The Anticancer Activity of Lycium barbarum Polysaccharide by Inhibiting Autophagy in Human Skin Squamous Cell Carcinoma Cells In Vitro and In Vivo

Abstract

Objective. This study is aimed at investigating the effects of Lycium barbarum polysaccharide (LBP) on the proliferation and apoptosis of human cutaneous squamous cell carcinoma A431 cells in vitro and in vivo via its regulation on autophagy. Methods. In vitro experiment: A431 cells were treated with different concentrations of LBP, and cell viability was measured by the CCK8 method. Flow cytometry was used to detect the cell apoptosis rate. The expression of Ki67, PCNA, cl-caspase-3, Bcl-2, and LC3II and the phosphorylation status of JNK and ERK1/2, as well as the effect of SP600125 cotreatment on the expression of autophagy and apoptosis-associated proteins, were determined via Western blot. In vivo experiment: a transplanted tumor model was established by subcutaneous injection of A431 cells to the nude mice. 50 mg/kg LBP was injected into the mice intraperitoneally; the survival rate of mice, volume, and weight of tumor were determined on the 30th day. The expression of Ki67 and MMP-2 proteins was measured by immunohistochemistry. Results. LBP at concentrations of 400 μg/ml and above was significantly cytotoxic to A431 cells, whereas, within the dose range of 50 μg/ml~200 μg/ml, LBP significantly inhibited the expression of Ki67 and PCNA proteins, promoted the expression of cl-caspase-3, inhibited the expression of Bcl-2 protein, downregulated the expression of autophagy marker LC3II, and reduced the phosphorylation of ERK1/2, whereas the level of JNK phosphorylation was upregulated. At the same time, the regulation of Beclin1, LC3II, Bcl-2, and cl-caspase-3 by LBP was effectively reversed by the cotreatment of SP600125. In addition, LBP increased the survival rate of transplanted nude mice, reduced tumor volume and weight, and downregulated the expression of Ki67 and MMP-2. Conclusion. LBP can induce apoptosis of A431 cells by inhibiting autophagy and can inhibit tumor growth in vivo.

Structural characterization and immunoregulatory activity of polysaccharides from Dendrobium officinale leaves

“…As an ideal cell model, macrophages are commonly used to evaluate immune‐regulatory activity. As active substances, polysaccharides can stimulate macrophages to secrete nitric oxide (NO), TNF‐α, and IL expression, thereby improving the resistance of organisms to pathogenic microorganism invasion (Zeng et al., 2019). NO is a highly reactive‐free radical and considerable cytotoxic mediator, contributes to anticancer and antimicrobial activities of macrophages (Li et al., 2015).…”

Lycium barbarum polysaccharide inhibits blue‐light‐induced skin oxidative damage with the involvement of mitophagy

“…Previous studies have shown that LBP has a great potential in the treatment of various physiological and pathological processes. 51,52 LBP is composed of a complex mixture of polysaccharides and proteoglycans. Its main constituents include arabinose, glucose, galactose, mannose, rhamnose, xylose, and galacturonic acid.…”

“…Previous studies have shown that LBP has a great potential in the treatment of various physiological and pathological processes 51,52 . LBP is composed of a complex mixture of polysaccharides and proteoglycans.…”

Halophyte Plants as Potential Sources of Anticancer Agents: A Comprehensive Review

“…A polysaccharide-rich aqueous extract from Chinese wolfberry fruits reduced the proliferation of SW480 and Caco-2 cell lines, as observed by the crystal violet and MTT assays, with IC 50 values of 600 and 650 µg/mL respectively, after 4 days of incubation, with a high capacity to arrest cellcycle progression in the G0/G1 phase [191]. An ethanol extract from the dried fruit residue of this species was cytotoxic toward A431 cells, with an IC 50 value of 873.7 µg/mL after 24 h of incubation, determined by water-soluble tetrazolium-8-[2-(2-methoxy-4-nitrophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2Htetrazolium] monosodium salt (CCK-8) assay [192]. The same authors conducted in vivo studies in mice submitted to an intraperitoneal injection of 50 mg/kg of the crude extract, reporting a lower volume and weight of the formed tumor and a higher survival rate of tumor-bearing nude mice [192].…”

“…An ethanol extract from the dried fruit residue of this species was cytotoxic toward A431 cells, with an IC 50 value of 873.7 µg/mL after 24 h of incubation, determined by water-soluble tetrazolium-8-[2-(2-methoxy-4-nitrophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2Htetrazolium] monosodium salt (CCK-8) assay [192]. The same authors conducted in vivo studies in mice submitted to an intraperitoneal injection of 50 mg/kg of the crude extract, reporting a lower volume and weight of the formed tumor and a higher survival rate of tumor-bearing nude mice [192]. Several phenolic amides were isolated from an ethanol extract from the stem of L. barbarum and tested toward glioma cell lines, using the MTS method [180].…”