İlhan Gürbüz

Screening of Turkish anti-ulcerogenic folk remedies for anti-Helicobacter pylori activity

The anti-Helicobacter pylori effect of the extracts and fractions obtained from seven Turkish plants, which are used in folk medicine for the treatment of gastric ailments including peptic ulcers, were studied against one standard strain and eight clinical isolates of H. pylori by using the agar dilution method. Flowers of Cistus laurifolius and Spartium junceum, cones of Cedrus libani, herbs and flowers of Centaurea solstitialis ssp. solstitialis, fruits of Momordica charantia, herbaceous parts of Sambucus ebulus, and flowering herbs of Hypericum perforatum were evaluated in this study. Results showed that all except one extract from six of these plants showed activity against the microorganism with MICs between 1.95 and 250 microg/ml, with S. junceum being the only inactive species. Amongst the active plants the inhibitory properties of C. laurifolius were found prominent.

Anti-ulcerogenic activity of some plants used as folk remedy in Turkey.

Five herbal remedies used as gastroprotective crude drugs in Turkey were assessed for anti-ulcerogenic activity using the EtOH-induced ulcerogenesis model in rat. The crude drugs investigated comprises fruits of Elaeagnus angustifolia L. (Elaeagnaceae), fresh fruits of Hibiscus esculentus L. (Malvaceae), fresh roots of Papaver rhoeas L. (Papaveraceae), leaves of Phlomis grandiflora H.S. Thomson (Lamiaceae) and fresh fruits of Rosa canina L. (Rosaceae). Extracts were prepared according to the traditional indications of use. Under our experimental conditions, all extracts exhibited statistically significant gastroprotective effect with better results for Phlomis grandiflora and Rosa canina (100%). At the concentration under study, both crude drugs were more effective than the reference compound misoprostol at 0.4 mg/kg. Even the weakest anti-ulcerogenic effect observed for Papaver rhoeas roots was found statistically potent (95.6%). Histopathological studies confirmed the results of the in vivo test.

Anti-ulcerogenic effect of Momordica charantia L. fruits on various ulcer models in rats

The mature fruits of Momordica charantia L. (Cucurbitaceae) are used externally for the rapid healing of wounds and internally for the treatment of peptic ulcers in Turkish folk medicine. For the evaluation of the latter activity, ethanol-induced ulcerogenesis model in rats was employed. The olive oil extract of the material as well as dried-powdered fruits in filtered honey showed significant and dose-dependent anti-ulcerogenic activity against this model. A potent and dose-dependent inhibitory activity was also observed by the administration of ethanol extract of the fruits. For the bioassay-guided fractionation, the material was first extracted with hexane and then by ethanol and both extracts were found active against the same ulcer model. Furthermore, ethanol extract of the fruits showed significant activity against HCl-EtOH induced ulcerogenesis in indomethacin-pretreated rats and diethyldithiocarbamate-induced ulcer models.

Effects of Cistus laurifolius L. flowers on gastric and duodenal lesions

The flowers and flower buds of Cistus laurifolius L. are used for the treatment of peptic ulcers. Through the bioassay-guided fractionation of the material, using water immersion and immobilisation-induced stress ulcer model, the EtOH-precipitated part from the aqueous extract (E-H2O decreases) was determined to be the active fraction. For the evaluation of the mode of action, the activity of E-H2O decreases was tested using various ulcer models in rats and mice and this fraction was found active against pylorus ligation-, abs. ethanol-, indomethacin-, indomethacin plus HCl/EtOH-induced gastric and cysteamine-induced duodenal lesions while ineffective against serotonin-induced gastric lesions. The active fraction showed its activity not only on per os administration but also after subcutanous injection. According to the results of biochemical studies, the active fraction showed a potent antiacid activity. In addition, histopathological, and toxicological studies were conducted with the active fraction.

In vivo gastroprotective effects of five Turkish folk remedies against ethanol-induced lesions

Through evaluation of the data accumulated in Data Bank of Turkish Folk Remedies (TUHIB), five plant remedies, which are used to treat stomach ache were selected to test for their anti-ulcerogenic potency. In order to confirm the claimed activities, either decoction or methanol extracts were prepared from the roots of Asphodelus aestivus and Cichorium intybus, herbs of Equisetum palustre and Viscum album ssp. album and fruits of Laurus nobilis, according to their folkloric application way and tested for their effects on ethanol-induced gastric ulcer model in rats. Pharmacological experiments clearly demonstrated that the relevant extracts of all the plants given orally showed significant stomach protection against this model of ulcerogenesis. Results were further evaluated by using histopathological techniques.

Evaluation of in vivo Biological Activity Profile of Isoorientin

Anti-nociceptive, anti-inflammatory and gastroprotective activities of the known C-glycosyl flavonoid, isoorientin, were studied in rats and mice. For the anti-nociceptive activity assessment the p-benzoquinone-induced writing test, for the anti-inflammatory activity the carrageenan-induced hind paw edema model in mice, and for the gastroprotective activity the EtOH-induced ulcerogenesis model in rats were used. Isoorientin was shown to possess significant anti-nociceptive and anti-inflammatory activities at 15 mg/kg and 30 mg/kg doses, without inducing any apparent acute toxicity as well as gastric damage. However, the compound did not possess any significant gastroprotective activity against EtOH-induced ulcerogenesis.

