Phenolic composition and biological activities of Juniperus drupacea Labill. berries from Turkey.

The present study was designed to define the phenolic profile and the biological potential of berries methanol extract of Juniperus drupacea Labill. from Turkey. The total phenolic content (Folin-Ciocalteau assay) was 48.06±0.99mgGAE/g extract. The HPLC-DAD-ESI-MS analysis allowed the determination of the complete phenolic profile of J. drupacea berries. Phenolic acids represented more than 60% of the total phenolics, and tyrosol was the major one (1324±0.64µg/g extract); within the flavonoids amentoflavone was detected as the main constituent (927±0.35µg/g extract). The extract exhibited good antioxidant properties, as determined by different in vitro models: DPPH test (IC(50) 0.38±0.02mg/mL), reducing power (12.63±0.14ASE/mL), Fe(2+) chelating ability (IC(50) 2.26±0.06mg/mL), and TBA test (IC(50) 2.47±1.13µg/mL). Cytotoxicity against Artemia salina was highlighted (LC(50) 489.47±27.8µg/mL), and a significant decrease (p⩽0.05; p⩽0.01) in HepG2 cells viability was observed at the higher concentrations (5-10µg/mL). The extract displayed good antibacterial activity towards Gram-positive bacteria and in particular Staphylococcus aureus was the most susceptible strain (MIC 78.12µg/mL).

Antibacterial activity of Helleborus bocconei Ten. subsp. siculus root extracts.

AIM OF THE STUDY: Roots of Helleborus bocconei Ten. subsp. siculus (Schiffner) Merxm. & Podl. are widely used in veterinary folk medicine in Sicily (Italy) to diagnose and cure lower respiratory tract infections in cattle. This study intended to evaluate the in vitro antibacterial activity of the methanolic root extract of Helleborus bocconei Ten. subsp. siculus, and of the bufadienolide and ecdysteroid fractions extracted from its roots, against strains belonging to species commonly associated with respiratory tract infections. MATERIALS AND METHODS: The phytochemical screening of the previously prepared plant extracts was carried out by chemical, thin-layer chromatography and spectroscopic methods. The in vitro antibacterial activity of the extracts against seven different standard bacterial strains was evaluated by broth microdilution. RESULTS: According to the present study, Helleborus bocconei Ten. subsp. siculus roots contain bufadienolides and ecdysteroids, and the extracts containing these compounds, as well as the crude methanolic root extract, show antibacterial activity against microorganisms responsible for respiratory infections. In particular, the bufadienolide extract has the highest inhibitory activity against all the tested organisms, and, as the other extracts, shows the lowest MIC values (100mug/ml) against Moraxella catarrhalis and Streptococcus pneumoniae. CONCLUSIONS: Since the roots of Helleborus bocconei Ten. subsp. siculus contain substances with antibacterial activity, the traditional use of this plant may also derive from its antibacterial properties.

Anti-ulcer, anti-inflammatory and antioxidant activities of the n-butanol fraction from Pteleopsis suberosa stem bark.

Pteleopsis suberosa Engl. et Diels (Combretaceae) is a tree distributed in many African countries. The decoction from the stem bark is orally administered for the treatment of gastric ulcers in traditional medicine. Previous pharmacological studies reported the anti-ulcer activity of extracts from P. suberosa stem bark. In the present study, the anti-ulcer and anti-inflammatory effects of the n-butanol fraction (RBuOH) obtained from a methanol extract of P. suberosa bark were investigated on ethanol-induced gastric ulcers in rats and carrageenan-induced paw oedema in mice. Misoprostol (0.50 mg/kg, p.o.) and indomethacin (8.00 mg/kg, p.o.) were used as positive controls for anti-ulcer and anti-inflammatory activities, respectively. Results showed that RBuOH treatment significantly reduced the incidence of gastric lesions (50 mg/kg, P<0.05; 100 and 200 mg/kg, P<0.01) and restored the decreased levels of total sulfhydryl groups (T-SH) and non-protein sulfhydryl groups (NP-SH) (50, 100 mg/kg, P<0.05; 200 mg/kg, P<0.01) in the stomach homogenate. Moreover, RBuOH treatment attenuated MDA levels as index of lipid peroxidation in gastric mucosa. Administration of RBuOH at the same dosage (50, 100 and 200 mg/kg) reduced significantly (P<0.01) carrageenan-induced paw oedema in dose-dependent manner (from 42.81% to 87.81% inhibition, 5h after carrageenan injection). The anti-inflammatory effect of RBuOH at 200 mg/kg was comparable with that of indomethacin. Finally, RBuOH proved to possess elevated free radical scavenger capacity on 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay (IC(50) 23.48 microg/ml) which may contribute to the observed anti-ulcer and anti-inflammatory activities.

