Method of preparing culture support factor from insects

#This application is based upon and claims the benefit of priority from prior Japanese Patent Applications No. 2002-104118 filed Apr. 5, 2002, the entire contents of which are incorporated herein by reference.

#1. Field of the Invention

#The present invention relates to a method of preparing a culture support factor useful in culturing cells and tissues of animals, in particular, insects.

#The accompanying drawing, which is incorporated in and constitutes a part of the specification, illustrates presently preferred embodiments of the invention, and together with the general description given above and the detailed description of the preferred embodiments given below, serves to explain the principles of the invention.

#The single FIGURE is a graph showing the test results of a cell proliferation activity when a culture support factor prepared from the armyworm larvae by an example of the present invention is used.

#The lava or pupa to be used as a raw material in the present invention is not particularly limited. Any species of insect may be used. However, a lava or pupa of an insect belonging to the order Lepidoptera is preferably used. Particularly preferable examples may include, but not limited to, lavae and pupae of armyworm, cutworm, and silkworm. Similar activity can be obtained when Lucilia cuprina is used. Therefore, insects of the order Diptera may be used in the present invention.

#The steam sterilization step of the present invention can be performed by using a customary steam sterilization apparatus. The sterilization temperature generally ranges from 105° C. to 130° C., preferably from 110° C. to 130° C., and most preferably from 120° C. to 125° C. The sterilization time generally ranges from 1 minute to 2 hours, more preferably from 5 minutes to 1 hour, and further preferably, from 5 minutes to 20 minutes.

#The steam sterilization step plays an important role in the present invention especially when larvae ware used as raw materials. If the sterilization is performed by boiling instead of steam sterilization, the activity of the culture support factor finally recovered through extraction is rarely detected. The reason has not yet been revealed. However, it is conceivable that, in the case of steam sterilization, the culture support factor can be recovered while maintaining its activity, whereas, in the case of boiling sterilization, either a proliferation inhibitor still remains adversely effective or a proliferation support factor (culture support factor) cannot be activated.