Mechanistic Insight into the Enhanced Anti-Pulmonary Hypertension Efficacy of Wogonin Co-Amorphous

Abstract

Background: Pulmonary hypertension (PH) remains a life-threatening rare disease characterized by inflammation and oxidative stress in pulmonary artery smooth muscle cells (PASMCs). Wogonin (Wog), a plant-derived polyphenolic compound extracted from Scutellaria baicalensis Georgi, exhibits notable antioxidant activity and anti-PH efficacy, whereas its clinical applications are greatly limited by poor aqueous solubility. Methods: Herein, an innovative wogonin-aloperine co-amorphous (Wog-Alop) was developed to improve the aqueous solubility and, thus, anti-PH efficacy of Wog. Results: As expected, the aqueous solubility of Wog-Alop is about 40-fold that of Wog; meanwhile, the Wog-Alop demonstrates better oral bioavailability and anti-PH efficacy than Wog; moreover, the Wog-Alop exhibits significantly enhanced capacity to attenuate oxidative stress in human PASMCs compared to Wog. Conclusions: The results suggested that Wog-Alop could not only improve the solubility of Wog, thereby enhancing its oral bioavailability but also alleviate Wog's oxidative stress effects. These synergistic effects ultimately culminate in the enhanced anti-PH efficacy of Wog. In summary, the present study developed an innovative co-amorphous strategy for the delivery of Wog and improved its anti-PH efficacy.

Keywords: co-amorphous; oxidative stress; pulmonary hypertension; solubility; wogonin.

Figure 1

Preparation and characterization of Wog-Alop. (A) Preparation process of Wog-Alop; (B) PXRD patterns of wogonin, aloperine, Wog+Alop and Wog-Alop; (C) DSC patterns of wogonin, aloperine and Wog-Alop; (D) FTIR patterns wogonin, aloperine and Wog-Alop; (E) Stability of Wog-Alop in illumination, high humidity, high temperature (Alop: aloperine; Wog: wogonin; Wog+Alop: the physical mixture of wogonin and aloperine; Wog-Alop: Wogonin-aloperine co-amorphous).

Figure 2

In vitro dissolution (A) and solubility states (B) of Wog-Alop in water.

Figure 3

The dissolving process of insoluble drugs in aqueous environment.

Figure 4

In vivo pharmacokinetics of Wog-Alop.

Figure 5

Effect of Wog-Alop on hemodynamics and myocardial electrophysiology of rats from each group. (A) Schematic diagram of in vivo anti-PH efficacy experiments; (B) Effect of Wog-Alop on P-wave duration; (C) Effect of Wog-Alop on RVSP. Data are expressed as the mean ± SD, n = 6, ^### p < 0.001 vs. control group, ^#### p < 0.0001 vs. control group; **** p < 0.0001 vs. model group, *** p < 0.001 vs. model group, ** p < 0.01 vs. model group.

Figure 6

Effect of Wog-Alop on the right ventricular remodeling of rats from each group. (A) Effect of Wog-Alop on right ventricular remodeling (40×); (B) Effect of Wog-Alop on RVMI; (C) Effect of Wog-Alop on RVHI. Data are expressed as the mean ± SD, n = 6, ^#### p < 0.0001 vs. control group; * p < 0.05 vs. model group.

Figure 7

Effect of Wog-Alop on pulmonary vascular remodeling of rats from each group. (A) Resorcinol basic fuchsin staining and PCNA immunofluorescence of lung tissues; (B) Effect of Wog-Alop on the medial wall thickness of small pulmonary artery vessels; (C) Effect of Wog-Alop on PCNA positive cells of lung tissue. Data are expressed as the mean ± SD, n = 6, ^### p < 0.001 vs. control group, ^# p < 0.05 vs. control group, *** p < 0.001 vs. model group, * p < 0.05 vs. model group.

Figure 8

Effects of different drug treatments on abnormal proliferation and ROS in PDGF-BB-induced PASMCs. (A) Representative images of ROS levels in PDGF-BB-induced PASMCs; (B) Effects of 3 μM Wog, Alop, Wog+Alop (PM), and Wog-Alop (CAM) treatments on the abnormal proliferation of PDGF-BB-induced PASMCs; (C) Effects of 3 μM Wog, Alop, Wog+Alop (PM), and Wog-Alop (CAM) treatments on ROS levels in PDGF-BB-induced PASMCs (n = 3, ^## p < 0.01 vs. Control group, ^### p < 0.001 vs. Control group; * p < 0.05, ** p < 0.01 vs. Model group).

Figure 9

Effects of 3 μM Wog, Alop, Wog+Alop (PM), and Wog-Alop (CAM) treatments on MDA level (A), CAT activity (B), GPx activity (C), and GSH levels (D) in PDGF-BB-induced PASMCs (n = 3, ^### p < 0.001 vs. Control group, ^#### p < 0.0001 vs. Control group; * p < 0.05 vs. Model group, ** p < 0.01 vs. Model group, *** p < 0.001 vs. Model group, **** p < 0.0001 vs. Model group).