A monoclonal antibody-based immunoassay for the determination of oxyresveratrol from Artocarpus lacucha Buch.-Ham

Oxyresveratrol is a major active compound in the heartwood of Artocarpus lacucha. It plays an important role in anti-tyrosinase, antioxidant, anti-inflammatory, antiviral and neuroprotective properties. There are many A. lacucha commercial products available on the market for skin whitening and anti-aging effects. To evaluate the quality of raw material from the plant, a monoclonal antibody (MAb) against oxyresveratrol was generated in this study. The immunogen was prepared by the Mannich reaction for the conjugation of oxyresveratrol and cationized bovine serum albumin (cBSA). The conjugation of oxyresveratrol-cBSA at a ratio of 1:50 was used for the immunization. The novel MAb (E4) was specific to oxyresveratrol and resveratrol. An indirect competitive enzyme-linked immunosorbent assay (ELISA) using the MAb (E4) was developed for the determination of oxyresveratrol. The linear range for the measurement of oxyresveratrol was 63-500 ng/mL and the precision (% relative standard deviation) was found to be <10% with the percentages of recovery from 95.93-103.55%. According to the validation analysis, the established ELISA can be applied for the determination of oxyresvertrol in the heartwood of A. lacucha and samples of the traditional drug Puag-Haad. With reliability and high sensitivity, this assay can provide an alternative approach for the quantitative analysis of oxyresveratrol in A. lacucha samples.

Preparative and Rapid Purification of Saponins from Asparagus racemosus Root by High Performance Centrifugal Partition Chromatography

High performance centrifugal partition chromatography (HPCPC) was applied to the rapid isolation and purification of saponin glycosides in Asparagus racemosus Willd. root. A two-phase solvent system composed of CHC13-MeOH-water (4:4:2, v/v) in descending mode was used for the separation, yielding shatavarin.IX (1) and asparacoside (2) in one step. Asparanin A (3) and shatavarin V (4) were separated by repeated HPCPC fractionation using CH₂Cl₂- MeOH-water (4:4:2, v/v) as the solvent system, followed by either gel-filtration or TLC. Their structures were identified by NMR spectroscopy and ESI/MS'- The A. racemosus extracts and 1, 2, 3 and 4 were cytotoxic towards human hepato- and prostate-carcinoma cell lines (IC₅₀ 14-37 μM), while primary human fibroblasts were less vulnerable (IC₅₀ 22-66 μM), i.e., every saponin glycoside showed selectivity towards carcinoma cells compared with normal fibroblasts. HPCPC has proven rapidity to separate complex mixtures of phytochemicals yielding quantities suited to biological studies.

Preparative and Rapid Purification of Saponins from Asparagus racemosus Root by High Performance Centrifugal Partition Chromatography

High performance centrifugal partition chromatography (HPCPC) was applied to the rapid isolation and purification of saponin glycosides in Asparagus racemosus Willd. root. A two-phase solvent system composed of CHCl3-MeOH-water (4:4:2, v/v) in descending mode was used for the separation, yielding shatavarin IX (1) and asparacoside (2) in one step. Asparanin A (3) and shatavarin V (4) were separated by repeated HPCPC fractionation using CH2Cl2-MeOH-water (4:4:2, v/v) as the solvent system, followed by either gel-filtration or TLC. Their structures were identified by NMR spectroscopy and ESI/MS. The A. racemosus extracts and 1, 2, 3 and 4 were cytotoxic towards human hepato- and prostate-carcinoma cell lines (IC50 14–37 μM), while primary human fibroblasts were less vulnerable (IC50 22–66 μM), i.e., every saponin glycoside showed selectivity towards carcinoma cells compared with normal fibroblasts. HPCPC has proven rapidity to separate complex mixtures of phytochemicals yielding quantities suited to biological studies.

