Antioxidative and radical scavenging effects of olive cake extract.

The antioxidative activity of different butanol extract fractions of olive cake was investigated. Four fractions showed marked antioxidative activity in comparison with BHT. Fractions tested also showed good hydrogen donating abilities, indicating that they had effective activities as radical scavengers. Coumaric, ferulic, cinnamic acids and oleuropein were isolated.

Screening of antibiotic resistant inhibitors from local plant materials against two different strains of Staphylococcus aureus.

The inhibitory effects of methanolic extracts of 19 Jordanian plants and their combinations with seven antibiotics, on the resistance of Staphylococcus aureus were checked. Methicillin resistant S. aureus (MRSA), which was isolated from patient and a standard strain of S. aureus were used. Our results showed that there are variations in the effect of some combinations used on the resistant and the standard strains probably due to structural changes. Common results between the two strains showed that combinations of gentamicin and chloramphenicol could be improved by the use of plant materials, whereas nalidixic acid activity cannot be improved when combined with plant materials.

Screening of antibiotic resistant inhibitors from local plant materials against two different strains of Pseudomonas aeruginosa.

The methanolic extracts of 19 Jordanian plants were combined with seven different antibiotics and applied to check the inhibitory effects of the combination on the resistance of Pseudomonas aeruginosa. A resistant strain of Ps. aeruginosa, which was isolated from a patient and a standard strain of the same microorganism were used in this study. Our results showed that there are significant variations in the effects of some combinations used on the resistant and the standard strains probably due to structural changes. Almost all the plant materials used in combination with penicillin G and erythromycin allowed full growth of the standard strain, while the combination with some plant materials like Gundelia tournefortii L. and Lepidium sativum L. inhibited the growth of the resistant strain. Chloramphenicol, gentamicin and cephalosporin can be given advantageously with almost all the plant materials used with few exceptions on the resistant strain. Nalidixic acid activity was improved significantly when combined with all plant materials and tested on standard strain. On the other hand, its activity on the resistant strain was slightly improved using the same combinations.

Second derivative ultraviolet spectrophotometry and HPTLC for the simultaneous determination of vitamin C and dipyrone.

Two accurate, precise and sensitive thin layer chromatographic (TLC) and second derivative UV-spectrophotometric procedures are described for the simultaneous determination of ascorbic acid and dipyrone in pure form and in pharmaceutical dosage forms. The TLC method involved direct application of methanolic solutions of tested samples on silica gel TLC plates using water:methanol (95:5 v/v) as developing system. The developed plates were then directly scanned at 260 nm using a TLC scanner. The second method depends on second derivative UV-spectrophotometry with zero crossing technique of measurement. Second derivative amplitudes at 280 and 272 nm were selected for the determination of ascorbic acid and dipyrone, respectively. Both methods show good linearity, precision and reproducibility. They are simple and do not require manipulation prior to analysis. The proposed methods have been successfully applied to the determination of the drugs in various pharmaceutical dosage forms such as tablets and ampoules.

Electrochemical study on the determination of tinidazole in tablets.

The electrochemical reduction of tinidazole has been carried out in aqueous solution in the pH range 1.8-11.3 by differential-pulse (DP) polarography. Tinidazole exhibits one or two reduction peaks depending on pH. In strongly acidic solution (pH < 4.5), one reduction peak was obtained and it was suitable for analytical purposes. A method for the determination of tinidazole by DP polarography in Britton-Robinson buffer of pH 3.0, which allows quantification over the range 0.03-7.30 microg/ml, was proposed. The method was successfully applied to the determination of tinidazole in tablets with mean recovery and relative standard deviation of 98.7 and 3%, respectively. Excipients did not interfere in the determination.

Transtorine, a new quinoline alkaloid from Ephedra transitoria.

Transtorine (1), a new quinoline alkaloid, isolated from the aerial part of Ephedra transitoria by column chromatography, was identified as 4-quinolone-2-carboxylic acid. The structure was determined by spectroscopic methods. Transtorine exhibited growth inhibitory activity against the common bacteria, Enterobacter cloacae, Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus.

Effects of allocryptopine, an alkaloid isolated from Glaucium arabicum on rat isolated ileum and urinary bladder.

