Eun Bang Lee

Pharmacological study on piperine

Systematic pharmacological studies on piperine have revealed that this compound elicited diverse pharmacological activities; CNS depressant activity characterized by antagonism against electroshock seizure and by muscle relaxant activity in mice; antipyretic activity in typhoid vaccinated rabbits; analgesic activity as evaluated by tail-clip pressure and writhing syndrome in mice; antiinflammatory activity in carrageenin-induced edema in rats.

Studies on protective effect of DA-9601,Artemisia asiatica extract, on acetaminophen- and CCI4-induced liver damage in rats

The hepatoprotective effect of DA-9601, a quality-controlled extract ofArtemisia asiatica, on liver damage induced by acetaminophen (APAP) and carbon tetrachloride (CCI4) was investigated by means of serum-biochemical, hepatic-biochemical, and histopathological examinations. Doses of DA-9601 (10, 30, or 100mg/kg) were administered intragastrically to each rat on three consecutive days i.e. 48 h, 24 h and 2 h before a single administration of APAP (640 mg/kg, i.p.) or CCl4 (2 ml/kg, p.o.). Four h and 24 h after hepatotoxin treatment, the animals were sacrificed for evaluation of liver damage. Pretreatment of DA-9601 reduced the elevation of serum ALT, AST, LDH and histopathological changes such as centrilobular necrosis, vacuolar degeneration and inflammatory cell infiltration dose-dependently. DA-9601 also prevented APAP- and CCl4-induced hepatic glutathione (GSH) depletion and CCl4-induced increase of hepatic malondialdehyde (MDA), a parameter of lipid peroxidation, in a dose-dependent manner. These findings suggest that pretreatment with DA-9601 may reduce chemically induced liver injury by complex mechanisms which involve prevention of lipid peroxidation and preservation of hepatic GSH.

Anti-inflammatory activity of methanol extract of Kalopanax pictus bark and its fractions.

The methanol extract of Kalopanax pictus bark was evaluated on anti-inflammatory and anti-nociceptive activities in animal models. The extract produced a significant inhibition of vascular permeability at doses of 1 and 3 g/kg, p.o. in mice and of leucocyte emigration at doses of 0.15 and 0.3 g/rat, s.c., in CMC-pouch of rats. However, the extract (0.25 and 3 g/kg, p.o.) did not show anti-inflammatory activity in carrageenan induced edema of rats. The extract at a dose of 2.5 g/kg, p.o. inhibited writhing syndromes, whereas it did not exhibit anti-nociceptive in Randall-Selitto assay. The methanol extract was then partitioned with n-hexane, chloroform, ethyl acetate and butanol to give each soluble fraction and finally water soluble fraction. Among those fractions, the inhibitory effect on vascular permeability in mice was produced by ethyl acetate soluble fraction in this activity-guided fractionation. The methanol extract showed low acute toxicity in mice. These results suggest that the methanol extract of Kalopanax pictus bark has an anti-inflammatory activity which is distributed in the ethyl acetate fraction.

Antithrombotic effects by oral administration of novel proteinase fraction from earthworm eisenia andrei on venous thrombosis model in rats

A novel proteinase fraction, SPP-501, was purified from the earthworm, Eisenia andrei, and its antithrombotic effects compared with those of urokinase and t-PA (tissue type-plasminogen activator) in a thrombosis model, induced by the insertion of a stainless wire coil into the inferior vena cava. SPP-501, urokinase and t-PA were administrated once a day for 14 days. On the oral administration of SPP-501, as well as urokinase and t-PA, the thrombus weight was dramatically decreased. The euglobulin lysis time (ELT) was also shortened by SPP-501, but urokinase and t-PA failed to dissolve the euglobulin clot. Conversely, urokinase and t-PA produced detectable fibrinogen/fibrin degradation products (FDP), but SPP-501 did not. Thrombin induced platelet aggregation was desensitized in the SPP-501 treatment groups. With a high dose of SPP-501 (45 mg/kg), the APTT (activated partial thromboplastin time) was prolonged. These results suggest that SPP-501 shows both antithrombotic and fibrinolytic activities when orally administered.

