Beneficial Effects of Pomegranate on Lipid Metabolism in Metabolic Disorders.

Pomegranate (Punica granatum Linn) is used in the prevention and treatment of metabolic syndrome in recent decades. Imbalances in lipid metabolism are profound features of metabolic disorders. In vivo and in vitro studies have shown that extracts of different pomegranate fractions (peels, flowers, juice, and seeds) regulate lipid metabolism in metabolic-disorder-associated diseases such as atherosclerosis, nonalcoholic fatty liver disease, and type 2 diabetes, helping to alleviate the development of diseases. Amelioration of oxidative stress and the inflammatory response is considered an important reason underlying the regulation of lipid metabolism by pomegranate extracts. Mitochondria, the major cellular site for lipid oxidation, are strongly associated with cellular oxidative and inflammatory status and are likely to be a target for pomegranate extract action. This review summarizes the main findings about the effects of different pomegranate fraction extracts on lipid metabolism in metabolic-disorder-associated diseases and analyses how pomegranate extracts achieve their effects. Furthermore, it also provides an important basis for the research and development of pomegranate-related nutrients or drugs.

Effects of pomegranate peel polyphenols on lipid accumulation and cholesterol metabolic transformation in L-02 human hepatic cells via the PPARγ-ABCA1/CYP7A1 pathway.

To study the effect of pomegranate peel polyphenols on lipid accumulation and cholesterol metabolic transformation in human hepatic cells, purified pomegranate peel polyphenols (PPPs), their main component, punicalagin (PC), and the metabolite of PC, pomegranate ellagic acid (PEA), were chosen as the polyphenols to be tested. At the same time the human hepatocyte cell line L-02 was selected as the experimental cell and a model of steatotic L-02 hepatocytes in vitro was constructed in this paper. The results showed that PPPs, PC and PEA in different concentrations could decrease the total cholesterol (TC) content and increase the total bile acid (TBA) content, and so possess a lipid-lowering effect. The order of the lipid-lowering effect from strong to weak is PEA > PPPs > PC. The relative mRNA expression of peroxisome proliferator-activated receptor γ (PPARγ), ATP-binding cassette transporter A1 (ABCA1) and cholesterol 7α hydroxylase (CYP7A1) was up-regulated by PPPs, PC and PEA in a dose-dependent manner. The effect on the relative mRNA expression can be listed in descending order as: PEA > PPPs > PC. Similar results were found in a western blot analysis. The PPARγ protein, ABCA1 protein and CYP7A1 protein were up-regulated in L-02 cells treated with the three tested polyphenols. All the results indicated that PPPs, PC and PEA could regulate upstream the expression of PPARγ, ABCA1 and CYP7A1, both at transcript and protein levels, to activate the PPARγ-ABCA1/CYP7A1 cell signaling pathway and enhance cholesterol metabolism in L-02 cells. Therefore, PPPs, as a kind of natural material, may be paid more attention in the prevention and treatment of diseases related to excessive cholesterol accumulation.

Mild hypothermia protects against early brain injury in rats following subarachnoid hemorrhage via the TrkB/ERK/CREB signaling pathway.

Subarachnoid hemorrhage (SAH) is a severe neurological disease, which is associated with a significant number of cases of premature mortality and disability worldwide. Mild hypothermia (MH) has been proposed as a potential therapeutic strategy to reduce neuronal injury following SAH. The present study aimed to investigate the mechanisms of MH's protective role in the process of SAH. The present study demonstrated that MH was able to protect against early brain injury in a rat model of SAH. Treating SAH rats with MH reduced the release of reactive oxygen species and prevented activation of apoptotic cascades. Furthermore, the protective effects of MH were shown to be mediated by enhanced activity of the tropomyosin receptor kinase B/extracellular signal­regulated kinases/cAMP response element binding protein (TrkB/ERK/CREB) pathway. Inhibition of TrkB/ERK/CREB activity using a small molecule inhibitor largely abolished the beneficial effects of MH in SAH rats. These results outline an endogenous mechanism underlying the neuroprotective effects of MH in SAH.

Linalool Inhibits LPS-Induced Inflammation in BV2 Microglia Cells by Activating Nrf2.

Linalool, a natural compound of the essential oils, has been reported to have anti-inflammatory effects. This study aimed to investigate the anti-inflammatory effects and mechanism of linalool in LPS-stimulated BV2 microglia cells. BV2 microglia cells were stimulated with LPS in the presence or absence of linalool. The production of inflammatory mediators TNF-α, IL-1ß, NO, and PGE2 as well as Nrf2, HO-1 expression were detected. Our results showed that linalool inhibited LPS-induced TNF-α, IL-1ß, NO, and PGE2 production in a dose-dependent manner. Linalool also inhibited LPS-induced NF-κB activation. Treatment of linalool induced nuclear translocation of Nrf2 and expression of HO-1. In addition, our results showed that the anti-inflammatory effect of linalool was attenuated by transfection with Nrf2 siRNA. In conclusion, these results suggested that linalool inhibits LPS-induced inflammation in BV2 microglia cells by activating Nrf2/HO-1 signaling pathway.

In vitro steatosis hepatic cell model to compare the lipid-lowering effects of pomegranate peel polyphenols with several other plant polyphenols as well as its related cholesterol efflux mechanisms.

This study was aimed to compare the relative activities of the purified pomegranate peels polyphenols (PPPs) with some other plant polyphenols including punicalagin, ellagic acid, gallic acid, phlorizin, and epigallocatechin gallate (EGCG) on the lipid metabolism regulation, and the cholesterol efflux mechanisms of PPPs and punicalagin were also investigated. In this paper, a convenient and accurate in vitro HL7702 steatosis hepatic cell model was applied to evaluate the lipid-lowering effects of the tested polyphenols. The results showed that PPPs possessed the strongest lipid-lowering effects. Prevention group (treated with polyphenols when establishing of steatosis model) was more effective than treatment group (treated with polyphenols after establishment of steatosis model). Punicalagin displayed the strongest lipid-lowering effects among all the tested components of pomegranate peel polyphenols. Moreover, PPPs and punicalagin (10, 20, 40 µg/mL) significantly increased the mRNA expression of LXRα (Liver X receptor alpha) and its target genes-ABCA1 (ATP-binding cassette transporter A1) in a dose-dependent manner in HL7702 steatosis hepatic cells. The high mRNA expression of LXRα and ABCA1, next to lovastatin, was observed in cells treated with 40 µg/mL of PPPs. These in vitro findings suggested that PPPs might have great potential in the clinic treatment of hyperlipemia.

Inhibitory effect of Pulsatilla chinensis polysaccharides on glioma.

Malignant glioma is a very devastating disease. Conventional surgery, radio-and chemotherapy are of limited benefit to improve the cure of patients with malignant astrocytomas. In this research, we evaluated the inhibitory effect of Pulsatilla chinensis polysaccharides (PCPS) on glioma in vivo and in vitro. PCPS had a significant anti-proliferative effect on C6 glioma in vitro assay. Meanwhile a remarkable inhibitory effect PCPS on the growth of C6 glioma and prolongation of life survival could be observed in vivo, comparable to carmustine (BCNU) administration. Moreover PCPS treatment to tumor bearing mice could not only decrease the body weight loss, but also elevate the thymus and spleen indices. In addition, PCPS administration to tumor bearing mice could relieve the liver and kidney damage with decreased levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT) and urea, and enhance superoxide dismutase (SOD) and catalase (CAT) enzyme activities with lower MDA levels in the plasma of tumor bearing mice. The above data proved that PCPS had strong antitumor activity and could be considered as a possible candidate drugs for the glioma therapy.