In vivo activity assessment of a “honey-bee pollen mix” formulation

Honey-bee pollen mix (HBM) formulation is claimed to be effective for the treatment of asthma, bronchitis, cancers, peptic ulcers, colitis, various types of infections including hepatitis B, and rheumatism by the herb dealers in northeast Turkey. In the present study, in vivo antinociceptive, anti-inflammatory, gastroprotective and antioxidant effects of pure honey and HBM formulation were evaluated comparatively. HBM did not show any significant gastroprotective activity in a single administration at 250 mg/kg dose, whereas a weak activity was observed after three days of successive administration at 500 mg/kg dose. On the other hand, HBM displayed significant antinociceptive (p <0.01) and anti-inflammatory (p <0.01) activities at 500 mg/kg dose orally without inducing any apparent acute toxicity or gastric damage. HBM was also shown to possess potent antilipidperoxidant activity (p <0.01) at 500 mg/kg dose against acetaminophen-induced liver necrosis model in mice. On the other hand, pure honey did not exert any remarkable antinociceptive, anti-inflammatory and gastroprotective activity, but a potent antilipidperoxidant activity (p <0.01) was determined. Results have clearly proved that mixing pure honey with bee pollen significantly increased the healing potential of honey and provided additional support for its traditional use. Total phenolic and flavonoid contents of HBM were found to be 145 and 59.3 mg/100 g of honey, which were estimated as gallic acid and quercetin equivalents, respectively.

Anti-ulcerogenic activity and isolation of the active principles from Sambucus ebulus L. leaves.

ETHNOPHARMACOLOGICAL RELEVANCE Sambucus ebulus L. has a very prominent place in Turkish folk medicine. Leaves of the plant are practiced externally to relieve rheumatic pain, to treat abscess, for wound healing and internally against hemorrhoids and stomachache. In a previous work, aqueous extract of the leaves was shown to possess potent antiulcerogenic activity on water immersion and immobilization-induced stress ulcer model in rats. This study aims to investigate the antiulcerogenic activity profile of the plant on various in vivo peptic ulcer models and gastric biochemical parameters and through bioassay-guided processing to isolate the active constituent (s) and to elucidate its structure. MATERIALS AND METHODS Among the subextracts obtained by successive solvent extractions from the MeOH extract of the leaves, the butanol subextract exerted significant antiulcerogenic activity against water-immersion and immobilization-induced stress ulcer model in rats as the bioassay model. This subextract was then subjected to successive chemical separation techniques (precipitation, column chromatography based on ion-exchange, silica gel and sephadex) and the activity of each fraction/subfraction was tested using the same bioassay model. After determination of active principles, further studies were performed on the active subextract by using various in vivo test models (ethanol-, serotonin-, pyloric ligation-induced ulcerogenesis) in rats as well as biochemical methods for the evaluation of antiulcerogenic potential. RESULTS Bioassay-guided fractionation procedures yielded two flavonol glycosides as the active antiulcerogenic principles. The structures of these compounds were elucidated as isorhamnetin-3-O-monoglycoside and quercetin-3-O-monoglycoside by using (1)H, (13)C-NMR, and FAB-MS techniques. CONCLUSION This study has proven the folkloric use of Sambucus ebulus leaves for the treatment of gastric ailments in Turkish folk medicine. The antiulcerogenic activity of the two flavonol glycosides isolated in the present study was not previously reported elsewhere.

NEW AND KNOWN CONSTITUENTS FROM IRIS UNGUICULARIS AND THEIR ANTIOXIDANT ACTIVITY

A new compound, 1,3-O-diferuloylsucrose (1), and a synthetically known compound, 5,7-dihydroxy-6-methoxychromone (2), along with several known natural products, irilone (3), 4�c ,5,7-trihydroxy-6-methoxyflavanone (4), tectorigenin (5), kaempferol (6), 4�c ,5,7-trihydroxy-3�c ,8-dimethoxyflavanone (7), 8-methoxyeriodictyol (8), hispidulin (9), and mangiferin (10) were isolated from the rhizomes of Iris unguicularis. Compounds 1, 6, 8 and 10 showed a considerable DPPH radicals scavenging activity. Their structures have been deduced through different spectroscopic techniques. The structure of compound 2 was also confirmed by single-crystal X-ray diffraction techniques as well.

Anti-ulcerogenic lignans from Taxus baccata L.

Four lignan type compounds, lariciresinol, taxiresinol, isolariciresinol and 3-demethyl-isolariciresinol, were isolated from the heartwood of Taxus baccata L. (Taxaceae) growing in Turkey through chromatographic techniques. In vivo anti-ulcerogenic potency of these compounds was investigated on ethanol-induced ulcerogenesis model in rats at two different doses, 50 and 100 mg/kg. All compounds were shown to possess significant anti-ulcerogenic activity at both doses. However, the effect of taxiresinol was the most prominent.