Hepatoprotective effects of Astragalus kahiricus root extract against ethanol-induced liver apoptosis in rats / 中国天然药物

The hepatoprotective activity of the ethanol extract of Astragalus kahiricus (Fabaceae) roots against ethanol-induced liver apoptosis was evaluated and it showed very promising hepatoprotective actions through different mechanisms. The extract counteracted the ethanol-induced liver enzymes leakage and glutathione depletion. In addition, it demonstrated anti-apoptotic effects against caspase-3 activation and DNA fragmentation that were confirmed by liver histopathological examination. Moreover, the phytochemical study of this extract led to the isolation of four cycloartane-type triterpenes identified as astrasieversianin II (1), astramembrannin II (2), astrasieversianin XIV (3), and cycloastragenol (4). The structures of these isolates were established by HRESI-MS and 1D and 2D NMR experiments. The antimicrobial, antimalarial, and cytotoxic activities of the isolates were further evaluated, but none of them showed any activity.

Investigation of the vasodilator effect of the new synthesized compound 2-alkylthio-4-ethyl-4-methyl-4,5dihydro-lh imidazolin-5-one oxime [Oxime] on the ischaemic rat hind limb by using laser doppler flowmetry technique

The potential vasodilator effect of the novel compound 2-alkylthio-4-ethyl-4-methyl-4,5 dihydro-lH-imidazolin-5-one oxime [oxime] was investigated in a model of hind limb ischaemia induced in rats by unilateral ligation of the right femoral artery using Laser Doppler Flowmetry. The effect of oxime was compared with that of isoprenaline or L-arginine. Test drugs and oxime were injected systemically into the femoral vein or applied locally on the planter surface of the rat hind paw. Serum level of nitrite [NO[2] and nitrate [NO[3] were measured by ELISA. Immediately after operative induction of right hind limb ischaemia, blood flow ratio [Right/Left limb ratio: BFR] decreased to 0.33-0.39 in different groups. The intravenous [i.v.] administration of oxime increased BFR in a dose-dependent manner. Compared with pre-drug BFR, oxime administered at doses of 0.064, 0.128 or 0.256 mg/kg increased BFR by 78.8, 228.9 and 605.9%, respectively. Meanwhile, L-arginine given i.v. at 100 mg/kg increased BFR by 460%. Isoprenaline given i.v. at 1 micro g/kg increased BFR by 174.3%, while isoprenaline combined with oxime [0.064 mg/kg] increased BFR by 302.7%. Similarly, after topical application of oxime, BFR increased by 13.5, 161.1 and 333.3%, respectively. L-arginine given at 1000 mg/kg increased BFR by 389.7%. Isoprenaline given at 10 micro g/kg increased BFR by 131.6%, while isoprenaline administered in combination with oxime [0.064 mg/kg] increased BFR by 208.3%. The concentration of NO in serum was significantly increased after systemic or topical administration of either 0.128 and 0.256 mg/kg oxime or 100 and 1000 mg/kg L-arginine, respectively. It is concluded that systemic or topical oxime results in marked enhancement of blood flow in the rat ischaemic hind limb. This effect of oxime is likely to be mediated through the release of NO

Antiamnestic properties of [-]-beta-hydrastine: modulation of benzodiazepine-induced anterograde amnesia of inhibitory avoidance task in mice

A number of convulsant drugs were found to improve memory function though in doses that would be hazardous to humans. [-]-beta-Hydrastine; a less hazardous convulsant, was investigated for potential antiamnestic properties by testing its effect on retention memory of an inhibitory avoidance task in mice. [-]-beta-Hydrastine was found to enhance memory function where one training session was enough for the animals to learn the task only when 0.025, 0.05, 0.1, or 0.2 mg/kg of the drug was injected immediately after training. Midazolam [1mg/kg] intraperitoneally administered 30-mm before or immediately after a two-session training induced anterograde and retrograde amnesia respectively. [-]-beta Hydrastine was able to block midazolam-induced anterograde amnesia, where 0.05 and 0.1 mg/kg of hydrastine injected immediately after, rather than before, training were enough to increase the step-down latency in the test session. Furthermore, 0.1 mg/kg of [-]-beta-hydrastine enhanced acquisition and retrieval memory. These effects were shown not to be due to hyperalgesic or motoric qualities respectively, though the effect of [-]-beta-hydrastine on acquisition was reversed with pretest adminstration of the drug. The antiamnestic dose of [-]-beta-hydrastine was 1/398 its convulsive dose 50%. In conclusion, this work showed [-]-beta-hydrastine to be a much less hazardous antiamnestic drug than the rest of its class of brain stimulants. It also suggests the involvement of benzodiazepine system in the antiamnestic properties of [-]-beta-hydrastine with enhanced receptor sensitivity following acute stress