Anoectochilus roxburghii polysaccharide prevents carbon tetrachloride-induced liver injury in mice by metabolomic analysis.

Anoectochilus roxburghii (Wall.) Lindl, a traditional Chinese medicine, is used for the effective treatment of liver disease in China. Anoectochilus roxburghii polysaccharide (ARPT) is an important constituent of Anoectochilus roxburghii. ARPT exerts a hepatoprotective effect and contributes directly to the therapeutic benefit of Anoectochilus roxburghii. However, the hepatoprotective mechanism of ARPT requires further elucidation. The present study was designed to assess the effects and underlying mechanism of ARPT when used to pretreat carbon tetrachloride (CCl4)-induced liver injury in mice. Mice were randomly divided into three groups: control group (no ARPT treatment or liver injury), model group (liver injury induced with CCl4), and the ARPT group (ARPT pretreatment followed by liver injury). A metabolomic method, based on liquid chromatography combined with mass spectrometry (LC-MS) and pattern recognition analysis, was applied. The data were analyzed with principal component analysis (PCA) and orthogonal partial least squares-discriminant analysis (OPLS-DA), to determine differentiating metabolites in the serum and liver tissue between the experimental groups. The PCA and OPLS-DA scores plots of the serum and liver tissue samples based on the LC-MS data showed a clear separation between the control and liver injury model group, while the ARPT-treated group showed a trend of close with the control. There were eleven metabolites [PS(O-18:0/0:0), phosphocholine, phenylalanine, hippuric acid, α-ketoisovaleric acid, metyrosine, leucinic acid, ketoleucine, Cer(d18:1/19:0), α-kamlolenic acid, and 4-formyl indole] were identified as candidate biomarkers in the serum samples, eight such metabolites (valine, phosphohydroxypyruvic acid, phosphocholine, ornithine, indole, xanthine, uridine, and glucose 6-phosphate) were found in the liver tissue samples, and one metabolite (phosphocholine) was observed in both the serum and liver tissue samples. These endogenous metabolites are considered to be in response to the hepatoprotective effects of ARPT and are involved in amino acid metabolism, lipid metabolism, gut bacteria metabolism, energy metabolism, and the methylation pathway. These findings suggest that ARPT mitigates the metabolic effect of CCl4-induced hepatotoxicity in mice by affecting at least five different pathways. LC-MS-based metabolomics provides a powerful approach for identifying potential biomarkers and for elucidating the protective mechanisms of traditional Chinese medicines against disease.

Effects of supplemental lighting with different light qualities on growth and secondary metabolite content of Anoectochilus roxburghii.

BACKGROUND: Anoectochilus roxburghii is a widespread herbaceous plant with high medicinal value. Wild A. roxburghii resources face extinction due to their slow growth rate and over exploitation. The growing market demand has led to advances in the field of artificial planting of A. roxburghii. Methods to increase the economic benefits of cultivation and the production of medicinal ingredients are very useful. METHODS: A. roxburghii was exposed to red light, blue light (BL), yellow light (YL), green light, or white light as supplemental lighting at night (18:00-02:00) in a greenhouse or were left in darkness (control, CK) to investigate the effects of various light qualities on growth indices, photosynthetic pigments, chlorophyll fluorescence, root vitality, stomatal density, soluble proteins, sugars, and the accumulation of secondary metabolites. RESULTS: Supplementation of BL had a positive effect on A. roxburghii growth and secondary metabolite accumulation. Leaf number, stem diameter, fresh weight, dry weight, chlorophyll a content, and secondary metabolite (total flavonoids, total polyphenols) content increased significantly. YL treatment showed significantly higher soluble sugar and polysaccharide contents than the control. DISCUSSION: BL treatment was conducive to promoting the growth and accumulation of secondary metabolites (total flavonoids, total polyphenols); YL treatment significantly increased the content of soluble sugar and polysaccharides more than the control. Polysaccharides and total flavonoids are important medicinal ingredients of Anoectochilus, so future research will focus on the combination of blue and YL.

Protective effect of a polysaccharide from Anoectochilus roxburghii against carbon tetrachloride-induced acute liver injury in mice.

