Analysis of the utilization value of different tissues of Taxus×Media based on metabolomics and antioxidant activity.

BACKGROUND: Taxaceae, is a class of dioecious and evergreen plant with substantial economic and ecology value. At present many phytochemical analyses have been performed in Taxus plants. And various biological constituents have been isolated from various Taxus species. However, the difference of compounds and antioxidant capacity of different tissues of T. media is not clear. RESULTS: In the present study, we investigated the metabolites and antioxidant activity of four tissues of T. media, including T. media bark (TB), T. media fresh leaves (TFL), T. media seeds (TS), T. media aril (TA). In total, 808 compounds, covering 11 subclasses, were identified by using UPLC-MS/MS. Paclitaxel, the most popular anticancer compound, was found to accumulate most in TS, followed by TB, TFL and TA in order. Further analysis found that 70 key differential metabolites with VIP > 1.0 and p < 0.05, covering 8 subclasses, were screened as the key differential metabolites in four tissues. The characteristic compounds of TFL mainly included flavonoids and tanninsis. Alkaloids and phenolic acids were major characteristic compounds of TS and TB respectively. Amino acids and derivatives, organic acids, saccharides and lipids were the major characteristic compounds of TA. Additionally, based on FRAP and ABTS method, TS and TFL exhibited higher antioxidant activity than TB and TA. CONCLUSION: There was significant difference in metabolite content among different tissues of T. media. TFL and TS had higher metabolites and antioxidant capacity than other tissues, indicating that TFL and TS were more suitable for the development and utilization of T. media in foods and drinks.

Transcriptional Analysis of Tea Plants (Camellia sinensis) in Response to Salicylic Acid Treatment.

Salicylic acid (SA) is an important plant hormone and signal required for establishing resistance to diverse pathogens and plant diseases. The abundant polyphenols in tea plants also defend plants from biotic and abiotic stresses. However, whether exogenous SA would increase the resistance of tea plants to adversity and the relationship between SA and polyphenols are still poorly understood. Here, we carried out SA treatment on tea seedlings and performed transcriptome sequencing. SA treatment inhibited the phenylpropanoid and flavonoid metabolic pathways but promoted the lignin metabolic pathways. The increased accumulation of lignin in tea leaves after treating with SA indicated that lignin might coordinate SA, enhance, and improve plant defense and disease resistance. Simultaneously, an SA-inducible flavonoid glucosyltransferase (CsUGT0554) specifically involved in 7-OH site glycosylation was characterized in vitro. These results provided valuable information about the effects of SA on tea seedlings and the molecular basis for SA-mediated immune responses.

Effect of thermal process on the key aroma components of green tea with chestnut-like aroma.

BACKGROUND: Chestnut-like aroma is one of the unique qualities of Chinese green tea and has become an important factor influencing consumer decisions. However, the chemical formation mechanism of chestnut-like aroma during green tea processing remains unclear. In this study, the dynamic changes of key components contributing to chestnut-like aroma and their precursors were analyzed in fresh leaves, fixation leaves, first baking tea leaves, and green tea. RESULTS: The thermal process had an important effect on volatile components in tea leaves, causing a significant decrease of alcohols and esters and a significant increase of ketones, acids, phenols, and sulfur compounds. Furthermore, 31 volatiles were identified as the key odorants responsible for chestnut-like aroma of green tea, including dimethyl sulfide, methyl isobutenyl ketone, 2-methylbutanal, 2,4-dimethylstyrene, d-limonene, methyl 2-methylvalerate, linalool, decanal, longifolene, phenylethyl alcohol, l-α-terpineol, jasmone, and so on. And the majority of these odorants were only formed in the drying stage. Additionally, isoleucine, theanine, methionine, and glucose were found to be involved in the formation of chestnut-like aroma of green tea. CONCLUSION: The drying process played a vital important role in the formation of chestnut-like aroma of green tea. © 2022 Society of Chemical Industry.