Quantification of Saponins in Asparagus racemosus by HPLC-Q-TOF-MS/MS

Asparagus racemosus Willd. or Shatavari (Asparagaceae family) is an important medicinal plant in Ayurvedic medicine as a rejuvenate for women. A method for quantitative analysis of saponin glycosides bioactive constituents in A. racemosus is reported. A high performance liquid chromatography quadrupole time of flight mass spectrometry (HPLC-Q-TOF-MS/MS) method was developed and validated for simultaneous determination of five saponin glycosides, asparacoside, shatavarin IX, shatavarin IV, asparanin A and shatavarin V in A. racemosus extracted with 70% MeOH. The method was validated through intra-and inter-day precision, with the relative standard deviation (RSD) less than 6%, limits of detection (LOD) and limits of quantification (LOQ) <10 and 50 ng, respectively. Overall recoveries ranged from 95% to 105%, with RSD ranging from 0.7% to 4.5%. The method was applied to saponin glycoside contents in the leaves, stems, and roots of A. racemosus sourced from different geographical locations, including four provinces in Thailand, and a sample from India. Saponin glycosides were detected predominantly in the roots, the part used in traditional medicines and these showed wide variations in saponin glycoside profiles from undetectable to 12 mg/g dry weight. The quality control of A. racemosus is crucial for reliable and predictable therapies and only methods like the one developed has the necessary flexibility, sensitivity, accuracy, and selectivity for reliable routine quality control.

Quantification of Saponins in Asparagus racemosus by HPLC-Q-TOF-MS/MS

Asparagus racemosus Willd. or Shatavari (Asparagaccae family) is an important medicinal plant in Ayurvedic medicine as a rejuvenate for women A method - for quantitative analysis of saponin glycosides bioactive constituents in A. racemosus is reported. A high performance liquid chromatography quadrupole time of flight mass spectrometry (HPLC-Q-TOF-MS/MS) method was developed and validated for simultaneous determination of five saponin glycosides, asparacoside, shatavarin IX, shatavarin IV, asparanin A and shatavarin V in A. racemosus extracted with 70% MeOH. The method was validated through intra- and inter-day precision, with the relative standard deviation (RSD) less than 6%, limits of detection (LOD) and limits of quantification (LOQ) <10 and 50 ng, respectively. Overall recoveries ranged from 95% to 105%, with RSD ranging from 0.7% to 4.5%. The method was applied to saponin glycoside contents in the leaves, stems, and roots of A. racemosus sourced from different geographical locations, including four provinces in Thailand, and a sample from India. Saponin glycosides were detected predominantly in the roots, the part used in traditional medicines and these showed wide variations in saponin glycoside profiles from undetectable to 12 mg/g dry weight. The quality control of A. raceinosus is crucial for reliable and predictable therapies and only methods like the one developed has the necessary flexibility, sensitivity, accuracy, and selectivity for reliable routine quality control.

An Enzyme-linked Immunosorbent Assay for Genistein 7-O-[α-rhamnopyranosyl-(1→6)]-β-glucopyranoside Determination in Derris scandens using a Polyclonal Antibody

INTRODUCTION

Genistein 7-O-[α-rhamnopyranosyl-(1→6)]-β-glucopyranoside (GTG) is a major bioactive compound in Derris scandens. It is responsible for anti-inflammatory activity by inhibition of cyclooxygenase and lipoxygenase. There are many commercial products of D. scandens available in Thailand.

OBJECTIVE

To develop an enzyme-linked immunosorbent assay (ELISA) for the quantitative analysis of GTG in plant material and derived products using a polyclonal antibody.

METHODS

An immunogen was synthesised by conjugating GTG with a carrier protein. The polyclonal antibody against GTG (GTG-PAb) was produced in New Zealand white rabbits. The ELISA method was validated for specificity, sensitivity, accuracy, precision and correlation with HPLC.

RESULTS

The polyclonal antibody was specific to GTG and genistin within the range of compounds tested. The GTG ELISA was applied in the range 0.04-10.00 μg/mL with a limit of detection of 0.03 μg/mL. The recovery of GTG in spiked Derris scandens extracts ranged from 100.7 to 107.0%, with a coefficient of variation less than 7.0%. The intra- and inter-assay variations were less than 5.0%. The ELISA showed a good correlation with HPLC-UV analysis for GTG determination in samples, with a coefficient of determination (r² ) of 0.9880.

