Phytochelatin-Mediated Cultivar-Dependent Cd Accumulations of Lactuca sativa and Implication for Cd Pollution-Safe Cultivars Screening.

Cd pollution-safe cultivar (Cd-PSC) is a feasible strategy to minimize Cd contamination in leafy vegetables. The shoot Cd concentrations of 23 Lactuca sativa cultivars under Cd stress ranged from 0.124 to 2.155 mg·kg-1 with a maximum cultivar difference of 8 folds. Typical Cd-PSC C16 (L) and high-Cd-accumulating cultivar C13 (H) were screened to investigate the mechanisms of Cd accumulations in L. sativa through determining Cd concentrations, Cd subcellular distributions, phytochelatin profiles, and phytochelatin biosynthesis-related genes' expressions. Higher Cd distribution in a heat stable fraction in C13 (H) indicated that the high Cd accumulation trait of C13 (H) mainly depended on the Cd-phytochelatin complexes. Root phytochelatin concentrations were significantly elevated in C13 (H) (5.83 folds) than in C16 (L) (2.69 folds) (p < 0.05) under Cd stress. Significantly downregulated expressions of glutathione S-transferase rather than the regulation of phytochelatin synthesis genes in the root of C13 (H) might be responsible for sufficient glutathione supply for phytochelatins synthesis. These findings suggested that phytochelatin elevation in C13 (H) would favor the Cd root to shoot transportation, which provides new insights into the phytochelatin-related cultivar-dependent Cd accumulating characteristic in L. sativa.

[Combined anti-bitterness strategy for extremely bitter characteristics of Andrographis Herba decoction and mechanism].

Three kinds of excipients were selected to investigate the anti-bitterness effect on the extremely bitter characteristics of Andrographis Herba decoction, and the optimal combined anti-bitterness formula was obtained. The preparation principle of different excipients was clarified by virtual screening and experimental verification to explore the advantages of the three kinds of excipients in the combined anti-bitterness effect. Sensory evaluation showed that mPEG_(2000)-PLLA_(2000), γ-cyclodextrin(γ-CD), and aspartame all had good anti-bitterness effect, which reduced the bitterness intensity of Andrographis Herba decoction by 0.5, 6, and 3 points, respectively. The anti-bitterness effect was superior when 0.15% mPEG_(2000)-PLLA_(2000), 1.60% γ-CD, and 0.04% aspartame were combined, and the taste score of the Andrographis Herba decoction decreased from 8 points(severe bitterness) to 1 point(almost no bitterness). Quantum chemistry calculations showed that mPEG_(2000)-PLLA_(2000) reduced the electrostatic potential of bitter groups, which spontaneously combined with it and formed a physical barrier, hindering the binding of bitter components to receptors. The interaction between γ-CD and bitter components was studied. It was found that the surface area and free energy of γ-CD decreased and the dipole moment increased, indicating that γ-CD included bitter components and self-assembled to form supramolecules. Molecular docking showed that hydroxy at position 14 and carbonyl at position 16 of andrographolide, and hydroxy at position 3 and 4, carbonyl at position 14, and five-membered lactone ring of dehydrated andrographolide were possibly the main bitter groups. The binding free energies of aspartame to bitter receptors TAS2 R10, TAS2 R14, and TAS2 R46 were-3.21,-1.55, and-2.52 kcal·mol~(-1), respectively, indicating that aspartame competed to inhibit the binding of bitter groups to bitter receptors. The results of content determination showed that the free amounts of andrographolide and dehydrated andrographolide in Andrographis Herba decoction were 0.23% and 0.28% respectively, while after adding flavor masking excipients, the dissociation amount of andrographolide and dehydrated andrographolide in the decoction decreased to 0.13% and 0.20%, respectively. The above results show that mPEG_(2000)-PLLA_(2000) involves some bitter components into it through micellar self-assembly to reconcile the entrance bitterness, and γ-CD includes the remaining bitter components in the real solution to control the main bitter taste. Aspartame further competes to inhibit the combination of bitter components and bitter receptors, and improves the taste to be sweet. Multi-excipients combined with anti-bitterness strategy significantly reduces the free concentration of bitter substances in Andrographis Herba decoction, and optimizes the taste of the decoction.

Ventromedial Thalamus-Projecting DCN Neurons Modulate Associative Sensorimotor Responses in Mice.

