Immunomodulatory properties of Alternanthera tenella Colla aqueous extracts in mice

• Main Authors: R.N.M. Guerra, H.-A.W. Pereira, L.M.S. Silveira, R.S.G. Olea
• Format: Article
• Language: English
• Published: Associação Brasileira de Divulgação Científica 2003-09-01
• Series: Brazilian Journal of Medical and Biological Research
• Subjects: Antitumor activity; Antibody; Immunomodulation; Ehrlich ascites; Alternanthera
• Online Access: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2003000900011
• ISSN: 0100-879X; 1414-431X

Plants from the genus Alternanthera are thought to possess antimicrobial and antiviral properties. In Brazilian folk medicine, the aqueous extract of A. tenella Colla is used for its anti-inflammatory activity. The present study investigated the immunomodulatory property of A. tenella extract by evaluating the antibody production in male albino Swiss mice weighing 20-25 g (10 per group). The animals received standard laboratory diet and water ad libitum. The effect of A. tenella extract (5 and 50 mg/kg, ip) was evaluated in mice immunized with sheep red blood cells (SRBC 10%, ip) as T-dependent antigen, or in mice stimulated with mitogens (10 µg, Escherichia coli lipopolysaccharide, LPS, ip). The same doses (5 and 50 mg/kg, ip) of A. tenella extract were also tested for antitumor activity, using the Ehrlich ascites carcinoma as model. The results showed that 50 mg/kg A. tenella extract ip significantly enhanced IgM (64%) and IgG2a (50%) antibody production in mice treated with LPS mitogen. The same dose had no effect on IgM-specific response, whereas the 5 mg/kg treatment caused a statiscally significant reduction of anti-SRBC IgM-specific antibodies (82%). The aqueous extract of A. tenella (50 mg/kg) increased the life span (from 16 ± 1 to 25 ± 1 days) and decreased the number of viable tumor cells (59%) in mice with Ehrlich ascites carcinoma. The present findings are significant for the development of alternative, inexpensive and perhaps even safer strategies for cancer treatment.