Comparison of gas-phase free-radical populations in tobacco smoke and model systems by HPLC. (1/84)

We used an improved method for trapping carbon-centered radicals (.R) from the gas-phase to compare radical suites trapped from various tobacco smoke and model smoke systems. Using a nitroxide trap, 3-amino-2,2,5,5-tetramethyl-1-pyrrolidinyloxy (3AP), on solid support, we trapped radicals directly from the gas phase, washed them off the support, and analyzed them with HPLC. Separation of the trapped radicals showed that each tobacco type produced a unique radical suite of 4-10 distinct peaks. Gas mixtures used to model tobacco smoke consisted of nitric oxide, air, isoprene, and methanol. The model systems produced radical suites of four major and several minor peaks, two of which matched peaks in tobacco smoke chromatograms. Quantities of radicals trapped from tobacco smoke were: 54 +/- 2 nmol .R per Marlboro cigarette, 66 +/- 9 nmol .R per Djarum clove cigarette, and 185 +/- 9 nmol .R per Swisher Sweet cigar. In these experiments oxygen competes with the nitroxide trap for gas-phase radicals. A kinetic analysis of the O2 competition shows that actual radical concentrations in the smoke were approximately 100-fold higher than measured.  (+info)

A prospective study evidencing rhinomanometric and olfactometric outcomes in women taking oral contraceptives. (2/84)

BACKGROUND: The aim of this prospective study was to evaluate the changes in olfactory sensitivity of oral contraceptive (pill) users. METHODS: Sixty women underwent rhinomanometric and olfactometric determinations during the follicular, periovular and luteal phases of the menstrual cycle, and at day 7, 14 and 21 of contraceptive intake. Thirty-one women used 30 microg ethinyl oestradiol plus 75 microg gestodene and 29 women used 20 microg ethinyl oestradiol plus 150 microg desogestrel. RESULTS: Rhinomanometry showed higher but not statistically significant values during the periovular phase than in the follicular and luteal phases. Olfactometry showed a higher sensitivity during the follicular and periovular phases than during the luteal phase of the menstrual cycle. The rhinomanometric surveys in pill users were statistically different from those of the luteal phase (P < 0.02) and the follicular and periovular phases (P < 0.001). The olfactometric thresholds during the period of contraceptive use were statistically different from those of the follicular phase for a few odorous substances, and from those of the periovular phase for each odorous substance, but similar to those of the luteal phase (P = NS). CONCLUSIONS: Unlike the rhinomanometric airflow and trans-nasal pressure, the olfactory threshold to odours seems to depend on the variations of the ovarian steroids during the menstrual cycle and on the iatrogenic effects of oral contraceptives.  (+info)

Determination of antioxidant activity of herbs by ESR. (3/84)

Water extracts of 32 herbs that are constituents of curry and curry powder were screened for superoxide anion radical (O2.-) scavenging activity. Among the screened samples, only clove, allspice, and basil were shown to decrease DMPO-O2.- adduct yields by more than 50% at 0.25 mg/mL as measured by an ESR spin trapping technique based on the HPX-XOD reaction. To study the mechanism of the O2.- scavenging activity, Km values were obtained from a Lineweaver-Burk plot for XOD in the presence of different concentrations of HPX, and the IC50 values at different DMPO concentrations were compared. Clove and basil directly eliminated O2.- like superoxide dismutase (SOD), whereas allspice reduced the amount of O2.- by inhibition of formation of O2.-.  (+info)

Photoelectrochemical solar cell using extract of Eugenia jambolana Lam as a natural sensitizer. (4/84)

The extract of Jambol o (java plum), Eugenia jambolana Lam, was used as a natural sensitizer of a wide band-gap semiconductor (TiO2) in photoelectrochemical solar cells. The natural dye, adsorbed onto the semiconductor surface, absorbs visible light and promotes electron transfer across the dye/semiconductor interface. Photogenerated current and voltage as high as 2.3 mA and 711 mV, respectively, were obtained and effective conversion of visible light into electricity was achieved. The use of a natural product as the semiconductor sensitizer enables a faster and simpler production of cheaper and environmentally friendly solar cells.  (+info)

Aphrodisiac activity of 50% ethanolic extracts of Myristica fragrans Houtt. (nutmeg) and Syzygium aromaticum (L) Merr. & Perry. (clove) in male mice: a comparative study. (5/84)

