In vitro antiproliferation activity of Typhonium flagelliforme leaves ethanol extract and its combination with canine interferons on several tumor-derived cell lines

Background and aim: Tumor disorder is one of the degenerative diseases that affected human and animals and recently is tend to increase significantly. The treatment of tumor diseases can be performed through surgical, chemotherapy, radiotherapy, biological substances, and herbs medicine. Typhonium flagelliforme leaves extract known to have an antiproliferation activity, while interferons (IFNs) one of the cytokines that first used as an antiviral agent was also known to have antitumor activity. Nowadays, the treatment of tumors using a traditional way, including the use of herbal substances, becomes popular. Some limitations of the antitumor activity due to resistant development of the cell to some substances were one of the problems on why the treatment of cancer was unsuccessful. This study aimed to elaborate the synergistic effect on the antiproliferation and anti-angiogenesis activities of the combinations between T. flagelliforme leaves ethanol extract and canine natural (natural canine IFN [nCaIFN]) and recombinant (recombinant canine IFN [rCaIFN]) IFNs on tumor-derived cell lines to find the new potential antitumor substances.

Materials and methods: The extraction of T. flagelliforme leaves was performed using the maceration method and followed by phytochemical screening assays. According to the result of LC₅₀ by the brine shrimp lethality test, the dose used for T. flagelliforme extract was 120 ppm while the dose of IFNs was 10² U/ml. The tumor-derived cell lines (canine squamous cell carcinoma [CSCC], canine mammary gland benign mixed tumor/MCM-IPB-B3, and feline squamous cell carcinoma [FSCC]) and normal rabbit endothelial cells were cultured and maintained on Dulbecco's Modified Eagle's Medium DMEM/Ham-F12 medium supplemented with 10% fetal calf serum, antibiotic, and antifungal. The antiproliferation activity was assayed by calculated the total cell number after treated with the tested substances. The antiangiogenesis assay was performed using in vitro method on rabbit normal endothelial cells and in ovo using chicken chorioallantoic membrane (CAM).

Results: The phytochemical screening test of the T. flagelliforme leaves ethanol extract indicated that the compound consisted of flavonoid, steroid, and tannin. The antiproliferation activity was increased in the combination of substances compared to the single exposure of each substance on all tested tumor-derived cell lines. There was no significantly different on the antiproliferation activity between a combination of T. flagelliforme with nCaIFN or rCaIFN in every single tested cell lines, but the comparison of this activity among the three tumor-derived cell lines seem that the antiproliferation activity is more effective on CSCC cell lines compared to the canine mammary gland benign mixed tumor and FSCC cell lines. A similar pattern of synergistic effect was also detected on the anti-angiogenesis activity in vitro using rabbit endothelial cells as well as in ovo assays. The most effective of the in vitro and in ovo anti-angiogenesis activity was observed on the combination substances between T. flagelliforme extract and rCaIFN compared to other treatments.

Conclusion: There was a synergistic effect on the antiproliferation and antiangiogenesis activities of the combination between T. flagelliforme and canine IFNs (natural and recombinant) and this result could be developed as another alternative on the cancer treatments.

Keywords: Typhonium flagelliforme; antiangiogenesis; antiproliferation; canine interferons; ethanol extract; tumor cell lines.