Evaluation of the Antidiabetic Properties of S-1708 Mulberry Variety.

BACKGROUND: Diabetes is a metabolic disease prevalent worldwide in all age group of people. The source of diabetes is due to an oxidation process that can produce free radicals. An increase in oxidative free radicals in the body is reported to be one of the several causes of diabetes. The best remedy to combat oxidative stress is the use of antioxidants, which inhibit and scavenge free radicals. AIM: This study has been undertaken to evaluate the antioxidant activity and antidiabetic effect of mulberry leaf extract in diabetic mice. MATERIALS AND METHODS: Antioxidant activity of mulberry leaves was determined by 2,2-diphenyl-1-picryl-hydrazyl (DPPH) and ferric reducing/antioxidant power (FRAP) assay. Antidiabetic assay of mulberry leaf extract was analyzed by oral administration of leaf extract up to 3 weeks in diabetic mice induced by streptozotocin. RESULTS: In vitro antioxidant activity in both DPPH and FRAP assays showed significantly (P < 0.05) higher inhibition of free radicals than that with ascorbic acid. Diabetic mice fed with mulberry leaf extract showed increment (+25.88%) in body weight and a significant reduction in blood glucose concentration (-71.58%). Further, glucose-6-phosphate dehydrogenase enzyme activity was significantly (P < 0.05) increased, whereas activities of other enzymes particularly catalase, serum glutamic oxaloacetic transaminase, serum glutamic pyruvic transaminase were decreased in diabetic mice after oral administration of mulberry leaf extracts. Histology of liver revealed regeneration of hepatocytes, central vein, and nucleus. CONCLUSION: This study demonstrated that S-1708 mulberry variety has a potential therapeutic value in diabetes and related complications. SUMMARY: Diabetes mellitus is a grave metabolic deviations and responsible for many complications affecting various organs in the human body. In spite of the known antidiabetic medicine available in the market, diabetes and the associated impediments sustained to be a major medical crisis. Medicinal plants have been proven to be useful in diabetes due to their rich therapeutic value. In the current study, S-1708 mulberry variety not only authenticated the earlier results obtained from other medicinal plants but also turn out to be known as a potential source for treating diabetes by demonstrating tremendous ant- diabetic properties. Abbreviations used: S-1708, DPPH, FRAP.

Cyclooxygenase-2-derived endogenous prostacyclin reduces apoptosis and enhances embryo viability in mouse.

The role of prostaglandins (PGs) in apoptosis in preimplantation mice embryo development is reported in this study. It is known that apoptosis plays a very important role in normal mice embryo development. Very few reports are available on this subject. Embryos (6-8 cells) were cultured in the presence of a selective cyclooxygenase (COX)1 inhibitor (SC560), a selective COX2 inhibitor (NS398) and a selective prostacyclin synthase (PGIS) inhibitor (U51605) in a 48-h culture. In another experiment, culture media were supplemented with prostaglandin E2 (PGE2) and prostaglandin I2 (PGI2 or prostacyclin) analogues. The apoptosis was evaluated by detection of active caspase-3. It was strongly detected in the presence of selective COX-2 and PGIS inhibitors, which can be decreased by a PGI2 analogue. In our embryo transfer experiment, the implantation rate decreased with exposure to either the COX2 or the PGIS inhibitor which is increased further after PGI2 supplementation. The level of PGI2 is also higher at the 8-16-cell stage, compaction and blastocyst stage than PGE2. All these results indicate that COX2-derived PGI2 plays an important role in preimplantation embryo development and acts as an antiapopetic factor in in vitro culture.

Effect of cyclooxygenase on "window of implantation" in mouse.

The major determinants of uterine receptivity are the ovarian progesterone and estrogen hormones, respectively. Different prostaglandins (PGs) have been elucidated in reproduction and also in this process of implantation in various ways. The blastocyst undergoes implantation on the uterine epithelium in defined hormone prepared period known as "implantation window". However, any definitive role of PGs in the window of receptivity remains elusive. It is demonstrated herein that selective COX1 inhibitor (SC560) and selective COX2 inhibitor (nimesulide) separately had no significant effect on blastocyst implantation while combination of both inhibitors in lower dose showed partial delay in implantation by more than 24h and became implanted beyond the window of implantation, i.e. on D6 but these implantation sites were significantly reduced on D10 and the pregnancy is lost in significant number. However, the higher doses of inhibitors in combination completely prevented implantation. Embryos retrieved from these treated mice showed significantly lower number of embryonic cells (77+/-3.3 and 65.2+/-3.9) than the optimum number of embryonic cells (93.4+/-2.6). The lower doses of both the inhibitors reduced uterine PGE2 and PGI2 content on D5 but did not inhibit as efficiently as higher doses. In addition, our immunohistochemistry result shows that there was no COX1 and COX2 localization on D5 of treated mice but COX2 begins expressing on D6 like normal D5 of pregnancy. Therefore, we can conclude that embryos implanted after the delay showed defective post-implantation development because of lower number of embryonic cells of implanting blastocyst and implantation beyond the proper time in window of receptivity.

Evidence of increased endometrial vascular permeability at the time of implantation in the short-nosed fruit bat, Cyanopterus sphinx.

Early embryonic development and implantation were studied in tropical short-nosed fruit bat Cyanopterus sphinx. We report preimplantation development and embryo implantation. Different stages of cleavage were observed in embryo by direct microscopic examination of fresh embryos after retrieving them either from the oviduct or the uterus at different days, up to the day of implantation. Generally, the embryos enter the uterus at the 8-cell stage. Embryonic development continued without any delay and blastocyst were formed showing attachment to the uterine epithelium at the mesometrial side of the uterus. A distinct blue band was formed in the uterus. The site of blastocyst attachment was visualized as a blue band following intravenous injection of pontamine blue. Implantation occurred 9+/-0.7 days after mating. This study reports that bat embryonic development can be studied like other laboratory animals and that this bat shows blue dye reaction, indicating the site and exact time of implantation. This blue dye reaction can be used to accurately find post-implantational delay. We prove conclusively that this species of tropical bat does not have any type of embryonic diapause.

Ovulation induction by antiestrogens in an Indian tropical vespertillionid bat, Scotophilus heathi.

The ovulation induction property of ICI 182,780 a pure antiestrogen and enclomiphene citrate (ENC) was carried out in Scotophilus heathi, an Indian tropical vespertillionid bat, during December to February i.e., preovulatory period. This bat ovulates two ova naturally and shows ovulatory asynchrony. The study showed that 100 ìg of ENC followed by 10 IU hCG resulted in significantly lower number of ovulation. Whereas, the pure antiestrogen ICI 182,780 at a dose of 100 ìg followed by 10 IU hCG resulted in ovulation induction (4.2 +/- 0.4), which is significantly different in comparison to other groups. This is possibly the first report of ovulation induction using this pure antiestrogen i.e., ICI 182,780 in any bat as well as in any animal model that exhibits temporary anovulation similar to polycystic ovary disease (PCOD). This antiestrogen may be useful to induce ovulation in PCOD patients.