1. The alkaloid, allocryptopine, was isolated from the chloroform extract of Glaucium arabicum. 2. The effect of allocryptopine on urinary bladder and ileal smooth muscles was investigated in this study. 3. Allocryptopine, in concentrations from 1 x 10(-5) to 3 x 10(-3) M caused a concentration-dependent contraction of rat isolated urinary bladder and a concentration-dependent relaxation of rat ileal smooth muscles. 4. Theophylline (10(-5) M) shifted to the left the allocryptopine concentration-effect curve on ileum and increased the maximum inhibitory effect of allocryptopine. 5. Methylene blue (10(-3) M) had no significant effect on the concentration-effect curve of allocryptopine of the ileum. 6. Phentolamine (10(-6) M) shifted to the right the allocryptopine concentration-effect curve of urinary bladder. 7. These observations suggest that allocryptopine induces a relaxing effect on the ileum by inhibiting phosphodiesterase enzyme, and thus elevating cellular cAMP and its contractile effect on the urinary bladder by affecting alpha-adrenergic receptors in this tissue.

Spectrophotometric determination of enzymatically generated hydrogen peroxide using Sol-Gel immobilized horseradish peroxidase.

Peroxidase entrapment in different Sol-Gel matrices was successful. The enzyme did not show a decrease in activity for at least 2 months as well as storage at room temperature and dry condition for periods exceeding 3 weeks. It was evident that the enzymatic activity was a function in the type of the alkoxysilane precursor. In addition, the optimum temperature which resulted in maximum enzymatic activity was also dependent on the type of Sol-Gel matrix. Excellent results were obtained for the determination of glucose in serum samples using soluble glucose oxidase in conjunction with the Sol-Gel entrapped peroxidase. The enzymatically produced hydrogen peroxide is oxidized by the entrapped peroxidase yielding oxygen which oxidizes the faint blue variamine blue into the intensely violet colored species (the molar absorptivity is about 1.8 x 10(4) 1 mol(-1) cm(-1)). The characteristics of this chromogenic system as well as optimized conditions for its use in the spectrophotometric determination of enzymatically generated hydrogen peroxide were investigated. Excellent agreement between the results obtained by the proposed method and the widely used standard method, utilizing a commercial reagents kit, was always observed.

Relaxant effects of Ferula sinaica root extract on rabbit and guinea pig smooth muscle.

The effects of an ethanol extract of Ferula sinaica roots on the smooth muscles of rabbit and guinea pig were tested in vitro using isolated segments of intestine, trachea and aorta. The extract inhibited the spontaneous movements of rabbit jejunum and guinea pig ileum and acetylcholine-induced contractions. The extract also inhibited the contractions of rabbit tracheal smooth muscle induced by acetylcholine stimulation and the contractions of guinea pig tracheal smooth muscle induced by histamine stimulation. Furthermore, the extract inhibited the contractions of rabbit aorta induced by norepinephrine stimulation. These inhibitions were concentration-dependent and reversible.

Effects of a Ferula sinaica root extract on the uterine smooth muscle of rat and guinea pig.

The effects of an ethanolic extract of Ferula sinaica roots on the uterine smooth muscles of rats and guinea pigs were tested in vitro using isolated uterine horns. The extract inhibited the spontaneous movements of rat and guinea pig uterine smooth muscle and also the contractions induced by oxytocin stimulation. These effects were concentration-dependent and reversible by tissue washing. These data suggest that this plant extract may have some antioxytocic potential.

Observations on the pharmacology of thalicminine, an oxyaporphine alkaloid from Thalictrum isopyroides.

1. The effects of the oxyaporphine alkaloid thalicminine on guinea-pig isolated ileum, trachea, aorta and pulmonary artery and on blood pressure and heart rate of anesthetized guinea-pigs were studied. 2. Thalicminine (1-300 microM) caused the relaxation of the longitudinal ileal segments. The relaxation induced by 300 microM was followed by vigorous contractions. 3. Thalicminine caused only mild relaxation of the trachea. 4. Thalicminine (0.3-300 microM) caused concentration-dependent relaxation of epinephrine-precontracted aorta and main pulmonary artery. 5. Propranolol (1 microM) failed to reduce the relaxation or to affect the EC50 value of thalicminine on the ileum or the pulmonary artery. 6. Quinacrine (10 microM), on the other hand, potentiated thalicminine-induced relaxation and reduced the EC50 on the aorta and the pulmonary artery suggesting the interference of thalicminine with arachidonic acid metabolism. 7. In anesthetized animals, intravenous injections of 0.37-1.1 mg kg of thalicminine caused transient reduction of systolic and diastolic blood pressure and heart rate. Both parameters returned to their normal values in about 10 min.

