Induction of apoptosis in HepG2 human hepatocellular carcinoma cells by a novel derivative of ursodeoxycholic acid (UDCA)

The effects of ursodeoxycholic acid (UDCA) and its novel derivative, named as HS-1030, on the proliferation of HepG2, human hepatocellular carcinoma cells were investigated. Whereas UDCA had no significant effect in a concentration range we have tested, HS-1030 inhibited the proliferation of HepG2 cells in a concentration dependent manner. Surprisingly, HS-1030 had no effect on the proliferation of Human Chang liver cell which is a normal liver cell line. We also found that proliferation-inhibitory effect of HS-1030 was due to the induction of apoptosis of HepG2 cells, which was confirmed by observing the internucleosomal DNA fragmentation and morphological changes (i.e. cell shrinkage, nuclear condensation and the formation of apoptotic bodies). These results suggest that HS-1030 may be a good candidate as a drug for the treatment of liver cancer.     

Anti-cell adhesive effect of phenylacetylshikonin analogues related to their cytotoxicity in A549 cells

An attempt to estabilish the relationship between anti-cell adhesive action of phenylacetylshikonin anallogues and their cytotoxicity against A549 cells was done. In the one hour incubation with A549 cells, alpha-methoxyphenylacetyl-(9), alpha-acetoxyphenylacetyl-(13), 3,4-methylen-edioxyphenylacetyl-(15) and 4-(N,N-dimethylamino)-phenylacetylshikonin (17) analogues showed a high anti-cell adhesive activity (IC(100) value, 4-8 mug/ml), while halophenylacetyl-and dimethoxy-or trimethoxyphenylacetyl analogues expressed no activity at 40 mug/ml, indicating that the presence of a bulky group at C'-alpha and a polar group at C-4 of phenylacetyl moiety may be important. A similar structure activity relationship exists for the 48 hr cytotoxocity (ED(50)) of phenylacetylshikonin analogues in A 549 cells, but not in either K562 or L1210 cells. Furthermore, the difference between IC(100) values for anti-cell adhesive activity and ED(50) values for cytotoxicity of potent compound in A549 cells was not so great (1.5 to 3 times). Based on these observations, it is proposed that the anti-cell adhesive action of phenylacetylshikonins might be responsible for their cytotoxicity in A549 cells.     

Inhibitory effects of ginseng total saponins on hypoxia-induced dysfunction and injuries of cultured astrocytes

The effects of ginseng total saponins (GTS) on hypoxic damage of primary cultures of astrocytes were studied. Hypoxia was created by placing cultures in an air tight chamber that was flushed with 95% N(2)/5% CO(2) for 15 min before being sealed. Cultures showed evidence of significant cell injury after 24 h of hypoxia (increased lactate dehydrogenase (LDH) content in the culture medium, cell swelling and decreased glutamate uptake and protein content). Addition of GTS (0.1, 0.3 mg/ml) to the cultures during the exposure to hypoxic conditions produced dose-dependent inhibition of the LDH efflux. GTS (0.1, 0.3 mg/ml) also produced significant inhibition of the increased cell volume of astrocytes measured by [(3)H]O-methyl-D-glucose uptake under the hypoxic conditions. Decreased glutamate uptake and protein content was inhibited by GTS. These data suggest that GTS prevents astrocytic cell injury induced by severe hypoxiain vitro.     

Topical anti-inflammatory activity of dianemycin isolated fromStreptomyces sp. MT 2705-4

In order to develop new anti-inflammatory agents having different action mechanisms compared with nonsteroidal and steroidal anti-inflammatory drugs, the culture broths of various actinomycetes isolated from soil were screened using anin vivo mouse ear edma assay and one strain (Streptomyces sp. MT 2705-4: KCTC 8651P) was selected. Activity-guided purification led to the isolation of a polyether compound, dianemycin. Topically, dianemycin showed a potent anti-inflammatory activity in mouse ear edema induced by croton-oil or arachidonic acid. ED(50) value of dianemycin was found to be 0.8 mg/ear compared to 0.4 mg/ear of prednisolone in croton-oil ear edema. However, dianemycin did not show the inhibitory activity in UV-erythema and delayed hypersensitivity reaction. These results indicate that dianemycin is a potential topical anti-inflammatory agent.     

Inhibitory effects of plant extracts on adjuvant-induced arthritis

Twenty seven plant extracts were selected on the basis of ancient literature search for rheumatoid arthritis or similar syndrome. Methanol extract of each plant was prepared and administered orally to rats everyday at a dose of 200 mg/kg/day. Experimental arthritis was induced by subplantar injection of heat-killedMycobacterium butyricum to right hind paw of rats. This treatment provoked swelling of the treated paw in two phases, acute primary swelling and secondary arthritic swelling. An inhibition of secondary swelling was considered to be antiarthritic activity. Several plant methanol extracts such asAkebia quinata (caulis),Ephedra sinica (herba) andSophorae subprostrata (radix) were found to show significant inhibitory activity against secondary swelling at the dose tested. Our results strongly suggested an antiarthritic potential of these plant extracts.     

