Purification of polysaccharide from artificially cultivated Anoectochilus roxburghii (wall.) Lindl . by high-speed counter current chromatography and its antitumor activity

The evaluation of the anti-cancer effects of Anoectochilus roxburghii on hematological cancers in vitro

The cause of hematological cancers is the uncontrolled proliferation of hematopoietic and lymphoid tissues, and chemotherapy is used to treat cancer. However, adverse side effects of chemotherapy are common. Therefore, the use of plant extracts as a method for treating cancer is becoming increasingly popular. Anoectochilus roxburghii (wall.) Lindl. (A. roxburghii) is one of the original sources of the valuable medicinal plants known as the king medicine and the golden grass. This study investigated the potential anticancer effect of A. roxburghi (AR) on JURKAT, MM1S, THP1 and U266 cells. To test the cytotoxic and apoptotic effects of AR, hematological cancer cells were exposed to increasing doses of AR (0.1-0.5 µg/µl). The spectrophotometric MTT assay and the flow cytometric Annexin V staining were used to examine the viability and apoptosis of the cells, respectively. qRT-PCR was used to determine the expression levels of the apoptosis-related genes BAD, BAX, BIM and BCL-2. Our results show that AR treatment decreased cell viability and induced apoptosis in each cell line. Our RT-PCR data showed that AR significantly increased the expression levels of the pro-apoptotic BAX gene in JURKAT and MM1S cells, whereas it significantly increased the expression levels of both BAX and BIM in U266 cells. This is the first study to investigate how AR modulates apoptosis in hematological cancer cells. As a result, AR therapy may be a promising treatment modality for the treatment of cancer.

Molecular and Functional Analysis of Trehalose-6-Phosphate Synthase Genes Enhancing Salt Tolerance in Anoectochilus roxburghii (Wall.) Lindl

Trehalose is a reducing disaccharide, acting as a protectant against various environmental stresses in numerous organisms. In plants, trehalose-6-phosphate synthase (TPS) plays a crucial role in trehalose biosynthesis. Anoectochilus roxburghii (Wall.) Lindl. is a prominent species of the Anoectochilus genus, widely utilized as a health food. However, the functional analysis of TPS in this species has been limited. In this study, TPS genes were cloned from A. roxburghii. The ArTPS gene, with an open reading frame spanning 2850 bp, encodes 950 amino acids. Comparative and bioinformatics analysis revealed that the homology was presented between the ArTPS protein and TPSs from other plant species. The ORF sequence was utilized to construct a prokaryotic expression vector, Pet28a-ArTPS, which was then transformed into Escherichia coli. The resulting transformants displayed a significant increase in salt tolerance under the stress conditions of 300 mmol/L NaCl. Quantitative RT-PCR analysis demonstrated that the expression of ArTPS genes responded to NaCl stress. The accumulation of G6P was upregulated, whereas the content of T6P exhibited an opposite expression trend. The glycometabolism products, including trehalose, exhibited notable changes under NaCl stress, although their variations may differ in response to stimulation. The content of kinsenoside, a characteristic product of A. roxburghii, was significantly upregulated under NaCl stress. These results suggest that the ArTPS genes function in response to NaCl stimulation and play a key role in polysaccharide and glycoside metabolism in Anoectochilus. This study provides new insights into the engineering modification of the health food A. roxburghii to enhance the medicinal activity of its ingredients.

Isolation, structural and bioactivities of polysaccharides from Anoectochilus roxburghii (Wall.) Lindl.: A review

Anoectochilus roxburghii (Wall.) Lindl. (A. roxburghii), a valuable herbal medicine in China, has great medicinal and edible value. Polysaccharides, as one of the main active components of A. roxburghii, comprise glucose, arabinose, xylose, galactose, rhamnose, and mannose in different molar ratios and glycosidic bond types. By varying the sources and extraction methods of A. roxburghii polysaccharides (ARPS), different structural characteristics and pharmacological activities can be elucidated. ARPS has been reported to exhibit antidiabetic, hepatoprotective, anti-inflammatory, antioxidant, antitumor, and immune regulation activities. This review summarizes the available literature on the extraction and purification methods, structural features, biological activities, and applications of ARPS. The shortcomings of the current research and potential focus in future studies are also highlighted. This review provides systematic and current information on ARPS to promote their further exploitation and application.

