Bioactive 12-oleanene triterpene and secotriterpene acids from Maytenus undata.

The aerial parts of Maytenus undata yielded four new 12-oleanene and 3,4-seco-12-oleanene triterpene acids, namely, 3-oxo-11alpha-methoxyolean-12-ene-30-oic acid (1), 3-oxo-11alpha-hydroxyolean-12-ene-30-oic acid (2), 3-oxo-olean-9(11), 12-diene-30-oic acid (3), and 3,4-seco-olean-4(23),12-diene-3, 29-dioic acid (20-epi-koetjapic acid) (5), together with the known 3, 11-dioxoolean-12-ene-30-oic acid (3-oxo-18beta-glycyrrhetinic acid) (4), koetjapic acid (6), and the 12-oleanene artifact 3-oxo-11alpha-ethoxyolean-12-ene-30-oic acid (7). Koetjapic acid (6) inhibited the growth of Staphylococcus aureus, methicillin-resistant S. aureus, and Pseudomonas aeruginosa, with an MIC range of 3.125-6.25 microg/mL. The new 3,4-secotriterpene acid 20-epi-koetjapic acid (5) potently inhibited rat neonatal brain microglia phorbol ester-stimulated thromboxane B(2) (IC(50) = 0.5 microM) and superoxide anion (IC(50) = 1.9 microM) generation.

Hirsutinolides from Vernonia cinerascens.

The aerial parts of Vernonia cinerascens, collected in Saudi Arabia, yielded a new hirsutinolide, together with three known lactones. The structure of the new compound was elucidated using, 1H NMR, 13C NMR, 1H-1H COSY, 1H-13C HETCOR and HMBC.

Cell culture assay system for the evaluation of natural product-mediated anti-Hepatitis B virus activity.

Utilizing the hepatitis B virus (HBV)-producing hepatoblastoma cell line, HepG2.2.15, which is stably transfected with the cloned HBV genome, methods were devised to examine the effects of test substances on intracellular extrachromosomal HBV DNA levels and secretion of hepatitis B surface antigen (HBsAg). The known inhibitor of HBV replication, dideoxycytosine (ddC), had a minor effect on the secretion of HBsAg, but >90% of intracellular extrachromosomal HBV DNA expression was lost at a non-cytotoxic drug concentration (25µM). This inhibitory effect was reversed when ddC was removed from the medium. Of 19 plant materials tested, extracts from the aerial parts of Clematis sinensis Lour, and Clerodendron inerme R. Br. significantly inhibited the secretion of HBsAg into the culture medium at non-cytotoxic concentrations, but had no effect on intracellular extrachromosomal HBV DNA levels. This system is useful for the evaluation of test materials, or combinations of test materials, for their potential to inhibit HBV markers.

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.

Isolation and characterization of two antimicrobial agents from mace (Myristica fragrans).

The two antimicrobial resorcinols malabaricone B [1] and malabaricone C [2] were isolated from mace, the dried seed covers of Myristica fragrans. Both compounds exhibited strong antifungal and antibacterial activities. Structure modifications by methylation or reduction resulted in diminished activity.

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.

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.

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.

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.

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.

Evaluation of Artemisia inculta for anti-inflammatory activity in rats.

The ethanolic extract of Artemisia inculta has been screened for anti-inflammatory, analgesic and antipyretic activities on suitable experimental models. It has been found to produce significant inhibition of carrageenan induced paw edema and cotton pellet induced granuloma pouch and a significant decrease in the prothrombin time in rats. It failed to produce any analgesic or antipyretic activity on the hot plate reaction time and yeast induced hypyrexia tests in mice. It also did not produce any effect on the platelet aggregation and fibrinogen level in the rats. Amongst the phytoconstituents detected in this plant, flavonoids may be responsible for the observed anti-inflammatory effect of the ethanolic extract.

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.

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.

The antimicrobial activity of garlic and onion extracts.

Aqueous extracts of garlic (Allium sativum) and onion (Allium cepa) were tested for activity against Gram-positive organisms, Gram-negative organisms and fungi. A significant growth inhibition was shown by most of the organisms, tested at random. A quantitative assessment of the activity was carried out by determining the minimum bacteriostatic and bactericidal concentrations of the extracts against Gram-positive and Gram-negative organisms. Garlic extract showed greater activity as compared to the extract of onion. The activity of the garlic extract on the mouth flora of volunteers was then investigated. A mouth wash containing 10% garlic in quarter Ringer solution produced a drastic reduction in the number of oral bacteria.