Effects of eicosapentaenoic acid and docosahexaenoic acid on chylomicron and VLDL synthesis and secretion in Caco-2 cells

Construction of lipid-biomacromolecular compounds for loading and delivery of carotenoids: Preparation methods, structural properties, and absorption-enhancing mechanisms

Due to the unstable chemical properties and poor water solubility of carotenoids, their processing adaptation and oral bioavailability are poor, limiting their application in hydrophilic food systems. Lipid-biomacromolecular compounds can be excellent carriers for carotenoid delivery by taking full advantage of the solubilization of lipids to non-polar nutrients and the water dispersion and gastrointestinal controlled release properties of biomacromolecules. This paper reviewed the research progress of lipid-biomacromolecular compounds as encapsulation and delivery carriers of carotenoids and summarized the material selection and preparation methods for biomacromolecular compounds. By considering the interaction between the two, this paper briefly discussed the effect of these compounds on carotenoid water solubility, stability, and bioavailability, emphasizing their delivery effect on carotenoids. Finally, various challenges and future trends of lipid-biomacromolecular compounds as carotenoid delivery carriers were discussed, providing new insight into efficient loading and delivery of carotenoids.

Production and Optimization of Conjugated Linoleic and Eicosapentaenoic Acids by Bifidobacterium lactis in Cold-Pressed Soybean Cake

Background and Purpose

In regard to the biosynthesis of conjugated linoleic acid (CLA) and eicosapentaenoic acid (EPA) by some bacteria, the objective of this study was to evaluate the efficiency of solid-state fermentation based on soybean pressed cake (SPC) to produce CLA and EPA by Bifidobacterium lactis. The objective of this study was to evaluate the efficiency of solid-state fermentation based on SPC to produce CLA and EPA by B. lactis.

Methods

Process conditions including humidity, inoculation level, and temperature parameters were optimized by adopting the response surface methodology (RSM) method (response surface method) and the design expert software. Accordingly, a homogeneous SPC paste substrate at 60, 70, and 80% humidity was prepared with different inoculation levels at 30, 37, and 44°C to assess the strain behavior. The introduced SPC consisted of 60% humidity, 2% inoculation level at 37°C, and 60% humidity, and 4% inoculation level at 30 and 44°C; it also included 6% inoculation level at 37°C, 70% humidity at 2% inoculation level, at 30 and 44°C, and 4% inoculation level at 37°C. Also, SPC with 80% humidity at 2% and 4% inoculation levels, and at 30 and 44°C was obtained. To confirm the accuracy of the conditions, an experiment was conducted according to the defined requirements.

Results

The results were compared with the predicted data, which showed a significant difference. Under optimized conditions, with an inoculation level of 4% on the SPC medium with 70% humidity and at 37°C, B. lactis strains could yield 9cis-, 11 trans-linoleic and eicosapentaenoic at 0.18 and 0.39% of the total fatty acids.

Conclusion

So, the potential benefits of using SPC as an inexpensive substrate for the commercial production of CLA and EPA should be noted.

Fixed-time and continuous assays of very-low-density lipoprotein secretion rate from rat liver: mean vs. instantaneous velocity

Aim of the study

The secretion rate of triglyceride from rat liver is assayed by the measurement of triglyceride accumulation in plasma when its clearance is inhibited. The aim of the study was to measure and compare the secretion rate of triglyceride from rat liver by two methods of fixed-time and continuous assays.

Material and methods

A single dose of 200 mg of poloxamer-407 (P-407) was injected i.p. into starved male rats. The secretion rate of triglyceride was measured by fixed-time and continuous assays.

Results

The time course for the changes of serum triglyceride following injection of P-407 showed three distinct phases: a lag period of about 30 minutes, a linear increase in serum triglyceride that lasted more than 4 hours, and a slight decline of triglyceride accumulation that lasted about 24 hours. The mean rate of triglyceride secretion was 234.1 ±9.6 mg/dl/h during the linear phase. The linear phase was divided into five time protocols of 240, 180, 120, 60, and 30 minutes and the secretion rate was measured at three points of time in each protocol. The mean rate of triglyceride secretion was 3.91 ±0.15, 3.83 ±0.16, 3.76 ±0.29, 3.57 ±0.43 and 3.13 ±0.34 mg/dl/min in these protocols respectively. In the kinetic assay, the change in the absorbance per three successive five minutes (ΔA/Δt) was measured and the secretion rate was calculated as 3.82 ±0.11 mg/dl/min.

Conclusions

The rate of triglyceride secretion can be measured by both fixed-time and kinetic assays and was about 3.82 ±0.11 mg/dl/min. The results of the two methods are more corresponded as the mean and instantaneous velocity respectively.

Role of BAF60a/BAF60c in chromatin remodeling and hepatic lipid metabolism

The switching defective/sucrose non-fermenting (SWI/SNF) complexes play an important role in hepatic lipid metabolism regulating both transcriptional activation and repression. BAF60a is a core subunit of the SWI/SNF chromatin-remodeling complexes that activates the transcription of fatty acid oxidation genes during fasting/glucagon. BAF60c, another subunit of SWI/SNF complexes, is recruited to form the lipoBAF complex that activates lipogenic genes, promoting lipogenesis and increasing the triglyceride level in response to feeding/insulin. Interestingly, hepatocytes located in the periportal and perivenous zones of the liver display a remarkable heterogeneity in the activity of various enzymes, metabolic functions and gene expression. Especially, fatty-acid oxidation was shown to be mostly periportal, whereas lipogenesis was mostly perivenous. Therefore, the present review highlights the role of of SWI/SNF regulating lipid metabolism under nutritional and hormonal control, which may be associated with hepatocyte heterogeneity.