Selenite affected photosynthesis of Oryza sativa L. exposed to antimonite: Electron transfer, carbon fixation, pigment synthesis via a combined analysis of physiology and transcriptome.

Selenium (Se) is a microelement that can counteract (a)biotic stresses in plants. Excess antimony (Sb) will inhibit plant photosynthesis, which can be alleviated by appropriate doses of Se but the associated mechanisms at the molecular levels have not been fully explored. Here, a rice variety (Yongyou 9) was exposed to selenite [Se(IV), 0.2 and 0.8 mg L-1] alone or combined with antimonite [Sb(III), 5 and 10 mg L-1]. When compared to the 10 mg L-1 Sb treatment alone, addition of Se in a dose-dependent manner 1) reduced the heat dissipation efficiency resulting from the inhibited donors, Sb concentrations in shoots and roots, leaf concentrations of fructose, H2O2 and O2•-; 2) enhanced heat dissipation efficiency resulting from the inhibited accepters value, concentrations of Chl a, sucrose and starch, and the enzyme activity of adenosine diphosphate glucose pyrophosphorylase, sucrose phosphate synthase, and sucrose synthase; but 3) did not alter gas exchange parameters, concentrations of Chl b and total Chl, enzyme activity of soluble acid invertase, and values of maximum P700 signal, photochemical efficiency of PSI and electron transport rate of PSI. Se alleviated the damage caused by Sb to the oxygen-evolving complex and promoted the transfer of electrons from QA to QB. When compared to the 10 mg L-1 Sb treatment alone, addition of Se 1) up-regulated genes correlated to synthesis pathways of Chl, carotenoid, sucrose and glucose; 2) disturbed signal transduction pathway of abscisic acid; and 3) upregulated gene expression correlated to photosynthetic complexes (OsFd1, OsFER1 and OsFER2).

Application of inorganic selenium to reduce accumulation and toxicity of heavy metals (metalloids) in plants: The main mechanisms, concerns, and risks.

Anthropogenic activities such as mining, industrialization and subsequent emission of industrial waste, and agricultural practices have led to an increase in the accumulation of metal(loid)s in agricultural soils and crops, which threatens the health of people; the risk is more pronounced for individuals whose survival depends on food sources from several contaminated regions. Selenium (Se) is an element essential for the normal functioning of the human body and is a beneficial element for plants. Se deficiency in the diet is a common issue in many countries around the world, such as China and Egypt. >40 diseases are associated with Se deficiency. In practice, Se compounds have been applied through foliar sprays or via base application of fertilizers to increase Se concentration in the edible parts of crops and to satisfy the daily Se intake. Moreover, Se at low concentrations has been used to mitigate the toxicity of many metal(loid)s. In this review, we present an overview of the latest knowledge and practices with regards to the utilization of Se to reduce the uptake/toxicity of metal(loid)s in plants. We have focused on the following issues: 1) the current status of understanding the mechanisms of detoxification and uptake restriction of metal(loid)s regulated by Se; 2) the optimal dose and speciation of Se, and stage of plant growth that is optimal for application; 3) the differences in the efficiency of different application methods of Se including seed priming, base application, and foliar spray of Se fertilizers; 4) the possibility of using Se along with other methods to reduce multiple metal(loid) accumulation in crops; and 5) potential risks when Se is used to reduce metal(loid) accumulation in crops.

Effect of Electromyographic Biofeedback Therapy on Muscle Strength Recovery in Children with Guillain-Barré Syndrome.

GBS, as an immune-mediated acute inflammatory peripheral neuropathy (Tan and Halpin et al.), with the characteristics of acute onset and rapid progression, is mainly manifested with damages in nerve root and peripheral nerve. The purpose of the study was to investigate the effect of electromyographic biofeedback therapy on muscle strength recovery in children with Guillain-Barré syndrome (GBS). A total of 62 GBS children patients admitted to our hospital from June 2014 to December 2018 were selected and divided into control group (n = 30) and experimental group (n = 32) according to the order of admission. The children patients in the control group received physical therapy combined with occupational therapy (PT + OT), while based on the treatment in the control group, the experimental group children patients were treated with electromyographic biofeedback therapy. After that, the recovery of nerve and muscle at different time points, muscle strength score, gross motor function measure (GMFM) score, and Barthel index (BI) score of the children patients before and after treatment were compared between the two groups. There were no significant differences in the recovery of nerve and muscle of the children patients between the two groups at T 0 and T 1 (P > 0.05), and the recovery of nerve and muscle of the children patients in the experimental group was significantly better than that in the control group at T 2, T 3, and T 4 (P < 0.001); the muscle strength score, GMFM score, and BI score of the children patients in the experimental group were significantly better than those in the control group after treatment (P < 0.001). The application of electromyographic biofeedback therapy for the treatment of GBS can effectively relieve clinical symptoms, promote rapid recovery, and improve treatment efficacy in children patients, which is worthy of application and promotion.

Underlying mechanisms responsible for restriction of uptake and translocation of heavy metals (metalloids) by selenium via root application in plants.

