Volatile 1-octanol of tea (Camellia sinensis L.) fuels cell division and indole-3-acetic acid production in phylloplane isolate Pseudomonas sp. NEEL19.

Tea leaves possess numerous volatile organic compounds (VOC) that contribute to tea's characteristic aroma. Some components of tea VOC were known to exhibit antimicrobial activity; however, their impact on bacteria remains elusive. Here, we showed that the VOC of fresh aqueous tea leaf extract, recovered through hydrodistillation, promoted cell division and tryptophan-dependent indole-3-acetic acid (IAA) production in Pseudomonas sp. NEEL19, a solvent-tolerant isolate of the tea phylloplane. 1-octanol was identified as one of the responsible volatiles stimulating cell division, metabolic change, swimming motility, putative pili/nanowire formation and IAA production, through gas chromatography-mass spectrometry, microscopy and partition petri dish culture analyses. The bacterial metabolic responses including IAA production increased under 1-octanol vapor in a dose-dependent manner, whereas direct-contact in liquid culture failed to elicit such response. Thus, volatile 1-octanol emitting from tea leaves is a potential modulator of cell division, colonization and phytohormone production in NEEL19, possibly influencing the tea aroma.

Antiangiogenic effects of AG36, a triterpenoid saponin from Ardisia gigantifolia stapf.

AG36 is a triterpenoid saponin from Ardisia gigantifolia stapf. Our recent studies proved that AG36 displayed prominent cytotoxicity against breast cancer cells both in vitro and in vivo. However, whether AG36 has antiangiogenic properties is unknown. Therefore, in the present study, we evaluated the antiangiogenic effect of AG36 and the underlying mechanism. The results indicated that AG36 could significantly inhibit the proliferation, migration and invasion of human umbilical vein endothelial cells (HUVEC). Further antiangiogenic molecular mechanism investigation showed that AG36 significantly suppressed phosphorylated FAK and AKT, and downregulated the expressions of vascular endothelial growth factor (VEGF) and vascular endothelial growth factor receptor 2 (VEGFR2) in HUVECs. PI3K inhibitor (LY294002) and FAK inhibitor (PF562271) pretreatment could markedly enhance AG36-induced inhibition of HUVEC proliferation and p-FAK suppression, respectively. In addition, AG36 inhibited the tumor growth in xenograft model and expressions of p-VEGFR2 and p-Akt in vivo. Molecular docking simulation indicated that AG36 formed hydrogen bonds and hydrophobic interactions within the ATP binding pocket of VEGFR2 kinase domain. The present study firstly revealed the high antiangiogenic potency and related underlying molecular of AG36, demonstrating that AG36 maybe a potential antiangiogenic cancer therapy agent or lead candidate.

Optimization of extraction of loquat flowers polyphenolics and its antioxidant and anti-polyphenol oxidase properties.

In this study, the conditions of extraction of loquat flowers polyphenolics were optimized through response surface methodology (RSM). Proper extraction conditions were: solid to liquid ratio 1 g per 50 mL and ethanol concentration 50% at 61°C for 9 min. Furthermore, the antioxidant and anti-polyphenol oxidase (PPO) activity of purified total polyphenolics (PTP) were investigated. PTP displayed strong antioxidant activity with IC50 values of 126.3 ± 8.9, 162.4 ± 6.3 and 94.97 mg ascorbic acid equivalent/g dry weight (mg AAE/d.w.) for ABTS, DPPH, and FRAP assays. In addition, PTP has a substantial inhibitory activity on PPO (IC50 = 115 ± 9.2 µg/mL). From the kinetics analysis, it was proved to be a reversible and mixed-type inhibitor of PPO with KI and KIS values of 76.77 µg/mL and 227.86 µg/mL, respectively. Further, the molecular mechanism underlying the inhibition of PPO by PTP was investigated by molecular docking techniques. The results showed that PTP units could form interaction with the catalytic pocket of PPO through the interaction with amino acid residues in the enzyme active center. The antioxidant activities of PTP together with its effect on PPO activity provide a strong starting point for their practical usage in the food industry.

