Effect of Aerva lanata on cell-mediated immune responses and cytotoxic T-lymphocyte generation in normal and tumor-bearing mice

Abstract

Cell-mediated immunity offers protection against virus-infected cells and tumor cells, involves activation of natural killer (NK) cells, production of antigen-specific cytotoxic T-lymphocytes, and release of various cytokines in response to an antigen. Administration of an ethanolic extract of Aerva lanata was found to stimulate cell-mediated immunological responses in normal and tumor-bearing BALB/c mice. A significant enhancement in NK cell activity in both normal and tumor-bearing hosts was observed after administration of A. lanata. Antibody-dependent cellular cytotoxicity (ADCC) and antibody-dependent complement-mediated cytotoxicity (ACC) were significantly enhanced as well in both sets of treated hosts. In addition, in vivo production of IL-2 and IFNg were each significantly enhanced by extract treatment. The stimulatory effect of A. lanata on cytotoxic T-lymphocyte (CTL) production was determined by Winn’s neutralization assay using CTL-sensitive EL4 thymoma cells. A. lanata treatment caused a significant increase in CTL production in both in vivo and in vitro models, in each case as indicated by a significant increase in the life-spans of tumor-injected mice. Taken together, all of these results in the murine model indicate that administration of an ethanolic extract of A. lanata could enhance the cell-mediated anti-tumor response.

Keywords::

• NK cell activity
• antibody-dependent cell-mediated cytotoxicity
• antibody-dependent complement-mediated cytotoxicity
• cytotoxic T-lymphocytes
• mixed-lymphocyte reaction

Acknowledgements

The authors are sincerely thankful to Dr Ramadasan Kuttan, Research Director, Amala Cancer Research Centre, for his valuable suggestions.

Declaration of interest

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.