ETHNOPHARMACOLOGICAL RELEVANCE: Anoectochilus roxburghii (Wall.) Lindl. is traditionally used for the treatment of various types of chronic and acute hepatitis in China. Considering that Anoectochilus roxburghii polysaccharide (ARPT) is the main constituent of Anoectochilus roxburghii, the present study was designed to investigate the hepatoprotective effect of ARPT and its possible mechanism in carbon tetrachloride (CCl4)-induced mice. MATERIAL AND METHODS: The hepatoprotective activity of ARPT (150, 300 and 500mg/kg) were investigated on CCl4-induced acute liver damage in mice. The activities of alanine transaminase (ALT), aspartate transaminase (AST) were determined in serum. The hepatic levels of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px) and malondialdehyde (MDA) were measured in liver homogenates. The levels of cytochrome P450 sub family 2E1 (CYP2E1), tumor necrosis factor alpha (TNF-α), interleukin-1 beta (IL-1ß), interleukin-6 (IL-6), monocyte chemoattractant protein-1 (MCP-1), macrophage inflammatory protein-2 (MIP-2), KC (Murine IL-8 ortholog), transforming growth factor-beta1 (TGF-ß1), Bcl-2 and Bax were measured by quantitative real-time polymerase chain reaction (qRT-PCR). The expressions of CYP2E1, nuclear factor-kappa B (NF-κB) p65 and caspase-3 were evaluated by western blot assays. The hepatic levels of TNF-α, IL-6, MIP-2 and TGF-ß1 were measured by enzyme-linked immunosorbent assay (ELISA). Furthermore, histopathological observation and terminal-deoxynucleoitidyl transferase mediated nick end labeling assay (TUNEL) were carried out on the separated livers of mice. RESULTS: ARPT significantly decreased serum ALT and AST activities, hepatic MDA level, and markedly enhanced antioxidant enzyme (SOD, CAT and GSH-Px) activities and GSH level in hepatic tissue, in a dose-dependent manner, when compared to the model group. Histopathological observation revealed the hepatoprotective effect of ARPT against the damage. Furthermore, ARPT remarkably inhibited CYP2E1 mRNA expression, decreased NF-κB p65 expression and therefore to prevent the secretion of pro-inflammatory cytokines (TNF-α and IL-6) and chemokines (MCP-1, MIP-2 and KC), suppressed TGF-ß1 expression and hepatocytes apoptosis. Moreover, ARPT could prevent DNA fragmentation based on TUNEL assay results. CONCLUSION: These findings suggested that ARPT possessed hepatoprotective effect against CCl4-induced hepatotoxicity in mice and the action might in part be through reducing oxidative stress, inflammation and apoptosis.

Physicochemical Properties and Antioxidant Capacity of Chinese Olive (Canarium album L.) Cultivars.

In this study, the physicochemical characteristics and antioxidant potentials of 10 Chinese olive cultivars were investigated. Considerable differences were found between cultivars in weight, edible yield, water content, size, shape, total soluble solids, and total titratable acidity. The major sugars and organic acids in all the cultivars were glucose, fructose, and malic acid. Phenolics were the most abundant antioxidants (1174.0 to 1799.6 mg gallic acid equivalents/100 g fresh weight). Twelve phenolic compounds were identified and quantified by UPLC-MS/MS. Six compounds were identified first in the Chinese olive, with 3-O-galloylquinic acid and geraniin isomers as the most abundant compounds. The results also indicated that the phenolic content (TPC) correlated with the antioxidant properties of Chinese olive fruit extracts. A principal component analysis indicated that the Tantou and Tanxiang cultivars were a valuable source, with high TPC and antioxidant activity, whereas Maken22, Changying, and Green changying cultivars may be eaten fresh and had high sugar and low phenolic contents. This information will be useful for selecting suitable cultivars for industry and the market.

Antioxidant and hepatoprotective activities of polysaccharides from Anoectochilus roxburghii.

The physicochemical properties (molecular weights and monosaccharide compositions), antioxidant and hepatoprotective activities of polysaccharides (ARPPs: ARPP30, ARPP60 and ARPP80) isolated from Anoectochilus roxburghii were investigated. ARPP80 exhibited relatively strong antioxidant activities in a concentration-dependent manner. In mice subjected to carbon tetrachloride-induced hepatotoxicity, ARPP80 pretreatment significantly (p<0.01) reduced the levels of aspartate and alanine amino transferases and malonyldialdehyde, prominently (p<0.01) restored the levels of superoxide dismutase, catalase, glutathione peroxidase and reduced glutathione in serum or liver homogenate. These hepatoprotective effects were comparable to those of the standard drug silymarin at the same dose (200mg/kg). The study clearly demonstrated that ARPPs, especially ARPP80, might be suitable as functional foods or hepatoprotective drugs.

Genome-wide transcriptome and expression profile analysis of Phalaenopsis during explant browning.

BACKGROUND: Explant browning presents a major problem for in vitro culture, and can lead to the death of the explant and failure of regeneration. Considerable work has examined the physiological mechanisms underlying Phalaenopsis leaf explant browning, but the molecular mechanisms of browning remain elusive. In this study, we used whole genome RNA sequencing to examine Phalaenopsis leaf explant browning at genome-wide level. METHODOLOGY/PRINCIPAL FINDINGS: We first used Illumina high-throughput technology to sequence the transcriptome of Phalaenopsis and then performed de novo transcriptome assembly. We assembled 79,434,350 clean reads into 31,708 isogenes and generated 26,565 annotated unigenes. We assigned Gene Ontology (GO) terms, Kyoto Encyclopedia of Genes and Genomes (KEGG) annotations, and potential Pfam domains to each transcript. Using the transcriptome data as a reference, we next analyzed the differential gene expression of explants cultured for 0, 3, and 6 d, respectively. We then identified differentially expressed genes (DEGs) before and after Phalaenopsis explant browning. We also performed GO, KEGG functional enrichment and Pfam analysis of all DEGs. Finally, we selected 11 genes for quantitative real-time PCR (qPCR) analysis to confirm the expression profile analysis. CONCLUSIONS/SIGNIFICANCE: Here, we report the first comprehensive analysis of transcriptome and expression profiles during Phalaenopsis explant browning. Our results suggest that Phalaenopsis explant browning may be due in part to gene expression changes that affect the secondary metabolism, such as: phenylpropanoid pathway and flavonoid biosynthesis. Genes involved in photosynthesis and ATPase activity have been found to be changed at transcription level; these changes may perturb energy metabolism and thus lead to the decay of plant cells and tissues. This study provides comprehensive gene expression data for Phalaenopsis browning. Our data constitute an important resource for further functional studies to prevent explant browning.