Hemagglutination activity of Radix Isatidis detected by microcalorimetry

In this study, microcalorimetry was adopted to establish a novel method for detecting the     hemagglutination process of Radix Isatidis (Banlangen in Chinese, BLG), and to evaluate the hemagglutination activity diversity of BLG from various habitats.  The hemagglutination biothermokinetics curves of positive  reagent (phytohemagglutinin, PHA) and 8 batches BLG from different regions of the hemagglutination with 20% rabbit erythrocyte were recorded by microcalorimetry, then biothermokinetics parameters were abstracted, the hemagglutination utility of samples were calculated and analyzed by principal component analysis (PCA) and cluster analysis (CA), meanwhile the results were authenticated by micro-plate agglutination.  It showed that  the hemagglutination was an exothermic reaction, the reaction rate constant (k: 0.039−73.6 min⁻¹), maximum  reaction power (P_max: −1 140.2 − 988.2 μW) and reaction enthalpy (H_i: −529.9 − 717.9 μJ) had good linear   correlation with BLG extraction concentration (0.2 − 1.0 g·mL⁻¹, r > 0.97), and PCA showed P_max (531 − 1 335 μW) and H_t (585.2 − 989.2 μJ) could represent the hemagglutination activity diversity of BLG samples, just  confirming with the results of micro-plate agglutination (the agglutination dilution was 3 − 11 respectively).  According to the hemagglutination utility, the BLG samples from Good Agriculture Practice (GAP) regions, main producing area and general regions could be clustered correctly; meanwhile, the biothermokinetics curves   with perfect distinctive fingerprint and specificity could give out more information for the quality control and evaluation for BLG.  In conclusion, the microcalorimetry method established for detecting the hemagglutination activity of BLG samples on rabbit erythrocyte is sensitive and reliable, and could be adopted as an effective technique in detection aggulatination precisely, quantitatively and consecutively; and provide a novel approach for examining and evaluating quality for Chinese herbal medicine with aggulatinative activity such as BLG.