Cardiolipin-Targeted NIR-II Fluorophore Causes "Avalanche Effects" for Re-Engaging Cancer Apoptosis and Inhibiting Metastasis.

Restoring innate apoptosis and simultaneously inhibiting metastasis by a molecular drug is an effective cancer therapeutic approach. Herein, a large rigid and V-shaped NIR-II dye, DUT850, is rationally designed for potential cardiolipin (CL)-targeted chemo-phototheranostic application. DUT850 displays moderate NIR-II fluorescence, excellent photodynamic therapy (PDT) and photothermal therapy (PTT) performance, and ultra-high photostability. More importantly, the unique rigid V-shaped backbone, positive charge, and lipophilicity of DUT850 afford its specific recognition and efficient binding to CL; such an interaction of DUT850-CL induced a spectrum of physiological disruptions, including translocation of cytochrome c, Ca2+ overload, reactive oxygen species burst, and ATP depletion, which not only activated cancer cell apoptosis but also inhibited tumor metastasis both in vitro and in vivo. Furthermore, the tight binding of DUT850-CL improves the phototoxicity of DUT850 toward cancer cells (IC50 as low as 90 nM) under safe 808 nm laser irradiation (330 mW cm-2). Upon encapsulation into bovine serum albumin (BSA), DUT850@BSA exerted a synergetic chemo-PDT-PTT effect on the 4T1 tumor mouse model, eventually leading to solid tumor annihilation and metastasis inhibition, which could be followed in real time with the NIR-II fluorescence of DUT850. This work contributed a promising approach for simultaneously re-engaging cancer cell apoptotic networks and activating the anti-metastasis pathway by targeting a pivotal upstream effector, which will bring a medical boon for inhibition of tumor proliferation and metastasis.

Genome-wide identification, characterization, and expression analysis of tea plant autophagy-related genes (CsARGs) demonstrates that they play diverse roles during development and under abiotic stress.

BACKGROUND: Autophagy, meaning 'self-eating', is required for the degradation and recycling of cytoplasmic constituents under stressful and non-stressful conditions, which helps to maintain cellular homeostasis and delay aging and longevity in eukaryotes. To date, the functions of autophagy have been heavily studied in yeast, mammals and model plants, but few studies have focused on economically important crops, especially tea plants (Camellia sinensis). The roles played by autophagy in coping with various environmental stimuli have not been fully elucidated to date. Therefore, investigating the functions of autophagy-related genes in tea plants may help to elucidate the mechanism governing autophagy in response to stresses in woody plants. RESULTS: In this study, we identified 35 C. sinensis autophagy-related genes (CsARGs). Each CsARG is highly conserved with its homologues from other plant species, except for CsATG14. Tissue-specific expression analysis demonstrated that the abundances of CsARGs varied across different tissues, but CsATG8c/i showed a degree of tissue specificity. Under hormone and abiotic stress conditions, most CsARGs were upregulated at different time points during the treatment. In addition, the expression levels of 10 CsARGs were higher in the cold-resistant cultivar 'Longjing43' than in the cold-susceptible cultivar 'Damianbai' during the CA period; however, the expression of CsATG101 showed the opposite tendency. CONCLUSIONS: We performed a comprehensive bioinformatic and physiological analysis of CsARGs in tea plants, and these results may help to establish a foundation for further research investigating the molecular mechanisms governing autophagy in tea plant growth, development and response to stress. Meanwhile, some CsARGs could serve as putative molecular markers for the breeding of cold-resistant tea plants in future research.

Transcriptomic and Metabolic Insights into the Distinctive Effects of Exogenous Melatonin and Gibberellin on Terpenoid Synthesis and Plant Hormone Signal Transduction Pathway in Camellia sinensis.

