TON1 recruiting motif 21 positively regulates the flavonoid metabolic pathway at the translational level in Arabidopsis thaliana.

MAIN CONCLUSION: This study reveals that TRM21 acts as a positive regulator of flavonoid biosynthesis at the translational level in Arabidopsis, impacting both secondary metabolites and genes associated with root hair growth. TRM (TONNEAU1-recruiting motif) superfamily proteins are reported to be involved in microtubule assembly. However, the functions of this protein family are just beginning to be uncovered. Here, we provide metabolomic and genetic evidence that 1 of the 34 TRM members, TRM21, positively regulates the biosynthesis of flavonoids at the translational level in Arabidopsis thaliana. A loss-of-function mutation in TRM21 led to root hair growth defects and stunted plant growth, accompanied by significant alterations in secondary metabolites, particularly a marked reduction in flavonoid content. Interestingly, our study revealed that the transcription levels of genes involved in the flavonoid biosynthesis pathway remained unchanged in the trm21 mutants, but there was a significant downregulation in the translation levels of certain genes [flavanone 3-hydroxylase (F3H), dihydroflavonol-4-reductase (DFR), anthocyanidin reductase (ANR), flavanone 3'-hydroxylase (F3'H), flavonol synthase (FLS), chalcone synthase (CHS)]. Additionally, the translation levels of some genes related to root hair growth [RHO-related GTPases of plant 2 (ROP2), root hair defective 6 (RHD6), root hair defective 2 (RHD2)] were also reduced in the trm21 mutants. Taken together, these results indicate that TRM21 functions as a positive regulator of flavonoid biosynthesis at the translational level in Arabidopsis.

Effects and Stress-Relieving Mechanisms of Dark Tea Polysaccharide in Human HaCaT Keratinocytes and SZ95 Sebocytes.

A new skincare application scenario for dark tea, a unique and post-fermented tea popular in the health food industry, was developed in this paper. The effects of dark tea polysaccharide (DTP) on stress-induced skin problems and its mechanism of action were investigated by modeling cortisone-induced stress injury in human HaCaT keratinocytes and SZ95 sebaceous gland cells. The results showed a reduced cortisol conversion induced by cortisone under the action of DTP with a concentration of 200 µg/mL, probably by inhibiting the expression of the HSD11B1 enzyme. DTP was also able to suppress the cortisone-induced elevation of lipid levels in SZ95 sebocytes at this concentration. In addition, the composition and structure of DTP were verified by ultrafiltration, ultraviolet-visible spectrophotometry (UV-VIS), high-performance anion-exchange chromatography with pulsed amperometric detection (HPAEC-PAD) and infrared spectroscopy. In brief, DTP has a unique and significant stress-relieving effect, which provides new ideas for the development of new ingredients for the skin care industry.

CFD Modeling and Simulation of the Axial Dispersion Characteristics of a Fixed-Bed Reactor.

In this study, the axial dispersion characteristics of a fixed-bed reactor with different packed structures were investigated via computational fluid dynamics (CFD) simulation. The discrete element method was employed to develop the physical model of a fixed bed. Then, CFD simulations were performed to investigate the flow resistance coefficient under different Reynolds numbers. The prediction values were in fair agreement with those calculated by the Carman equation, thereby validating the proposed CFD model. The tracer pulse method and the step method were employed to evaluate the residence time distribution characteristics in the fixed-bed reactors where the mean residence time and axial dispersion coefficient were calculated. The distribution characteristics of the tracer concentration and fluid velocity were also obtained and used to explain the mixing performance of the fixed bed. This simulation study can contribute to the optimization design and scaling up of reactors with porous packed structures.

Ginsenoside 20(S)-protopanaxadiol induces cell death in human endometrial cancer cells via apoptosis.

BACKGROUND: 20(S)-protopanaxadiol (20(S)-PPD), one of the aglycone derivatives of major ginsenosides, has been shown to have an anticancer activity toward a variety of cancers. This study was initiated with an attempt to evaluate its anti-cancer activity toward human endometrial cancer by cell and xenograft mouse models. METHODS: Human endometrial cancer (HEC)-1A cells were incubated with different 20(S)-PPD concentrations. 20(S)-PPD cytotoxicity was evaluated using MTT assay. Apoptosis was detected using the annexin V binding assay and cell cycle analysis. Cleaved poly (ADP-ribose) polymerase (PARP) and activated caspase-9 were assessed using western blotting. HEC-1A cell tumor xenografts in athymic mice were generated by inoculating HEC-1A cells into the flank of BALB/c female mice and explored to validate 20(S)-PPD anti-endometrial cancer toxicity. RESULTS: 20(S)-PPD inhibited HEC-1A cell proliferation in a dose-dependent manner with an IC50 value of 3.5 µM at 24 h. HEC-1A cells morphologically changed after 20(S)-PPD treatment, bearing resemblance to Taxol-treated cells. Annexin V-positive cell percentages were 0%, 10.8%, and 58.1% in HEC-1A cells when treated with 0, 2.5, and 5 µM of 20(S)-PPD, respectively, for 24 h. 20(S)-PPD subcutaneously injected into the HEC-1A cell xenograft-bearing mice three times a week for 17 days manifested tumor growth inhibition by as much as 18% at a dose of 80 mg/kg, which sharply contrasted to controls that showed an approximately 2.4-fold tumor volume increase. These events paralleled caspase-9 activation and PARP cleavage. CONCLUSION: 20(S)-PPD inhibits endometrial cancer cell proliferation by inducing cell death via a caspase-mediated apoptosis pathway. Therefore, the 20(S)-PPD-like ginsenosides are endowed with ample structural information that could be utilized to develop other ginsenoside-based anticancer agents.

Comparative Study on Bioactivities from Lingzhi or Reishi Medicinal Mushroom, Ganoderma lucidum (Agaricomycetes), Gives an Insight into the Fermentation Broth Showing Greater Antioxidative Activities.

Ganoderma lucidum is one of the most famous mushrooms in traditional Chinese medicine. At present, the fully utilized parts of G. lucidum are mainly fruiting body and spore powder. The wild and artificially cultivated G. lucidum fruiting body is costly and rare. Therefore, how to improve the utilization of G. lucidum by means of fermentation is worth investigating. The present study was to perform submerged fermentation of G. lucidum and compare the bioactivities of G. lucidum submerged fermentation broth and fruiting body extract. After the extraction and submerged fermentation methods were optimized, the optimum conditions for extraction were determined as ethanol extraction at 80°C with a solid-to-liquid ratio of 1:30, and those for submerged fermentation were cultivation on malt extract medium for 6 days at 30°C. Under the optimum conditions, the antioxidative activity and tyrosinase inhibition rate of the fermentation broth were 1.2-4.1 fold higher than those of the ethanol extract. Cytotoxicity analysis showed that the ethanol and water extracts and the fermentation broth effectively inhibited pancreatic cancer cells and prostate cancer cells, with much smaller effect on nontumor human embryonic kidney (HEK293T). These results demonstrate that the submerged fermentation could improve the utilization value of G. lucidum and the fermentation broth can be used as an antioxidant additive applied in food, drugs, and cosmetics.