Synergistic ultrasound pulsed electric field extraction of litchi peel polyphenols and determination of their properties.

The effects of pulsed electric field combined with ultrasound (PEF-US) on the recovery of polyphenols from litchi peels were investigated. In addition, the optimal purification parameters for polyphenol extracts and their biological activities were also explored in this study. Single-factor and orthogonal experiments were used to optimize the extraction conditions of polyphenols. After optimization, the total phenol content (TPC) of the sample extracted by PEF-US was 2.30 times higher than that of the sample extracted by traditional hot-water extraction. The mechanism of PEF-US enhancing polyphenol recovery was also revealed by morphological analysis of the powder surface. LX-7 was the best resin by comparing the purification effect of nine macroporous resins. The optimum conditions for purification of litchi peel polyphenols by LX-7 resin were also optimized through adsorption and desorption experiments. UHPLC-MS and HPLC results revealed that gentisic acid, catechin, procyanidin A2 and procyanidin B1 are four main substances in purified samples. The results of bioactivity experiments showed that the purified polyphenol samples had strong antioxidant and antibacterial activity. Overall, PEF-US is an efficient method for recovering polyphenols from litchi peels. Our study also provides a strategy for the comprehensive utilization of fruit processing waste.

Loss of the mitochondrial citrate carrier, Slc25a1/CIC disrupts embryogenesis via 2-Hydroxyglutarate.

Biallelic germline mutations in the SLC25A1 gene lead to combined D/L-2-hydroxyglutaric aciduria (D/L-2HGA), a fatal systemic disease uniquely characterized by the accumulation of both enantiomers of 2-hydroxyglutaric acid (2HG). How SLC25A1 deficiency contributes to D/L-2HGA and the role played by 2HG is unclear and no therapy exists. Both enantiomers act as oncometabolites, but their activities in normal tissues remain understudied. Here we show that mice lacking both SLC25A1 alleles exhibit developmental abnormalities that mirror human D/L-2HGA. SLC25A1 deficient cells undergo premature senescence, suggesting that loss of proliferative capacity underlies the pathogenesis of D/L-2HGA. Remarkably, D- and L-2HG directly induce senescence and treatment of zebrafish embryos with the combination of D- and L-2HG phenocopies SLC25A1 loss, leading to developmental abnormalities in an additive fashion relative to either enantiomer alone. Metabolic analyses further demonstrate that cells with dysfunctional SLC25A1 undergo mitochondrial respiratory deficit and remodeling of the metabolism and we propose several strategies to correct these defects. These results reveal for the first time pathogenic and growth suppressive activities of 2HG in the context of SLC25A1 deficiency and suggest that targeting the 2HG pathway may be beneficial for the treatment of D/L-2HGA.

Preparation of carboxymethylcellulose / ZnO / chitosan composite hydrogel microbeads and its drug release behaviour.

In this study, a novel carboxymethylcellulose / ZnO / chitosan (CMC / ZnO / Cs) hydrogel microbeads loaded with crosslinked porous starch / curcumin (CPS / Cur) were designed and prepared to improve the encapsulation efficiency of curcumin for drug delivery to specific sites. It was found that the total pore volume of crosslinked porous starch (CPS) was increased by 1150 % when compared to the native starch (NS), and the adsorption ratio of curcumin by CPS was enhanced by 27 % when compared to NS. Secondly, the swelling ratio of composite hydrogel microbeads was within 25 % in an acidic environment at pH 1.2, and the swelling ratio of hydrogel microbeads sharply increased to 320 % ~ 370 % at pH 6.8 and 7.4. In addition, the results of in vitro simulated release experiments showed that the released amount of hydrogel microbeads loaded with NS/Cur and CPS/Cur in SGF were within 7 % in simulated gastric fluid (SGF). The highest released amount of curcumin was 65.26 % for hydrogel beads loaded with CPS/Cur, which was 26 % lower than that of hydrogel microbeads loaded with Cur in simulated intestinal fluid (SIF). In simulated colonic fluid (SCF), the released amount of hydrogel microbeads loaded with CPS/Cur and Cur were 73.96 % and 91.69 %, respectively. In conclusion, pH-sensitive drug delivery system with good drug stability and bioavailability were successfully prepared with carboxymethylcellulose / ZnO / chitosan bead, suitable targeting drug delivery to the small intestine.

Inhibition of the mitochondrial citrate carrier, Slc25a1, reverts steatosis, glucose intolerance, and inflammation in preclinical models of NAFLD/NASH.

