Effect of (-)-cathinone, a psychoactive alkaloid from khat (Catha edulis Forsk.) and caffeine on sexual behaviour in rats.

The effect of (-)-cathinone, caffeine and their combinations was studied on the sexual behaviour of male rats. Male sexual activities were assessed by recording the erectile responses (grooming of genitalis, yawning/stretching and homosexual mounting), in the absence of females. The copulatory behaviour was observed by caging males with receptive females brought into oestrus with s.c. injection of oestradiol benzoate and progesterone. The copulatory pattern of male rats (mounting, intromissions, ejaculations and refractory period) was recorded. The oral treatment of cathinone (5 mg kg-1 day-1), caffeine (50 mg kg-1 day-1) and their combinations for 15 days increased arousal (motivation) in male rats as evidenced by increased mounting performance and anogenital investigatory behaviour. However, erectile and ejaculatory responses, measured in the present study, showed no stimulant effect. It is conceivable from the present results that cathinone, the psychostimulant constituent of khat modified masculine pattern behaviour and caffeine also changed the effect of cathinone when administered concomitantly. However, our data provide no evidence that cathinone could be considered as an aphrodisiac.

Effect of ambrein, a major constituent of ambergris, on masculine sexual behavior in rats.

The effect of ambrein, a major constituent of ambergris, was studied on the sexual behavior of male rats. The rats were administered ambrein in doses of 100 and 300 mg/kg body weight. Male sexual activities were assessed by recording the erectile responses (penile erection) and homosexual mountings in the absence of female. The copulatory studies were carried out by caging males with receptive females brought into estrus with subcutaneous injections of estradiol benzoate and progesterone. The copulatory pattern of treated male rats (mountings, intromissions, ejaculations and refractory period), the pendiculations (yawns/stretches) and orientation activities towards females, the environment and themselves, were recorded. Ambrein produced recurrent episodes of penile erection, a dose-dependent, vigorous and repetitive increase in intromissions and an increased anogenital investigatory behavior, identifying the drug used in the present study as a sexual stimulant. It is conceivable from the present results that the ambrein-modified masculine sexual behavior in male rats supports the folk use of this drug as an aphrodisiac.

Pharmacological and safety evaluation studies on Lepidium sativum L., Seeds.

An ethanolic extract of Cress (Lepidium sativum L.) seeds has been studied for anti-inflammatory, antipyretic and analgesic activities and to evaluate the safety of their acute and chronic use in rodents. The extract significantly inhibited carrageenan-induced paw edema and reduced the yeast-induced hyperpyrexia. It also prolonged the reaction time of mice on the hot plate. However, the extract exacerbated indomethacin-induced gastric mucosal damage. The coagulation studies showed a significant increase in fibrinogen level and an insignificant decrease in prothrombin time, confirming its coagulating property. The toxicity tests showed that the administration of extract in single doses of 0.5 to 3.0g/kg did not produce any adverse effects or mortality in mice, whereas the animals treated with extract (100 mg/kg/day) for a period of 3 months in drinking water showed no symptoms of toxicity except a statistically insignificant higher mortality rate. These findings suggest that the seeds of Cress (L. sativum) possess significant anti-inflammatory, antipyretic, analgesic and coagulant activities, and are free from serious side or toxic effects.

Protective effect of Swertia chirata against indomethacin and other ulcerogenic agent-induced gastric ulcers.

The effect of Swertia chirata has been studied on experimentally induced gastric ulcers in rats. The ethanolic extract of chirata significantly reduced the intensity of gastric mucosal damage induced by indomethacin and necrotizing agents. It produced a significant decrease in gastric secretion in pylorus-ligated rats. The extract inhibited acetylcholine-induced contraction of guinea pig ileum, suggesting its anti-cholinergic activity. Pretreatment of rats with the extract significantly prevented ethanol-induced gastric wall mucus depletion and restored the non-protein sulfhydryl (NP-SH) content in the glandular stomachs. These findings support the use of chirata for the treatment of gastric ulcers in traditional medicine.

Toxicity studies on Alpinia galanga and Curcuma longa.

Acute (24 h) and chronic (90 days) oral toxicity studies on the ethanolic extracts of the rhizomes of Alpinia galanga and Curcuma longa were carried out in mice. Acute dosages were 0.5, 1.0, and 3 g/kg body weight while the chronic dosage was 100 mg/kg/day as the extract. All external morphological, hematological, and spermatogenic changes, in addition to body weight and vital organ weights were recorded. During this investigation no significant mortality as compared to the controls was observed. The weight gain in the A. galanga treated animals was significant as in the control group while the C. longa-treated animals gained no significant weight after chronic treatment. C. longa treatment induced significant changes in heart and lungs weights upon chronic treatment. Hematological studies revealed a significant rise in the RBC level of A. galanga-treated animals and a significant fall in the WBC and RBC levels of the C. longa-treated animals as compared to the controls. The gain in weights of sexual organs and increased sperm motility and sperm counts were observed in both groups of extract-treated male mice, however, these changes were highly significant in the A. galanga-treated group. Both extracts failed to show any spermatotoxic effects.

