Liver protecting effects and molecular mechanisms of icariin and its metabolites.

As a detoxification and metabolism organ, the liver plays a vital role in human health. However, an excessive consumption of drugs and toxins, exposure to pathogenic viruses, and unhealthy living habits can lead to liver damage, which may even develop into liver cirrhosis and liver cancer. Epimedium brevicornum Maxim. is a traditional Chinese medicine and dietary supplement in which the flavonoid icariin is a main functional component. Although the protective mechanisms of icariin and its metabolites against liver injury are not yet comprehensively understood, an increasing number of studies have confirmed their liver-protective and anticancer effects. Indeed, icaritin, one of the metabolites of icariin, is currently utilized as an active component of an anti-cancer drug. This paper presents a review of the molecular mechanisms through which icariin and its metabolites actively protect against the occurrence and development of liver injury, and, thus, provides a comprehensive reference for further research and their application in liver protection.

Gamma-oryzanol protects human liver cell (L02) from hydrogen peroxide-induced oxidative damage through regulation of the MAPK/Nrf2 signaling pathways.

Gamma-oryzanol (Orz), a mixture of the ferulic acid ester of triterpene alcohols and phytosterols, was found abundantly in rice bran and rice bran oil which could be available and served as an antioxidant. The present study was to explore the potential protective effects of Orz on oxidative stress and cell apoptosis in human hepatic cells (L02 cells) induced by hydrogen peroxide (H2 O2 ). Flow cytometry detection and Hoechst 33258 staining showed that Orz significantly restored cell cycle and ameliorated apoptosis in H2 O2 -challenged L02 cells. Orz pretreatment inhibited H2 O2 -induced cell apoptosis by increasing the scavenging of hydroxyl radicals (OH·), and efficiently decreasing the production of nitric oxide (NO). Moreover, a loss of total antioxidant capacity (T-AOC) and adenosine triphosphatase (ATPase) were enhanced in H2 O2 -mediated L02 cells pretreated with Orz. Furthermore, preincubation with Orz reduced H2 O2 -mediated the proapoptotic protein of Bak expression and the phosphorylation of ASK1, p38, JNK, and ERK, and increased the anti-apoptotic protein of Bcl-xl expression and anti-oxidative stress proteins of Nrf2 and HO-1 expression. The findings suggested that Orz exerts the cytoprotective effects in H2 O2 -induced L02 cells apoptosis by ameliorating oxidative stress via inhibiting MAPK signaling pathway and activating Nrf2 signaling pathway. PRACTICAL APPLICATIONS: Gamma-oryzanol (Orz), a mixture of the ferulic acid ester of triterpene alcohols and phytosterols, was found abundantly in rice bran and rice bran oil which could be availably served as an antioxidant. In this study, it was found that Orz exerts the cytoprotective effects in H2 O2 -induced L02 cell apoptosis by ameliorating oxidative stress via the inhibition of MAPK signaling pathway and the activation of Nrf2 signaling pathway, which provides a theoretical basis for dietary adding natural products to prevent or treat oxidative stress-related diseases.

Edible and highly biocompatible nanodots from natural plants for the treatment of stress gastric ulcers.

The incidence rate of stress ulcers has increased in recent years, with an increase in life pressure, unavoidable trauma and other factors. The therapy of acute stress ulcers has always been an important challenge. Carbon dots (CDs) have been reported to show excellent biological activities, but research on the stress ulcer curative effect of CDs is unprecedented. Here, we prepared a series of semi-carbonized nanodots (SCNDs) from natural plants or herbs as precursors and the as prepared SCNDs were later proved to be effective in the treatment and inhibition of stress gastric ulcers in a rat model. One kind of SCND from edible and medicinal plants, charred Atractylodes macrocephala (SCNDs-1), is demonstrated in detail for its strong anti-stress gastric ulcer effect with inhibition up to 90% and shows extremely high biocompatibility and ultra-low toxicity. These SCNDs lead to the reduction of inflammatory factors and oxidative stress, and the protection of the gastric mucosa. The SCNDs also reduce the excessive neuroendocrine response caused by stress, regulate the energy metabolism and the structure of intestinal flora, improve the damage to the body caused by the stress state, thus alleviating the occurrence of stress-induced gastric ulcers. This work provides new insights into the preparation of carbon nanomaterials from natural plants through a semi-carbonization process and opens new ways to apply bio-active and bio-safe SCNDs in the modern pharmaceutical field.

Selective inactivation of Gram-negative bacteria by carbon dots derived from natural biomass: Artemisia argyi leaves.