Nonalcoholic fatty liver disease (NAFLD) and its evolution to inflammatory steatohepatitis (NASH) are the most common causes of chronic liver damage and transplantation that are reaching epidemic proportions due to the upraising incidence of metabolic syndrome, obesity, and diabetes. Currently, there is no approved treatment for NASH. The mitochondrial citrate carrier, Slc25a1, has been proposed to play an important role in lipid metabolism, suggesting a potential role for this protein in the pathogenesis of this disease. Here, we show that Slc25a1 inhibition with a specific inhibitor compound, CTPI-2, halts salient alterations of NASH reverting steatosis, preventing the evolution to steatohepatitis, reducing inflammatory macrophage infiltration in the liver and adipose tissue, while starkly mitigating obesity induced by a high-fat diet. These effects are differentially recapitulated by a global ablation of one copy of the Slc25a1 gene or by a liver-targeted Slc25a1 knockout, which unravel dose-dependent and tissue-specific functions of this protein. Mechanistically, through citrate-dependent activities, Slc25a1 inhibition rewires the lipogenic program, blunts signaling from peroxisome proliferator-activated receptor gamma, a key regulator of glucose and lipid metabolism, and inhibits the expression of gluconeogenic genes. The combination of these activities leads not only to inhibition of lipid anabolic processes, but also to a normalization of hyperglycemia and glucose intolerance as well. In summary, our data show for the first time that Slc25a1 serves as an important player in the pathogenesis of fatty liver disease and thus, provides a potentially exploitable and novel therapeutic target.

The mitochondrial citrate carrier, SLC25A1, drives stemness and therapy resistance in non-small cell lung cancer.

Therapy resistance represents a clinical challenge for advanced non-small cell lung cancer (NSCLC), which still remains an incurable disease. There is growing evidence that cancer-initiating or cancer stem cells (CSCs) provide a reservoir of slow-growing dormant populations of cells with tumor-initiating and unlimited self-renewal ability that are left behind by conventional therapies reigniting post-therapy relapse and metastatic dissemination. The metabolic pathways required for the expansion of CSCs are incompletely defined, but their understanding will likely open new therapeutic opportunities. We show here that lung CSCs rely upon oxidative phosphorylation for energy production and survival through the activity of the mitochondrial citrate transporter, SLC25A1. We demonstrate that SLC25A1 plays a key role in maintaining the mitochondrial pool of citrate and redox balance in CSCs, whereas its inhibition leads to reactive oxygen species build-up thereby inhibiting the self-renewal capability of CSCs. Moreover, in different patient-derived tumors, resistance to cisplatin or to epidermal growth factor receptor (EGFR) inhibitor treatment is acquired through SLC25A1-mediated implementation of mitochondrial activity and induction of a stemness phenotype. Hence, a newly identified specific SLC25A1 inhibitor is synthetic lethal with cisplatin or with EGFR inhibitor co-treatment and restores antitumor responses to these agents in vitro and in animal models. These data have potential clinical implications in that they unravel a metabolic vulnerability of drug-resistant lung CSCs, identify a novel SLC25A1 inhibitor and, lastly, provide the first line of evidence that drugs, which block SLC25A1 activity, when employed in combination with selected conventional antitumor agents, lead to a therapeutic benefit.

The Role of Fibroblast Growth Factor-Binding Protein 1 in Skin Carcinogenesis and Inflammation.

Fibroblast growth factor-binding protein 1 (FGFBP1) is a secreted chaperone that mobilizes paracrine-acting FGFs, stored in the extracellular matrix, and presents them to their cognate receptors. FGFBP1 enhances FGF signaling including angiogenesis during cancer progression and is upregulated in various cancers. Here we evaluated the contribution of endogenous FGFBP1 to a wide range of organ functions as well as to skin pathologies using Fgfbp1-knockout mice. Relative to wild-type littermates, knockout mice showed no gross pathologies. Still, in knockout mice a significant thickening of the epidermis associated with a decreased transepidermal water loss and increased proinflammatory gene expression in the skin was detected. Also, skin carcinogen challenge by 7,12-dimethylbenz[a]anthracene/12-O-tetradecanoyl-phorbol-13-acetate resulted in delayed and reduced papillomatosis in knockout mice. This was paralleled by delayed healing of skin wounds and reduced angiogenic sprouting in subcutaneous matrigel plugs. Heterozygous green fluorescent protein (GFP)-knock-in mice revealed rapid induction of gene expression during papilloma induction and during wound healing. Examination of wild-type skin grafted onto Fgfbp1 GFP-knock-in reporter hosts and bone marrow transplants from the GFP-reporter model into wild-type hosts revealed that circulating Fgfbp1-expressing cells migrate into healing wounds. We conclude that tissue-resident and circulating Fgfbp1-expressing cells modulate skin carcinogenesis and inflammation.