An in-vitro cocktail assay for assessing compound-mediated inhibition of six major cytochrome P450 enzymes

An efficient screening assay was developed and validated for simultaneous assessment of compound-mediated inhibition of six major human cytochrome P450 （CYP） enzymes. This method employed a cocktail of six probe substrates （i.e., phenacetin, amodiaquine, diclofenac, S-mephenytoin, dextromethorphan and midazolam for CYPIA2, 2C8, 2C9, 2C19, 2D6 and 3A4, respectively） as well as individual prototypical inhibitors of the six CYP enzymes in human liver microsomes under optimized incubation conditions. The corresponding marker metabolites （i.e., acetaminophen, N-desethylamodiaquine, 4-OH-diclofenac, 4-OH-S- mephenytoin, dextrorphan and 1-OH-midazolam） in the incubates were quantified using LC-MS/MS methods either by an internal standard （IS） calibration curve or a simpfified analyte-to-IS peak area ratio approach. The results showed that the IC5o values determined by the cocktail approach were in good agreement with those obtained by the individual substrate approach as well as those reported in the literature. Besides, no remarkable difference was observed between the two quantification approaches. In conclusion, this new cocktail assay can be used for reliable screening of compound-mediated CYP inhibition.

Advances in traditional Chinese medicine for cardiovascular disease therapy in 2020

Cardiovascular diseases are a major cause of morbidity and mortality worldwide and there is an urgent need to develop new pharmacotherapies for managing cardiovascular diseases.In China,traditional Chinese medicine has been used in clinical settings for thousands of years.Although traditional Chinese medicine is very popular,Western medicine experts have not yet accepted it because some ingredients and mechanisms of action for its therapeutic effect are not fully clear.Emerging evidence has established that traditional Chinese medicine inhibits oxidative stress and inflammatory response,suppresses apoptosis,promotes angiogenesis,regulates autophagy and gut microbiota,and modulates metabolomics,among others.Therefore,it has a beneficial role against cardiovascular disease occurrence and progression,such as atherosclerosis,hypertension,myocardial ischemia/reperfusion injury,myocardial infarction,cardiomyopathy,arrhythmia,cardiac remodeling,pulmonary arterial hypertension,and heart failure.In this review,we have summarized the research progress on the relevant mechanisms by which traditional Chinese medicine regulates cardiovascular diseases in 2020 to reveal its application to cardiovascular disease prevention and/or therapy.

Coupled 3D discrete-continuum numerical modeling of pile penetration in sand

A coupled discrete-continuum simulation incorporating a 3D aspect and non-circular particles was performed to analyze soil-pile interactions during pile penetration in sand.A self-developed non-circular particle numerical simulation program was used which considered sand near the pile as interacted particles using a discrete element method;the sand away from the pile was simulated as a continuous medium exhibiting linear elastic behaviors.The domain analyzed was divided into two zones.Contact forces at the interface between the two zones were obtained from a discrete zone and applied to the continuum boundaries as nodal forces,while the interface velocities were obtained from the continuum zone and applied to the discrete boundaries.We show that the coupled discrete-continuum simulation can give a microscopic description of the pile penetration process without losing the discrete nature of the zone concerned,and may significantly improve computational efficiency.

Bcl-2 enhances the formation of newborn striatal long-projection neurons in adult rat brain after a transient ischemic stroke

Objective It has been reported that B-cell lymphoma 2 （Bcl-2） enhances neurogenesis as well as supporting axonal growth after injury. In the present study, we investigated whether Bcl-2 overexpression plays a role in the formation of newborn striatonigral projection neurons in the adult rat brain after transient middle cerebral artery occlusion （MCAO）. Methods We infused human Bcl-2-expressing plasmid （pBcl-2） into the lateral ventricle immediately after 30 min of MCAO, injected 5＇-bromodeoxyuridine （BrdU） intraperitoneally to label proliferative cells, and microinjected fluorogold （FG） into the substantia nigra at 11 weeks of reperfusion followed by multiple immunostaining of striatonigral projection neurons at 12 weeks. Results We found that pBcl-2 treatment significantly increased the number of newborn neurons （BrdU＋-NeuN＋） in the striatum ipsilateral to the MCAO. We further detected newborn striatonigral projection neurons （BrdU＋-FG＋-NeuN＋） in the ipsilateral striatum at 12 weeks. More interestingly, the number of newborn striatonigral projection neurons （BrdU＋-FG＋） was significantly increased by pBcl-2 treatment compared to that by pEGFP, a control plasmid. Conclusion Taken together, we found that Bcl-2 overexpression in the brain enhanced the generation of newborn striatonigral projection neurons. This provides a potential strategy for promoting the reestablishment of neural networks and brain repair after ischemic injury.

Differential seeding and propagating efficiency ofα-synuclein strains generated in different conditions

Background:Accumulation of alpha-synuclein(α-syn)is a main pathological hallmark of Parkinson’s and related diseases,which are collectively known as synucleinopathies.Growing evidence has supported that the same protein can induce remarkably distinct pathological progresses and disease phenotypes,suggesting the existence of strain difference amongα-syn fibrils.Previous studies have shown thatα-syn pathology can propagate from the peripheral nervous system(PNS)to the central nervous system(CNS)in a“prion-like”manner.However,the difference of the propagation potency from the periphery to CNS among differentα-syn strains remains unknown and the effect of different generation processes of these strains on the potency of seeding and propagation remains to be revealed in more detail.Methods:Three strains of preformedα-syn fibrils(PFFs)were generated in different buffer conditions which varied in pH and ionic concentrations.Theα-syn PFFs were intramuscularly(IM)injected into a novel bacterial artificial chromosome(BAC)transgenic mouse line that expresses wild-type humanα-syn,and the efficiency of seeding and propagation of these PFFs from the PNS to the CNS was evaluated.Results:The three strains ofα-syn PFFs triggered distinct propagation patterns.The fibrils generated in mildly acidic buffer led to the most severeα-syn pathology,degeneration of motor neurons and microgliosis in the spinal cord.Conclusions:The differentα-syn conformers generated in different conditions exhibited strain-specific pathology and propagation patterns from the periphery to the CNS,which further supports the view thatα-syn strains may be responsible for the heterogeneity of pathological features and disease progresses among synucleinopathies.