Infections caused by Gram-negative bacteria have been an increasing problem worldwide. Meanwhile, the overuse of traditional antibiotics has caused an emergence of drug resistance. The development of new antibacterial agents, which can cope with the threat from drug-resistant bacteria, is urgently needed. Herein, carbon dots (ACDs) derived from Artemisia argyi leaves were obtained via a smoking simulation method and exhibited selective antibacterial ability of targeting Gram-negative bacteria. The bactericidal efficiency of ACDs (150 µg mL-1) for Gram-negative bacteria (Escherichia coli, Pseudomonas aeruginosa, and Proteusbacillus vulgaris) can reach 100%, while for Gram-positive bacteria (Staphylococcus aureus and Bacillus subtilis), ACDs have no significant antibacterial function, indicating that the particles can selectively target specific bacteria. The antibacterial mechanism for ACDs confirmed that ACDs could only damage the cell walls of Gram-negative bacteria but not that of Gram-positive bacteria. Moreover, ACDs can inhibit the activity of cell wall-related enzymes in Gram-negative bacteria by changing the enzymatic secondary structure. This work is of great significance for the development of new antibacterial nanomaterials derived from natural biomass as well as the treatment of infections caused by Gram-negative bacteria.

Clinical comparison of the efficacy of three different bowel preparation methods on the infectious complications following transrectal ultrasonography-guided prostate biopsy in nursing practice.

AIMS AND OBJECTIVES: To assess the effects of three different bowel preparation methods on the incidence of infectious complications in patients who underwent transrectal ultrasonography-guided prostate biopsy. BACKGROUND: The standard bowel preparation protocol for prostate biopsy has not been established. DESIGN: A retrospective study in a single centre. METHODS: From January 2013-December 2015, the clinical records of 1,130 patients who underwent prostate biopsy were, respectively, reviewed. All the patients received metronidazole prophylaxis before biopsy. The patients were divided into three groups according to the bowel preparation methods: patients in Group A (n = 402) received only soapy enema; patients in Group B (n = 413) received polyethylene glycol; while patients in Group C (n = 315) received polyethylene glycol plus povidone-iodine enema. Infectious complications were classified as fever (>37.5°C), urinary tract infection and sepsis. The postoperative adverse events were also observed. RESULTS: The overall postbiopsy infectious complications were observed in 48 (4.25%) patients of all the cases, including 23 (5.72%) cases in Group A, 20 (4.84%) cases in Group B and five patients (1.59%) in Group C. There was significant difference among the groups (p = .018). In detail, these infectious complications included 22 (1.95%) cases of fever and 26 (2.30%) cases of urinary tract infection. No sepsis was observed among the total patients. The incidence of adverse events was 14.43% (58/402) occurred in Group A, 25.91% (107/413) in Group B and 26.67% (84/315) in Group C. The difference was statistically significant. CONCLUSIONS: Our study confirmed that combined preparation regimens of polyethylene glycol with povidone-iodine enema could significantly reduce the postbiopsy infection rate. Conventional soapy enema is associated with less adverse events. RELEVANCE TO CLINICAL PRACTICE: Findings of this study provide useful evidence-based information for healthcare professionals. The application of combined preparation regimens of polyethylene glycol with povidone-iodine enema resulted in better improvement in the prevention of postbiopsy infection.

The grinding tip of the sea urchin tooth exhibits exquisite control over calcite crystal orientation and Mg distribution.

The sea urchin tooth is a remarkable grinding tool. Even though the tooth is composed almost entirely of calcite, it is used to grind holes into a rocky substrate itself often composed of calcite. Here, we use 3 complementary high-resolution tools to probe aspects of the structure of the grinding tip: X-ray photoelectron emission spectromicroscopy (X-PEEM), X-ray microdiffraction, and NanoSIMS. We confirm that the needles and plates are aligned and show here that even the high Mg polycrystalline matrix constituents are aligned with the other 2 structural elements when imaged at 20-nm resolution. Furthermore, we show that the entire tooth is composed of 2 cooriented polycrystalline blocks that differ in their orientations by only a few degrees. A unique feature of the grinding tip is that the structural elements from each coaligned block interdigitate. This interdigitation may influence the fracture process by creating a corrugated grinding surface. We also show that the overall Mg content of the tooth structural elements increases toward the grinding tip. This probably contributes to the increasing hardness of the tooth from the periphery to the tip. Clearly the formation of the tooth, and the tooth tip in particular, is amazingly well controlled. The improved understanding of these structural features could lead to the design of better mechanical grinding and cutting tools.