Toxicity studies in mice of ethanol extracts of Foeniculum vulgare fruit and Ruta chalepensis aerial parts.

Acute (24-h) and chronic (90-day) oral toxicity studies on the ethanolic extracts of Foeniculum vulgare fruit and Ruta chalepensis aerial parts were carried out in mice. Acute dosages were 0.5, 1.0 and 3 g/kg while the chronic dosage was 100 mg/kg per day of extract. All external morphological, haematological and spermatogenic changes, in addition to body and vital organ weights were recorded. The extracts caused no significant acute or chronic mortality as compared to controls during this investigation. The treated male mice gained significant weight during chronic treatment while a loss or no significant change in weight was noticed in the female mice treated with the same extracts. Haematological studies revealed a significant fall in RBC level of R. chalepensis-treated animals. Both the extracts failed to show spermatotoxic effects.

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.

Pharmacological studies on aerial parts of Calotropis procera.

The decoction of the aerial part of Calotropis procera is commonly used in Saudi Arabian traditional medicine for the treatment of variety of diseases including fever, joint pain, muscular spasm and constipation. The present investigation was undertaken to confirm its claimed activity in traditional medicine. The ethanol extract of the plant was tested on laboratory animals for its antipyretic, analgesic, anti-inflammatory, antibacterial, purgative and muscle relaxant activities. The results of this study showed a significant antipyretic, analgesic and neuromuscular blocking activity. On smooth muscle of guinea pig ileum, the extract produced contractions which was blocked by atropine supporting its use in constipation. The extract failed to produce significant anti-inflammatory and antibacterial activities. Our phytochemical studies on the aerial parts of C. procera showed the presence of alkaloids, cardiac glycosides, tannins, flavonoids, sterols and/or triterpenes. However, the chemical constituents responsible for the pharmacological activities remains to be investigated. The safety evaluation studies revealed that the use of extract in single high doses (up to 3 g/kg) does not produce any visible toxic symptoms or mortality. However, prolong treatment (90 days) causes significantly higher mortality as compared to control group.

The toxicity of Catha edulis (khat) in mice.

A large number of people in East Africa and Southern Arabia chew khat leaves because of its pleasurable and stimulating effects. Due to its habit forming property, the khat has been classified as a "Substance of Abuse" by the World Health Organization. In view of the large number of medical problems reported in khat chewers, the present study was undertaken to investigate the chronic toxicity of khat in mice. Three groups of mice were treated with aqueous solution of khat extract in the dose of 50, 100, and 200 mg/kg. body weight daily by oral intubation route for 6 weeks. The results indicated a dose-dependent decrease in body weight, an increase in the incidence of mortality and induction of site specific body and eye lesions. The histopathological examination of the lesions revealed reactive hyperplasia and necrosis in the lymphoid tissues. The necrotic areas in the subcutaneous tissues showed the presence of numerous polymorphs.

Influence of tea and coffee beverages on prostacyclin synthesis by the rat aorta.

Influences of 2.5 and 5% (w/v) aqueous tea and coffee beverages administered ad lib. to rats for two weeks on PGI2 synthesis by the rat thoracic aorta in vitro were investigated using a rat platelet antiaggregatory bioassay and HPLC methods. The 2.5% beverages did not affect PGI2 synthesis; however, the 5% beverages significantly decreased PGI2 synthesis. The observed decreases were significantly abolished in presence of exogenous arachidonic acid suggesting a beverage-induced inhibition of precursor release. The ability of the beverages to inhibit PGI2 synthesis may partly contribute towards better understanding of the biochemical mechanisms underlying some of the beverages-induced actions in vivo.

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.

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.

The induction of dominant lethal mutations upon chronic administration of khat (Catha edulis) in albino mice.

The mutagenicity of a methanolic extract of khat has been evaluated on male germ cells using the dominant lethal test in albino mice. An aqueous solution of khat extract was administered orally in doses of 50, 100 and 200 mg/kg body wt., respectively, to 3 different groups of male mice for a period of 6 weeks. At the end of treatment each male mouse was allowed to mate with 2 different groups of 3 females each, on 2 consecutive weeks. These females were necropsied on the 13th day of their presumptive mating, and the number of implants in each female and the ratio of live and dead embryos were determined. The results of this study showed that the treatment of male mice over a period of 6 weeks produced a dose-dependent reduction in the rate of fertility in the first week after mating, which was irreversible in the second week at the highest dose (200 mg/kg). Khat extract also induced post-implantation loss during the first week following treatment. However, a comparison of the results of the first and second weeks showed a reversible pattern of dominant lethality.

Effect of Trigonella foenum-graecum and Ammi majus on calcium oxalate urolithiasis in rats.

