Cytotoxic Evaluation of Four Haplophyllum. Species with Various Tumor Cell Lines

Abstract

Total extracts of the aerial parts of four Haplophyllum. species (Rutaceae) including Haplophyllum stapfianum. Hand.-Mazz., H. tuberculatum. (Forssk.) Adr. Juss., H. acutifolium. (DC.) G. Don, and H. viridulum. Soják were tested for in vitro. cytotoxicity against 11 tumor cell lines and normal peripheral blood mononuclear cells (PBMCs). Cytotoxicity of Haplophyllum. species were also compared with Ruta graveolens. L. (Rutaceae) extract. Cytotoxic activity of extracts was evaluated by the WST-1 assay and expressed as IC₅₀ values. The results obtained indicated that among hematopoietic tumor cell lines, strong cytotoxic activity was observed from H. stapfianum., H. tuberculatum., and H. acutifolium. against RAMOS cell line with IC₅₀ values of 12.3, 25.3, and 23.7 µg/mL, respectively; H. stapfianum. and H. tuberculatum. against U937 cell line with IC₅₀ values of 15.6 and 29.3 µg/mL; and H. tuberculatum. against RPMI-8866 cell line with IC₅₀ = 31.8 µg/mL. Testing plant extracts on solid tumor cell lines revealed that all Haplophyllum. species have markedly high cytotoxicity against LNCap-FGC-10, a prostate adenocarcinoma cell line, except H. viridulum.. H. tuberculatum. also showed strong cytotoxic effect against 5637, a bladder carcinoma cell line (IC₅₀ = 23.3 µg/mL). Investigating cytotoxic activity of R. graveolens. resulted in higher IC₅₀ values against all tumor cell lines except LNCap-FGC-10 (IC₅₀ = 27.6 µg/mL). Cytotoxicity evaluation of Haplophyllum. species on PBMCs revealed that resulting IC₅₀ values for H. stapfianum. and H. acutifolium. on tumor cell lines with high cytotoxic activity were significantly lower than the IC₅₀ values obtained for PBMCs (p < 0.05).

Keywords:

• Cell line
• cytotoxicity
• Haplophyllum
• IC₅₀
• Ruta
• Rutaceae
• WST-1