Rabu, 3 Oktober 2012
Astragalus is an herb that has been used in Chinese herbal medicine for thousands of years for wasting/ thirsting syndrome, to promote urination and reduce edema, to promote healing, and after significant loss of blood.
Although by different name and description, astragalus has been used for immune stimulation for centuries.
Astragalus has been widely studied in vitro and in vivo for its immune-potentiating activity in malignancies. Astragalus extracts exhibited immunopotentiating activity and one fraction of the herb was capable of fully correcting in-vitro T-cell function deficiency. Further research in mice with immunosuppression from cyclophosphamide or radiation treatment demonstrated that astragalus extracts enhanced antibody production and this effect was associated with increased T-cell activity. In-vitro studies demonstrated that urological neoplasms suppressed macrophage function and that this suppression was reversed by astragalus extract.
A meta-analysis of astragalus-based Chinese herbs and platinum-based chemotherapy for advanced non-small-cell lung cancer (34 randomized studies representing 2,815 patients) concluded that astragalus may increase the effectiveness of platinum-based chemotherapy. Combined results from the meta-analysis demonstrate overall benefit. Twelve studies reported reduced risk of death at 12 months. Thirty studies reported improved tumor response. Performance status in most studies was stable or improved. Among the studies reporting median survival, none included confidence intervals, P values of variance. Therefore, a meta-analysis of median survival could not be done. Despite this, the authors of the analysis concluded that combining astragalus with platinum-based chemotherapy in the treatment of non-small-cell lung cancer may increase survival, tumor response, performance status, and reduce chemotherapy toxicity when compared to platinum-based chemotherapy alone.
Based on preliminary animal studies and limited human research, astragalus may decrease blood sugar levels. Based on anecdotal reports and preliminary laboratory research, astragalus may increase the risk of bleeding. Preliminary reports of human use in China and animal research suggests possible blood pressure lowering effects. Due to a lack of well-designed studies, no firm conclusions can be drawn. Nonetheless, people with abnormal blood pressure or taking blood pressure medications should use caution and be monitored by a qualified healthcare professional.
Astragalus may help prevent the immunosuppression caused by chemotherapy agents. Additionally, there is some indication that astragalus may also potentiate the cytotoxic effects of certain chemotherapy agents. Herb-drug interactions of astragalus with chemotherapy drugs have not been studied.