Chemopreventive effects of Xiang Sha Liu Jun Zi Tang on paclitaxel-induced leucopenia and neuropathy in animals

Paclitaxel frequently induces peripheral neuropathy and myelosuppression during cancer treatment. According to the National Health Insurance Research Database of Taiwan, traditional Chinese medicine doctors widely use Xiang Sha Liu Jun Zi Tang (XSLJZT) to treat breast cancer patients who have received paclitaxel. We explored the combined therapeutic effects of XSLZJT with paclitaxel. XSLJZT did not exhibit significant cytotoxic effects on P388-D1 cells; however, the combination of XSLJZT (100 and 500 mg/kg) with paclitaxel prolonged the survival rate in P388–D1 tumor-bearing mice compared to paclitaxel-only. In addition, XSLJZT was found to enhance white blood cells (WBC) counts and promote leukocyte rebound in paclitaxel-induced leukopenia in mice. XSLJZT also reduced paclitaxel-induced mechanical pain and inhibited c-Fos protein expression in the L4-6 spinal cords of Wistar rats. Moreover, paclitaxel-induced shortening of the nerve fibers of dorsal root ganglion cells was ameliorated by pre-treatment with XSLJZT. Therefore, we suggest that XSLJZT could be used as an adjunct for cancer patients, as the formula could decrease paclitaxel-induced neuropathy and myelosuppression.

Two polyamines -responsive WRKY transcription factors from Anoectochilus roxburghii play opposite functions on flower development

Anoectochilus roxburghii is a rare and precious plant with medicinal and healthcare functions. Embryo abortion caused the lack of resources. Polyamine promoted its flowering and stress resistance in our previous study. But the mechanism remains unclear. The WRKY transcription factor family has been linked to a variety of biological processes in plants. In this study, two WRKY TFs (ArWRKY5 and ArWRKY20) of A. roxburghii, which showed significant response to Spd treatment, were identified and functionally analyzed. Tissue specific expression analyzation showed both of them mostly present in the flower. And ArWRKY5 expressed highest in the flower bud stage (-1 Flowering), while ArWRKY20 showed the highest expression in earlier flower bud stage (-2 Flowering) and the expression gradually decreased with flowering. The transcriptional activation activity assay and subcellular localization revealed that ArWRKY5 and ArWRKY20 were located in the nucleus and ArWRKY20 showed transcriptional activity. The heterologous expression of ArWRKY5 in Arabidopsis thaliana showed earlier flowering, while overexpression of ArWRKY20 delayed flowering. But the OE-ArWRKY20 lines had a robust body shape and a very significant increase in the number of rosette leaves. Furthermore, stamens and seed development were positively regulated by these two ArWRKYs. These results indicated that ArWRKY5 and ArWRKY20 not only play opposite roles in the floral development, but also regulate the plant growth and seed development in A. thaliana. But their specific biological functions and mechanism in A. roxburghii need to be investigated further.

Effect of Burkholderia ambifaria LK-P4 inoculation on the plant growth characteristics, metabolism, and pharmacological activity of Anoectochilus roxburghii

BACKGROUND

Plant growth-promoting bacteria (PGPB) represents a common biological fertilizer with remarkable effect in improving crop production and environmental friendliness.

METHODS

In the present work, we presented a detailed characterization of plant morphology and physiology, metabolism, and pharmacological activity of A. roxburghii between Burkholderia ambifaria LK-P4 inoculation and un-inoculation (CK) treatment by routine analytical techniques (include microscopy and enzymatic activity assays and so on) coupled with metabolomics approaches.

