Vasorelaxant and Hypotensive Effects of Galla chinensis in Rats.

Previous studies have revealed the medicinal and therapeutic effects of Galla chinensis. However, no studies have focused on the antihypertensive effects of G. chinensis. Therefore, we aimed to determine the vasorelaxant and hypotensive effects of G. chinensis 50% ethanolic extract (GCE). To evaluate the vascular relaxing effect of GCE, experiments were conducted using aortic segments dissected from Sprague Dawley rats. GCE showed a vasorelaxant effect via the nitric oxide/cyclic guanosine 3',5'-monophosphate pathway, inhibiting Ca2+ channels, and activating K+ channels. The hypotensive effects of GCE were evaluated in spontaneously hypertensive rats (SHRs). The SHRs were randomly divided into a control group and orally administered GCE group (100 or 300 mg/kg). The systolic and diastolic blood pressure decreased significantly by -19.47 ± 4.58% and -31.14 ± 7.66% in the GCE 100 mg/kg group, and -21.64 ± 2.40% and -31.91 ± 5.75% in the GCE 300 mg/kg group at 4 h after administration. Considering its vasorelaxant and hypotensive effects, our results indicate that GCE may be a valuable solution for the control of hypertension. However, further studies on the long-term administration and toxicity of GCE are required.

A chromosome-scale genome of Rhus chinensis Mill. provides new insights into plant-insect interaction and gallotannins biosynthesis.

Rhus chinensis Mill., an economically valuable Anacardiaceae species, is parasitized by the galling aphid Schlechtendalia chinensis, resulting in the formation of the Chinese gallnut (CG). Here, we report a chromosomal-level genome assembly of R. chinensis, with a total size of 389.40 Mb and scaffold N50 of 23.02 Mb. Comparative genomic and transcriptome analysis revealed that the enhanced structure of CG and nutritional metabolism contribute to improving the adaptability of R. chinensis to S. chinensis by supporting CG and galling aphid growth. CG was observed to be abundant in hydrolysable tannins (HT), particularly gallotannin and its isomers. Tandem repeat clusters of dehydroquinate dehydratase/shikimate dehydrogenase (DQD/SDH) and serine carboxypeptidase-like (SCPL) and their homologs involved in HT production were determined as specific to HT-rich species. The functional differentiation of DQD/SDH tandem duplicate genes and the significant contraction in the phenylalanine ammonia-lyase (PAL) gene family contributed to the accumulation of gallic acid and HT while minimizing the production of shikimic acid, flavonoids, and condensed tannins in CG. Furthermore, we identified one UDP glucosyltransferase (UGT84A), three carboxylesterase (CXE), and six SCPL genes from conserved tandem repeat clusters that are involved in gallotannin biosynthesis and hydrolysis in CG. We then constructed a regulatory network of these genes based on co-expression and transcription factor motif analysis. Our findings provide a genomic resource for the exploration of the underlying mechanisms of plant-galling insect interaction and highlight the importance of the functional divergence of tandem duplicate genes in the accumulation of secondary metabolites.

The effect of polyphenol-containing solutions on in situ biofilm formation on enamel and dentin.

OBJECTIVES: To investigate the effects of Chinese gallnut extracts and pure tannic acid on in situ biofilm formation on enamel and dentin samples over 24 h. METHODS: Bovine enamel and dentin samples were buccally fixed on maxillary splints. Six volunteers wore the splints for 24 h, and rinsed their mouths with tap water (control), 1% tannic acid- and 1% Chinese gallnut extracts-containing solution twice a day, 3 min after the splints were placed in the mouth and before night sleep. Live/dead staining was used for fluorescence microscopic (FM) visualization and quantification of bacteria viability of biofilms formed on enamel and dentin samples. Biofilm coverage was evaluated and recorded by FM and scanning electron microscopy (SEM). In addition, biofilms were analyzed by transmission electron microscopy (TEM). The Kruskal-Wallis test was used to analyze biofilm data. RESULTS: Rinsing with tannic acid- and Chinese gallnut extracts-containing solutions significantly reduced in situ biofilm coverage on enamel and dentin samples (P < 0.05). The bacterial viability of biofilms formed on enamel samples was significantly reduced compared to the control (P < 0.05). TEM analysis revealed an increase in pellicle's electron density and thickness and only few or no bacteria adherent to the pellicle in the experimental samples. CONCLUSIONS: Rinsing with tannic acid- and Chinese gallnut extracts-containing solutions can effectively inhibit in situ biofilm formation, modify the ultrastructure of biofilms on enamel and dentin surfaces and significantly reduce the bacterial viability of biofilm on enamel surfaces. CLINICAL SIGNIFICANCE: Tannic acid- and Chinese gallnut extracts-containing solutions might be used for dental biofilm management.

The inhibition of Chinese gallnut on bacteria in plaque biofilms / 实用口腔医学杂志

Objective:To observe the inhibition of Chinese gallnut on bacteria in plaque biofilms by the use of artificial mouth.Methods:Water extract of Chinese Gallnut was prepared and liquid media two-fold dilution method was used to determine the minimal inhibition concentration(MIC)of the drug on S.mutans,A.viscosus,S.sanguis and S.oralis.Individual bacteria plaque biofilms in artificial mouth were created.The inhibition of Chinese gallnut on the bacteria in plaque biofilms was studied by colony counting.Results:In bacteria suspension gallnut water extract inhibited the growth of the four kinds of bacteria.The MIC of the extract on S.mutans,A.viscous and S.sanguis was 64 mg/ml,that on S.oralis 8 mg/ml.The plaque biofilms formed by the four kinds of bacteria could be inhibited by 2 mg/ml-128 mg/ml of the extract dose-dependently.At the highest tested conentration(128 mg/ml)the gallnut water extract could not completely clear up the colonyforming unite(CFU)of the becteria.Conclusion:Chinese gallnut water extract can inhibit the growth of bacteria in suspension and in plaque biofilms,the bacteria in biofilms may have stronger resistance to the extract.

The effects of Chinese gallnut on the vitality of oral plaque biofilms in vitro / 实用口腔医学杂志

Objective:To observe the effects of gallnut water extract on the vitality of plaque biofilms.Methods:The oral plaque biofilms were obtained through bonding the enamel fragments to the bucca of the mindibular first molar for 24 h.The two groups of the biofilms were treated by gallnut water extract at 6 mg/ml and saline(control) for three minutes respectively.The effect of gallnut water extract on the vitality of plaque biofilms was observed by Ethidium bromide/Fluorescein diacetate (EB/FDA) staining and confocal laser scan microscope(CLSM).Results:All specimens had early biofilm formed,The percent vitality of the plaque biofilms treated with gallnut water extract and the control was 37.10?9.63 and 60.78?7.60 respectively(P