Abdulazim S. Salhab

Hypoglycemic effects of Teucrium polium

Teucrium polium has a folk reputation as a hypoglycemic agent. The hypoglycemic activity of an aqueous decoction of plant aerial parts was tested in normoglycemic and streptozotocin-hyperglycemic rats. Results indicate that this extract caused significant reductions in blood glucose concentration 4 h after intravenous administration and 24 h after intraperitoneal administration. This effect could be due to enhancement of peripheral metabolism of glucose rather than an increase in insulin release.

DIRECT RELAXANT EFFECTS OF GARLIC JUICE ON SMOOTH AND CARDIAC MUSCLES

The effects of garlic juice on smooth and cardiac muscles of rabbit and guinea pig were tested in vitro using isolated segments of aorta, trachea and intestines and isolated rabbit hearts. Garlic juice inhibited the contractions of rabbit and guinea pig aortic rings induced by norepinephrine in Ca(2+)-free and Ca(2+)-containing Krebs-Henseleit solutions. Also, garlic juice inhibited the contractions of rabbit and guinea pig tracheal smooth muscles induced by acetylcholine and histamine, respectively, in both Ca(2+)-free and Ca(2+)-containing Krebs-Henseleit solutions. Furthermore, garlic juice inhibited the spontaneous movements of rabbit jejunum and guinea pig ileum and inhibited the force of contraction of isolated rabbit hearts in a concentration-dependent manner. All inhibitions were reversible. These data suggest that the hypotensive action of garlic juice may be due, at least in part, to a direct relaxant effect on smooth muscles.

Effects of Inula viscosa leaf extracts on abortion and implantation in rats.

The anti-implantation and mid-term abortifacient effects exhibited by administration of Inula viscosa leaf extracts, were studied in rats. The aqueous extract administered i.p. on day 1-6 of gestation, totally diminished fetal implantation and caused a significant (P<0.05) reduction in the number of corpora lutea and blood progesterone levels. Meanwhile, administration on day 13-15 of gestation exhibited mid-term abortion. Furthermore, petroleum ether and dichloromethane, but not methanol, extracts exhibited pronounced abortifacient effects. The results of this study are in agreement with the traditional reputation of this plant as abortifacient. Further, the plant possesses anti-implantational and luteolytic effects.

Meloxicam inhibits rabbit ovulation

The nonsteroidal antiinflammatory, selective cyclo-oxygenase-2 (COX-2) inhibitor, meloxicam, was tested to assess its effect on rabbit ovulation. Meloxicam in different doses was administered intraperitoneally (ip) to adult female Californian rabbits at 2, 5, 8, and 24 h postcoitus with sperm-positive rabbits. Rabbits were killed on Day 10 of gestation. Meloxicam produced significant inhibition of ovulation in rabbits. This inhibition of ovulation by meloxicam was dose- and time-dependent. Ovulation in rabbits was completely inhibited by a single ip administration of meloxicam (20 mg/kg) when the drug was administered at 2 and 5 h postcoitus, whereas neither ovulation nor implantation were inhibited (pregnancy rate 75%) by the same dose administered 24 h postcoitus (approximately 14 h post ovulation). Further, ovulation was completely inhibited by 10 mg/kg of meloxicam when the drug was administered at 5 or 8 h postcoitus, but there was less inhibition of ovulation when 10 mg/kg of the drug was administered at 2 or 24 h postcoitus (pregnancy rate 25 and 80%, respectively). Corpora lutea, maternal plasma progesterone, ovary fresh weight, and maternal body weight gain were affected by meloxicam treatment. Histopathological findings observed in the ovaries of treated rabbits included microscopic dilatation of graffian follicles, particularly mature follicles. Some of the follicles were cystically dilated in addition to severe hemorrhage within the follicles which lost ova. These results show that ovulation can be inhibited in rabbits by meloxicam. Further studies are needed to assess the value of selective COX-2 inhibitors as potential nonhormonal contraceptive agents.

Further investigation on meloxicam contraceptivity in female rabbits: luteinizing unruptured follicles, a microscopic evidence.

Meloxicam, a selective cyclooxygenase-2 inhibitor, was administered orally or intravaginally, to sperm-positive female rabbits to assess its effect on ovulation. A single oral dose (20 mg/kg), administered 5 h postcoitus resulted in 100% contraceptive rate. On the other hand, for females receiving meloxicam suppositories (14.9 mg/kg), 5 h postcoitus, the contraceptive rate was 62.5% compared to placebo. The decrease in the contraceptive effect of meloxicam suppository may be due to the rejection of the dose by some females. Corpora lutea, maternal plasma progesterone, ovary fresh weight and maternal body weight gain were not affected by meloxicam treatment compared to placebo. Histopathologically, the surface of the ovary of meloxicam-treated females appears irregular and dilated due to the presence of different-sized cysts. Some of the cystic follicles were retained ova. Further, immunohistochemical stains for estrogen and progesterone receptors showed positive staining in granulosa cells and the wall of the unruptured follicle. It is concluded that contraceptive effect of meloxicam in female rabbits resulted in a failure of follicular rupturing.

