Non-toxic and non teratogenic extract of Thuja orientalis L. inhibited angiogenesis in zebra fish and suppressed the growth of human lung cancer cell line

Lung cancer is a malignant tumour with minimal survival rate and the current treatments are not showing complete remission of tumour and have many side effects. Thus a natural herbal medicine with good anti-cancer properties is highly demanded. Thuja orientalis L. is a traditionally used medicine to cure cough, bronchitis, excessive menstruation, asthma, skin infection and premature baldness. In addition, recent studies have revealed that it has anti-proliferative and anti-cancer activity. Angiogenesis is the main reason for the propagation and metastasis of cancers. We therefore intended to study the effects of the leaf extract of Thuja orientalis L. on angiogenesis as well as lung cancer cell growth. We have tested the anti-angiogenesis efficiency by alkaline phosphatase assay and also analysed the in vivo toxicity and teratogenic effects of various concentration of Thuja orientalis L. extract by establishing an in vivo zebra fish (Danio rerio), a promising model for cancer research which share genetic structure similarity to that of human beings. Also we demonstrated an anti-cancer effect of leaf extract from Thuja orientalis L. on human lung cancer cell line (A549) by MTT and trypan blue assay. The results revealed that the Thuja orientalis L. extract is efficient in repressing lung tumour cell growth significantly (p < 0.01) in all treatments (2.4 mg/ml to 0.3 mg/ml) except 0.15 mg/ml compared to the control. The in vivo toxicity assay has proven that it is non-toxic at concentrations 0.6 mg/ml, 0.3 mg/ml and 0.15 mg/ml in zebrafish. The teratogenic assays revealed the therapeutic index (TI) as 0.808 with 0.7029 mg/ml as LC50 concentration at 24 h which is within the desirable value (below 1) for drug administration. Noticeable inhibition of angiogenesis also was observed in treatment with 2.4 mg/ml to 0.3 mg/ml. Overall we found that Thuja orientalis L. plant leaf extract exhibits better anti-cancer properties as we have validated by in vitro and in vivo analysis.