CONCLUSION

An ELISA was established for GTG determination in Derris scandens. The GTG-PAb can react with GTG and genistin, but genistin has not been found in the plant. Therefore, the ELISA can be used for high throughput quality control of GTG content in D. scandens and its products. Copyright © 2016 John Wiley & Sons, Ltd.

Regulation of cancer-related genes - Cyp1a1, Cyp1b1, Cyp19, Nqo1 and Comt - expression in β-naphthoflavone-treated mice by miroestrol

OBJECTIVE

The effects of miroestrol (MR), an active phytoestrogen from Pueraria candollei var. mirifica, on expression of cancer-related genes were determined.

METHODS

Seven-week-old female ICR mice (n = 5 each) were subcutaneously administered estradiol (E2, 0.5 mg/kg/day) or MR (0.5 or 5 mg/kg/day) daily for 7 days. Some were given ER or MR in combination with β-naphthoflavone (BNF, 30 mg/kg/day) for the last 3 days. The expression of cancer-related genes including cytochrome P450 1A (Cyp1a), cytochrome P450 1B1 (Cyp1b1), aromatase P450 (Cyp19), NAD(P)H: quinone oxidoreductase 1 (Nqo1) and catechol-O-methyltransferase (Comt) were evaluated.

KEY FINDINGS

In the presence of BNF, MR suppressed hepatic CYP1A1 activity and CYP1A2 activity, expression of CYP1B1 mRNA and expression of CYP1A1/2 and CYP1B1 protein. E2, by contrast, did not. MR restored expression levels of hepatic NQO1 and uterine COMT in BNF-treated mice. Furthermore, MR increased expression of uterine CYP19 to the same extent as E2.

CONCLUSION

MR may be superior to E2 as it downregulates expression of CYP1. Moreover, MR normalized expression of both NQO1 and COMT, the protective enzymes, in murine liver and uteri. These results support the use of MR as an alternative supplement for menopausal women, MR having the extra benefit of reducing cancer risk.

Preparation and application of a monoclonal antibody against the isoflavone glycoside daidzin using a mannich reaction-derived hapten conjugate

INTRODUCTION

Daidzin and its aglycone daidzein are major pharmacologically active compounds of soybean (Glycine max), kudzu (Pueraria lobata), and kwao kruea khao (P. mirifica). Pharmacological activities of daidzin are mediated by its more potent metabolites daidzein and equol; however, daidzin is the predominant compound found in these medicinal plants, and the efficacy and safety of equol depend on the amount of daidzin consumed.

OBJECTIVE

To develop a specific monoclonal antibody (MAb)-based indirect competitive enzyme-linked immunosorbent assay (icELISA) for standardisation of daidzin content in herbal medicines or nutraceuticals.

METHODOLOGY

The Mannich reaction was used for the synthesis of a highly immunogenic conjugate between daidzin and a cationised carrier protein. Splenocytes of hyperimmunised mice were fused with myeloma cells to generate a hybridoma secreting antibody against daidzin.

RESULTS

The icELISA showed high selectivity and acceptable sensitivity for daidzin determination (1.56-100 ng/mL) with high reproducibility (coefficients of variation were < 5%). The icELISA was a reliable analytical method for daidzin in Glycine max, Pueraria lobata and P. mirifica, for which daidzin recoveries from spiked samples were 98.99-104.94%. Daidzin content of these plant-derived products determined using the icELISA were in close agreement with those determined by a HPLC-UV method.

CONCLUSION

The icELISA is useful for specific daidzin determination because of its reliability, low cost, speed and high throughput.

Development of a Rapid Immunochromatographic Strip Test for the Detection of Mulberroside A

INTRODUCTION

Mulberroside A (MuA) is the major active anti-tyrosinase compound in the root bark extract of Morus alba L. (Moraceae). Typically, MuA is widely employed as an active ingredient in whitening cosmetics. A rapid and simple assay system utilizing a small quantity of test sample is essential for the detection of MuA in large number of samples. An immunoassay using highly specific MuA polyclonal antibodies may be useful for the determination of small quantities of MuA in test samples.

