Cho WC, Leung KN.

Department of Clinical Oncology, Queen Elizabeth Hospital, Hong Kong, SAR, China. chocs@ha.org.hk

Astragalus membranaceus is a common traditional Chinese medicinal plant widely used as a tonic to enhance the body’s natural defense mechanisms. In this study, bioactive fractions were isolated from the roots of Astragalus membranaceus. One of these fractions, designated as AI, was found to be the most potent with respect to its mitogenicity on murine splenocytes. Effects of AI on both specific and nonspecific immunity in mouse models were examined. Results showed that AI could exhibit mitogenic and co-mitogenic activities on mouse splenocytes, both in vitro and in vivo. Experiments in human cell culture demonstrated that AI was also active on human lymphocytes. It was found that AI was mitogenic to T cell depleted population but virtually inactive on B cell depleted population. Intraperitoneal injection of AI into mice markedly augmented the antibody response to sheep red blood cells. Besides, both the influx of macrophages into the peritoneal cavity and the phagocytic activity of macrophages were found to be enhanced by AI in vivo. On the other hand, AI could significantly increase the interleukin-2 receptor expression on mouse splenocytes in vitro. In terms of immunorestorative activity, it was found that AI could restore the lymphocyte blastogenic response of the older mice to values that are normally found in the younger mice. Moreover, administration of AI in vivo could partially restore the depressed immune functions in tumour-bearing mice and cyclophosphamide-treated mice. Collectively, the results clearly showed that AI could exhibit immunomodulating and immunorestorative effects, both in vitro and in vivo.

PMID: 17611061 [PubMed - in process]

Cancer prevalence is defined as the total number of people living with cancer at any point in time. It includes both people diagnosed with cancer in the past (who are still alive) as well as people recently diagnosed.

Cancer prevalence is not a measure of how common a cancer is. This number is reflected by cancer incidence, which is the number of people newly diagnosed with cancer in a given time period (usually one year). Prevalence is affected both by the incidence of a cancer and by how long people normally live with the disease.

For example, lung cancer is the second most common cancer in both men and women, but lung cancer prevalence is not as high as that of some less common cancers because people with lung cancer tend not to live as long once diagnosed.

The following numbers come from the US National Cancer Institute’s Surveillance Epidemiology and End Results (SEER) database for the year 2002, the most recent year for which reliable estimates are available. These are estimates based on a sampling of the US population. Numbers may not add up due to rounding to the nearest 1,000.

References

National Cancer Institute. SEER Cancer Statistics Review, 1975-2002. 2006.
Available at: http://seer.cancer.gov/csr/1975_2002/
Accessed January 31, 2006.
Revised: 02/22/2006