M. Tariq

Evaluation of turmeric (Curcuma longa) for gastric and duodenal antiulcer activity in rats

An ethanol extract of turmeric was studied in rats for its ability to inhibit gastric secretion and to protect gastroduodenal mucosa against the injuries caused by pyloric ligation, hypothermic-restraint stress, indomethacin, reserpine and cysteamine administration and cystodestructive agents including 80% ethanol, 0.6 M HCl, 0.2 M NaOH and 25% NaCl. An oral dose of 500 mg/kg of the extract produced significant anti-ulcerogenic activity in rats subjected to hypothermic-restraint stress, pyloruic ligation and indomethacin and reserpine administration. The extract had a highly significant protective effect against cystodestructive agents. The reduction in the intensity of ulceration of cysteamine-induced duodenal ulcers was not found to be statistically significant. Turmeric extract not only increased the gastric wall mucus significantly but also restored the non-protein sulfhydryl (NP-SH) content in the glandular stomachs of the rats.

Studies on ruta chalepensis, an ancient medicinal herb still used in traditional medicine

An ethanolic extract of the aerial parts of Ruta chalepensis was studied for its anti-inflammatory, antipyretic, analgesic and CNS depressant activities. The extract produced a significant inhibition of carrageenan-induced paw oedema and cotton pellet granuloma in rats. The studies on spontaneous motor activity in mice and conditioned avoidance responding (CAR) in rats showed a dose-dependent depression of the central nervous system in treated animals. Reduction of yeast-induced hyperthermia in mice confirmed its reputed antipyretic activity. The extract did not produce any significant changes in prothrombin time and fibrinogen level. It also failed to produce any analgesic activity in the hot plate reaction-time test in mice. Phytochemical screening of the aerial parts of the plant showed the presence of alkaloids, flavonoids, coumarins, tannins, volatile oil, sterols and/or triterpenes.

Effect of Salvia haematodes on sexual behaviour of male rats.

The effect of an ethanolic extract of Salvia haematodes roots was studied on the sexual behaviour of male rats. In the initial experiments, male sexual responses were assessed by recording penile erection, licking and grooming of genitals and copulatory movement in absence of females. In the second set, copulatory behaviour was observed by caging males with a receptive female brought into estrus with s.c. injection of estradiol benzoate and progesterone. The frequencies of mounting and intromission and latency of the ejaculation were recorded. The results show that the extract (500 mg/kg, orally) produced a significant increase in episodes of penile erection. The drug was found to enhance the orientation of males towards the female by increased anogenital investigatory behaviour and enhanced licking and grooming of the genitals. The extract also increased the ejaculation latency. These findings support the folk use of this plant as aphrodisiac and for the treatment of premature ejaculation.

An evaluation of the male reproductive toxicity of cathinone.

(-)-Cathinone is the major psychoactive component of khat plant (Catha edulis Forssk.). Khat has been shown to produce reproductive toxicity in human beings and experimental animals. However, the chemical constituents of khat leaves responsible for sexual dysfunction are not known. In the present study cathinone enantiomers have been investigated for their reproductive toxicity in rats. Cathinone produced a dose-dependent decrease in food consumption and suppressed the gain in body weight. There was a significant decrease in sperm count and motility and increase in the number of abnormal sperms in cathinone treated animals. Histopathological examination of testes revealed degeneration of interstitial tissue, cellular infiltration and atrophy of Sertoli and Leydigs cells in cathinone treated animals. Cathinone also produced a significant decrease in plasma testosterone levels of the rats. Although both enantiomers of cathinone produced deleterious effects on male reproductive system, (-)-cathinone was found to be more toxic. From this study it may be concluded that the cathinone content in khat may be partially or totally responsible for the reproductive toxicity in khat chewers.

Anti-inflammatory activity of some Saudi Arabian medicinal plants

Five plants which have been used for the treatment of rheumatism, arthritis and gout in the traditional medicine of Saudi Arabia, were evaluated for their anti-inflammatory properties. Of these the ethanolic extract of Capparis decidua and the aqueous extract of Capparis spinosa were found to possess significant anti-inflammatory activity against carrageenan induced oedema in rats. These two plants were also tested for their antipyretic and analgesic activity. C. decidua was found to possess significant antipyretic effect. Both of them are devoid of analgesic activity.