Evaluation of the antioxidant properties and bioavailability of free and bound phenolic acids from Trichilia emetica Vahl.

Trichilia emetica Vahl. is commonly used in folk medicine of Mali for the treatment of various diseases. In this study, the content and the antioxidant activity of phenolic acids from Trichilia emetica root were evaluated. Free phenolic acids were extracted with a mixture of methanol and 10% acetic acid. Bound phenolic acids were released using first alkaline and then acid hydrolysis. All fractions were quantified separately by HPLC. After alkaline hydrolysis, a remarkable increase in caffeic acid, ferulic acid, p-coumaric acid, syringic acid, vanillic acid, protocathecuic acid and gallic acid content was observed, showing that most of phenolic acids in the drug are present as bound forms. Moreover, the extracts submitted to alkaline hydrolysis showed high antioxidant properties in two in vitro assays: autooxidation of methyl linoleate (MeLo) and ascorbate/Fe(2+)-mediated lipid peroxidation in rat microsomes. An in vivo study was also performed to investigate the intestinal absorption of phenolic acids after oral administration of Trichilia emetica extracts. Results showed high levels of phenolic acids, free or conjugated to glucuronide, in the plasma of rats treated with the hydrolyzed extract. Due to the absence of chlorogenic acid in plasma samples, the presence of caffeic acid seems to be derived from hydrolysis of chlorogenic acid in the gastrointestinal tract.

Cardiovascular effects of the aqueous extract of Gynostemma pentaphyllum Makino.

In the present study, the cardiovascular activity of the aqueous extract of Gynostemma pentaphyllum Makino leaves was investigated in the anaestetized guinea-pigs and has been compared with two of its isolated gypenosides (III, VIII) and with verapamil, a well-known Ca-antagonistic drug. The results obtained showed that the intravenous administration of the decoction of G. pentaphyllum (2.5, 5 and 10mg/kg) produced a protective effect against pitressin-induced coronaryspasm, arrhythmias and pressor response. Extract also increased the dose of ouabain required to cause ventricular tachyarrhythmias and lethality. Further extract reversed ouabain-induced persistent ventricular tachycardia and restored sinus rhythm in a dose-dependent manner. The results obtained have also shown that gypenosides III and VIII caused similar protective effects in both experimental models used; however, the duration of the action is lower than that of the extract containing corresponding quantities of gypenosides III and VIII.

Hepatoprotective and antibacterial effects of extracts from Trichilia emetica Vahl. (Meliaceae).

Trichilia emetica Vahl. (Meliaceae) is a tree widely distributed in Tropical Africa. It has been used in Mali folk medicine for the treatment of various illnesses. The aim of this work was to study the hepatoprotective and antibacterial effects of a crude aqueous extract from Trichilia emetica root. An ethyl ether fraction from the aqueous extract was also prepared and studied. We have examined the hepatoprotective activity of the extracts on CCl4-induced damage in rat hepatocytes, their toxicity using the brine shrimp bioassay and their antibacterial activity against clinical isolated bacterial strains, which are commonly responsible for respiratory infections. A preliminary phytochemical analysis showed a high polyphenolic content in the aqueous extract and the presence of limonoids in the ethyl ether fraction. These latter compounds may be considered responsible for the good activity against the bacterial strains tested. Trichilia emetica extracts exerted also a significant (P<0.05) hepatoprotective effect at a dose of 1000 microg/ml both on plasma membrane and mitochondrial function as compared to silymarin used as a positive control. These activities may be a result of the presence of either polyphenols or limonoids. Finally, both the aqueous extract and its ethyl ether fraction did not show toxicity (LC50>1000 microg/ml) in the brine shrimp bioassay.

Hepatoprotective activity of Trichilia roka on carbon tetrachloride-induced liver damage in rats.

Trichilia roka Chiov. (Meliaceae) is a tree widely distributed in tropical Africa. It has been used in Mali folk medicine for the treatment of various illnesses. A decoction of the roots is taken as a remedy for colds and pneumonia, and it is used as a diuretic and in hepatic disorders. We have evaluated the hepatoprotective effects of a decoction of Trichilia roka root on CCl4-induced acute liver damage in rats. Treatment with the decoction showed a significant protective action made evident by its effect on the levels of glutamate oxalacetate transaminase and glutamate pyruvate transaminase in the serum, on the protein content and lipid peroxidation levels in the liver homogenate. Histopathological changes produced by CCl4, such as necrosis, fatty change, ballooning degeneration and inflammatory infiltration of lymphocytes around the central veins, were clearly recovered by the treatment with Trichilia root decoction. On fractionating this extract into diethyl ether-soluble and water-soluble fractions, the activity was retained in the diethyl ether-soluble fraction. Moreover, the administration of decoction prevented a preferential deposition of collagen around the sinusoidal cell layer, which is responsible for the perisinusoidal fibrosis in the early stage of CCl4 damage. This study showed that treatment with Trichilia roka extracts or silymarin (as reference) appeared to enhance the recovery from CCl4-induced hepatotoxicity. The hepatoprotective properties of Trichilia roka may be correlated to polyphenol content of the decoction and its diethyl ether-soluble fraction.

