beta-Glucosidase activity in fetal bovine serum renders the plant glucoside, hypoxoside, cytotoxic toward B16-F10-BL-6 mouse melanoma cells.

Abstract

By using p-nitrophenyl-beta-D-glucopyranoside as substrate, beta-glucosidase activity was observed in fetal bovine serum (FBS). This activity could be inhibited by heat inactivation of the serum. Gel chromatography of FBS indicated the presence of beta-glucosidase activity with an apparent molecular mass of 29 kDa. In McCoy's 5A medium supplemented with non-heat inactivated FBS, the diglucoside hypoxoside ([E]-1,5-bis[4'beta-D-glucopyranosyloxy-3'-hydroxyphenyl]pent-4-en - 1-yne) showed cytotoxicity toward B16-F10-BL-6 mouse melanoma cells. In incubations where the media were supplemented with FBS previously heat inactivated at 56 degrees C for 1 h or more, no cytotoxicity was observed in the presence of hypoxoside. The aglucone of hypoxoside, rooperol ([E]-1,5-bis[3',4'-dihydroxyphenyl]pent-4-en-1-yne), showed cytotoxicity regardless of whether the serum was heat inactivated or not. The kinetics of the heat inactivation of the beta-glucosidase activity in FBS coincided with the loss of apparent cytotoxicity of hypoxoside. High performance liquid chromatography analysis showed that rooperol could be generated by incubation of hypoxoside in non-heat inactivated FBS, but that this ability was lost in serum that was heat inactivated for 1 h or longer. Newborn bovine serum did not contain any beta-glucosidase activity whereas it was found in three different commercial sources of FBS. This observation is of practical importance because conventional heat inactivation of FBS at 56 degrees C for 30 min was not sufficient to inactivate the beta-glucosidase activity completely.

• Authors: E J Theron, C F Albrecht, P B Kruger, K Jenkins, M J van der Merwe
• Journal: In vitro cellular & developmental biology. Animal (In Vitro Cell Dev Biol Anim) Vol. 30A Issue 2 Pg. 115-9 (Feb 1994) ISSN: 1071-2690 [Print] Germany
• PMID: 8012653 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Alkynes
• Culture Media
• Glucosides
• hypoxoside
• beta-Glucosidase

Topics

• Alkynes (metabolism, pharmacology)
• Animals
• Cattle
• Cell Death (drug effects)
• Chromatography, Gel
• Chromatography, High Pressure Liquid
• Culture Media
• Fetal Blood (enzymology)
• Glucosides (metabolism, pharmacology)
• Hot Temperature
• Kinetics
• Melanoma, Experimental (pathology)
• Mice
• Molecular Weight
• Tumor Cells, Cultured
• beta-Glucosidase (blood)