Anti-inflammatory activity of Commiphora molmol.

The petroleum ether extract of the oleo-gum resin of Commiphora molmol, at a dose of 500 mg/kg body weight, produced significant inhibition of carrageenan induced inflammation and cotton pellet granuloma. The extract also showed significant antipyretic activity in mice. Further studies on the fractionation of phytoconstituents and their mechanism of action are in progress.

Clastogenic evaluation of cathinone and amphetamine in somatic cells of mice.

Clastogenic effects of cathinone, the active principle from khat (Catha edulis) and amphetamine, a compound having similar chemical structure and pharmacological activity, have been studied on the somatic cells of mice. Both of them produced marked clastogenic activity and affected the cell proliferation in the bone marrow of mice. They induced a significant increase in the frequency of micronucleated polychromatic erythrocytes at higher doses. These results substantiate our earlier observations on the clastogenic and mitodepressive activity of cathinone on the meristematic region of Allium cepa, and indicate that cathinone may be responsible for the mutagenic effect of khat reported by other workers. The clastogenic effects of amphetamine are being reported for the first time. Further studies are required to substantiate these findings and to study whether cathinone and amphetamine produce a direct clastogenic effect or whether they act as spindle poisons.

Cytological Effects of Khat (Catha Edulis) in Somatic and Male Germ Cells of Mice

Cytological effects of khat (Catha edulis), a popular drug of abuse from Southern Arabia and Eastern Africa, have been studied in Swiss albino mice. The studies on the somatic system involved the use of micronucleus test and the cytological analysis of the mitotic index in the femoral cells of mice. In the micronucleus test, the mice were treated with different doses of khat extract (125, 250 and 500 mg/kg, p.o.) 30 and 6 hours before sacrificing the animals. The polychromatic erythrocytes were screened for the induction of micronuclei. For the analysis of bone marrow cytotoxicity, the mice were treated with the dose of 125, 250 and 500 mg/kg, body weight, p.o. daily for 5 consecutive days. The animals were sacrificed and the femoral cells were microscopically examined for the mitoses. Following the same schedule of treatment, studies on the cytogenetic analysis of meiotic chromosomal aberrations and the sperm head abnormality were undertaken. Khat extract significantly increased the frequency of micronucleated polychromatic erythrocytes, induced bone marrow depression and reduced the mitotic index of the somatic cells. It induced significant chromosomal aberrations viz., aneuploids, autosomal univalents, univalents of the sex chromosomes and polyploids. The frequency of abnormal sperms was also increased.

Preliminary toxicity studies on ethanol extracts of the aerial parts of Artemisia abyssinica and A. inculta in mice.

Ethanolic extracts of the aerial parts of Artemisia abyssinica and A. inculta were subjected to acute toxicity observations in mice for 24 h and chronic toxicity evaluation for 3 months. External morphological changes, visceral toxicity, haematological changes, spermatogenic dysfunction and effect on body weight and vital organ weight were recorded. In both the chronically treated groups, no significant acute mortality was observed up to 3 g/kg p.o. There was no weight gain in A. abyssinica chronically-treated mice while the weight gain of A. inculta-treated animals matched that of the control group. Significant sperm damage was observed in A. abyssinica-treated mice while A. inculta failed to produce any significant spermatotoxic effect.

Comparative study of cathinone and amphetamine on brown adipose thermogenesis

The effect of cathinone and amphetamine on brown adipose tissue thermogenesis and its modification with propranolol and timolol has been studied in rats. Both cathinone and amphetamine produced significant dose dependent increases in intracapsular brown adipose tissue (IBAT) and rectal temperatures. Amphetamine was found to be three times more potent as compared to cathinone, on a dose basis. Pretreatment of animals with propranolol and timolol individually inhibited cathinone and amphetamine induced hyperthermia. These findings suggest the involvement of beta adrenergic receptors in cathinone and amphetamine induced thermogenesis.