Alginate immobilization of Morus alba L. cell suspension cultures improved the accumulation and secretion of stilbenoids

Morus alba L. (Moraceae) has been used in traditional medicine for the treatment of several illnesses. Recent research also revealed several pharmacological activities from many groups of secondary metabolites, including the stilbenoids mulberroside A, oxyresveratrol, and resveratrol, which are promising compounds for cosmetic and herbal supplement products. In our previous study, cell cultures of M. alba showed high productivity of these compounds. In this study, we attempted to develop immobilized cell cultures of M. alba and to test the effect of elicitors and precursors on the production of stilbenoids. The immobilization of the M. alba cells significantly promoted the secretion of mulberroside A into the extracellular matrix and culture media to 60%, while enhancing the level of oxyresveratrol and resveratrol by 12- and 27-fold, respectively. The elicitation of immobilized cells with a combination of 50 µM methyl jasmonate and 0.5 mg/mL yeast extract for 24 h promoted a twofold increase in the production of all three stilbenoids. Furthermore, the addition of 0.05 mM L-phenylalanine, 0.03 mM L-tyrosine, or a combination resulted in the enhancement of mulberroside A production for up to twofold. The addition of L-tyrosine significantly enhanced the production of oxyresveratrol and resveratrol. This is the first report of stilbenoid production using immobilized cell cultures of M. alba. The cultures have benefits over normal cell suspension cultures by promoting the secretion of mulberroside A and enhancing the levels of oxyresveratrol and resveratrol. Thus, it could be a candidate method for the production of these stilbenoids.

A pilot pharmacokinetic study of miroestrol and deoxymiroestrol on rabbit sera using polyclonal antibody-based icELISA analysis

Miroestrol (ME) and deoxymiroestrol (DME) are the most potent phytoestrogens and bioactive markers in Pueraria candollei var. mirifica tuberous roots. To understand their pharmacokinetic profiles, a pharmacokinetic study of ME and DME, at 0.43 and 0.21 mg per kg body weight, respectively, in three rabbits was performed after orally administering a single dose of P. candollei var. mirifica enriched fraction extract. Two established polyclonal antibody-based indirect competitive enzyme-linked immunosorbent assays were validated to determine ME and DME in rabbit sera. In rabbits, the area under the 0- to 48-hr concentration-time curve of ME and DME were 854.92 and 1,692.84 ng·h/ml, respectively. The maximum concentration of ME was measured 1 hr after administration as 69.62 ± 8.28 ng/ml, and the maximum concentration of DME was measured at 3 hr as 81.8 ± 5.43 ng/ml. These results provide an initial approach for designing and studying the relationship between the ME and DME levels and their therapeutic effects based on their pharmacokinetic profiles.

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.

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.

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.