Comparative Study of Intestinal Absorption Characteristics of Chlorogenic Acid Components in the Normal and Myocardial Hypertrophy Rats

OBJECTIVE To compare the absorption characteristics of chlorogenic acid and its isomers, neochlorogenic acid and cryptochlorogenic acid, in different intestinal segments of rats under two distinct physiological states: normal and myocardial hypertrophy. This study aims to provide a theoretical basis for the clinical use and product development of chlorogenic acid components.

METHODS  Based on intestinal perfusion model in vivo, the HPLC was optimized and established to determine low, medium, and high concentrations(100, 200, 400 μg·mL⁻¹) content changes of chlorogenic acid, neochlorogenic acid and cryptochlorogenic acid in the duodenum, jejunum, ileum and colon for 0−120 min, and the absorption rate constant(K_a) and the apparent absorption coefficient(P_app) were calculated.

RESULTS  The absorption mechanism of neochlorogenic acid and cryptochlorogenic acid in the small intestine of rats in both states was passive diffusion, while chlorogenic acid was actively transported in the jejunum and colon. There was no significant difference in the K_a values of chlorogenic acid and cryptochlorogenic acid absorption parameters under the same mass concentration conditions in the same intestinal segment of normal rats. In the duodenum, under medium and low mass concentration conditions, the K_a value of neochlorogenic acid was significantly lower than that of chlorogenic acid(P<0.05), and its absorption capacity in other intestinal segments was similar to chlorogenic acid and neochlorogenic acid; There was no significant difference in the absorption parameters K_a of chlorogenic acid, neochlorogenic acid, and cryptochlorogenic acid among myocardial hypertrophy rats. In normal rats, the absorption rate of chlorogenic acid and cryptochlorogenic acid in different intestinal segments were as follows: duodenum>ileum>jejunum>colon, while neochlorogenic acid were as follows: duodenum≈ileum>jejunum>colon; In myocardial hypertrophy rats, the absorption rate of the three were: ileum>duodenum>jejunum>colon. Compared with normal rats, under pathological conditions, medium and high concentrations of chlorogenic acid, neochlorogenic acid, and cryptochlorogenic acid significantly increased P_app in each intestinal segment and K_a significantly increased in the ileum.

CONCLUSION  Under normal conditions, the intestinal absorption characteristics of chlorogenic acid and cryptochlorogenic acid are similar, while the absorption capacity of neochlorogenic acid in the duodenum is weaker than both. The pathological state promotes the absorption of chlorogenic acid, cryptochlorogenic acid, and neochlorogenic acid in different intestinal segments, with the optimal absorption site transitioning from the duodenum to the ileum. The research results suggest that when using the three components as pharmacological substances to treat cardiovascular diseases, targeted transportation to the ileum can be considered to increase absorption and enhance drug efficacy. This study provides a theoretical basis for the clinical use and product development of chlorogenic acid components.