Exploration of Root-associated Bacteria from the Medicinal Plant Platycodon grandiflorum.

The present study was performed to investigate root-associated bacteria from Platycodon grandiflorum, a medicinal plant commonly grown in East Asia. Isolates were obtained from the rhizosphere or root interior with various culture media, and phylogenetic analyses were performed based on their 16S rDNA sequences. In consideration of practical applications, traits related to plant growth promotion and niche adaptation were assessed in several endophytic strains with fewer biosafety concerns. The effects of a bacterial inoculation on seedling and mature plant growth were evaluated. Seventeen genera that encompassed more than 30 bacterial lineages were successfully retrieved from the roots, the majority of which have not been reported as P. grandiflorum-associated bacteria, particularly for non-negligible Proteobacteria. Although nitrogen-fixing or phosphate-solubilizing and indole acetic acid-producing activities were recorded in all of the strains selected, these strains were beneficial or detrimental to plant growth as evidenced by their influence on the length of seedlings and biomass of mature plants. Among the 4 endophytic Rhizobium species tested in the present study, the potentially novel Rhizobium sp. BF-E16, which was more compatible with the non-leguminous medicinal plant P. grandiflorum, was identified. Other than plant growth-promoting traits, characteristics such as plant constituent-hydrolyzing activities need to be taken into consideration and their roles clarified when investigating plant growth-promoting rhizobacteria.

[Herbal cake-partitioned moxibustion improves intestinal epithelial barrier dysfunction by suppressing TNF-α-mediated apoptosis pathway of intestinal epithelium in rats with Crohn's disease].

OBJECTIVE: To observe the effect of herbal cake-partitioned moxibustion (Moxi) on tumor necrosis factor (TNF)-α/ TNF receptor 1 (TNFR1)-associated death domain (TRADD) / Fas-associated death domain (FADD) pathway-mediated apoptosis of intestinal epithelial cells in Crohn's disease (CD) rats, so as to explore its underlying mechanisms in the treatment of CD. METHODS: Forty-eight SD male rats were randomly divided into normal, model, Moxi and medication groups (n＝12 rats in each). The CD model was established by intra-annual perfusion of 2，4，6-trinitrobenzene sulfonic acid (TNBS) solution (TNBS∶50% alcohol＝2∶1, 3 mL/kg), once every 7 days, 4 times altogether. For rats of the Moxi group, moxibustion was given to "Tianshu" (ST25) and "Qihai" (CV6), two moxa-cones every time, once daily for 10 days. For rats of the medication group, intragastric perfusion of mesalazine solution was given twice daily for 10 days. After the treatment, the colonic epithelium tissue was sampled. The epithelial cells were purified and cultured to establish an in vitro intestinal epithelial barrier, and added with TNF-α (a pro-inflammatory factor, 100 ng/mL) in the culture medium for 24 h for making an increased epithelial permeability model. The permeability of intestinal epithelial cell barrier was evaluated by detecting the fluorescence yellow transmittance of the TNF-α-incubated cell medium. Western blot was used to detect the expression levels of TNFR1, TRADD, receptor-interacting protein 1 (RIP1), FADD and zinc finger protein A20 (A20, a ubiquitination enzyme for inhibiting activation of TRADD and RIP1) of the cultured intestinal epithelium cells. The apoptosis of the TNF-α-incubated intestinal epithelial cells was detected by flow cytometry. RESULTS: After modeling and compared with the normal group, the fluorescence yellow transmittance of intestinal epithelia cells, apoptosis rate, and expression levels of TNFR1, TRADD, and RIP1 proteins were significantly increased (P<0.001, P<0.01), and the expression of A20 was significantly decreased (P<0.01) in the model group. In comparison with the model group, the fluorescence yellow transmittance of intestinal epithelial cells, the apoptosis rate and expression levels of TRADD, RIP1 and FADD were remarkably down-regulated (P<0.001, P<0.01), and the expression of A20 was significantly up-regulated (P<0.01) in both the Moxi and medication groups. CONCLUSION: Herbal cake-partitioned moxibustion may down-regulate the permeability of intestinal epithelial barrier and the apoptosis of intestinal epithelial cells by way of suppressing TNF-α-mediated cellular apoptosis pathway of intestinal epithelium in CD rats.