OBJECTIVE

To establish a rapid qualitative MuA test, an immunochromatographic strip test was developed using anti-MuA polyclonal antibodies (anti-MuA PAb).

METHODOLOGY

The qualitative assay was based on a competitive immunoassay where the detection reagent consisted of anti-MuA PAb colored with colloidal gold particles. The capture reagent was a MuA-ovalbumin (MuA-OVA) conjugate immobilized on the test strip membrane.

RESULTS

A sample containing MuA and the detection reagent were incubated together with immobilized capture reagent on a nitrocellulose membrane. When MuA was present, it competed with the immobilized conjugates on the strip membrane to bind a limited amount of colored antibodies; thus, a positive sample showed no color on the capture spot zone. The detection limit for the strip test was 2 µg/mL. The developed immunochromatographic strip test was utilized to determine MuA in plants, medical preparations and cosmetic samples.

CONCLUSION

This immunochromatographic strip test is advantageous as a rapid, simple and sensitive screening method for the detection of MuA in plant extracts, cosmetic samples and pharmaceutical products.

Enhanced Mulberroside A Production from Cell Suspension and Root Cultures of Morus alba Using Elicitation

Morus alba L. has been used in Asian traditional medicine as an anti-inflammatory, anti-asthmatic, anthelmintic and as a whitening agent in cosmetic products. Mulberroside A is the major active compound from M. alba root bark. In this study, cell suspension and root cultures of M. alba were established, and the effect of the elicitors on the enhancement of mulberroside A production in M. alba was investigated. The cell suspension and root cultures of M. alba were exposed to elicitors and then mulberroside A contents were determined by an indirect competitive ELISA method. High levels of mulberroside A were obtained by addition of 100 and 200 μM salicylic acid with 24 h exposure time in cell suspension cultures (37.9 ± 1.5 and 34.0 ± 4.7 mg/g dry wt., respectively). Furthermore, addition of yeast extract at 2 mg/mL with 24 h exposure time can significantly increase mulberroside A contents from both cell suspension (3.2-fold) and root cultures (6.6-fold). Mulberroside A contents from both cell suspension and root cultures after treatment with elicitors are similar or higher than those found in the intact root and root bark of several years old M. alba. These results indicate that mulberry tissue cultures using the elicitation method are interesting alternative sources for mulberroside A production.

Enhanced Mulberroside A Production from Cell Suspension and Root Cultures of Morus alba Using Elicitation

Morus alba L. has been used in Asian traditional medicine as an anti-inflammatory, anti-asthmatic, anthelmintic and as a whitening agent in cosmetic products. Mulberroside A is the major active compound from M. alba root bark. In this study, cell suspension and root cultures of M. alba were established, and the effect of the elicitors on the enhancement of mulberroside A production in M. alba was investigated. The cell suspension and root cultures of M. alba were exposed to elicitors and then mulberroside A contents were determined by an indirect competitive ELISA method. High levels of mulberroside A were obtained by addition of 100 and 200 μM salicylic acid with 24 h exposure time in cell suspension cultures (37.9 ± 1.5 and 34.0 ± 4.7 mg/g dry wt., respectively). Furthermore, addition of yeast extract at 2 mg/mL with 24 h exposure time can significantly increase mulberroside A contents from both cell suspension (3.2-fold) and root cultures (6.6-fold). Mulberroside A contents from both cell suspension and root cultures after treatment with elicitors are similar or higher than those found in the intact root and root bark of several years old M. alba. These results indicate that mulberry tissue cultures using the elicitation method are interesting alternative sources for mulberroside A production.

