Enrichment of flavonoid aglycones in licorice extract enhanced anti-inflammatory potential,but its hypnotic effect was not altered

OBJECTIVE Licorice is used throughout the world as a traditional herbal remedy.According to Chinese traditional medicine licorice alone can be used to treat inflammation.Although there have been some studies investigated the anti-inflammatory ingredients of licorice,but for the potency of flavonoid glycoside and their aglycones on inflammation are not evaluated.This study was designed to assess the contributions of licorice flavonoid glycosides and their aglycons to its anti-inflammatory and hypnotic effects.METHODS For the flavonoid aglycone's enrichment,the extract of licorice(EL)was fermented in submerged culture of the edible fungus Grifola frondosa HB0071 mycelia which can produce β-glucosidase and catalyze the flavonoid glycosides to aglycones.EL and fermented extract of licorice(FEL) were used in this study.The anti-inflammation test was carried out in arachidonic acid(AA)-induced ear edema model and the hypnotic test was performed by using electroencephalogram(EEG) analysis method in normal freely moving SD rats.The chemicals constituents were analyzed by HPLC.RESULTS During fermentation,the falvonoid glycosides of licorice were hydrolyzed by the time process.Along with fermentation time,the concentration of the major flavonoid glycosides,liquiritin and isoliquiritin were decreased obviously,and simultaneously their aglycons,liquiritigenin and isoliquiriti.genin were remarkably increased in FEL.Moreover,the content of another major constituent glycyrrhi.zic acid and glycyrrhetinic acid were not changed after the fermentation.In AA-induced mice ear ede.ma test,after topical application,FEL(effective dose range:5-20 μg·ear-1) showed more potent inhibito.ry activity than EL(effective dose range:25-100 μg·ear-1).On the other hand,oral administration of EL and FEL exhibited the same hypnotic potency and both enhanced the total sleep time including rapid eye movement(REM) sleep and non-REM sleep time.CONCLUSION These results suggested that the enrichment of flavonoid aglycons such as liquiritigenin and isoliquiritigenin enhanced the anti-inflam.matory potency of licorice extract,and this potentiation has nothing to do with glycyrrhizic acid or glycyr.rhetinic acid.In addition,enrichment of flavonoid aglycones did not alter the hypnotic effect of licorice.

Methane emissions from shale gas production sites in southern Sichuan,China:A field trial of methods

Shale gas is an important alternative natural gas source that can meet China's growing energy demand.However,methane emissions during shale gas production could largely determine whether it could be considered as a bridging clean energy source.In this study,we performed methane emission measurements using three methods(on-site optical gas imaging,on-site methane patrolling,and downwind measurement)at shale gas production sites in Sichuan province,China,covering 18 well sites with 81 wells.The results showed that flowback water tanks were the major methane sources,with valves,separators,chemical injection pumps,and pneumatic controllers as other sources.The methane concentrations inside the 18 sites ranged from 1.42 to 459μmol mol−1,with over 59%of the sites having the highest concentration less than 50μmol mol−1.The optical gas imaging method,with its low detection limit over 5000μmol mol−1,could not capture the emission effectively.The three successful downwind measurements resulted in site level emission rates between 0.02 and 0.17 kg h−1.When divided by the number of wells at each site,the emission intensity was 4%–28%of the wellhead emission factor for natural gas production in China.More measurements are required to better quantify methane emissions from shale gas sites in China.For sites in mountainous regions or long-term low-wind regions,detection methods other than downwind measurements should be suitable for quantifying site-level emissions.

Time-Consistent Portfolio Policy for Asset-Liability Mean-Variance Model with State-Dependent Risk Aversion

In reality,when facing a multi-period asset-liability portfolio selection problem,the risk aversion attitude of a mean-variance investor may depend on the wealth level and liability level.Thus,in this paper,we propose a state-dependent risk aversion model for the investor,in which risk aversion is a linear function of current wealth level and current liability level.Due to the time inconsistency of the resulting multi-period asset-liability mean-variance model,we investigate its time-consistent portfolio policy by solving a nested mean-variance game formulation.We derive the analytical time-consistent portfolio policy,which takes a linear form of current wealth level and current liability level.We also analyze the influence of the risk aversion coefficients on the time-consistent portfolio policy and the investment performance via a numerical example.

Risk and Potential:An Asset Allocation Framework with Applications to Robo-Advising

We propose a novel dynamic asset allocation framework based on a family of mean-variance-induced utility functions that alleviate the non-monotonicity and time-inconsistency problems of mean-variance optimization.The utility functions are motivated by the equivalence between the mean-variance objective and a quadratic utility function.Crucially,our framework differs from mean-variance analysis in that we allow different treatment of upside and downside deviations from a target wealth level.This naturally leads to a different characterization of possible investment outcomes below and above a target wealth as risk and potential.Our proposed asset allocation framework retains two attractive features of mean-variance optimization:an intuitive explanation of the investment objective and an easily computed optimal strategy.We establish a semi-analytical solution for the optimal trading strategy in our framework and provide numerical examples to illustrate its behavior.Finally,we discuss applications of this framework to robo-advisors.

Survey on Multi-period Mean-Variance Portfolio Selection Model

Due to the non-separability of the variance term,the dynamic mean-variance(MV)portfolio optimization problem is inherently difficult to solve by dynamic programming.Li and Ng(Math Finance 10(3):387-406,2000)and Zhou and Li(Appl Math Optim 42(1):19-33,2000)develop the pre-committed optimal policy for such a problem using the embedding method.Following this line of research,researchers have extensively studied the MV portfolio selection model through the inclusion of more practical investment constraints,realistic market assumptions and various financial applications.As the principle of optimality no longer holds,the pre-committed policy suffers from the time-inconsistent issue,i.e.,the optimal policy computed at the intermediate time t is not consistent with the optimal policy calculated at any time before time t.The time inconsistency of the dynamic MV model has become an important yet challenging research topic.This paper mainly focuses on the multi-period mean–variance(MMV)portfolio optimization problem,reviews the essential extensions and highlights the critical development of time-consistent policies.