Spontaneous Electrical Activity in the Nervous System and its Modification by Biogenic Amines in the Silkworm Bombyx Mori (L)

The present study was carried out to examine the effects of biogenic amines on the spontaneous electrical activity of the nervous system in the silkworm Bombyx mori. The activity recorded from different segments of the ventral nerve cord differed in the frequency and number of spike categories firing. The activity was highest between the subesophageal ganglion and 1st thoracic ganglion. Lower activity was recorded in the thoracic part of the cord and the activity increased in the abdominal cord. More or less the same level of activity was recorded from all the abdominal segments of the cord. The above trend was the same from the 1st day to the 7th day of the 5th instar of the silkworm. However, the overall level of activity increased from the 1st day to the 7th day in tune with the increasing complexity of the peripheral nervous system in the silkworm as the 5th instar progressed. Treatment of the cord with solutions of putative neurotransmitter substances, viz. epinephrine (EP), norepinephrine (NEP), dopamine (DA) and 5-hydroxytryptamine (5-HT) at different concentrations from 1x10-8 M to 1x10-4 M showed elevation at lower concentrations anddecrease at 1x10-4 M. The concentration at which maximum elevation could be elicited varied between the above transmitters. Biochemical analyses revealed the presence of these biogenic amines in the silkworm nervous system. Thus the possibility remains that one or more of these substances could act as neurotransmitters in the silkworm nervous system.Keywords: Silkworm; 5th Instar; Spontaneous electrical activity;Biogenic amines; Neurotransmitters

ANTIDIABETIC EFFECT AND PHYTOCHEMICAL SCREENING OF ETHANOLIC EXTRACT OF POLYALTHIA CERASOIDES STEM BARK IN STREPTOZOTOCIN INDUCED DIABETIC ALBINO RATS

Objective: Polyalthia cerasoides stem bark is used in treatment the of various diseases. Some tribes of North Orissa used the stem bark in the treatment of diabetes. We investigated the effect of four different solvent (n-hexane, ethyl acetate, ethanol and aqueous) extracts of Polyalthia cerasoides stem bark on streptozotocintozocin (STZ) 45 mg/kg b. wt. induced diabetic rats.Methods: Normal control and diabetic control groups were allowed with free access to water throughout the experiment. Oral administration of four different solvent (n-hexane, ethyl acetate, ethanol and aqueous extracts of P. cerasoides stem bark to 12 hrs fasted normal and STZ induced diabetic rats at a dose of 200, 400 and 600 mg/kg b. wt for acute studies. (Determination of effective extract and dose:  Each group was maintained with six rats)The fasting blood glucose FBG levels were checked for every 2 hrs (1h, 3h, 5h & 7h). Chronic study:  (Each group was maintained with six rats)The normal and diabetic groups were supplemented with optimum dosage 400mg ethanol extract of P. cerasoides (PcEE) stem bark and 20 mg of glibinclamide (Glb) a standard drug treated diabetic group for 21 days.Results: Acute administration of P. cerasoides stem bark reduced FBG[A1]  levels in ethanol extract atthe dosee 400 and 600 mg/ kg b. wt (48.5% and 32.4%, P<0.05) in the diabetic rats only. It does not affect the normal FBG levels in normal rats. In chronic treatment significant reduction in FBG levels in diabetic rats (51.6%). Body weight also increased in extract treated animals. The maximal antidiabetic effect was obtained in 400 mg PcEE[A2]  which was similar to Glb treated group. The PcEE treated diabetic rats also confirmed the significant recovery of liver and kidney destruction.Conclusion: Our study has revealed the therapeutic effect of PcEE for diabetes and its related complications.Â