Since selenium (Se) was shown to be an essential element for humans in 1957, the biofortification of Se to crops via foliar spraying or soil fertilization has been performed for several decades to satisfy the daily nutritional need of humans. Appropriate doses of Se were found to counteract a number of abiotic and biotic stresses, such as exposure to heavy metals (metalloids) (HMs), via influencing the regulation of antioxidant systems, by stimulation of photosynthesis, by repair of damaged cell structures and functions, by regulating the metabolism of some substances and the rebalancing of essential elements in plant tissues. However, few concerns were paid on why and how Se could reduce the uptake of a variety of HMs. This review will mainly address the migration and transformation of HMs regulated by Se in the soil-plant system in order to present a hypothesis of why and how Se can reduce the uptake of HMs in plants. The following aspects will be examined in greater detail, including 1) how the soil characteristics influences the ability of Se to reduce the bioavailability of HMs in soils and their subsequent uptake by plants, which include soil Se speciation, pH, water regime, competing ions and microbes; 2) how the plant root system influenced by Se affects the uptake or the sequestration of HMs, such as root morphology, root iron plaques and root cell wall; 3) how Se combines with HMs and then sequesters them in plant cells; 4) how Se competes with arsenic (As) and thereby reduces As uptake in plants; 5) how Se regulates the expression of genes encoding functions involved in uptake, translocation and sequestration of HMs by Se in plants.

Controlling the cleavage of the inter- and intra-molecular linkages in lignocellulosic biomass for further biorefining: A review.

The abundant intermolecular linkages among cellulose, hemicellulose and lignin significantly limit the utilization of the most promising renewable biomass. Process control with solvents, catalysts and temperature is of significant importance providing ways to break the above linkages, and benefiting to the further conversion of the main biomass components to small molecular products. This article discusses the effect of catalyst under hydrothermal and organosolv treatment emphasizing the cleavage of the intermolecular linkage. Acidic catalysts show good performance on cleaving the linkages between carbohydrates and lignin. Basic catalysts promoted the dissolution of lignin component. Hydrogenolysis assisted conversion of lignin can efficiently break the intermolecular linkages to yield lignin-derived bio-oil, especially in co-solvent reaction system. Besides, the effects of single solvent and co-solvent systems, as well as the cleavage of the intramolecular linkages to yield target chemicals are also included. Several further study strategies are proposed.

The effects of galangin on a mouse model of vitiligo induced by hydroquinone.

Galangin, the main active component of Alpinia officinarum Hance, was tested in a mouse model of vitiligo induced in C57BL/6 mice by the topical application of 2 mL of 2.5% hydroquinone daily to shaved areas (2 × 2 cm) of dorsal skin for 60 days. Thirty days after the final application of hydroquinone, galangin (0.425, and 4.25 mg/kg) was administered orally for 30 days. The hair colour darkened when it grew back after treatment, and histological analysis showed that the number of melanin-containing hair follicles had increased after treatment with all doses of galangin groups and 8-methoxypsoralen (8-MOP, the positive control) compared with the untreated vitiligo group (p < 0.05). The number of skin basal layer melanocytes and melanin-containing epidermal cells had also increased significantly with the application of 4.25 mg/kg of galangin. The concentration of tyrosinase (TYR) in serum was found to have increased, whereas the content of malondialdehyde and the activity of cholinesterase had decreased after treatment with all doses of galangin and 8-MOP, compared with control (p < 0.05). The expression of TYR protein in treated areas of skin also increased with the application of 4.25 mg/kg galangin and 8-MOP. In conclusion, the results showed that galangin was able to improve vitiligo induced by hydroquinone in mice, with the activity related to concentrations of TYR, expression of TYR protein, activity of malondialdehyde and content of cholinesterase. Galangin may therefore be a potential candidate for the treatment of vitiligo, subject to further investigation.

[Study on protective effect of acteoside on cellular model of Alzheimer's disease induced by okadaic acid].

OBJECTIVE: To investigate the effect of acteoside on SK-N-SH nerve cell injury induced by okadaic acid (OA). METHOD: SK-N-SH nerve cells were processed with 20 nmol * L OA to establish the Alzheimer's disease (AD) cellular model, and 5, 10, 20 mg . L-1 acteoside was used to antagonize against its effect. Cell morphology was observed under inverted microscope. The cell survival rate was detected with MTT, and the LDH release rate was measured by enzyme label kit. Western blot was applied to determine the expression of phosphorylation tau proteins in nerve cells. RESULT: The acteoside could significantly improve SK-N-SH cell morphology, enhance the cell survival rate, decrease the cell LDH release rate and the expression of phosphorylated tau proteins at p-Ser 199/202 and p-Ser 404 sites, up-regulated the expression of at non-phosphorylated tau proteins at Ser 202 site and Ser 404 sites. CONCLUSION: Acteoside has significant protective effect on nerve cell injury induced by OA.

[Grey relational analysis on fingerprint of Vernonia anthelmintica extracts and its effect on proliferation of A375 human melanoma cells].

OBJECTIVE: To establish the fingerprint of Vernonia anthelmintica extracts of different ethanol concentrations to study the effect of common peak components on the proliferation of A375 human melanoma cells and the correlation between fingerprint and pharmacodynamics of V. anthelmintica extracts, in order to provide both theoretical basis and data support for establishing a traditional Chinese medicine quality control mode with the combination of fingerprint and pharmacology. METHOD: HPLC was applied to establish fingerprint of V. anthelmintica extracts of different ethanol concentrations and the similarity evaluation was made. MTT was used to study the proliferation of A375 human melanoma cells. Grey relation analysis was adopted to analyze the correlation between fingerprint and pharmacology of V. anthelmintica. RESULT: The HPLC fingerprint of different V. anthelmintica ethanol extracts showed 13 common peaks with the proliferation effect on A375 human melanoma cells. The 4th peak had the largest contribution and highest correlation to cell proliferation. CONCLUSION: Different V. anthelmintica ethanol extracts have different fingerprints, which show a certain correlation between their common peaks and effect on cell proliferation.