Cytotoxic activity of aqueous extract from Holodiscus discolor (Pursh) Maxim. leaves

Holodiscus discolor (Pursh) Maxim. (Rosaceae) is a shrub used in traditional medicine of Native Americans for the treatment of viral and skin diseases. Antifungal [1], antibacterial [2] and cytotoxic [3] activities of leaf extracts have been described. Based on these data, time (24, 72h) and dose (1–150µg/ml) dependent toxic effects of the leaf extract were investigated in vitro in human skin carcinoma cells A431. Cytotoxicity was measured by MTT assay for cell viability, and LDH leakage was used for determiniation of membrane integrity. Significant correlation in time was observed, when proliferation was inhibited in lower extract concentrations than cell lysis arose. The aqueous extract of Holodiscus discolor leaves has been analyzed for cytotoxic activity for the first time.

Table 1: ED₅₀ and maximal effects for MTT and LDH toxicity tests. The values are mean±SE of 4 separate experiments performed in duplicates. Statistical significance was calculated by Student's t-test, when ***p<0,001; (24h vs. 72h)

	MTT		LDH
	ED50 (µg/ml)	max. inhibition (%)	ED50 (µg/ml)	max. effect (%)
24h	41,2±1,12	45,3±3,19	90,4±1,10	21,4±4,56
72h	31,9±1,30***	26,2±4,43***	71,9±1,03***	17,7±0,28

Acknowledgements: Institute of Experimental Endocrinology SAS, Grant Agency VEGA SR No. 1/4289/07 and Comenius University Grant UK/77/06.

References: [1] McCutcheon, A.R. et al. (1994) J Ethnopharmacol 44: 157–169. [2] Jantová, S. et al. (2000) Phytother Res 14: 601–603.

3. Jantová, S. et al. (2001) Phytother Res 15: 22–25.