The phenolics, antioxidant activity and in vitro digestion of pomegranate (Punica granatum L.) peels: an investigation of steam explosion pre-treatment.

Pomegranate peels, the main byproduct of pomegranate production, are rich in phenolic compounds that are known for their effective antioxidant properties and have vast application prospects. In this study, steam explosion, an environmentally friendly technique, was applied to pretreat pomegranate peels for phenol extraction. We investigated the effects of explosion pressure, duration, and particle size on the content of total and individual phenolics, and antioxidant activity of pomegranate peels before and after in vitro digestion. The optimal conditions for a steam explosion for pomegranate peels in terms of total phenol content were a pressure of 1.5 MPa, a maintenance time of 90 s, and a particle size of 40 mesh. Under these conditions, pomegranate peel extract presented a higher yield of total phenols, gallic acid, and ellagic acid. However, it also had a lower content of punicalin and punicalagin, compared to the unexploded peels. There was no improvement in the antioxidant activity of pomegranate peels after the steam explosion. Moreover, the content of total phenol, gallic acid, ellagic acid, punicalin, and punicalagin, as well as the antioxidant activity of pomegranate peels, all increased after gastric digestion. Nevertheless, there was a large variation in the pomegranate peel processed by different pressure, duration, and sieve fractions. Overall, this study demonstrated that steam explosion pre-treatment could be an efficient method for improving the release of phenolics, especially gallic acid, and ellagic acid, from pomegranate peels.

Cytotoxicity and Apoptosis Induced by Chenopodium ambrosioides L. Essential Oil in Human Normal Liver Cell Line L02 via the Endogenous Mitochondrial Pathway Rather Than the Endoplasmic Reticulum Stress.

Chenopodium ambrosioides L. (C. ambrosioides) has been used as dietary condiments and as traditional medicine in South America. The oil of Chenopodium ambrosioides L. (C. ambrosioides) can be used as a natural antioxidant in food processing. It also has analgesic, sedating, and deworming effects, and can be used along with the whole plant for its medical effects: decongestion, as an insecticide, and to offer menstruation pain relief. This study was conducted to investigate the cytotoxicity and apoptosis effects of an essential oil from C. ambrosioides in vitro. The cytotoxicity evaluation of the essential oil from C. ambrosioides on human normal liver cell line L02 was assessed by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay. AO/EB dual fluorescent staining assay and Annexin V-FITC were used for apoptosis analysis. The changes in mitochondrial membrane potential (MMP) were analyzed with 5,5,6,6'-tetrachloro-1,1,3,3,-tetraethyl-imidacarbocyanine iodide (JC-1) dye under a fluorescence microscope. The level of apoptosis related protein expression was quantified by Western blot. The L02 cells were treated with the essential oil from C. ambrosioides at 24, 48, and 72 h, and the IC50 values were 65.45, 58.03, and 35.47 µg/mL, respectively. The AO/EB staining showed that viable apoptotic cells, non-viable apoptotic cells, and non-viable non-apoptotic cells appeared among the L02 cells under the fluorescence microscope. Cell cycle arrest at the S phase and cell apoptosis increased through flow cytometry in the L02 cells treated with the essential oil. MMP decreased in a concentration-dependent manner, as seen through JC-1 staining under the fluorescence microscope. In the L02 cells as shown by Western blot and qPCR, the amount of the apoptosis-related proteins and the mRNA expression levels of cytochrome C, Bax, Caspase-9, and Caspase-3 increased, Bcl-2 decreased, and Caspase-12, which is expressed in the endoplasmic reticulum, showed no obvious changes in protein amount or mRNA expression level. The essential oil form C. ambrosioides had a cytotoxic effect on L02 cells. It could inhibit L02 cell proliferation, arrest the cell cycle at the S phase, and induce L02 cell apoptosis through the endogenous mitochondrial pathway.

Acute Elevated Resistin Exacerbates Mitochondrial Damage and Aggravates Liver Steatosis Through AMPK/PGC-1α Signaling Pathway in Male NAFLD Mice.

Resistin was identified as a link between obesity and insulin resistance and is associated with many diseases in mice. Deciphering the related development and molecular mechanism is necessary for the treatment of these diseases. Previous studies have revealed that increased resistin levels are correlated with lipid accumulation and play a role in non-alcoholic fatty liver disease (NAFLD) development. However, the exact mechanisms underlying these processes remain unclear. To further clarify whether acute elevated resistin level exacerbated liver steatosis, a high-fat diet-induced NAFLD animal model was used and treated with or without resistin for 6 days. We discovered that resistin altered mitochondrial morphology, decreased mitochondrial content, and increased lipid accumulation in HFD mice. qRT-PCR and western blot analysis showed that acute elevated resistin significantly altered the gene expression of mitochondrial biogenesis and liver lipid metabolism molecules in HFD mice. Consequently, in vitro experiments verified that resistin reduced the mitochondrial content, impaired the mitochondrial function and increased the lipid accumulation of palmitate-treated HepG2 cells. Additionally, we demonstrated that resistin upregulated proinflammatory factors, which confirmed that resistin promoted the development of inflammation in NAFLD mice and palmitate-treated HepG2 cells. Signaling-transduction analysis demonstrated that acute elevated resistin aggravated liver steatosis through AMPK/PGC-1α pathway in male mice. This reveals a novel pathway through which lipogenesis is induced by resistin and suggests that maintaining mitochondrial homeostasis may be key to treatments for preventing resistin-induced NAFLD aggravation.

