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The effects on memory and learning ability of the Korean herbal medicine, Saenhyetang (SHT), which is consisted of nine herbs, were investigated. Hot water extracts (HWE-SHT) and ethanol extracts (EE-SHT) were used for the studies. It was shown that N-methyl-d-aspartate (NMDA) receptor 2B (NR2B) was increased in the forebrains of SHT-administrated mice (HWE-SHT), leading to enhanced activation of NMDA receptors, facilitating synaptic potentiation in response to stimulation at 10-100Hz. These HWE-SHT-treated mice exhibit superior ability in learning and memory in various behavioral tasks, showing that NR2B is enhanced by HWE-SHT treatment and also is critical in gating the age-dependent threshold for plasticity and memory formation. NMDA receptor-dependent modifications, which were mediated in part by HWE-SHT administration, of synaptic efficacy, therefore, represent a mechanism for associative learning and memory. Results suggest that oriental medical enhancement of NR2B attributes such as intelligence and memory in mammals is feasible. On the other hand, to examine the effects of EE-SHT on the learning and memory in experimental mice, the passive and active avoidance responses were studied. The EE-SHT ameliorated the memory retrieval deficit induced by ethanol, but not other memory impairment in mice. EE-SHT (10, 20mg/100g, p.o.) did not affect the passive avoidance responses of normal mice in the step through and step down tests, the conditioned and unconditioned avoidance responses of normal mice in the shuttle box and lever press performance tests, and the ambulatory activity of normal mice in normal condition. However, EE-SHT was shown to significantly decrease the spontaneous motor activity during the shuttle box test, and also to prolong the sleeping time induced by pentobarbital in mice at 20mg/kg. These results suggest that EE-SHT has an ameliorating effect on memory retrieval impairment and a weak tranquilizing action.

The anti-thrombic properties of the Korean herbal medicine, Dae-Jo-Hwan (DJW) were investigated. Water extracts, a 70% methanol (MeOH) extract and an ethyl acetate (EtOAc) soluble fraction (III) from DJW inhibited platelet-activating factor (PAF)-induced platelet aggregation in vitro and in vivo assays. The extracts of DJW and eleven herbs from which it is derived, except for Panax ginseng Meyer, Angelica sinensis (OLIV.) DIELS and Schisandra chinensis Baill., inhibited AA-induced blood platelet aggregation to various extents. The effects observed with total DJW was synergistic over-additive rather that additive since the sum of single contributions was lower than the effect of the total extract. Fraction III was specially protected against the lethality of PAF, while verapamil did not afford any protection. Exogenously applied arachidonic acid (AA) (100 microM) led to a 89% platelet aggregation, the release of 14 pmol of ATP, and the formation of either 225 pg of thromboxane A2 (TXA2) or 45 pg of prostaglandin E2 (PGE2), each parameter being related to 10(6) platelets. An application of DJW 5 min before AA, dose-dependently diminished aggregation, ATP-re lease, and the synthesis of TXA2 and PGE2, with IC(50) values of 70, 87, 65 and 72 microg/ml, respectively. The similarity of the IC(50) values suggests the inhibition of cyclooxygenase (COX) by DJW as the primary target, thus suppressing the generation of TXA2, which induces platelet aggregation and the exocytosis of ATP by its binding on TXA2-receptors. These results indicate that DJW shows anti-thrombotic action on human platelets and inhibits the action of PAF in vivo by an antagonistic effect on PAF. Therefore, it may be useful in treating disorders caused by PAF.

The anti-thrombic properties of the Korean herbal medicine, Dae-Jo-Hwan (DJW), which is consisted of 11 herbs (indicated as concentrations) of Rehmanniae radix 24%, Hominis placenta 5%, Testudinis carapax 9%, Eucommiae cortex 9%, Asparagi radix 9%, Phellodendri cortex 9%, Achyranthis radix 7%, Liriopis tuber 7%, Angelicae sinensis radix 7%, Ginseng radix 6%, and Schizandrae fructus 3%, were investigated. The extracts of DJW and its 11 herbs, except G. radix, A. sinensis radix and S. Fructus, inhibited the endotoxin-induced hepatic venous thrombosis in high cholesterol diet-treated rats. Also the extract inhibited the endotoxin-induced decrease in blood platelets and fibrinogen, and endotoxin-induced increase in fibrin degradation products (FDP) on disseminated intravascular coagulation in normal rats. In in vitro experiments, the extract was shown to have inhibitory effect on collagen- and ADP-induced blood platelet aggregation, on thrombin-induced conversion of fibrinogen to fibrin and on the activity of plasminogen or plasmin. In conclusion, the protection of extracts of Korean herbs on the ischemic infarction induced artificially might be related to their inhibitory effects on DIC, platelet coagulation and thrombic action.

The anti-obesity effects of crude saponin (CS) of Korean red ginseng (KRG) were investigated in the rat fed a high-fat (HF) diet. Male Sprague-Dawley (SD) rats became obese by feeding the HF diet over 5 weeks, while the control rats were fed a normal diet, and then both groups were treated with CS (200 mg/kg, i.p.) for 3 weeks. The body weight, food consumption, adipose tissues, and expression of appetite peptides such as leptin and neuropeptide Y (NPY) were investigated in rats fed normal and HF diet after treatment of CS. Administration of CS reduced body weight, food intake, and fat content in HF diet rats in a manner similar to those of the normal diet fed rats. The hypothalamic NPY expression and serum leptin level were reduced in HF diet rats after CS treatment. Our results suggest that CS may be useful in the treatment of obesity and related disorders as anti-obesity agents.