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An aqueous extract from the aerial parts of Brickellia cavanillesii attenuated postprandial hyperglycemia in diabetic mice during oral glucose and sucrose tolerance tests. Experimental type-II DM was achieved by treating mice with streptozotocin (100 mg/kg) and β-nicotinamide adenine dinucleotide (40 mg/kg). These pharmacological results demonstrated that B. cavanillesii is effective for controlling fasting and postprandial blood glucose levels in animal models. The same aqueous extract also showed potent inhibitory activity (IC(50) = 0.169 vs 1.12 mg/mL for acarbose) against yeast α-glucosidase. Bioassay-guided fractionation of the active extract using the α-glucosidase inhibitory assay led to the isolation of several compounds including two chromenes [6-acetyl-5-hydroxy-2,2-dimethyl-2H-chromene (1) and 6-hydroxyacetyl-5-hydroxy-2,2-dimethyl-2H-chromene (2)], two sesquiterpene lactones [caleins B (3) and C (4)], several flavonoids [acacetin (5), genkwanin (6), isorhamnetin (7), kaempferol (8), and quercetin (9)], and 3,5-di-O-caffeoylquinic acid (10). Chromene 2 is a new chemical entity. Compounds 2, 4, 7, and 9 inhibited the activity of yeast α-glucosidase with IC(50) 0.42, 0.28, 0.16, and 0.53 mM, respectively, vs 1.7 mM for acarbose. Kinetic analysis revealed that compounds 4 and 7 behaved as mixed-type inhibitors with K(i) values of 1.91 and 0.41 mM, respectively, while 2 was noncompetititive, with a K(i) of 0.13 mM. Docking analysis predicted that these compounds, except 2, bind to the enzyme at the catalytic site.

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Valerian is the common name given to the crude drug consisting of the underground organs of the species Valeriana. Valeriana edulis ssp. procera Meyer is the Mexican valerian. The aim of the present work was to elucidate the neuropharmacological profile of a hydroalcohol extract of Valeriana edulis roots at doses of 100, 300 and 1000 mg/kg in several experimental models. A dose-dependent anticonvulsant and anxiolytic-like effect of V. edulis was demonstrated. In addition, the extract decreased rotarod performance and traction force and prolonged the pentobarbital-induced sleeping time at high doses. Concomitant administration of valerian extract and pentobarbital showed a synergistic effect on motor coordination and traction force in mice. The anxiolytic-like effect of V. edulis was compared with diazepam and with diphenhydramine and doxylamine, the latter in order to consider the H(1)-antihistamine effect as another possibility to explain, at least in part, the central nervous system depressant effect of valerian. These results also underlie the medical and industrial use of this species and allowed the conclusion that the extract of V. edulis has central nervous depressant properties similar to, but with some differences to V. of ficinalis, a very well known species.

The rationale of this investigation was to examine the antinociceptive properties of the essential oil obtained from Rosmarinus officinalis aerial parts, using a rat model of arthritic pain. The essential oil (100, 300 and 600 mg/kg, I. P.) produced a dose-dependent antinociceptive effect, manifested as a significant reduction in the dysfunction in the pain-induced functional impairment model in the rat (PIFIR model), mainly at high doses. Chemical constituents of the essential oil were further analyzed by gas chromatography-mass spectrometry (GC/MS). The major compounds in the essential oil were alpha-pinene (14.10 %), camphene (11.47 %), beta-pinene (12.02 %), myrcene (3.31 %), alpha-phellandrene (7.87 %), eucalyptol (8.58 %), 2-bornanone (3.42 %), camphor (8.75 %), isoborneol (3.48 %), borneol (4.85 %) and borneol acetate (6.49 %). The antinociceptive effects of R. officinalis essential oil were tested in combination with 0.12 mg/kg WAY100635, s. c. (an antagonist of 5-HT(1A) receptors) or 1 mg/kg naloxone, i. p. (an antagonist of endogenous opioids receptors), demonstrating in both cases an inhibition of the antinociceptive response. This study suggests an involvement, at least in part, of the serotonergic system via 5-HT(1A) receptors and endogenous opioids in the antinociceptive effect of R. officinalis essential oil in the PIFIR model.

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It has been declared frequently that valerian may potentiate the effect of other central nervous system (CNS) depressant drugs, however there has been a lack of experimental data. We have evaluated the profile of the interactions between the ethanol extract of Valeriana edulis spp procera and six CNS depressant drugs using an exploratory model to test the sedative effect in mice. All the compounds tested showed a dose-dependent sedative effect with the following ED50 values: valerian 181.62, diazepam 1.21, ethanol 1938, pentobarbital 11.86, buspirone 1.04, haloperidol 0.41 and diphenhydramine 17.06 mg kg-1. An isobolographic analysis was used to evaluate the sedative interaction of the intraperitoneal co-administration of 1:1 fixed-ratio combination of equi-effective doses of valerian extract with each CNS depressant drug. The ED50 theoretical (Zadd) and experimental (Zexp) for each combination were: valerian+diazepam,Zadd=91.41 mg kg-1, Zexp=81.64 mg kg-1; valerian+ethanol, Zadd=1060.22 mg kg-1, Zexp=687.89 mg kg-1; valerian+pentobarbital, Zadd=96.74 mg kg-1, Zexp=151.83 mg kg-1; valerian+buspirone, Zadd=91.33 mg kg-1, Zexp=112.73 mg kg-1; valerian+haloperidol, Zadd=91.01 mg kg-1, Zexp=91.52 mg kg-1; valerian+diphenhydramine, Zadd=99.34 mg kg-1, Zexp=123.52 mg kg-1. Neither synergistic nor attenuate effects were found in any of the combinations evaluated. We concluded that the valerian extract did not potentiate the sedative effect of commonly prescribed CNS depressant drugs as was expected. The additive effect found through the isobolographic analysis suggested that the sedative effect of V. edulis resulted from the activation of common mechanisms of haloperidol, diazepam, buspirone, pentobarbital, diphenhydramine and ethanol.

An extract (100 mg/kg) of the stem bark of Hintonia standleyana caused a significant decrease in blood glucose levels in both normal and streptozotocin (STZ)-diabetic rats when compared with vehicle-treated groups (p < 0.05). From the active extract, 3- O- beta- D-glucopyranosyl-23,24-dihydrocucurbitacin F ( 1), 5- O-beta- D-glucopyranosyl-7-methoxy-3',4'-dihydroxy-4-phenylcoumarin ( 2) and 5- O-[ beta- D-apiofuranosyl-(1-->6)- beta- D-glucopyranosyl]-7-methoxy-3',4'-dihydroxy-4-phenylcoumarin ( 3) were isolated. Coumarin 3 is a new natural product and was identified by spectroscopic methods. Compounds 1 and 3 did not decrease blood glucose levels in normal rats. However, in two different long-term subacute experiments, using animals with a developing diabetes condition and with STZ-induced diabetes, both compounds at daily doses of 10 mg/kg (developing diabetes condition) or 30 mg/kg (STZ-induced diabetes condition) provoked a significant antihyperglycemic activity (p < 0.05). Furthermore, compound 3 restored normal blood glucose levels in STZ-induced diabetic rats. In all cases, the groups treated with the active principles and the extract showed less body weight lost than the glibenclamide-treated and diabetic control groups (p < 0.05). These results showed that the antihyperglycemic active principles of H. standleyana are both 4-phenylcoumarins and cucurbitacin glycosides.