The deep cerebellar nuclei (DCN) integrate various inputs to the cerebellum and form the final cerebellar outputs critical for associative sensorimotor learning. However, the functional relevance of distinct neuronal subpopulations within the DCN remains poorly understood. Here, we examined a subpopulation of mouse DCN neurons whose axons specifically project to the ventromedial (Vm) thalamus (DCNVm neurons), and found that these neurons represent a specific subset of DCN units whose activity varies with trace eyeblink conditioning (tEBC), a classical associative sensorimotor learning task. Upon conditioning, the activity of DCNVm neurons signaled the performance of conditioned eyeblink responses (CRs). Optogenetic activation and inhibition of the DCNVm neurons in well-trained mice amplified and diminished the CRs, respectively. Chemogenetic manipulation of the DCNVm neurons had no effects on non-associative motor coordination. Furthermore, optogenetic activation of the DCNVm neurons caused rapid elevated firing activity in the cingulate cortex, a brain area critical for bridging the time gap between sensory stimuli and motor execution during tEBC. Together, our data highlights DCNVm neurons' function and delineates their kinematic parameters that modulate the strength of associative sensorimotor responses.

Traditional Uses, Pharmacological Effects, and Molecular Mechanisms of Licorice in Potential Therapy of COVID-19.

The current Coronavirus disease 2019 (COVID-19) pandemic has become a global challenge, and although vaccines have been developed, it is expected that mild to moderate patients will control their symptoms, especially in developing countries. Licorice, not only a food additive, but also a common traditional Chinese herbal medicine, which has several pharmacological effects, such as anti-inflammation, detoxification, antibacterial, antitussive, and immunomodulatory effects, especially in respiratory diseases. Since the outbreak of COVID-19, glycyrrhizin, glycyrrhizin diamine and glycyrrhizin extract have been widely studied and used in COVID-19 clinical trials. Therefore, it is a very interesting topic to explore the material basis, pharmacological characteristics and molecular mechanism of licorice in adjuvant treatment of COVID-19. In this paper, the material basis of licorice for the prevention and treatment of COVID-19 is deeply analyzed, and there are significant differences among different components in different pharmacological mechanisms. Glycyrrhizin and glycyrrhetinic acid inhibit the synthesis of inflammatory factors and inflammatory mediators by blocking the binding of ACE 2 to virus spike protein, and exert antiviral and antibacterial effects. Immune cells are stimulated by multiple targets and pathways to interfere with the pathogenesis of COVID-19. Liquiritin can prevent and cure COVID-19 by simulating type I interferon. It is suggested that licorice can exert its therapeutic advantage through multi-components and multi-targets. To sum up, licorice has the potential to adjuvant prevent and treat COVID-19. It not only plays a significant role in anti-inflammation and anti-ACE-2, but also significantly improves the clinical symptoms of fever, dry cough and shortness of breath, suggesting that licorice is expected to be a candidate drug for adjuvant treatment of patients with early / mild COVID-19.

[Study on potential hepatotoxicity of main monomers of Polygonum multiflorum based on liver micro-tissue].

In this study, we aimed to establish a rat liver micro-tissue evaluation system to evaluate the hepatotoxicity of the main monomers in Polygonum multiflorum. Rat primary hepatocytes were isolated and purified by two-step in situ perfusion method to prepare hepatic parenchymal cells. The ultra-low adsorption plate and the inverted model were used to establish an in vitro hepatotoxicity evaluation system. After the system was established, the main monomer components(monanthone with emodin type, rhein, emodin, emodin-8-O-ß-D-glucopyranoside, physcion) of P. multiflorum were selected for in vitro hepatotoxicity evaluation. This study showed that the primary cells of the liver can form liver micro-tissues in the low adsorption plate method and the mold perfusion method, with good liver structure and function, which can be used to evaluate the hepatotoxicity of the drug to be tested after long-term administration. The five monomers to be tested in P. multiflorum can significantly affect the proliferation of primary liver micro-tissues in rats in a dose-and time-dependent manner. The hepatotoxic effects were as follows: monanthone with emodin type > rhein > emodin > emodin-8-O-ß-D-glucopyranoside > physcion. The results suggested that the emodin-type monoterpene and rhein might be the potential hepatotoxic components, while the metabolites of emodin-8-O-ß-D-glucoside and emodin methyl ether showed more toxic risks. The rat primary hepatocyte micro-tissue model system established in this experiment could be used to achieve long-term drug administration in vitro, which was consistent with the clinical features of liver injury caused by long-term use of P. multiflorum. The experimental results provided important information and reference on the clinical application and toxic component of P. multiflorum.