Development of an immunoassay for rapid screening of vardenafil and its potential analogues in herbal products based on a group specific monoclonal antibody.
Vardenafil is a phosphodiesterase-5 (PDE-5) inhibitor for the treatment of erectile dysfunction (ED). Undeclared vardenafil and related analogues adulterated in herbal products are a threat to public health. To screen vardenafil and its analogues in herbal matrix rapidly, an immunoassay based on a group specific monoclonal antibody (McAb) was developed. Glutaraldehyde was used to link vardenafil to immunogen and coating-antigen, respectively. Through the assessment of the structural specificity of eight anti-vardenafil McAbs, the McAb of 4B9 was characterized as being specific to the common structure of vardenafil and its analogues. An indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) was established based on this McAb, the limit of detection of vardenafil was 5.0 ng mL(-1), the calibration curve was linear from 5.0 to 40 ng mL(-1) (R(2)=0.952) with an IC(50) value of 18.2 ng mL(-1). In the extracts of 20 Chinese traditional drugs, the detection capability (CCbeta) of vardenafil was 0.08 mg g(-1), the recoveries were 76-116% and the coefficients of variation (CV%) were 9.7%-16.2%. The ic-ELISA was in good agreement with LC-UV when detected herbal products containing vardenafil and its analogue. The method is a suitable tool for screening vardenafil and its analogues as illegal additives in herbal products.
Guo
Jie-Biao
JB
State Key Laboratory of Food Science and Technology, OAI Joint Research Institute, Nanchang University, Nanchang 330047, PR China.
Xu
Yang
Y
Huang
Zhi-Bing
ZB
He
Qing-Hua
QH
Liu
Shi-Wen
SW
D000911:Antibodies, Monoclonal / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D005976:Glutaral / Q000737:chemistry; D029001:Herbal Medicine; D007093:Imidazoles / Q000032:analysis* / Q000737:chemistry / Q000276:immunology; D057230:Limit of Detection; D010726:Phosphodiesterase Inhibitors / Q000032:analysis* / Q000737:chemistry / Q000276:immunology; D010879:Piperazines / Q000032:analysis* / Q000737:chemistry / Q000276:immunology; D028321:Plant Preparations / Q000737:chemistry; D013450:Sulfones / Q000032:analysis / Q000737:chemistry / Q000276:immunology; D014227:Triazines / Q000032:analysis / Q000737:chemistry / Q000276:immunology; D000069058:Vardenafil Dihydrochloride
D000911:Antibodies, Monoclonal; D007093:Imidazoles; D010726:Phosphodiesterase Inhibitors; D010879:Piperazines; D028321:Plant Preparations; D013450:Sulfones; D014227:Triazines; D000069058:Vardenafil Dihydrochloride; D005976:Glutaral