Studies On The Biotic Resources Containing Abundant DNJ And The Relationship Between DNJ Content In Silkworm Powder And Its Effects On Reducing Blood Glucose

1-deoxynojirimycin (DNJ) and its ramifications are effectiveα-glucosidase inhibitors and therefore play a major role for mulberry to reduce blood glucose. Silkworms feed on mulberry leaves most of their lives and can accumulate DNJ into the level much higher than that in mulberry leaves. There is no systemic description in previous research in the field such as the changing law of DNJ content in different mulberry breed leaves and in different parts of silkworm body, the effects of germicidal treatment against the whole silkworm powder on DNJ content, the relationship between DNJ content and the effects on reducing the blood glucose, as well as the fact whether or not there is DNJ besides mulberry and silkworm, in the other moraceae plant, in insects or in the Chinese traditional medicine used for reducing the blood glucose. Therefore, the DNJ content in the whole silkworm powder from different instars of silkworm larvae as well as its effects on reducing blood glucose, the effect of radicidation on the whole silkworm powder and on DNJ content as well as the effects on reducing blood glucose, the DNJ content in different mulberry breeds and in different development stages of mulberry leaves, in some Moraceae plants and Ulmaceae plants, in some edible insects and in the 64 Chinese traditional medicines for curing diabetic, the effects of some edible insects on blood sugar and blood fat, were all studied in detail in this paper in order to find the new biotic resources containing abundant DNJ so as to serving as the effective Chinese traditional medicine and healthy food for reducing blood glucose. The central results were as follows:1. The DNJ content in the silkworm powder from different instars larvae and the effects on reducing blood glucose were mensurated and the results revealed that the DNJ content decreased with the development of instars and reached the top level in the second instar molting silkworm, while in the prepupa stage, there was no any DNJ in the silkworm. There were remarkable differences on the effects of reducing the blood glucose between the whole silkworm powders from the different instar larvae. The fasting blood glucose was reduced notably by the whole silkworm powder from the third instar molting silkworm, and then the same effect occurred in the full appetite larvae in the fourth instar but in the lower level. As for the postprandial blood glucose, it was reduced greatly by the whole silkworm powder from prepupa stage silkworm, next came from the third day larvae in the fifth instar. Thus it can be concluded that the effects of reducing the blood glucose from the whole silkworm powder did not depend upon the content of DNJ and there must be some other active materials in the silkworm body which reduce the blood glucose.2. The whole silkworm powder and its compound were treated with radicidation of 7kGy ⁶⁰Coγradial and the colony total number was counted according to the international standard GB/T 4789.2-2003. The colony total number in the group of radicidation treatment was much less than that in the control group and met the needs for hygiene in food and Chinese traditional medicine. More important, the radicidation treatment made no obvious difference on the DNJ content and the effects of reducing blood glucose. When the whole silkworm powders were preserved in the condition of normal temperature and cold storage for 6 months, the colony total number increased evidently in the sample of nonradicadation, on the contrary, it was no obvious increase for the radicidation samples. There were no remarkable differences for the DNJ content as well as its effects on reducing blood glucose between the samples of preconservation and postconservation as well as between the samples with different conservation way, while the value of postprandial blood glucose in the test mice fed with the whole silkworm powder after the treatment of radicidation was lower than that in other treatments. All these revealed that the treatment of radicidation with 7 kGy ⁶⁰Coγradial could kill effectively the microorganisms in the whole silkworm powder and it had no influence on the active ingredient DNJ and the effect on reducing the blood glucose.3. The DNJ content was mensurated in many kinds of biotic resources and even in the Chinese traditional medicines. There were no DNJ in the leaves from 3 Moraceae plants and 4 Ulmaceae plants. There were notable differences for the DNJ content in the mulberry leaves between the different development stages and between the different mulberry breeds. The DNJ content showed the maximum value in the winter buds in the test of 10 stages from the formation of winter bud to the late mature period of mulberry leaves in spring. It also displayed the highest level both in the breed Sha2 and Qiuyu in all the 18 test mulberry breeds, about one fold higher than that in the low DNJ content breed such as Mengyinheilu. In the 64 Chinese traditional medicines curing the diabetics, there was no DNJ except for those containing silkworms and mulberries, as revealed that the active ingredients of reducing blood glucose and curing the diabetics was not DNJ in these medicines. As for the insects ingesting mulberry leaves, the DNJ content in Phthonandria atrineata Butler., Rondotia menciana Moore. and Bombyx mandarina Leech. were 0.7757%, 1.0646% and 0.3926%, respectively. There was no DNJ in the 4 other insects ingesting mulberry as well as 13 insects which did not ingest mulberry. The main DNJ source in nature was mulberry trees. The insects could accumulate DNJ only by ingesting mulberry, while different insects possessed different ability in accumulating DNJ.4. The effects of 5 edible insects such as Cryptotympana atrata Fabricius. on the mouse blood glucose and blood fat were discussed in this paper by animal test. The fasting blood glucose in the mice fed by the diet containing the insect powders of Locusta migratoria Meyer. was reduced remarkably, while the postprandial blood glucose was notably reduced in the mice fed by the insect powder of Cryptotympana atrata Fabricius., as all performed poorer than that by the whole silkworm powder. The insect powders of Clanis bilineata Walker., Tenebrio molito L. and Locusta migratoria Meyer. even increased the level of postprandial blood glucose instead of reducing it. The total cholesterol in the mice blood serum was reduced in a different level by the insect powder, and the insect powder of Cryptotympana atrata Fabricius. and fifth instar silkworm larvae performed excellently. The powders of Tenebrio molito L., Locusta migratoria Meyer., fifth instar silkworm and Brachytrupes portentosus Lichtenstein. reduced wondrously the triglycerides in mice blood serum, among them the powders of Brachytrupes portentosus Lichtenstein. and silkworm approached to the top level.