrate both bioactive compounds, butyric acid and alkylglycerol, within the same molecule. Free butyric acid and AKG would be also released, which are lipid products of interest as well.

Lipids as Delivery Systems to Improve the Biological Activity of Bioactive Ingredients

“…Torres et al [116] have recently synthesized structured alkyldiacylglycerols containing residual short-chain fatty acids at sn-2 and sn-3 locations by enzymatic transesterification of 1-O-Octadecyl glycerol and ethyl butyrate. The potential bioaccessibility of this synthetic alkylglycerol was later assayed by simulating the intestinal digestion of the molecule by pancreatic enzymes under in vitro conditions [117]. This study showed that the suggested bioactive structure of 1-O-alkyl-sn-glycerol retaining a short-chain residue was produced after intestinal hydrolysis as the major hydrolysis product, in the form of 2-butyroil-1-O-octadecyl glycerol.…”

“…It has been stated that efficient pro-drugs of butyrate should have a sufficiently stable bond between the carrier and butyrate residue to increase its in vivo half-life [118]. In the performed in vitro intestinal digestion study [117], it was shown that the traditional tributyrin proposed as pro-drug of butyrate was completely hydrolyzed to butyric acid, in contrast to the obtained stable esterified form of butyric acid as 2-butyroil-1-Ooctadecyl glycerol, showing the potential of this synthetic molecule as carrier of butyrate.…”

Unusual Ether Lipids and Branched Chain Fatty Acids in Sea Cucumber (Cucumaria frondosa) Viscera and Their Seasonal Variation

“…Diacylglyceryl ethers (DAGE) and monoacylglyceryl ethers (MAGE) have been reported in several marine animals, such as in the livers of dogfish and shark [ 7 ] and deep-sea squids ( Berryteuthis magister ) [ 8 ]. In the last two decades, ether lipids have attracted the interest of researchers due to their health promoting effects in humans, specifically for their potential in cancer therapy but also because they have been used to improve the bioavailability of other lipid molecules such as butyric acid or omega-3 FA [ 9 , 10 , 11 , 12 ].…”

Discrimination against diacylglycerol ethers in lipase-catalysed ethanolysis of shark liver oil

“…Immune stimulators properties have also been attributed to dietary ingestion of these substances (Palmblad, Samuelsson & Brohult, 1990). In addition, recent studies indicate the these compounds could improve the bioavailability of othe lipid molecules such as butyric or omega-3 fatty acids (Martín, Morán-Valero, Señoráns, Reglero & Torres, ;Torres, Vázquez, Señoráns & Reglero, 2009).…”