RESULTS

Morphological and physiological results showedthat the P4 bacteria could significantly increase plant stomatal density, freshweight, survival rate,and the content of total flavonoids in leaves but reducethe amount of free amino acid. Furthermore, metabolite data showed that fatty acids (linoleic acid, linolenic acid, stearic acid) and active substance (kyotorphin and piceatannol) were specifically up-regulated in P4 inoculation. It was also demonstrated that the differential metabolites were involved in citrate cycle, glyoxylate and dicarboxylate metabolism, and biosynthesis of unsaturated fatty acids pathway. In addition, pharmacological efficacy found that A. roxburghii under P4 inoculation can significantly decrease (p < 0.05) blood glucose levels and protect the organs of mice with similar effect of Glibenclamide tablets.

CONLUSION

Overall, it can be seen that the exogenous P4 bacteria can promote the growth and increase content of special metabolites in A. roxburghii. This study provided theoretical basis and supported for the high-yield and high-quality bionic cultivation of A. roxburghii.

Characterization of phenylalanine ammonia-lyase genes facilitating flavonoid biosynthesis from two species of medicinal plant Anoectochilus

Background

Anoectochilus roxburghii and Anoectochilus formosanus, belong to the Anoectochilus genus, have been used for Chinese herbal drugs as well as health food. Phenylalanine ammonia-lyase (PAL), the key enzyme in primary metabolism and phenylpropanoid metabolism, produces secondary metabolites (flavonoids) in plants, which are beneficial for the biosynthesis of phenylpropanoid metabolites.

Methods

The PAL genes were cloned from A. formosanus and A. roxburghii according to our previous transcriptomic analysis. The PALs were introduced into pCAMBIA2300-35S-PAL-eGFP to generate 35S-PAL-eGFP. The constructs were further used for subcellular localization and transgenic Arabidopsis. The expression of AfPAL and ArPAL under precursor substance (L-Phe), NaCl, UV, and red-light were analyzed by real-time quantitative PCR (RT-qPCR).

Results

AfPAL and ArPAL , encoding 2,148 base pairs, were cloned from A. formosanus and A. roxburghii. The subcellular localization showed that the ArPAL and AfPAL were both localized in the nucleus with GPF. Quantitative RT-PCR analysis indicated that the ArPAL and AfPAL genes function in the phenylalanine pathway as well as response to induced conditions. Overexpression of the AfPAL and ArPAL could increase flavonoids and anthocyanin content in the transgenic Arabidopsis.

Discussion

The results suggest that AfPAL and ArPAL play a crucial role in the flavonoid biosynthesis in Anoectochilus. Also, our study provides new insights into the enrichment of secondary metabolites of traditional Chinese medicines A. formosanus and A. roxburghii, which can improve their medicinal active ingredients and be used for drug discovery in plants.

Evaluation of in vitro cytotoxicity and in vivo potential toxicity of the extract from in vitro cultivated Anoectochilus roxburghii Lindl

Anoectochilus roxburghii Lind. (A. roxburghii) has promising anti-oxidant, hyperglycemic, hepatoprotective, and immunomodulatory activities as well as anti-tumor effects. However, the pharmacological actions of in vitro cultured plants remain to be determined. Therefore, the objective of the study was to assess in vitro cytotoxicity and in vivo potential toxicity of an extract derived from in vitro cultivated A. roxburghii, termed as iARE. The total flavonoid content and predominant flavonoid compounds of extract were identified and quantitatively analyzed. The in vitro cytotoxicity of iARE was examined using several cancer and normal cell lines. The apoptotic activity and expression of apoptosis-associated genes were also examined in MCF7 cells to determine the underlying mechanisms related to anti-proliferative effects. In vivo potential toxicity of iARE was assessed following acute and subchronic oral administration in Sprague Dawley rats. Quercetin, kaempferol, and isorhamnetin were three flavonoid components identified in iARE. The extract exerted cytotoxic effects on various cancer cells but not normal fibroblasts. Apoptosis in MCF7 cells was induced by iARE in a concentration-dependent manner associated with increased Bax/Bcl-2 ratio and reduced mitochondrial membrane potential ΔΨm, leading to release of cytochrome c, activation of caspase-3/7 and caspase-9, and cleavage of PARP. In the acute oral toxicity study, no mortality or toxicological signs were observed in rats at 1000 or 5000 mg/kg. In a subchronic oral toxicity study, iARE at a dosage of up to 1000 mg/kg produced no mortality or treatment-related adverse effects on general behavior, food intake, body weight, relative organ weights. No apparent marked changes in the histopathology of the liver and kidney were detected. Data demonstrated that iARE induced in vitro cytotoxic effects in cancer cells are associated with lackof invivo toxicity. Thus, iARE was suggested to be considered as apotential therapeutic candidate for cancer treatment.

