Growth inhibition and apoptosis of Ehrlich ascites carcinoma cells by the methanol extract of Eucalyptus camaldulensis.

BACKGROUND

Eucalyptus camaldulensis Dehnh. (Myrtaceae) is a tall evergreen tree found commonly in Bangladesh. Its use in traditional folk medicine for the treatment of various health complications are well known.

OBJECTIVE

To explore the in vivo antitumor effect of Eucalyptus camaldulensis stem bark methanol extract (ME) against Ehrlich's ascites carcinoma (EAC) in Swiss albino mice.

METHODS

The antitumor activity of ME was studied by determining viable tumor cell count, recording tumor weight and survival time, observing morphological changes and nuclear damage of EAC cells, and estimating hematological as well as biochemical parameters of experimental mice (25, 50 and 100 mg/kg/day for 5 d, i.p.).

RESULTS

ME showed 96% (p < 0.001) cell growth inhibition and reduced tumor burden significantly (81.4%; p < 0.01) when compared with control mice. It also increased the lifespan of EAC-bearing mice significantly (71.36%; p < 0.01). It also restored the altered hematological and biochemical parameters towards normal level. The high LD50 value (1120 mg/kg) of ME indicated its low host toxic effects. ME-treated EAC cells showed membrane blebbing, chromatin condensation, nuclear fragmentation (apoptotic features) in Hoechst 33342 staining under fluorescence microscope. The DNA profile in agarose gel (1.5%) electrophoresis also confirmed that ME caused EAC cell death by apoptosis.

CONCLUSIONS

Results showed that ME exhibits strong anticancer activity through apoptosis and stimulation of host immunity. Thus, E. camaldulensis may be considered as a promising resource in cancer chemotherapy.