The abortifacient effects of castor bean extract and Ricin-A chain in rabbits

The abortifacient effect of castor bean extract and ricin-A chain was evaluated in rabbits on day 18 of pregnancy. Both castor bean extract (administered orally or intraperitoneally) and ricin-A chain (intraperitoneally) terminated pregnancy when administered for three consecutive days. Treated rabbits experienced a significant decrease in maternal body weight gain. Meanwhile, the control group (receiving boiled castor bean extract) gained 4% in maternal body weight during the course of treatment. A significant reduction in progesterone, but not estrogen, plasma level was detected in all treated rabbits compared to control rabbits. Furthermore, a significant reduction in the protein contents of the placenta occurred in rabbits treated with ricin-A chain. Laparotomized rabbits exhibited dead fetuses, separation of placenta and blood clots. It is concluded that castor bean extract and ricin-A chain exhibited abortifacient effect along with maternal and fetal toxicity in pregnant rabbits.

The Calcium Antagonistic Effect of the Volatile Oil of Teucrium polium

AbstractThe effect of the volatile oil of Teucrium polium was investigated in vitro using isolated segments of rabbit intestine. The volatile oil was found to inhibit the spontaneous movements of the intestine and the contractions of the intestine induced by depolarization with high potassium (K+) solution. Also, the volatile oil was found to inhibit 45Ca influx in the intestine in a dose dependent manner. Our results suggest that the volatile oil inhibits Ca2+ influx through the potential dependent Ca2+ channels.

Antifertility Effect of Ethanolic Extract of Juniperus phoenica (L.) in Male Albino Rats

The plant Juniperus phoenica (L.) (Cupressaceae) is widely growing on the rocky soils of the Mediterranean regions. In Jordan, the plant is distributed in different locations and is used as a folk medicine to treat rheumatism, edema, and urinary tract diseases. This study aimed to investigate the antifertility effect of J. phoenica in male albino rats. Animals were administered single daily intraperitoneal injections of 400 or 800 mg/kg of J. phoenica cones ethanol extract or the vehicle (dimethyl sulfoxide) for 21 consecutive days. A marked dose-dependent decrease in the counts and motility of the sperms collected from the cauda epididymis of treated rats was observed compared with the control. Furthermore, pregnancy rate in females markedly reduced by 60% and 80% after mating with males treated with 400 or 800 mg/kg, respectively. At the same time, significant decreases were detected in seminal vesicles and testicular weight of rats that received 800 mg/kg as compared with control rats. Testosterone levels were decreased significantly in both treated groups as compared with control. Histologically, seminiferous tubules of treated rats showed marked arrests of spermatogenesis and a marked decrease in the number of mature sperms. Therefore, the results of this study suggest that the ethanolic extract of the cones of J. phoenica possesses potential antifertility effects.

Effects of Castor Bean Extract and Ricin A-Chain on Ovulation and Implantation in Rabbits

The anti-implantation and antiovulation effects of castor bean extract (CBE) and ricin A-chain (RAC) were evaluated in rabbits. Both CBE and RAC, administered intraperitoneally on days 5-9 of pregnancy, exhibited a pronounced decrease in maternal body weight gain and in death of all fetuses. A significant (p < 0.01) decrease of implantation sites resulted after rabbits were treated with RAC on the first 6 consecutive days of pregnancy. When female rabbits were treated with RAC for 10 consecutive days followed by human chorionic gonadotropin (hCG) (50 IU/kg intravenously), there was a 30% reduction in the number of corpora lutae. These data clearly indicate that CBE and RAC possess potent effects on implantation and ovulation in rabbits. The protein contents of castor bean extract, separated by polyacrylamide gel electrophoresis, revealed the presence of several protein bands, ricin toxin being a major constituent of the extract.

Effects of Ecballium elatrium Juice on Serum Bilirubin Concentration in Male Rats

AbstractThe effect of Ecballium elatrium juice on serum bilirubin concentration was examined in male rats. Jaundice was induced surgically by ligating the main bile duct. Intravenous administration of 0.05 ml of the juice two days after ligation resulted in a significant decrease in bilirubin concentration 24 h following the injection, while 0.1 ml produced a more pronounced decrease in bilirubin concentration 2.4, and 24 h after the injection. Intranasal administration of 0.1 ml of the juice also produced a significant decrease in bilirubin concentration and two doses produced more marked decrease.