[Severity Differences and Mechanisms of Algal Blooms Among Sections in Pengxi River of the Three Gorges Reservoir].

Since the impoundment of the Three Gorges Dam, 50% of the first-order tributaries in the reservoir area have had frequent algal blooms but with variations regarding the geographical locations of the seriously bloomed sections and the scope of the latter being influenced by the mainstream. This study took the Pengxi River, a first-order tributary of the reservoir area, as an example in order to explore the difference in eutrophication among the river sections and the influence of the Yangtze River on its tributaries. During the spring bloom season of 2019, sampling was carried out in one-week intervals for a total duration of one month. Seven sampling sections (PX1-PX7) were set up from the confluence to upstream. According to the profiles of vertical water temperature and conductivity of each section, the influence scope and form of the backwater of the Yangtze River were inferred; in addition, severity differences and mechanisms of algal blooms among sections were explored through the comparison of the hydrology, water quality, and sediment nutrients among Gaoyang Lake (PX5), which has had serious algal blooms, and the upstream (PX6) and downstream (PX4) sections of PX5, which are both 4 km away from PX5. The results showed that during the sampling month, the average ρ(Chl-a) in the confluence area of the Pengxi River (PX1-PX4) and in the upstream (PX5-PX7) were in the range of 14.55-44.00 µg·L-1 and 42.66-175.40 µg·L-1, respectively. The ρ(Chl-a) of PX5 was up to 413.00 µg·L-1, which was significantly higher than that of other sections (P<0.05). Temperature and conductivity results showed that the backwater from Yangtze River flowed into the Pengxi River from the middle and bottom layers during the period from April to May. The confluence (PX1-PX4) sections were in the intersection area of the backwater from Yangtze River and the upstream of the Pengxi River; thus, the waterbody was unstable, which was not conducive to the formation of algal blooms. However, the upstream (PX5-PX7) sections were not directly affected by the backwater from Yangtze River, leading the nutrient exchange mainly vertically. Most averages of n(TN)/n(TP) and n(DTN)/n(DTP) of PX4-PX6 were all greater than 16, indicating a phosphorus-limited state. During sampling, the average sediment total phosphorus of PX5 was 91% of that in upstream PX6, which was only 4 km away, whereas the surface water total phosphorus of PX5 was 180% of that in PX6. The important reason for this phenomenon is that the water surface width of PX5 was 3.6-4.7 times that of PX6, indicating longer wind fetch in the former section. Owing to the mountainous landscape in the Three Gorges Reservoir (TGR) region where windy weather is rare, the disturbance effect of wind and waves on PX5 was stronger than that of PX6, and the nutrients released from the sediment at the PX5 section caused by wind and waves resupplied the surface water more easily, causing more serious algal blooms at PX5 than those at the remaining sections in the Pengxi River. The main causes of the algal blooms in the tributaries of the TGR area lied in the stability of water stratification and the supply of internal phosphorus. The stability of water stratification was mainly affected by the backwater from Yangtze River, and the supply of internal phosphorus in the algal bloom season was affected by the special water stratification phenomenon of the tributaries of TGR-the "surface density layers." The duration and degree of weather disturbance to the surface density layers can be used to predict the time and scale of algal blooms.

Oxidative Stress Induction Is a Rational Strategy to Enhance the Productivity of Antrodia cinnamomea Fermentations for the Antioxidant Secondary Metabolite Antrodin C.

Antioxidant metabolites contribute to alleviating oxidative stress caused by reactive oxygen species (ROS) in microorganisms. We utilized oxidative stressors such as hydrogen peroxide supplementation to increase the yield of the bioactive secondary metabolite antioxidant antrodin C in submerged fermentations of the medicinal mushroom Antrodia cinnamomea. Changes in the superoxide dismutase and catalase activities of the cells indicate that ROS are critical to promote antrodin C biosynthesis, while the ROS production inhibitor diphenyleneiodonium cancels the productivity-enhancing effects of H2O2. Transcriptomic analysis suggests that key enzymes in the mitochondrial electron transport chain are repressed during oxidative stress, leading to ROS accumulation and triggering the biosynthesis of antioxidants such as antrodin C. Accordingly, rotenone, an inhibitor of the electron transport chain complex I, mimics the antrodin C productivity-enhancing effects of H2O2. Delineating the steps connecting oxidative stress with increased antrodin C biosynthesis will facilitate the fine-tuning of strategies for rational fermentation process improvement.