Melatonin and gibberellin are bioactive molecules in plants. In the present study, the role of exogenous melatonin (MT) and gibberellin (GA) in the tea plant was explored by transcriptome and metabolic analysis. Results showed that the growth of tea plant was enhanced by MT treatment. The pathways of terpenoid synthesis and plant-pathogen interaction were significantly strengthened, combined with the upregulation of LRR-RLK and transcription factors which contributed to the growth of tea plant. The internode elongation and leaf enlargement were hastened by GA treatment. Significantly modulated expression occurred in the plant hormonal signal transduction, complemented by the upregulation of phenylpropanoid biosynthesis and expansins to achieve growth acceleration, whereas the flavonoid synthesis was repressed in GA treatment. Therefore, the distinctive effect of MT and GA treatment on tea plant was different. The MT exhibited significant promotion in terpenoid synthesis, especially, TPS14 and TPS1. GA was prominent in coordinated regulation of plant hormonal signal transduction.

Novel triterpenoid saponins from residual seed cake of Camellia oleifera Abel. show anti-proliferative activity against tumor cells.

Four oleanane-type triterpenoid saponins were isolated from the seed cake of Camellia oleifera Abel.: camelliasaponin B1 and three new saponins, oleiferasaponin C1-C3 (1-3). Their structures were identified as 22-O-angeloyl-camelliagenin B 3-O-[ß-d-galactopyranosyl-(1→2)]-[ß-d-galactopyranosyl-(1→2)-α-l-arabinopyranosyl-(1→3)]-ß-d-glucopyranosiduronic acid methyl ester (1); 22-O-angeloyl-camelliagenin A 3-O-[ß-d-galactopyranosyl-(1→2)]-[ß-d-glucopyranosyl-(1→2)-ß-d-galactopyranosyl-(1→3)]-ß-d-glucopyranosiduronic acid methyl ester (2); and 28-O-cinnamoyl-camelliagenin B 3-O-[ß-d-galactopyranosylz-(1→2)] [ß-d-galactopyranosyl(1→2)-α-l-arabinopyranosyl-(1→3)]-ß-d-glucopyranosiduronic acid methyl ester (3) through 1D and 2D NMR, HR-ESI-MS, as well as GC-MS spectroscopic methods. The anti-proliferative activities of these four compounds were investigated on five human tumor cell lines (BEL-7402, BGC-823, MCF-7, HL-60 and KB). Compounds 1 and 2 and camelliasaponin B1 showed significant cytotoxic activities.

Qualitative and quantitative analysis of triterpene saponins from tea seed pomace (Camellia oleifera Abel) and their activities against bacteria and fungi.

A method using LC-ESI-IT-TOF/MS and LC/UV-ELSD was established to qualitatively analyze triterpene saponins obtained from the tea seed pomace (Camellia oleifera Abel). In addition, the quantitative analysis of oleiferasaponin A1 using LC/UV was developed. The purified total saponins did not exhibit any inhibitory effects at concentrations ranging from 0.1 to 10 mg/mL against the tested bacteria, except for Staphyloccocus aureus and Escherichia coli. By contrast, higher inhibitory activity was seen against the tested fungi, especially against Bipolaris maydis. Following treatment with an MIC value of 250 µg/mL for 24 h, the mycelial morphology was markedly shriveled in appearance or showed flattened and empty hyphae, with fractured cell walls, ruptured plasmalemma and cytoplasmic coagulation or leakage. These structural changes hindered the growth of mycelia.

A new saponin from tea seed pomace (Camellia oleifera Abel) and its protective effect on PC12 cells.

A new triterpenoid saponin, oleiferasaponin A1, was isolated from tea seed pomace (Camellia oleifera Abel). The structure of oleiferasaponin A1 was elucidated on the basis of chemical and physicochemical evidence and was found to be 22-O-cis-2-hexenoyl-A1-barrigenol 3-O-[ß-D-galactopyranosyl(1→2)] [ß-D-glucopyranosyl(1→2)-α-L-arabinopyranosyl(1→3)]-ß-D-glucopyranosiduronic acid. PC12 cells injured with H2O2 were used as the model to test the protective effects of oleiferasaponin A1. The results indicated that oleiferasaponin A1 can potentially prevent the H2O2-induced cell death of PC12 cells.