Bioassay-guided study of the anti-inflammatory effect of Anoectochilus burmannicus ethanolic extract in RAW 264.7 cells

ETHNOPHARMACOLOGICAL RELEVANCE

Anoectochilus species is a small terrestrial orchid found in tropical and subtropical rain forest. These orchids are traditionally used extensively in China, Taiwan, and Vietnam due to their medicinal properties and therapeutic benefits. They are employed for treatment in different systems, such as stomach disorders, chest pain, arthritis, tumor, piles, boils, menstrual disorders, and inflammation. Aqueous extract of Anoectochilus burmannicus (AB) has been previously reported to exhibit anti-inflammatory activities, however there is a lack of evidence regarding its bioactive compounds and the mechanism of its actions.

AIM OF THE STUDY

The objectives of this study were to identify the anti-inflammatory compound(s) in an ethanolic extract of AB and to determine its anti-inflammatory mechanisms in LPS-stimulated macrophages and also its safety.

MATERIALS AND METHODS

The ethanolic extract of AB (ABE) was prepared and subsequently subjected to polarity-dependent extraction using n-hexane and ethyl acetate, which would result in isolation of the n-hexane (ABH), ethyl acetate (ABEA), and residue or aqueous (ABA) fractions. The AB fractions were investigated to determine total phenolic and flavonoid content, antioxidant capacity, toxicity, and safety in RAW 264.7 macrophages, human PBMCs, and RBCs. After extraction anti-inflammation screening of each extract was performed by nitric oxide (NO) production assay. The active fractions were further examined for their effect on proinflammatory mediators. In addition, kinsenoside content in the active fractions was identified using LC-MS/MS. Cellular toxicity and genotoxicity of AB were also tested using the wing spot test in Drosophila melanogaster.

RESULTS

The data showed that ABEA had the highest phenolic content and level of antioxidant activities. ABE, ABEA, and ABA, but not ABH, significantly inhibited the LPS-stimulated NO production in the macrophages. Both ABEA and ABA reduced LPS-mediated expression of TNF-α, IL-6, iNOS, and COX-2 at both mRNA and protein levels. Besides, only ABEA notably diminished the LPS-stimulated p65 phosphorylation required for nuclear translocation and transcriptional activation of the nuclear factor-κB (NF-κB). Interestingly, liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis revealed ABA contained a high level of kinsenoside, a likely anti-inflammatory compound, while ABE and ABEA might require other compounds in combination with kinsenoside for the inhibition of inflammation. It was shown that all active fractions were neither cytotoxic nor genotoxic.

CONCLUSION

Our study demonstrated that the hydrophilic fractions of AB exhibit anti-inflammatory activity in LPS-stimulated macrophages. The mechanism used by the AB involves the scavenging of free radicals and the reduction of proinflammatory mediators, including IL-1β, IL-6, TNF-α, NO, iNOS and COX-2. The anti-inflammatory action of AB involves the suppression of the NF-κB signaling pathway by some unknown component(s) present in ABEA. This study found that kinsenoside is a major active compound in ABA which could be used as a biomarker for the quality control of the plant extraction. This study provides convincing significant information in vitro regarding the anti-inflammatory mechanism and preliminary evidence of the safety of Anoectochilus burmanicus. Therefore, the knowledge acquired from this study would provide supportive evidence for the development and standardization of the use of the extract of this plant as alternative medicine or functional food to prevent or treat non-communicable chronic diseases related to chronic inflammation.