Protective Effect of JXT Ethanol Extract on Radiation-Induced Hematopoietic Alteration and Oxidative Stress in the Liver.

This study aims at investigating the radioprotective effect of ethanol extract from Ji-Xue-Teng (JXT, Spatholobus suberectus) on radiation-induced hematopoietic alteration and oxidative stress in the liver. Mice were exposed to a single acute γ-radiation for the whole body at the dose of 6.0 Gy, then subjected to administration of amifostine (45 mg/kg) or JXT (40 g crude drug/kg) once a day for 28 consecutive days, respectively. Bone marrow cells and hemogram including white cells, red cells, platelet counts, and hemoglobin level were examined. The protein expression levels of pJAK2/JAK2, pSTAT5a/STAT5a, pSTAT5b/STAT5b, and Bcl-2 in bone marrow tissue; levels of reactive oxygen species (ROS); and the activity of superoxide dismutase (SOD), malondialdehyde (MDA), and glutathione peroxidase (GSH-Px) in serum and liver tissue were determined. At the end of the experiment, the effect of JXT on cell viability and G-CSF and G-CSFR levels in NFS-60 cells were tested by CCK-8 assay, ELISA, and flow cytometry. The results showed that the mice exposed to γ-radiation alone exhibited a typical hematopoietic syndrome. In contrast, at the end of the 28-day experiment, irradiated mice subjected to oral administration of JXT showed an obvious improvement on blood profile with reduced leucopenia, thrombocytopenia (platelet counts), RBC, and hemoglobin levels, as well as bone marrow cells. The expression of pJAK2/JAK2, pSTAT5a/STAT5a, and Bcl-2 in bone marrow tissue was increased after JXT treatment. The elevation of ROS was due to radiation-induced toxicity, but JXT significantly reduced the ROS level in serum and liver tissue, elevated endogenous SOD and GSH-PX levels, and reduced the MDA level in the liver. JXT could also increase cell viability and G-CSFR level in NFS-60 cells, which was similar to exogenous G-CSF. Our findings suggested that oral administration of JXT effectively facilitated the recovery of hematopoietic bone marrow damage and oxidative stress of the mice induced by γ-radiation.

[Effect of Kaixinsan on monoamine oxidase activity].

To observe the effect of antidepressant medicine prescription, Kaixinsan (KXS) on monoamine oxidase (MAO) activity, and explore the mechanism of KXS in elevating the levels of monoamine neurotransmitter from the perspective of metabolism, in vitro enzyme reaction system and C6 neuroglial cells, the effect of KXS at different concentrations on MAO-A and MAO-B activity was observed. In animal studies, the effect of KXS at different concentrations on MAO-A and MAO-B activities of brain mitochondrialin normal rats and solitary chronic unpredictable moderate stress (CMS) model rats after intragastric administration for 1, 2, 3 weeks. Results showed that 10 g•L⁻¹ KXS could significantly reduce the activity of MAO-A and MAO-B in enzyme reaction system; and in C6 cells, KXS within 0.625-10 g•L⁻¹ concentration range had no significant effect on the activity of MAO-A, but had obvious inhibitory effect on the activity of MAO-B in a dose dependent manner. KXS had no significant effect on the activity of MAO-A and MAO-B in brains of normal rats after action for 1, 2, 3 weeks. After 2 and 3 weeks treatment with 338 mg•kg⁻¹ dose KXS, MAO-A activity in the brain of CMS rats was decreased as compared with the model group (P<0.05), while KXS had no significant effect on MAO-B activity after 1, 2, 3 weeks of treatment. The results indicated that KXS had certain effect on in vitro MAO-A and MAO-B activity, had no effect on brain MAO-A and MAO-B activity in vivo in normal rats, and had certain inhibitory effect on MAO-A activity in brains of CMS rats.