Production of bioactive metabolites by submerged fermentation of the medicinal mushroom Antrodia cinnamomea: recent advances and future development.

Edible and medicinal mushrooms have usually been considered as a sustainable source of unique bioactive metabolites, which are valued as promising provisions for human health. Antrodia cinnamomea is a unique edible and medicinal fungus widespread in Taiwan, which has attracted much attention in recent years for its high value in both scientific research and commercial applications owing to its potent therapeutic effects, especially for its hepatic protection and anticancer activity. Due to the scarcity of the fruiting bodies, the cultivation of A. cinnamomea by submerged fermentation appears to be a promising substitute which possesses some unique advantages, such as short culture time period and its high feasibility for scale-up production. However, the amount of fungal bioactive metabolites derived from the cultured mycelia of A. cinnamomea grown by submerged fermentation is much less than those obtained from the wild fruiting bodies. Hence, there is an urgent need to bridge such a discrepancy on bioactive metabolites between the wild fruiting bodies and the cultured mycelia. The objective of this article is to review recent advances and the future development of the mycelial submerged fermentation of A. cinnamomea in terms of enhancement for the production of fungal bioactive components by the optimization of culture conditions and the regulation of fungal metabolism. This review provides valuable information for further biotechnological applications of A. cinnamomea as well as other mushrooms being the source of bioactive ingredients by submerged fermentation.

Regulation of autophagy by tea polyphenols in diabetic cardiomyopathy.

OBJECTIVE: To investigate the effect of tea polyphenols on cardiac function in rats with diabetic cardiomyopathy, and the mechanism by which tea polyphenols regulate autophagy in diabetic cardiomyopathy. METHODS: Sixty Sprague-Dawley (SD) rats were randomly divided into six groups: a normal control group (NC), an obesity group (OB), a diabetic cardiomyopathy group (DCM), a tea polyphenol group (TP), an obesity tea polyphenol treatment group (OB-TP), and a diabetic cardiomyopathy tea polyphenol treatment group (DCM-TP). After successful modeling, serum glucose, cholesterol, and triglyceride levels were determined; cardiac structure and function were inspected by ultrasonic cardiography; myocardial pathology was examined by staining with hematoxylin-eosin; transmission electron microscopy was used to observe the morphology and quantity of autophagosomes; and expression levels of autophagy-related proteins LC3-II, SQSTM1/p62, and Beclin-1 were determined by Western blotting. RESULTS: Compared to the NC group, the OB group had normal blood glucose and a high level of blood lipids; both blood glucose and lipids were increased in the DCM group; ultrasonic cardiograms showed that the fraction shortening was reduced in the DCM group. However, these were improved significantly in the DCM-TP group. Hematoxylin-eosin staining showed disordered cardiomyocytes and hypertrophy in the DCM group; however, no differences were found among the remaining groups. Transmission electron microscopy revealed that the numbers of autophagosomes in the DCM and OB-TP groups were obviously increased compared to the NC and OB groups; the number of autophagosomes in the DCM-TP group was reduced. Western blotting showed that the expression of LC3-II/I and Beclin-1 increased obviously, whereas the expression of SQSTM1/p62 was decreased in the DCM and OB-TP groups (P<0.05). CONCLUSIONS: Tea polyphenols had an effect on diabetic cardiomyopathy in rat cardiac function and may alter the levels of autophagy to improve glucose and lipid metabolism in diabetes.

Current Advances on the Structure, Bioactivity, Synthesis, and Metabolic Regulation of Novel Ubiquinone Derivatives in the Edible and Medicinal Mushroom Antrodia cinnamomea.