Hepatoprotective Effects of Polysaccharide from Anoectochilus roxburghii (Wall.) Lindl. on Rat Liver Injury Induced by CCl4

Purpose

The polysaccharide of Anoectochilus roxburghii (wall.) Lindl. (ARPS) is one of its important active ingredients. Hepatoprotective effects of ARPS on rat liver injury induced by CCl₄ were studied.

Methods

ARPS was extracted using the ultrasonic method and successfully purified by high-speed counter-current chromatography (HSCCC) with a two-phase aqueous system composed of 12.5% PEG 1000-20% K₂HPO₄:KH₂PO₄ (1:1). The HSCCC conditions were optimized, and the structure of ARPS was characterized. The hepatoprotective effects of ARPS against CCl₄-induced chronic hepatic injury in SD rats were evaluated.

Results

The results showed that ARPS was a water-soluble polysaccharide with a molecular weight of 28,518 Da. It was composed of mannose, ribose, glucose, and arabian sugar; its monosaccharide molar ratio was glucose:ribose:arabinose:mannose = 54.24:13.20:1.09:1.00. The purity of ARPS was determined by HPLC to be 96.93%. The intervention effects of ARPS on CCl₄-induced hepatic damage model in rats showed that ARPS could effectively reduce the activity of alanine amino transferase and aspartate amino transferase, decrease the content of malondialdehyde and nitric oxide synthesis, and increase the content of glutathione. Pathology revealed that liver plate order, liver cell degeneration, and edema were improved; inflammatory cell infiltration was not observed after ARPS intervention.

Conclusion

ARPS had the function of antioxidant for protecting CCl₄-induced injured liver, and the mechanisms were related to anti-lipid peroxidation, which could eliminate oxygen-free radicals and protect liver cells from attacks by free radicals.

Purification, structure and conformation characterization of a novel glucogalactan from Anoectochilus roxburghii

Anoectochilus roxburghii (AR) has been used in food, medicine and ornamental industries for a long time. Anion exchange resin was proposed to purify the sub-fraction of water-extracted AR polysaccharide (ARPP-70), and a homogeneous polysaccharide ARPP-70a was obtained. The structural features of ARPP-70a were characterized using gas chromatography-mass spectrometry (GC-MS), nuclear magnetic resonance (NMR) spectroscopy, and high performance size exclusion chromatograph coupled with multi-angle laser light scattering (HPSEC-MALLS). The relative weight average molecular weight for ARPP-70a was determined to be 14.8 kDa, and the molar ratio of glucose to galactose was 1.0:3.2. The structure of ARPP-70a was elucidated to be glucogalactan, with backbone comprising β-1,4-linked Galp and some α-1,4-linked Glcp. The conformation characteristics of ARPP-70a were supposed to exist as a random coil chain in 0.1 M NaNO₃ solution. Moreover, in vitro antioxidant activity assays revealed ARPP-70a exhibited appreciable antioxidant potential. To the best of our knowledge, this is the first study to obtain this type of glucogalactan, and provide systematic information on its structural and conformational properties. This study improved the understanding of the physicochemical characteristics of AR polysaccharide, which is beneficial for its further application in food and medicinal industry.

Detecting kinsenoside from Anoectochilus roxburghii by HPLC-ELSD with dual columns of NH2 and AQ-C18

INTRODUCTION

Kinsenoside is a characteristic component of Anoectochilus roxburghii and accounts for this herb's medicinal and edible values. No international certified standard method is available for kinsenoside analysis as well as extraction and preservation.