Micromorphological investigations on Entada africana Guill. et Perr. (Mimosaceae).

Entada africana Guill. et Perr., known in Mali by the common local name 'Samanéré' in the Bambara language, is one of the traditional Malian medicines prescribed for many illnesses. In the present investigation, micromorphological studies were carried out by scanning electron microscopy on the roots and the leaves. The correct identification of the morphological characters of drugs is of great interest for quality control in basic research and drug production, especially for imported items and for raw materials sold by traditional herbalists.

Antimicrobial activity of Mitracarpus scaber extract and isolated constituents.

The antimicrobial activity of a methanol extract and isolated constituents of Mitracarpus scaber, a species used in folk medicine by West African native people, was evaluated against Staphylococcus aureus and Candida albicans strains. The mitracarpus methanol extract possesses both antibacterial and antimycotic activities (minimum inhibitory concentration-MIC 31.25 and 62.50 microg ml-, respectively). This extract was subsequently fractioned and monitored by bioassays leading to the isolation of seven compounds screened for antibacterial and antimycotic activities. Among these compounds, gallic acid and 3,4,5-trimethoxybenzoic acid inhibited the growth of Staph. aureus (MIC 3.90 and 0.97 microg ml-). 4-Methoxyacetophenone and 3,4,5-trimethoxyacetophenone effectively inhibited C. albicans (MIC 1.95 microg ml-). The other compounds (kaempferol-3-O-rutinoside, rutin and psoralen) which were also isolated showed low antibacterial and antimycotic activities (125-500 microg ml-).

Hepatoprotective properties in the rat of Mitracarpus scaber (Rubiaceae).

The effect of Mitracarpus scaber on carbon tetrachloride-induced acute liver damage in the rat has been evaluated. Results showed that treatment with Mitracarpus scaber decoction resulted in significant hepatoprotection against CCl4-induced liver injury both in-vivo and in-vitro. In-vivo, Mitracarpus scaber pretreatment reduced levels of serum glutamate-oxalate-transaminase (P < 0.01 for 250, 500 and 1000 mg kg(-1)) and serum glutamate-pyruvate-transaminase (P < 0.05 for 250 mg kg(-1) and P < 0.01 for 1000 mg kg(-1)) previously increased by administration of CCl4. In-vitro results indicated that addition to the culture medium of Mitracarpus scaber extracts significantly reduced glutamate-oxalate-transaminase (P < 0.05 for 100 microg mL(-1) and P < 0.01 for 10 and 1000 microg mL(-1)) and lactate dehydrogenase activity (P < 0.05 for 10 microg mL(-1)). Mitracarpus treatment also resulted in a good ( > 93%) survival rate for the CCl4-intoxicated hepatocytes as demonstrated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay. Moreover, as in the in-vitro assay, Mitracarpus scaber had radical-scavenging properties, shown by its reaction with the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical (EC50, the extract concentration resulting in a 50% reduction in the absorbance of DPPH blank solution, = 41.64+/-1.5 microg mL(-1)). The results of this study showed that Mitracarpus scaber had antihepatotoxic potential, a finding which supports the validity of traditional usage of this drug in Mali for the treatment of liver diseases.

Effects of some Malian medicinal plants on the respiratory tract of guinea-pigs.

