Background & aim: Angiogenesis is associated with tumor growth and metastasis of tumor cells, this processes directly linked with the production of nitric oxide. In this study anticancer effects of hydroalcohoic extract of M. chamomilla and avastin (bevacizumab) were investigated via dimethyl thiazol diphenyltetrazolium bromide (MTT) cell viability assay and nitric oxide (NO) production level in colon cancer cell line (HT-29).

Methods: In the present experimental study, the HT-29 cell line was cultured in RPMI-1640 media supplemented with 10% (v/v) fetal bovine serum (FBS), 1% antibiotic solution (consisting of100 U/mL penicillin and 100 µg/ml streptomycin). After growing to a favorite confluent, 10⁴cells were seeded into separate 96-well culture microtiter plates and incubated at 37⁰C in an incubator with 5% CO₂ for 24 h prior to treatment. Every plate was treated with different   concentrations of the extract (1000, 1400, 1800, 2200, 2600 µg/ml of medium) and bevacizumab (100,200,300 µg/ml).  The production of NO was assessed by Griess reagent and the cell viability was determined by MTT assay. The results were compared by one-way ANOVA followed by Tukey-Kramer.

Result: The results of MTT assay indicated that the extract and bevacizumab anticancer effect is time and dose dependent. The highest percentage of cell death was observed after 48 h incubation which increased in the bevacizumab concentration (P<0.01). Fifty percent inhibitory concentration (IC50) of extract in 24 h and 48h was 1881 and 1669 µg/ml, respectively. Inhibition of nitric oxide (NO) production was maximum in 2600 µg/ml extract concentration.

Conclusion: The results of the present study demonstrated that bevacizumab and the hydroalcohoic extract of M. chamomilla had an inhibitory effect on NO production by HT-29. The production of NO by HT-29 was inhibited after treatment by the extract of M. chamomillamay contribute to angiogenesis via decreasing of NO production and has antimatastatic effect.