Protective effect of DA-9601, an extract ofArtemisiae Herba, against naproxen-induced gastric damage in arthritic rats.

Gastrointestinal irritation is the most frequent adverse effect in patients chronically taking nonsteroidal antiinflammatory drugs (NSAIDs) for the treatment of arthritic conditions. Gastroprotective effect of DA-9601, a new antiulcer agent fromArtemisiae Herba extract, against NSAID was evaluated in a rat model of arthritis that is similar in many aspects to human rheumatoid arthritis. Daily oral dosing of naproxen (30 mg/kg), one of the most commonly used NSAID, induced apparent gastric lesions as well as a significant decrease in mucosal prostaglandin E2 (PGE2) and prostaglandin F1α (PGF1α) levels. Coadministration of DA-9601 prevents naproxen-induced mucosal injury and depletion, of prostaglandins, in a dose-related manner. DA-9601 did not alter the antiinflammatory or analgesic effect of naproxen. The present results suggest that DA-9601 may be useful as a mucoprotectant against NSAIDs in clinical practice.

Effects of Opuntia ficus-indica var. saboten stem on gastric damages in rats

The effects of the dried stem powder ofOpuntia ficus-indica var. saboten (OF-s) were investigated on gastric lesion and ulcer models in rats. It showed significant inhibition in HCI ethanol-induced gastric lesion at the doses of 200 and 600 mg/kg p.o. and in HCI aspirin-induced gastric lesion at 600 mg/kg p.o. OF-s also showed significant inhibition in indomethacin-induced gastric lesion at the doses of 200 and 600 mg/kg, p.o. However, it did not affect both the aspirin-induced and Shay ulcers in rats. It also did not affect gastric juice secretion, acid output and pH. These data indicate that OF-s only possesses pronounced inhibitory action on gastric lesion without antiulcer activity in rats.

Comparison of green tea extract and epigallocatechin gallate on blood pressure and contractile responses of vascular smooth muscle of Rats

The present study was conducted to investigate the effects of green tea extract (GTE) on arte-rial blood pressure and contractile responses of isolated aortic strips of the normotensive rats and to establish the mechanism of action. The phenylephrine (10~p6~10~p5M)-induced contrac-tile responses were greatly inhibited in the presence of GTE (0.3–1.2 mg/mL) in a dose-depen-dent fashion. Also, high potassium (3.5x10-p2~5.6x1CTp2 M)-induced contractile responses were depressed in the presence of 0.6–1.2 mg/mL of GTE, but not affected in low concentration of GTE (0.3 mg/mL). However, epigallocatechin gallate (EGCG, 4–12 ug/mL) did not affect the contractile responses evoked by phenylephrine and high Kp+. GTE (5–20 mg/kg) given into a femoral vein of the normotensive rat produced a dose-dependent depressor response, which is transient. Interestingly, the infusion of a moderate dose of GTE (10 mg/kg/30 min) made a significant reduction in pressor responses induced by intravenous norepinephrine. However, EGCG (1 mg/kg/30 min) did not affect them. Collectively, these results obtained from the present study demonstrate that intravenous GTE causes a dose-dependent depressor action in the anesthetized rat at least partly through the blockade of adrenergic α1-receptors. GTE also causes the relaxation in the isolated aortic strips of the rat via the blockade of adrenergic α1-receptors, in addition to the unknown direct mechanism. It seems that there is a big differ-ence in the vascular effect between GTE and EGCG.

Biological Evaluation of Korean Medicinal Plants(III)

The extracts of sixty Korean plants were evaluated for their biological activities such as antitumor activities against Sarcoma 180, Leukemia SN-36 and Ehrlich ascites carcinoma, antimicrobial activities and behavioral observation in mice. The results are tabulated.

Central nervous depressant activity of piperine

Piperine showed a central nervous system depressant activity which was characterized by the antagonistic effect against chemoshock seizure as well as potent muscular incoordination in mice.

The NMR assignments of torilin fromTorilis japonica

A guaian type sesquiterpene, torilin, was isolated from the hexane extract of the fruits ofTorilis japonica. The1H- and13C-signals of this compound have been fully assigned utilizing1H-1H COSY, HMQC, and HMBC experiments.