Preliminary Report
Immunomodulation and antitumor activity by a polysaccharide–protein complex from Lycium barbarum

https://doi.org/10.1016/j.intimp.2004.01.023Get rights and content

Abstract

The modulation of a polysaccharide–protein complex from Lycium barbarum (LBP3p) on the immune system in S180-bearing mice was investigated. The mice inoculated with S180 cell suspension were treated p.o. with LBP3p (5, 10 and 20 mg/kg) for 10 days. The effects of LBP3p on transplantable tumors and macrophage phagocytosis, quantitative hemolysis of sheep red blood cells (QHS), lymphocyte proliferation, the activity of cytotoxic T lymphocyte (CTL), interleukin-2 (IL-2) gene expression and lipid peroxidation were studied. LBP3p could significantly inhibit the growth of transplantable sarcoma S180 and increase macrophage phagocytosis, the form of antibody secreted by spleen cells, spleen lymphocyte proliferation, CTL activity, IL-2 mRNA expression level and reduce the lipid peroxidation in S180-bearing mice. The effect is not dose-dependent in a linear fashion. A total of 10 mg/kg dose is more effective than 5 and 20 mg/kg doses. This suggests that LBP3p at 10 mg/kg has a highly significant effect on tumor weight and improves the immune system.

Introduction

During the past three decades, many polysaccharides and polysaccharide–protein complexes have been isolated from mushrooms, fungi, yeasts, algae, lichens and plants. The biological activities of these polysaccharides have attracted more attention recently in the biochemical and medical areas because of their immunomodulatory and antitumor effects [1]. The search for novel polysaccharides with antitumor properties stems from the basic shortcomings of cancer chemotherapy and radiotherapy. In particular, the great majority of chemical compounds, which have been identified as cytotoxic to cancer cells, are also toxic to normal cells [2]. Hence, the discovery and identification of new safe drugs, without severe side effects, has become an important goal of research in the biomedical sciences. The enhancement or potentiation of host defense mechanisms has been recognized as a possible means of inhibiting tumor growth without harming the host.

Lycium barbarum plays multiple roles in pharmacological and biological functions as a well-known Chinese traditional medicine and also a kind of food. L. barbarum polysaccharide–protein complex (LBP) is its important bioactive component. It was reported that the crude LBP could significantly suppress the growth of malignant tumor in vivo [3], [4]. However, the antitumor effect of LBP is speculative because of the unclear purity of the crude LBP and the mechanism of antitumor action of LBP is still not fully understood. In the present work, the immunomodulative effect of LBP3p, the third fraction of LBP, on S180-bearing mice was investigated and the lipid peroxidation was also discussed.

Section snippets

Preparation of LBP3p

L. barbarum was collected in Zhongning, Ningxia, China and identified by Prof. Qiong Luo, Medical School of Wuhan University, Wuhan, China. The voucher specimen of this plant (FST 505) is deposited in the Department of Food Science and Technology, Huazhong Agricultural University, Wuhan, China. A total of 100 g of dried powdered L. barbarum were first extracted with acetone/petroleum (1:1, 300 ml×3) to remove pigments. The dried residual plant material was then extracted with 80% ethanol (300

Effects of LBP3p on thymus indexes and tumor weights in S180-bearing mice

As shown in Table 1, 5 and 10 mg/kg LBP3p caused a significant increase in the thymus index compared with S180 control group. No significant increase was observed in CTX-treated animals. LBP3p could significantly inhibit the growth of mouse transplantable sarcoma S180. The inhibitory rate was 28.14%, 43.05% and 11.88%, respectively, when the concentration of LBP3p was 5, 10 and 20 mg/kg. The inhibitory effect of LBP3p 10 mg/kg was the strongest and close to that of CTX 20 mg/kg, a positive

Discussion

The relation between the occurrence, growth and decline of tumor and immune states is the essential problem of tumor immunology. The discovery and identification of new antitumor drugs, which can potentiate the immune function has become an important goal of research in immunopharmacology and oncotherapy. This study demonstrates the favourable antitumor effect of LBP3p, a polysaccharide–protein complex from L. barbarum and its immunomodulative activity. LBP3p could significantly inhibit the

References (19)

There are more references available in the full text version of this article.

Cited by (255)

  • Moringa oleifera, Lycium barbarum: A Perspective on New Sources of Phytochemicals, Lipids and Proteins

    2023, Sustainable Food Science - A Comprehensive Approach: Volumes 1-4
View all citing articles on Scopus
View full text