In recent years, Antrodia cinnamomea has attracted great attention around the world as an extremely precious edible and medicinal mushroom. Ubiquinone derivatives, which are characteristic metabolites of A. cinnamomea, have shown great bioactivities. Some of them have been regarded as promising therapeutic agents and approved into clinical trial by the U.S. Food and Drug Administration. Although some excellent reviews have been published covering different aspects of A. cinnamomea, this review brings, for the first time, complete information about the structure, bioactivity, chemical synthesis, biosynthesis, and metabolic regulation of ubiquinone derivatives in A. cinnamomea. It not only advances our knowledge on the bioactive metabolites, especially the ubiquinone derivatives, in A. cinnamomea but also provides valuable information for the investigation on other edible and medicinal mushrooms.

Construction of ICG encapsulated W18O49@MSN as a fluorescence carrier for real-time tracked photothermal therapy.

Photothermal therapy (PTT) has drawn tremendous attention because of its high therapeutic efficiency in targeting cells while minimizing the damage to normal tissues and organs. Tungsten oxide (W18O49, WO) plays a pivotal role in PTT development and its use in PTT systems has been extensively studied. However, it is difficult to control morphology of WO through conventional hydrothermal method. Which make its related researches have been limited up to now. In this study, we describe the construction and effects on tumor of a novel nanoplatform based on WO and indocyanine green (ICG) loaded in mesoporous silica nanoparticles (MSN) for dual-modal PTT and near-infrared imaging. (WO+ICG)@MSN could efficiently control WO shape without the need of surface modification due to its water-soluble of MSN. (WO+ICG)@MSN produced a PTT synergistic effect under irradiation of a single 808nm near-infrared (NIR) laser. Notably, an enhanced lethal effect of the 808nm laser triggering dual-modal therapy on B16 tumor cells was observed. The in vivo animal experiments showed that (WO+ICG)@MSN induced an effective solid tumor reduction under 808nm NIR light irradiation, revealing the potential of these nanocomposites as a NIR-mediated dual-modal therapeutic platform for cancer treatment.

Protective effects of berberine in an experimental rat osteoarthritis model.

Berberine shows anticancer, antibacterial, antiinflammatory and antioxidant effects and may be useful in many clinical applications. The effects of berberine on articular cartilage metabolism remain unknown, so this study was performed to evaluate these effects in vitro and in vivo. For the in vitro work, rat articular chondrocytes were cultured in a monolayer and matrix metalloproteinase-1 (MMP-1), -3, -13 and tissue inhibitor of metalloproteinase (TIMP-1) expression was evaluated by real-time quantitative PCR. Nitric oxide (NO) levels were determined using the Griess reaction, and glycosaminoglycan (GAG) release was measured using the dimethylmethylene blue method. For the in vivo work, berberine was administered by intraarticular injection, and the effects on MMPs and TIMP-1 were examined at the gene and protein levels. Berberine was found to inhibit the expression of MMP-1, -3 and -13, and increased the level of TIMP-1 at the mRNA level in a dose-dependent manner. In IL-1ß-induced rat articular chondrocytes, berberine decreased IL-1ß-induced GAG release and NO production. Meanwhile, high-dose berberine exhibited an anticatabolic effect in an IL-1ß-induced rat osteoarthritis (OA) model. These findings suggest that berberine may play a protective role in the development of OA and may be useful in the treatment of OA.

Effects of diallyl sulphide in chondrocyte and cartilage in experimental osteoarthritis in rabbit.

Diallyl sulphide (DAS) is known for its antioxidant, anticancer and detoxifying properties. The aim of this study was to investigate the effect of DAS on rabbit articular chondrocytes and cartilage in experimental osteoarthritis (OA) induced by anterior cruciate ligament transection (ACLT). DAS inhibited matrix metalloproteinase-1 (MMP-1), MMP-3 and MMP-13 expression in interleukin-1beta (IL-1ß)-induced chondrocytes. In an in vivo study, DAS ameliorated cartilage degradation as assessed by morphological and histological examination. Messenger RNA expression of MMP-1, MMP-3, MMP-13 and IL-1ß was inhibited by DAS in cartilage. In addition, DAS increased the collagen II level in cartilage. The results suggest that DAS may protect cartilage in the development of OA.