Crossopteryx febrifuga, Pteleopsis suberosa and Entada africana are used in Mali traditional medicine for fever and various respiratory diseases. We have investigated the effects of these three drugs in the form of a decoction on the respiratory tract using different experimental models. On citric acid-induced cough in guinea-pigs, the three drugs significantly decreased the number of coughs at the doses of 250 (P < 0.01), 500 (P < 0.05; P < 0.01) and 1000 (P < 0.01) mg kg(-1). The percent inhibition was respectively 62.86, 69.03 and 77.44% for C. febrifuga, 57.80, 53.90 and 61.40% for E. africana, and 37.13, 42.44 and 73.72% for P. suberosa. Codeine phosphate (10 mg kg(-1)) used as reference drug showed an inhibition of 76.32%. E. africana (1000 mg kg(-1)) reduced (65% inhibition) significantly (P < 0.05) bronchoconstriction induced by histamine (99.25% and 34.00% for control and extract, respectively). Furthermore, E. africana (1000 mg kg(-1)) provoked a bronchodilatation response when administered under basal conditions. On antigen-induced bronchospasm, C. febrifuga protected (54% inhibition) sensitized guinea-pigs with a pulmonary ventilation pressure (PVP) of 24.87% (control value < 55.00%). P. suberosa was inactive in both experimental models. The reference drug, disodium cromoglycate (10 mg kg(-1), i.v.) protected significantly (P < 0.05) with a PVP of 12.00% (78% of inhibition). This study confirmed the traditional use of these plants in the treatment of cough and other respiratory disorders.

Effects of Pteleopsis suberosa extracts on experimental gastric ulcers and Helicobacter pylori growth.

Pteleopsis suberosa Engl. et Diels was used in the traditional medicine of Mali for the treatment of gastric and duodenal ulcers. In an ethnopharmacological approach, Pteleopsis suberosa extracts of the stem bark were investigated for antiulcer and antibacterial activity against Helicobacter pylori standard strains and clinical isolates. The decoction, the traditional form of administration of the drug in Mali, and the methanolic extract were active against all the bacterial strains tested. The minimum inhibitory concentrations ranged from 62.5 to 500 microg/ml for the decoction and from 31.25 to 250 microg/ml for the methanolic extract. The results indicate that Pteleopsis suberosa may be a source of compounds with a therapeutic potential against gastric ulcers associated with Helicobacter pylori infections.

Isolation and characterization of Guiera senegalensis J.F.Gmel. active principles.

A combination of thin-layer chromatography, high-performance liquid chromatography, UV spectroscopy and NMR spectrometry techniques for analysis of flavonoid content of Guiera senegalensis J.F.Gmel. (Combretaceae) leaves is described. Four components, catechin, myricitrin, rutin and quercetin were evidenced and determined by HPLC.

Drugs used in Africa as dyes: I. Skin absorption and tolerability of Bixa orellana L.

Bixa orellana L. (Bixaceae) seed extract, used in Africa as a dye, was employed to evaluate the onset of the possible topical localized responses of the rabbit skin in single application, after repeated application and after UV exposure. Histologic studies were also carried out to evaluate the possible damage and penetration of Bixa colouring matter into the rabbit hairless skin and into the hairs. The study showed that Bixa orellana has a good cutaneous tolerability and may encourage the use as a source of colouring matter in cosmetology.

Antiulcer activity of Vernonia kotschyana sch. bip.

Vernonia root is a herbal remedy used in Mali folk medicine for treatment of gastritis and gastroduodenal ulcer. The clinical trial conducted in Mali on a small number of patients gave encouraging results. In our studies, the aqueous extract of Vernonia, administered before or after an ulcerogenous agent, reduces the number and severity of ethanol-induced ulcers. The extract does not produce changes in volume, pH and total acid output in pyloric-ligated animals.

Selective antimicrobial activities of Mitracarpus scaber Zucc. against Candida and Staphylococcus sp.

Different extracts of Mitracarpus scaber aerial parts were investigated for in vitro antibacterical and antimycotic activities against strains of laboratory microorganisms and clinical isolates responsible for skin infections. The diethyl ether extract possesses a rather good activity: the minimum inhibitory concentration ranged from 15.6-31.25 µg/ml against standard strains of Candida sp. and from 7.8-125 µg/ml against clinical isolates strains. Staphylococci were inhibited at 3.9-62.5 µg/ml (standard strains) and at 1.9-15.6 µg/ml (clinical isolates). The results confirm the rationale of the folkloric use of Mitracarpus in treating fungal and bacterial infections.

Antiulcer activity of Pteleopsis suberosa.

The bark Pteleopsis suberosa is commonly used in Mali for the treatment of gastric ulcers. The present study evaluated the antiulcerogenic property of chloroform, ethanol and aqueous extracts and of decoction of P. suberosa bark against ulcer lesions induced by ethanol and indomethacin in rats. The results tend to confirm the popular use of the plant.

Central nervous system activity of terpenoids from marine sponge.

Some terpenoids extracted from marine sponge: triacetylated disidein, 2-tetraprenyl benzoquinol and 4 hydroxy-3-tetraprenylbenzoic acid 2-polyprenyl benzoquinols, avarol and furospongin-1 were tested by multidimensional Irwin screening and with some tests for analgesic and muscle relaxant activity. The three prenylhydroquinols derivatives and avarol show a good analgesic activity and low toxicity.