Dicentrine Production from a Hairy Roots Culture of Stephania suberosa

A hairy roots culture of Stephania suberosa was established using Agrobacterium rhizogenes ATCC15834. The production of dicentrine was found to be (8.92 ± 0.07) mg/g dry wt on day 35 of culture. Effects of sucrose content, tyrosine, and medium strength on growth and dicentrine production of S. suberosa were investigated. 6% (w/v) sucrose was an optimum content for the growth and dicentrine accumulation in S. suberosa hairy roots. The utilization of a precursor from tyrosine feeding enhanced the dicentrine production. The medium with 1.0 mM of tyrosine had the highest effect on dicentrine accumulation in hairy roots at day 40 of culture [(14.73 ± 0.47) mg/g dry wt]. In addition, ¼ Murashige and Skoog medium was suitable for biomass and dicentrine production in hairy roots. This culture system has a potential to produce dicentrine from hairy roots of S. suberosa

Improvement of Pseudojujubogenin Glycosides Production from Regenerated Bacopa monnieri (L.) Wettst. and Enhanced Yield by Elicitors

Bacopa monnieri (L.) Wettst. was studied for shoot induction and regeneration on Murashige and Skoog (MS) medium supplemented with different plant growth regulators. Stem explants cultured on medium containing 0.1 mg/l thidiazuron (TDZ) resulted in the highest number of shoots (117 shoots/explant). Regenerated plants from medium with 0.5 mg/l TDZ contained the highest level of pseudojujubogenin glycosides [(30.62 d 1.29) mg/g dry wt] which was 2-fold higher than that of in vitro grown plants of the same age [(16.96 d 1.49) mg/g dry wt]. Plantlets regenerated from 0.1 mg/l TDZ also showed a high level of pseudojujubogenin glycosides [(27.94 d 1.19) mg/g dry wt]. The effect of elicitor on pseudojujubogenin glycosides accumulation in B. monnieri whole plant cultures was investigated. Chitosan at 150 mg/l and yeast extract at 2 mg/ml increased the pseudojujubogenin glycosides production [(40.83 d 2.24) mg/g dry wt and (40.05 d 2.37) mg/g dry wt, respectively] after 7 days, which was 6-fold higher than in the control cultures.

Production of Glycyrrhizin in Callus Cultures of Licorice

Licorice plants, Glycyrrhiza glabra, G. uralensis, and G. inflata, were investigated for callus induction using Murashige and Skoog (MS) medium combined with auxins and cytokinins. After 4 weeks of culture, 33-100% of leaf or stem explants formed calli. Maximum of shoot induction from callus cultures was achieved by G. inflata stem explants cultured on MS medium supplemented with 1 mg/l α-naphthaleneacetic acid (NAA) and 0.5 mg/l 6-benzyladenine (BA) (67%) which also gave maximum shoot formation per explant (two shoots per explant). These results indicated that all three Glycyrrhiza species regenerated shoots from callus cultures on MS medium combined with NAA and BA or only thidiazuron (TDZ; 0.1 and 0.5 mg/l). Glycyrrhizin contents of G. uralensis calli induced using MS medium in combination with NAA and BA [(27.60 ± 8.47) μg/g DW] or TDZ alone [(36.52 ± 2.45) μg/ g DW] were higher than those found in other combinations.

Artemisinin Production by Shoot Regeneration of Artemisia annua L. Using Thidiazuron

An efficient in vitro method for multiple shoot bud induction and regeneration has been developed in Artemisia annua L. using leaf and stem explants in various concentrations and combinations of plant growth regulators to evaluate the frequency of regeneration. The sources of explants as well as plant growth regulators in the medium were found to influence the multiple shoot induction. The result shows that the stem segment cultured on Murashige and Skoog (MS) medium supplemented with 0.1 mg/l thidiazuron (TDZ) gave a perfect shoot formation (100%) and good shoot multiplication (57 shoots/explant) after 2 weeks of culture. Healthy regenerated shoots were elongated and rooted in MS medium without hormones. The artemisinin content in plants regenerated from stem explants using 0.1 mg/l TDZ was (3.36 ± 0.36) μg/mg dry weight and two-fold higher than that of in vitro grown plants of the same age [(1.73 ± 0.23) μg/mg DW]. This system exhibited a potential for a rapid propagation of shoots from the stem explant and makes it possible to develop a clonal propagation of A. annua.