OBJECTIVE

To develop a more accurate analytical method of kinsenoside. The effects of extraction and drying methods of A. roxburghii on kinsenoside efficiency were investigated for the first time, as well as to examine the kinsenoside stability.

MATERIAL AND METHODS

The amino (NH₂ ) and AQ-C₁₈ columns for detecting kinsenoside extract was systematically compared by high-performance liquid chromatography evaporative light-scattering detector (HPLC-ELSD) and HPLC-diode-array detector (DAD), respectively. Kinsenoside, its epimer goodyeroside A and the degradation product during preservation were identified through HPLC-electrospray ionization mass spectrometry (ESI-MS).

RESULTS

An accurate method of kinsenoside detection by HPLC-ELSD with dual columns of NH₂ and AQ-C₁₈ was established. The ratio of C_{goodyeroside A} to C_kinsenoside (Y) was determined using the AQ-C₁₈ column method. The concentration detected by the NH₂ column was multiplied by 1/(1 + Y) as the corrected result. Using this novel method, the average deviations were reduced by 7.64%. Moreover, the efficiency of kinsenoside extraction with water was almost twice that of extraction with ethanol. Freeze drying also led to a higher extraction efficiency (38.47% increase) than hot-air drying did. Furthermore, the degradation of kinsenoside extract exceeded 70% when stored at 37 °C for 3 months.

CONCLUSION

This study provides a reliable experimental method and theoretical basis for the quality control of kinsenoside from A. roxburghii, as well as other glycosides.

Three-phase hollow fiber liquid-phase microextraction combined with HPLC for determination of three trace acidic plant growth regulators in Anoectochilus roxburghii (Wall.) Lindl

The analysis of plant growth regulators presents a challenge due to their trace quantities and complex matrices. A novel, simple, and effective analytical method for the determination of three trace acidic plant growth regulators in Anoectochilus roxburghii (Wall.) Lindl was developed to address this issue. Three-phase hollow fiber liquid-phase microextraction combined with high-performance liquid chromatography was applied for the enrichment, purification, and determination of three acidic plant growth regulators, namely, indole-3-acetic-acid, indole-3-butyric-acid, and (+)-abscisic acid. The factors affecting extraction performance, including extractant species, pH of donor and acceptor phases, salt addition dosage, extraction time, temperature, and stirring rate, were investigated and optimized. Under optimum conditions, the proposed method provided good linearity (R² , 0.9994-0.9999), low limit of detection (0.038-0.12 ng/mL), and acceptable relative recoveries (56.7-117.6%). The enrichment factors were between 153 and 328. The developed method was successfully applied to the enrichment and determination of plant growth regulators in Anoectochilus roxburghii (Wall.) Lindl and exhibited increased purification capacity, higher sensitivity, and decreased organic solvent consumption compared with conventional sample preparation methods. This method may provide a testing platform for the monitoring of plant growth regulator residues, ensuring the safe and effective use of traditional Chinese medicine.

Regulation of flowering time using temperature, photoperiod and spermidine treatments in Anoectochilus roxburghii

This study investigated the effects of different temperatures, photoperiods and spermidine concentrations on the flowering time regulation of Anoectochilus roxburghii by measuring changes in the soluble sugar, soluble protein, malondialdehyde and proline contents, and the peroxidase, superoxide dismutase and catalase activities in A. roxburghii flower buds. The flowering time could be advanced under 25/20 °C (day/night), 16/8-h (day/night) long day conditions or low spermidine concentrations. The plants grew more rapidly and flowering rates were greater. The flowering time could be delayed under a low temperature of 20/15 °C or 8/16-h short day conditions, resulting in a low flowering rate. Under a high temperature of 30/25 °C or high spermidine concentrations, the plants could not flower normally and even died. There were significant differences in the seven measured indices among the various treatments. Thus, different treatments had significant effects on the flowering time regulation and flowering quality of A. roxburghii, providing a reliable theoretical basis for further studies on the flowering-related regulatory mechanisms of A. roxburghii.