Tanakan Inhibits Platelet-Activating-Factor-Induced Platelet Aggregation in Healthy Male Volunteers

Abstract

An open study to investigate the PAF-acether antagonist activity of Tanakan in healthy male volunteers examined the effect of a single 15-ml oral dose on ex vivo platelet aggregation induced by adrenaline, adenosine diphosphate (ADP), collagen or PAF-acether. Aggregometry was performed on platelet-rich plasma samples from blood taken 1 h before dosing with Tanakan and 2, 4 and 8 h after intake of Tanakan. Following dosing with Tanakan there was a reduction in platelet aggregation at all doses of PAF, with 1 μM ADP and adrenaline, the most significant decreases occurred with 75 nM PAF-acether 4 h after intake (p < 0.05) and 300 nM PAF-acether 4 h (p < 0.01) and 8 after intake (p < 0.05). There were no concomitant changes in coagulation, skin bleeding time, haematological and biochemical laboratory tests, blood pressure or pulse. The results provide a possible explanation for the clinical efficacy of Tanakan in the treatment of peripheral vascular disease; they also confirm that a single oral dose of 15 ml Tanakan is well tolerated.

A double‐blind, placebo‐controlled, randomized trial ofGinkgo bilobaextract EGb 761® in a sample of cognitively intact older adults: neuropsychological findings

“…These include: increased cerebral blood flow (Cahn, 1985;Heiss and Zeiler, 1978;Tea et al, 1987), protection against hypoxia/ischemic damage (Cahn, 1985;Heiss and Zeiler, 1978;Tea et al, 1987;Karcher et al, 1984;Spinnewyn et al, 1986), platelet activating factor (PAF) antagonism (Borzeix, 1980;Braquet et al, 1985;Chung et al, 1987;Klein, 1988;Guinot et al, 1989), reduction in relative erythrocyte viscosity (Anadere et al, 1985;Költringer et al, 1989;Artmann et al, 1989Artmann et al, , 1991Költringer et al, 1995), radical scavenging properties (Chatterjee and Gabard, 1981;Pincemail et al, 1989;Barth et al, 1991;Dorman et al, 1992;Dumont et al, 1992), protection against cerebral edema (Gabard and Chatterjee, 1980;Otani et al, 1986;Sancesario and Kreutzberg, 1986;Borzeix, 1985;Attella et al, 1989), a myelin protective effect (Chatterjee and Gabard, 1984), increased neurotransmitter uptake (Ramassamy et al, 1992;Krištofiková et al, 1992) and neurotransmitter receptor density (Taylor, 1985;Huguet et al, 1994), decreased age-related cerebral changes (Barkats et al, 1994) and increased alpha wave activity with concomitant reduction in theta wave frequencies as measured by electroencephalography (Hofferberth, 1989(Hofferberth, , 1991(H...…”

Herbal Remedies in Psychiatric Practice

“…48,52 There is considerable evidence that Ginkgo extracts can improve vascular perfusion [53][54][55][56][57][58][59] by modulating vessel wall tone [60][61][62][63][64][65][66][67][68][69] and can decrease thrombosis 70 through antagonism of platelet activating factor. [71][72][73][74][75] Ischemic sites may benefit in particular from ginkgo treatment. [76][77][78][79][80][81][82][83][84] The antioxidant properties that have been attributed to the flavonoid components found in ginkgo are believed to play an important role in its postulated neuroprotective and ischemia-reperfusion-protective effects.…”

Effects of <i>Ginkgo bilob</i><i>a</i> Extract (EGb 761) on Arteriolar Spasm in a Rat Cremaster Muscle Preparation

“…Thus, it was necessary to confirm the finding that vaso spasm can be induced by rat serum and then to attempt to identify the substance in the serum whose action could be antagonized by EGb 761. As previous results had indi cated that EGb 761 has some platelet antiaggregant prop erties [3][4][5], the platelet factors thrombin and serotonin, as well as a thromboxane analogue (U46619), were used to induce vasospasm. To determine the constituent of EGb 761 that could be responsible for its effect of oppos ing vasospasm, the action ofginkgolide B, a triterpene iso lated from EGb 761, which has been identified as a spe cific antagonist of l-0-alkvl-2-acetyl-i/?-glycero-3-phosphorylcholine (also known as platelet-activating factor) [6], and an extract of G. biloba devoid of terpenes (CP 205) were examined on U46619-induced vasospasm.…”