Inhibitory effect of 17ß­estradiol on triglyceride synthesis in skeletal muscle cells is dependent on ESR1 and not ESR2.

The present study aimed to investigate the inhibitory effects and the mechanisms underlying 17ß­estradiol (E2) effects on triglyceride synthesis and insulin resistance in skeletal muscle tissues and cells. Ovariectomy (OVX) was performed on 6­month­old female rats treated with or without E2. Subsequently, various serum biochemical markers were measured. Additionally, pathological alterations of the uterus, liver and skeletal muscle were analyzed, and the content of triglycerides (TG) in muscle was detected. Differentiated myotubes formed by C2C12 cells were treated with palmitic acid (PA) or pretreated with E2, estrogen receptor (ESR) 1 agonist propylpyrazoletriol (PPT) and ESR2 agonist diarylpropionitrile (DPN). Subsequently, the mRNA or protein expression levels of ESR1/2, peroxisome proliferator activated receptor α (PPARα), CD36 molecule (CD36), fatty acid synthase (FASN), perilipin 2 (PLIN2), phosphorylated acetyl­CoA carboxylase α (p­ACACA), p­AKT serine/threonine kinase (p­AKT) and p­mitogen­activated protein kinase 8 (p­MAPK8) were analyzed in skeletal muscle or in C2C12 cells by reverse transcription­semi­quantitative polymerase chain reaction and western blotting. The present results suggested that treatment with E2 inhibited OVX­induced body weight gain, TG accumulation and insulin resistance. The protein or mRNA expression levels of ESR1, CD36, PPARα, p­ACACA and p­AKT were decreased, whereas the protein or mRNA expression levels of ESR2, PLIN2, FASN and p­MAPK8 were increased in the OVX group. Of note, treatment with E2 restored the expression levels of the aforementioned factors. In C2C12 cells, treatment with E2 or PPT reversed the alterations induced by treatment with PA. In contrast, pretreatment with DPN did not influence the effect of PA. Collectively, E2 was able to interact with ESR1, thus activating the CD36­PPARα pathway, decreasing the level of TG in the muscles and improving insulin resistance in skeletal muscles and C2C12 cells.

Effects of a standard high-fat diet with or without multiple deficiencies on bone parameters in ovariectomized mature rat.

The aim of this study was to determine the effects of a standard high fat diet (D12451) with or without vitamin D3, phosphorus, and calcium (i.e., high-fat diet [HFD] or high-fat deficient diet [HFDD]) on the bone parameters of ovariectomized female rats. Six-month-old of female Sprauge Dawley (SD) rats were randomly divided into six study groups: sham operation with standard chow diet (SSCD), sham operation with a HFD (SHFD), sham operation with a HFDD (SHFDD), ovariectomized (OVX), OVX with a HFD (OVX-HFD), and OVX with a HFDD (OVX-HFDD). A bilateral ovariectomy was administered to the OVX, OVX-HFD, and OVX-HFDD rats, while the SSCD, SHFD, and SHFDD rats were only given a laparotomy. Multiple analyses concerning the glucose and insulin tolerance, structure, bone strength, bone matrix, and mineralization of the rats were conducted in order to produce a detailed characterization of the effects of a HFD and a HFDD on postmenopausal osteoporotic rats. Seven months of HFD and HFDD feeding resulted in obesity and insulin resistance in female SD rats. A standard HFD increased the bone calcium content and bone strength of OVX rats. Conversely, the serum N-mid osteocalcin (N-MID-OT) and tartrate-resistant acid phosphatase (TRAP) levels in the OVX-HFDD group were increased, accompanied by a clear decrease in the bone mineral density (BMD), bone mineral content (BMC), bone calcium and bone strength, as well as reduced osteocalcin expression. A HFDD weakened the activity of the osteoblasts while aggravating bone loss and decreasing bone strength in ovariectomized rats, which may be due to the calcium, phosphorus and vitamin D3 deficiencies in the diet.

[Essential Oil of Chenopodium ambrosioides Induced Caspase-Dependent Apoptosis in SMMC-7721 Cells].

Objective: To investigate the inhibition of cell proliferation by essential oil of Chenopodium ambrosioides on the human liver cancer SMMC-7721 cells and human liver LO2 cells,and to study the mechanism of anti-tumor in vitro. Methods: The inhibition of cell proliferation by essential oil of Chenopodium ambrosioides was determined by MTT assay; the distribution of cell cycle was analyzed by flow cytometry( FCM) with PI staining; cell morphology and apoptosis effect of SMMC-7721 cells were observed by microscope; the apoptotic rate was quantified by FCM with Annexin V / PI double staining. Results: Essential oil of Chenopodium ambrosioides could significantly inhibit the cell proliferation in a concentration-time-dependent manner( P < 0. 05),and the IC50 values on SMMC-7721 cells were lower than human liver LO2 cells at 24,48 and 72 h,respectively( P < 0. 05); cell cycle of SMMC-7721 cells was arrested in G0/G1phase; morphological observation revealed that the cells were wrinkled and the cellular cohesiveness of cells was reduced; nuclear was condensed and in orange colour,of which were the late apoptotic features; and the apoptotic rate increased in a concentration-dependent manner( P < 0. 05),non-viable apoptotic rate was obviously decreased with caspase inhibitor in 100 µg / m L essential oil of Chenopodium ambrosioides( P < 0. 01). Conclusion: Essential oil of Chenopodium ambrosioides can inhibit SMMC-7721 cell proliferation, which may be related to inducing cell cycle arrest and caspase-dependent apoptosis.