Liposome encapsulation attenuated venenum bufonis induced vascular irritation in rabbit ear vein via regulating TLR/MAPK/NF-κB pathway

Abstract

Delisheng injection (DLS), composed of venenum bufonis (VB), Chinese blister beetle (CB), red ginseng (RG) and Astragalus membranaceus (AM), is a Chinese medicine injection with good efficacy for the treatment of different types of cancers, while the side effects of DLS, such as vascular irritation and inflammation, restrict its wide clinical applications. Based on our previous study, VB is a main contributor for the vascular irritation of DLS. To reveal the possible mechanism involved in VB-induced vascular irritation is of practical importance. Moreover, to find a way to alleviate VB-induced vascular irritation is of great necessity. In our present study, venenum bufonis liposome (VBL) was prepared by thin film dispersion method to attenuate VB-induced vascular irritation. Vascular irritation of VB and its liposome were evaluated in a rabbit model. Rabbits were divided into three groups: (1) the control group (K); (2) the VB group (VB); (3) the VBL group (VBL). Animals administrated with VB or VBL 0.12 mg kg⁻¹ were sacrificed at 6 h. Inflammatory cytokines and TLR/MAPK/NF-κB pathway-related proteins were examined, respectively. Our results showed that VB significantly increased serum proinflammatory cytokines, including interleukin-1β (IL-1β), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α), while it led to decreased anti-inflammatory cytokines interleukin-10 (IL-10) after intravenous administration. VB-induced vascular irritation was further confirmed by histopathological evaluation. Moreover, the results obtained from western blot and immunohistochemical analysis revealed that VB activated TLR/MAPK/NF-κB signaling pathway involving TLR2, TLR4, MyD88, p-Erk, p-JNK, p-P38, p-IκBα and p-NF-κB p65 protein. VB liposome decreased the VB-induced overexpression of TLR2, TLR4, MyD88, p-Erk, p-JNK, p-P38, p-IκBα and p-NF-κB p65. The anticancer activity of VB and VBL was also evaluated, and VBL still showed anticancer activity both in vivo and in vitro. Taken together, our finding demonstrated that VB induced vascular irritation was related to the regulation of the TLR/MAPK/NF-κB signaling pathway, and liposome encapsulation significantly attenuated VB-induced vascular irritation while maintaining its anticancer activity. The results of this study have important practical significance in guiding the safety clinical application of Chinese medicine injection.