The present study was undertaken to investigate the effect of Trigonella foenum-graecum seed and Ammi majus fruit on experimentally-induced kidney stones. Oxalate urolithiasis in male rats was produced by the addition of 3% glycolic acid to their diet. After 4 weeks, highly significant deposition in the kidneys was noticed and changes in water intake and body weight recorded. Daily oral treatment with T. foenum-graecum significantly decreased the quantity of calcium oxalate deposited in the kidneys thus supporting its use in Saudi folk medicine. The effects obtained by A. majus were, however, not significant.

Experimental studies on antirheumatic crude drugs used in Saudi traditional medicine.

A large number of herbal drugs are used in the traditional medicine of Saudi Arabia for the treatment of rheumatism, arthritis, gout and other forms of inflammation. In the present study seven of these crude drugs, namely Francoeuria crispa, Hammada elegans, Malus pumila, Ruta chalepensis, Smilax sarsaparilla, Achillea fragrantissima and Alpinia officinarum were tested against carrageenan-induced acute inflammation in rats. The plant materials were extracted with 96% ethanol. The dried extract was dissolved in water for pharmacological testing. The rats were administered an oral dose of 500 mg/kg body weight of each extract 1 h prior to production of inflammation by carrageenan injection (0.05 ml of 1% carrageenan suspension in the planter aponeurosis of the right hind foot). The paw volume was measured at 0,2,3 and 4 h after the injection. Four of the seven plants, namely Francoeuria crispa (24%), Malus pumila (23%), Ruta chalepensis (30%) and Smilax sarsaparilla (25%), produced significant inhibition of carrageenan-induced inflammation in rats. These plants also inhibited cotton pellet-induced exudation. Further studies are suggested to isolate the active principles and for the determination of the mechanism of action of these drugs.

Gastroprotective activity of ginger zingiber officinale rosc., in albino rats.

The cytoprotective and gastric anti-ulcer studies of ginger have been carried out in albino rats. Cytodestruction was produced by 80% ethanol, 0.6M HC1, 0.2M NaOH and 25% NaCl. Whereas gastric ulcers were produced by ulcerogenic agents including indomethacin, aspirin and reserpine, beside hypothermic restraint stress and by pylorus ligated Shay rat technique. The results of this study demonstrate that the extract in the dose of 500 mg/kg orally exert highly significant cytoprotection against 80% ethanol, 0.6M HC1, 0.2M NaOH and 25% NaCl induced gastric lesions. The extract also prevented the occurrence of gastric ulcers induced by non-steroidal anti-inflammatory drugs (NSAIDs) and hypothermic restraint stress. These observations suggest cytoprotective and anti-ulcerogenic effect of the ginger.

Studies on herbal aphrodisiacs used in Arab system of medicine.

Toxicity studies were conducted on Brassica rapa, Prunus amygdalus and Zingiber officinale, used as aphrodisiacs in Arab Medicine. During acute toxicity test observations were made for 24 h where all these plants showed no toxicity. The animals were treated for 3 months in chronic treatment. External morphological changes, visceral toxicity, haematological changes, effects on average body weight, vital organ weight, sperm contents, sperm motility and sperm abnormalities were recorded. The average body weight increase was significant in B. rapa and P. amygdalus treated animals. Haematological studies revealed reduction in WBC level in these groups. These changes were not significant in Z. officinale treated animals. In all three groups the visceral condition was normal and the percent lethality was insignificant as compared to the control. All these plant extracts significantly increased the sperm motility and sperm contents in the epididymides and vas deferens without producing any spermatotoxic effect.

Anti-inflammatory activity of Teucrium polium.

Teucrium polium is widely used by the folk-medicine practitioners in Saudi Arabia for the treatment of inflammations, rheumatism, diabetes and ulcers. Scientific reports are lacking to confirm these activities. The present study reports the effect of ethanolic extract of T. polium on carrageenan-induced acute inflammation, cotton-pellet granuloma and some of the biochemical parameters. The ethanolic extract of Teucrium polium at a dose of 500 mg/kg body weight produced significant inhibition of carrageenan-induced inflammation and cotton-pellet granuloma. Biochemical studies showed a significant decrease in glucose level. The presence of flavonoids and sterols might be responsible for the anti-inflammatory activity of this plant. Further studies on the fractionation of the phytoconstituents, and on their mechanism of action are in progress.

Saudi folk medicine: phytochemical and antimicrobial screening.

Plants of 25 families, encompassing 30 species were selected on the basis of their folklore uses and literature data for the present screening. Besides phytochemical screening the plant extracts were prepared and tested for their antimicrobial activity. The result of the testing showed that about 77% of these plants exhibited some level of antibacterial activity. The most common chemical constituents found in these plants were sterols and/or triterpenes, falvonoids, alkaloids and tannins. Volatile oils, volatile bases, saponins, coumarins, anthraquinones and cardiac glycosides were also detected.