Production of Isoflavonoids in Callus Cultures of Pueraria candollei var. mirifica

Pueraria candollei Wall. ex Benth. var. mirifica (Airy Shaw & Suvat.) Niyomdham was investigated for callus induction using Murashige and Skoog (MS) medium containing different plant growth regulators. After 8 weeks of culture, 66 - 100% of leaf or stem explants formed calli. Calli from stem explants cultured on MS medium supplemented with 0.5 mg/l thidiazuron (TDZ) gave the maximum of shoot induction (16%) and the highest level of total isoflavonoids [(50.39 ± 7.06) mg/g dry wt], which was 7-fold higher than that of the native tuber [(7.04 ± 0.29) mg/g dry wt]. These results suggest that addition of TDZ to the culture medium markedly enhances the production of isoflavonoids in calli induced from stem explants of P. candollei var. mirifica.

Methyl Jasmonate Elicitation Enhances Glycyrrhizin Production in Glycyrrhiza inflata Hairy Roots Cultures

Hairy roots were induced by infecting stems and leaves of Glycyrrhiza inflata with Agrobacterium rhizogenes ATCC 15834. The optimization of growth and glycyrrhizin accumulation of G. infl ata hairy roots was studied. Sucrose (6%, w/v) was optimal for growth and glycyrrhizin accumulation in G. infl ata hairy roots. Effects of elicitors like chitosan, methyl jasmonate, and yeast extract on glycyrrhizin production were studied. Methyl jasmonate (100 μM) was most efficient in enhancing glycyrrhizin production up to almost 109 μg/g dry weight on day 5 of elicitation. These results indicate that application of elicitors can enhance the capacity of G. inflata hairy roots to produce glycyrrhizin.

Production of polyclonal antibody against madecassoside and development of immunoassay methods for analysis of triterpene glycosides in Centella asiatica

INTRODUCTION

Centella asiatica (L.) Urban consists of two major triterpene glycosides, asiaticoside (AS) and madecassoside (MA), as active components used for wound healing and enhancing memory.

OBJECTIVE

To produce a polyclonal antibody against madecassoside (MA-PAb) and develop enzyme-linked immunosorbent assay (ELISA) and Eastern blotting methods for quantitative analysis of triterpene glycosides in Centella asiatica.

METHODS

An ELISA method was developed using polyclonal antibody against MA. An Eastern blotting method on the PES membrane was established for determination of MA and AS. The immunoassays were validated for sensitivity, precision, specificity and accuracy.

RESULTS

The prepared MA-PAb shows specificity to MA and AS. The measuring range of triterpene glycosides was 0.39-50 µg/mL using the ELISA method. An Eastern blotting method was developed for determining individual MA and AS, which could be detected in the range of 62.5-500 ng. The limit of detection for MA and AS was 31.25 ng. The two methods developed showed good specificity, precision, and accuracy, and also correlated with high-performance liquid chromatography.

CONCLUSION

These immunoassays have several advantages that include high sensitivity as well as being rapid and facile for determination of the triterpene glycosides in C. asiatica.

Dicentrine Production in Callus and Cell Suspension Cultures of Stephania Venosa

The highest dicentrine content (19.5 ± 0.3 mg/g dry weight) from callus culture of Stephania venosa was achieved from stem segments cultured on MS medium supplemented with TDZ 0.5 mg/L and NAA 1.0 mg/L. Cell suspension cultures were established from callus cultured on MS liquid medium with the same plant growth regulators. Dicentrine production from S. venosa cell suspension cultures was obtained in the range of 15–26 mg/g dry weight. Elicitation in cell suspension cultures by chitosan (50 mg/L) and salicylic acid (2 mg/L) for 6 days significantly increased dicentrine content. Our findings indicate that callus and cell suspension cultures of S. venosa can produce high levels of dicentrine as an alternative source of plant materials.