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. 2017 Jul 26;22(8):1250.
doi: 10.3390/molecules22081250.

A Novel Fluoroimmunoassay for Detecting Ruscogenin with Monoclonal Antibodies Conjugated with CdSe/ZnS Quantum Dots

Hongwei Zhang  1 , Tao Xu  2 , Lan Gao  3 , Xiufeng Liu  4 , Jihua Liu  5   6 , Boyang Yu  7
Affiliations

A Novel Fluoroimmunoassay for Detecting Ruscogenin with Monoclonal Antibodies Conjugated with CdSe/ZnS Quantum Dots

Hongwei Zhang et al. Molecules. .

Abstract

Ruscogenin (RUS) is a steroidal sapogenin found in Ruscus aculeatus and Ophiopogon japonicus with several pharmacological activities. In the work reported herein, a novel method termed competitive fluorescence-linked immunosorbent assay (cFLISA) based on monoclonal antibodies (mAbs) coupled with quantum dots (QDs) was developed for the quick and sensitive determination of RUS in biological samples. The mAbs against RUS were conjugated with CdSe/ZnS QDs by the crossing-linking reagents and an indirect cFLISA method was developed. There was a good linear relationship between inhibition efficiency and logarithm concentration of RUS which was varied from 0.1 to 1000 ng/mL. The IC50 and limit of detection (LOD) were 9.59 ng/mL and 0.016 ng/mL respectively, which much lower than the enzyme-linked immunosorbent assay (ELISA) method. The recoveries in plasma and tissues were ranged from 82.3% to 107.0% and the intra- and inter-day precision values were below 15%. The developed cFLISA has been successfully applied to the measurement of the concentrations of RUS in biological samples of rats, and showed great potential for the tissue distribution study of RUS. The cFLISA method may provide a valuable tool for the analysis of small molecules in biological samples and such an approach could be applied to other natural products.

Keywords: fluorescent immunosorbent assay; monoclonal antibody; quantum dots; ruscogenin; tissue distribution.

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Conflict of interest statement

The authors declare that there are no conflicts of interest.

Figures

Figure 1
Figure 1
The conjugation of QD620 and monoclonal antibody anti-RUS. (A) the gel electrophoretic mobility of QD620 before and after conjugation; (B) the fluorescence spectra of QD620 before and after conjugation (The excitation wavelength was set at 400 nm); (C) the TEM images of QD620-mAbs; (D) the FT-IR spectra of QD620, mAbs, and QD620-mAbs.
Figure 2
Figure 2
Comparison of the absorbance at 450 nm of mAb and QD620-mAb at different dilution times.
Figure 3
Figure 3
Fluorescence spectra of the FLISA based on QD-mAbs in the presence of various concentrations of RUS (0–10 μg/mL) under optimal experimental conditions (A); Standard curve for RUS (B). Each point represents the mean ± SD from three determinations in FLISA (excitation wavelength: 400 nm, emission wavelength: 620 nm).
Figure 4
Figure 4
The inhibition curves for the determination of RUS by indirect competitive ELISA and FLISA.
Figure 5
Figure 5
The structure of RUS and the analogues of RUS.
Figure 6
Figure 6
Concentration-time curves of RUS in rats tissues after oral administration (n = 6).
Figure 6
Figure 6
Concentration-time curves of RUS in rats tissues after oral administration (n = 6).
Figure 7
Figure 7
Schematic diagram of cFLISA.
See this image and copyright information in PMC

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References

    1. Cao G., Jiang N., Hu Y., Zhang Y., Wang G., Yin M., Ma X., Zhou K., Qi J., Yu B., et al. Ruscogenin Attenuates Cerebral Ischemia-Induced Blood-Brain Barrier Dysfunction by Suppressing TXNIP/NLRP3 Inflammasome Activation and the MAPK Pathway. Int. J. Mol. Sci. 2016;17:E1418. doi: 10.3390/ijms17091418. - DOI - PMC - PubMed
    1. Liu H., Zheng Y.F., Li C.Y., Zheng Y.Y., Wang D.Q., Wu Z., Huang L., Wang Y.G., Li P.B., Peng W., et al. Discovery of Anti-inflammatory Ingredients in Chinese Herbal Formula Kouyanqing Granule based on Relevance Analysis between Chemical Characters and Biological Effects. Sci. Rep. 2015;5:18080. doi: 10.1038/srep18080. - DOI - PMC - PubMed
    1. Yu B.-Y. Exploration on the Modern Research Methodology of Traditional Chinese Medicine, Based on the Systemic Research of Radix Ophiopogonis. Chin. J. Nat. Med. 2007;5:10–14.
    1. Kou J., Tian Y., Tang Y., Yan J., Yu B. Antithrombotic Activities of Aqueous Extract from Radix Ophiopogon japonicus and Its Two Constituents. Biol. Pharm. Bull. 2006;29:1267–1270. doi: 10.1248/bpb.29.1267. - DOI - PubMed
    1. Bi L.Q., Zhu R., Kong H., Wu S.L., Li N., Zuo X.R., Zhou S.M., Kou J.P., Yu B.Y., Wang H., et al. Ruscogenin attenuates monocrotaline-induced pulmonary hypertension in rats. Int. Immunopharmacol. 2013;16:7–16. doi: 10.1016/j.intimp.2013.03.010. - DOI - PubMed

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