The effect of cold storage during winter on the levels of COX-1 inhibitory activity of Eucomis autumnalis autumnalis extracts

Abstract

Levels of anti-inflammatory activity exhibited by Eucomis autumnalis autumnalis were affected by the environmental conditions during the period of winter dormancy. Bulbs stored at low temperatures (10 °C) showed a limited period of time during which the anti-inflammatory activity of the bulb extracts was higher than that of the control. This effect was evident for a longer period in the leaves. Extracts prepared from E . autumnalis (subspecies autumnalis ) bulbs, which were removed from the soil and stored at 8-10 °C during the winter months, exhibited significantly higher COX-1 inhibitory activity than those extracts prepared from control bulbs maintained in the soil in a greenhouse (15-24 °C) during winter, and from bulbs stored dry in paper bags (± 18 °C). A second harvest, performed on plants that had been returned to the soil after winter storage, was conducted half-way through the growing season. Higher COX-1 inhibitory activity was observed in the leaf extracts from the plants subjected to cold storage, than in the extracts from plants stored dry or in the greenhouse. No significant difference was observed at this stage between the activity of the bulb and root extracts from the different treatments. All extracts were prepared at a concentration of 250μg ml - 1 for comparison.