Fluorescent Labeling of Polymannuronic Acid and Its Distribution in Mice by Tail Vein Injection

Abstract

Polymannuronic acid (PM) possesses more pharmacological activities than sodium alginate, but there have been few studies on its absorption mechanism, tissue distribution, and pharmacokinetics. Studies of pharmacokinetics and tissue distribution are necessary to elucidate the pharmacological effects of PM. Thus, we used fluorescein isothiocyanate (FITC) to produce fluorescently labeled PM (FITC-PM) and detected the distribution and pharmacokinetics of PM in vivo via tail vein injection. The results demonstrate that the FITC-PM showed high stability in different pH solutions. After the tail vein injection, FITC-PM tended to be distributed in the kidney, followed by the liver and in the heart, spleen, and lungs at lower concentrations. Pharmacokinetic analysis showed that the elimination rate constant of FITC-PM was 0.24, the half-life time was 2.85 h, the peak concentration was 235.17 μg/mL, the area under the curve was 631.48 μg/mL·h, the area under the curve by statistical moment was 1843.15 μg/mL·h2, the mean residence time was 2.92 h, and the clearance rate was 79.18 mL/h. These results indicate that FITC-PM could be used for PM distribution and pharmacokinetic studies, and the studies of pharmacokinetics and tissue distribution provided basic information that can be used to further clarify PM pharmacodynamic mechanisms.

WITHDRAWN: Study on the pharmacokinetics of Polygonatum cyrtonema polysaccharide DPC1 through fluorescence labeling

“…The introduction of uorescent groups allows differentiation between the labeled polysaccharide and endogenous molecules and thus facilitates in vivo pharmacokinetic research. Highly sensitive uorescent molecular probes such as uorescein isothiocyanate (FITC) [12], uorescein diacetate (FDA) [13], cyanine dyes [14], and rhodamine [15] are used to label polysaccharides. Among them, rhodamine has greater photostability than FITC and other probes.…”

Effects of Polymannuronic Acid on the Intestinal Microbiota in Mice after Long-Term Intragastric Administration

“…The long-term administration of oral PM could indeed reduce serum TC and cholesterol ester levels in a concentration-dependent manner; however, there was no significant difference in FC levels. The distribution of PM in vivo in tissues showed that PM could target the liver [ 6 ], indicating that it could reduce serum cholesterol levels by targeting the liver, thereby improving lipid metabolism in the liver and promoting the function of lipid metabolism by the intestinal flora. This result also indicated that PM has the potential to alleviate fatty liver and highlighted its benefit in improving liver health.…”

“…Main reagents: PM was prepared in our laboratory, and its average molecular weight was 16.83 kDa (the average degree of polymerization of PM was 95) [ 6 ]. The total cholesterol enzyme-assay kit and free cholesterol enzyme-assay kit were purchased from Pulilai, Beijing, China.…”

“…It has various biological activities such as antitumor, antioxidant, immuneregulation, obesityinhibition, blood pressurelowering, blood lipidlowering, and blood glucoselowering effects [ 3 , 4 , 5 ]. PM was prepared by acid hydrolysis, pH precipitation, ion exchange column chromatography, and gel column chromatography [ 6 ]. In PM, all M residues are connected by a β-1, 4-glucoside bond.…”

In Vivo Pharmacokinetic Study of Polygonatum cyrtonema Polysaccharide DPC1 after Oral and Intraperitoneal Administration

“…The introduction of fluorescent groups allows differentiation between the labeled polysaccharide and endogenous molecules and thus facilitates in vivo pharmacokinetic research. Highly sensitive fluorescent molecular probes such as fluorescein isothiocyanate (FITC) [ 14 ], fluorescein diacetate (FDA) [ 15 ], cyanine dyes [ 16 ], and rhodamine [ 17 ] are used to label polysaccharides. Among them, rhodamine has greater photostability than FITC and other probes.…”