Abstract: An enzyme-linked immunosorbent assay (ELISA) was developed for determining mangiferin content in plant samples using a polyclonal antibody (PAb) against mangiferin. The developed ELISA showed a full measurement range from 0.12 to 31.25 μg/mL mangiferin with a relative standard deviation (RSD) less than 6% for both intra- and interassay precision levels. The accuracy was determined by a percent recovery experiment at three concentration levels and it showed 97.8%–103.7% recovery in Mangifera indica leaf samples. The developed ELISA exhibited a high correlation value (R2= 0.992) with the standard high-performance liquid chromatography (HPLC) method in various mangiferin-containing plant samples. Our results suggest that the validated ELISA methodology using a PAb against mangiferin can be applied to determine mangiferin content with high specificity, rapidity and simplicity in various mangiferin-containing plant samples. The mangiferin content in the mature leaves of fifty M. indica cultivars were determined using the developed ELISA. The mangiferin contents ranged from 1.94 ± 0.13% to 13.79 ± 0.84% dry wt. The Thawai cultivar leaves contained the highest level of mangiferin (13.79 ± 0.84% dry wt), but it is a rare cultivar. The Namdokmai, which is more commonly cultivated in Thailand, contain 12.41 ± 0.60% dry wt mangiferin; therefore, this cultivar leaf was recommended as the source of raw material for the pharmaceutical, nutraceutical and cosmetic product industries.
Practical Application: Currently, natural heath products are accepted worldwide for healthcare. Mangiferin-containing plants and products exhibit health benefits against oxidative stress-related diseases, such as cardiovascular diseases, cancer, dyslipidemia and diabetes. We have developed an ELISA with high specificity, rapidity and simplicity for the quality control of mangiferin-derived product production. Moreover, we found that the Namdokmai leaf, a Thai M. indica cultivar, was recommended as the source of raw material for the pharmaceutical, nutraceutical and cosmetic product industry because of its high mangiferin content and natural prevalence.