Effects of an aqueous extract of Ferula ovina on rabbit and guinea pig smooth muscle.

The effects of an aqueous extract of Ferula ovina were tested in vitro using isolated segments of rabbit and guinea pig intestine, trachea and aorta. The extract inhibited the spontaneous movements of rabbit jejunum and guinea pig ileum and the contractions induced by acetylcholine. The aqueous extract also inhibited the contractions of rabbit trachealis muscle induced by acetylcholine and the contractions of guinea pig trachealis muscle induced by histamine. These inhibitions were dose-dependent and reversible. However, the aqueous extract did not inhibit the contractions of rabbit and guinea pig aortic rings induced by norepinephrine. These data suggest that this plant has non-specific anticholinergic and antihistaminic antispasmodic effects.

Effects of 3,3'-di-O-methylquercetin on guinea-pig isolated smooth muscle.

The effects of the flavone 3,3'-di-O-methylquercetin (DOMQ) have been examined and compared with those of quercetin, on guinea-pig isolated ileum, trachea, and main pulmonary artery (MPA). Except for transient contractions induced by low concentrations (10(-8)-3 x 10(-6) M), DOMQ and quercetin (up to 3 x 10(-4) M) caused reduction of the tone and the phasic contractions of the ileum. A23187 reversed the inhibitory effects of quercetin but not those of DOMQ. DOMQ and quercetin caused concentration-dependent relaxation of the trachea and the adrenaline-contracted MPA. DOMQ shifted to the right the concentration-effect curves induced by acetylcholine on the ileum and the trachea, and by adrenaline on MPA and those induced by CaCl2 on ileum, trachea and MPA. DOMQ also inhibited the contractions induced, in Ca2+-free EGTA-containing buffer, by histamine on ileum and by adrenaline on MPA. These observations suggest that DOMQ inhibits Ca2+ influx, Ca2+ release from intracellular stores and, more likely, Ca2+ binding to intracellular receptor proteins.

Effects of hispidulin, a flavone isolated from Inula viscosa, on isolated guinea-pig smooth muscle.

1. In small concentrations (10(-7)-3 X 10(-6) M), hispidulin caused concentration-dependent contraction of isolated guinea-pig ileum and only mild relaxation of guinea-pig tracheal rings. 2. Larger concentrations (up to 3 X 10(-4) M) caused concentration-dependent relaxation of the ileum and the trachea. All the effects on the ileum and the trachea are reversible upon removal of the compound. 3. In concentrations from 10(-7) to 3 X 10(-4) M, hispidulin had no effect on the tone of the epinephrine-contracted rings of the guinea-pig main pulmonary artery. 4. Hispidulin caused a shift to the right of the acetylcholine concentration-effect curves on ileum and trachea and significantly inhibited the maximum contractions induced by acetylcholine. 5. In Ca2+-free, depolarizing solution, hispidulin caused both a shift to the right, and an inhibition of the maximum contractions, of the CaCl2 concentration-effect curves on ileum, trachea and pulmonary artery. 6. In Ca2+-free, EGTA-containing solution, hispidulin caused concentration-dependent inhibition of the contractions induced in the pulmonary artery by epinephrine and in the ileum by histamine. 7. These observations suggest that hispidulin may interfere with Ca2+ binding to the Ca2+-receptor protein(s) in the smooth muscle cell and/or with the agonist-induced Ca2+-release from intracellular stores. Less likely, hispidulin may interfere with Ca2+ influx through smooth muscle cell membrane.

Mode of action of the antimicrobial compound 5-bromo-5-nitro-1,3-dioxane (bronidox).

The mode of action of the antimicrobial agent, 5-bromo-5-nitro-1,3-dioxane (bronidox), was studied in detail for gram-positive and gram-negative bacteria, yeast and fungi. The studies included MIC testing, thiol inhibition of activity, intracellular leakage, oxygen consumption, incorporation of 3H-uridine, scanning electron microscopy, inhibition of enzyme activity (papain) and in vitro oxidation of thiols to disulfides. It appears that the primary mode of action of bronidox is the same as, or similar to, that of bronopol, i.e. the oxidation of essential protein thiol causing inhibition of enzyme activity and subsequent inhibition of microbial growth.