BACKGROUND: Spices are considered as sexual invigorators in the Unani System of Medicine. In order to explore the sexual function improving effect of Myristica fragrans Houtt. (nutmeg) and Syzygium aromaticum (L) Merr. & Perry. (clove) an experimental study was conducted in normal male mice. METHODS: The extracts (50% ethanolic) of nutmeg and clove were administered (500 mg/kg; p.o.) to different groups of male Swiss mice. Mounting behaviour, mating performance, and general short term toxicity of the test drugs were determined and compared with the standard drug Penegra (Sildenafil citrate). RESULTS: The extracts of the nutmeg and clove were found to stimulate the mounting behaviour of male mice, and also to significantly increase their mating performance. The drugs were devoid of any conspicuous general short term toxicity. CONCLUSION: The extracts (50% ethanolic) of nutmeg and clove enhanced the sexual behaviour of male mice.  (+info)

Effects of the molecular properties of mixed solvents on the elution of alkyl benzoates in RPLC. (6/84)

The retention behavior and mechanism of methyl, ethyl, propyl, isopropyl, buthyl and isobuthyl benzoates have been studied at different eluent compositions of aqueous mixtures with water-soluble organic solvents (methanol, ethanol, 1-propanol, 2-propanol, acetonitrile (AN), 1,4-dioxane and tetrahydrofuran (THF)) in RPLC. The retention of the solutes is discussed based on the solvent composition, solvent polarity (ETN value), preferential solvation, hydrogen bonding and solvent clusters of the eluents. The smaller ETN values and the larger preferential solvation of the mixed solvent eluted the solutes faster. The IR spectra of HDO suggested that the solvents, except for methanol and ethanol, break the hydrogen bonding between water molecules, resulting in fast elution of the solutes. Based upon the results, we chose an optimum solvent composition for the separation of benzoates and applied it to the determination of the benzoates in clove.  (+info)

Protective effect of Eugenia jambolana seed kernel on tissue antioxidants in streptozotocin-induced diabetic rats. (7/84)

Oxidative stress plays an important role in chronic complications of diabetes. In the present study the antioxidant effect of oral administration of ethanolic extract of Eugenia jambolana seed kernel on tissue antioxidant enzymes and lipid peroxidation in liver and kidney of streptozotocin-induced diabetic rats was evaluated. Administration of seed kernel to diabetic rats significantly decreased the levels of blood glucose, glycosylated hemoglobin and increased body weight gain, plasma insulin and hemoglobin. The diabetic rats showed the low activities of superoxide dismutase, catalase, glutathione peroxidase and reduced glutathione content in liver and kidney, which were restored to near normal levels by treatment with the seed kernel extract. The increased levels of lipid peroxidation and hydroperoxides in diabetic rats were reverted back to near normal levels after the treatment with seed kernel extract. Diabetic rats treated with seed kernel extract restored almost normal architecture of liver and kidney and were confirmed by histopathological examination. The present study reveals the efficacy of Eugenia jambolana seed kernel in the amelioration of diabetes, which may be attributed to its hypoglycemic property along with its antioxidant potential. The antioxidant effect of Eugenia jambolana seed kernel was also compared with glibenclamide, a standard hypoglycemic drug.  (+info)

Effect of 50% ethanolic extract of Syzygium aromaticum (L.) Merr. & Perry. (clove) on sexual behaviour of normal male rats. (8/84)

BACKGROUND: The flower bud of Syzygium aromaticum (L.) Merr. & Perry. (clove) has been used in Unani medicine since ancient times for the treatment of male sexual disorders. The present study is aimed to investigate the effect of 50% ethanolic extract of clove on general mating behaviour, libido, potency along with its likely gastric ulceration and adverse effects on sexually normal male albino rats. METHODS: The suspension of the extract was administered orally at the dose of 100, 250, and 500 mg / kg, to different groups of male rats (n = 6) once a day for seven days. The female albino rats involved in mating were made receptive by hormonal treatment. The general mating behaviour, libido and potency were determined and compared with the standard reference drug sildenafil citrate. The probable gastric ulceration and adverse effects of the extract were also evaluated. RESULTS: Oral administration of the extract significantly increased the Mounting Frequency, Intromission Frequency; Intromission Latency, Erections; Quick Flips, Long Flips as well as aggregate of penile reflexes and caused significant reduction in the Mounting Latency and Post Ejaculatory Interval. The most appreciable effect of the extract was observed at the dose of 500 mg/kg. The test drug was also found to be devoid of any conspicuous gastric ulceration and adverse effects. CONCLUSION: The results indicated that the 50% ethanolic extract of clove produced a significant and sustained increase in the sexual activity of normal male rats, without any conspicuous gastric ulceration and adverse effects. Thus, the resultant aphrodisiac effectivity of the extract lends support to the claims for its traditional usage in sexual disorders.  (+info)