Constituents of the herb ofIsodon excisus var.coreanus

The studies were carried out to evaluate the constituents in the aerial part ofIsodon excisus var.coreanus (Labiatae). From the aqueous fraction of methanol extract, compound 1 (alpha-[[3-(3, 4-dihydroxyphenyl)-1-oxo-2-propenyl]oxy]-3,4-dihydroxy-benzenepropanoic acid), compound II (9-methyl-dihydroferulic acid-4-O-beta-D-glucopyranosyl (1-->2)-alpha-L- rhamnopyranosyl (1-->4)-beta-D-glucopyranoside), compound III (ent-7alpha, 11alpha, 15beta-trihydroxy-kaur-16-en-1-O-beta-D-glucopyranoside) and compound IV (2alpha, 3beta, 7alpha, 23-tetrahydroxy-olean-12-en-28-oic acid 28-O-beta-D-glucopyranoside) were isolated and identified on the basis of their physicochemical and spectroscopic evidences[IR, FAB(-)MS,(1)H-NMR,(13)C-NMR, HMQC,(1)H-(1)H COSY and HMBC (Heteronuclear Multiple Bond Connectivity)]. Especially, New compounds II and III were named isodonin A and Isodonin B respectively.     

Effect of hepatic cirrhosis on the pharmacokinetics of theophylline in rats

The experimental hepatic cirrhosis was induced either by bile duct ligation (BDL) or by pretreatment with dimethylnitrosamine (DMNA). The pharmacokinetics of theophylline were studied after a single intravenous or a single oral administration. Using the ultrafiltration method, protein-drug binding experiments were also carried out. The bilirubin level was several-fold increased by BDL, but not by DMNA treatment. The albumin content was decreased in both cirrhotic groups. The total clearance (Clt, ml/kg/hr) of theophylline in both hepatic cirrhosis groups significantly decreased and the terminal half-life (t_1/2) in the cirrhotic rats was increased about two-fold after intravenous and oral administration. The volume of distribution at steady state (Vdss, ml/kg) was increased slightly in the cirrhotic groups. Protein binding in BDL (8.67±4.85%) decreased about four-folds, but in DMNA (73.00±9.85%) similar result, was observed as compared with the control. Increased free fraction of theophylline did not increase the volume of distribution in BDL. Therefore decreased total body clearance of theophylline was mainly due to decreased intrinsic clearance of theophylline in the liver. The absolute bioavailability of theophylline in these experiments was between 63.8 and 72.8%(66.1% in BDL, 63.8% in Sham operated and Control, 72.8% in DMNA). These results suggest that in the experimental hepatic cirrhosis model, administration route does not affect the disposition of theophylline.     

Clonazepam release from core-shell type nanoparticlesin vitro

AB-type amphiphilic copolymers (abbreviated as LE) composed of poly (L-leucine) (PLL) as the A component and poly (ethylene oxide) (PEO) as the B component were synthesized by the ring-opening polymerization of L-leucine N-carboxy-anhydride initiated by methoxy polyoxyethylene amine (Me-PEO-NH₂) and characterized. Core-shell type nanoparticles were prepared by the diafiltration method. Particle size distribution obtained by dynamic light scattering was dependent on PLL composition and the size for LE-1, LE-2 and LE-3 was 369.6±267, 523.4±410 and 561.2±364 nm, respectively. Shapes of the nanoparticles observed by transmission electron microscope (TEM) were almostly spherical. The critical micelle concentration (CMC) of the nanoparticles determined by a fluorescence probe technique was dependent on the composition of hydrophobic PLL, and the CMC for LE-1, LE-2 and LE-3 was 2. 0×10⁻⁶, 1.7×10⁻⁶ and 1.5×10⁻⁶ (mol/l), respectively. Clonazepam release from core-shell type nanoparticles in vitro was dependent on PLL composition and drug loading content.     

Pretreatment of low dose radiation reduces radiation-induced apoptosis in mouse lymphoma (EL4) cells

Induction of an adaptive response to ionizing radiation in mouse lymphoma (EL4) cells was studied by using cell survival fraction and apoptotic nucleosomal DNA fragmentation as biological end points. Cells in early log phase were pre-exposed to low dose of γ-rays (0.01 Gy) 4 or 20 hrs prior to high dose γ-ray (4, 8 and 12 Gy for cell survival fraction analysis; 8 Gy for DNA fragmentation analysis) irradiation. Then cell survival fractions and the extent of DNA fragmentation were measured. Significant adaptive response, increase in cell survival fraction and decrease in the extent of DNA fragmentation were induced when low and high dose γ-ray irradiation time interval was 4 hr. Addition of protein or RNA synthesis inhibitor, cycloheximide or 5,6-dichloro-1-β-d-ribofuranosylbenzimidazole (DRFB), respectively during adaptation period, the period from low dose γ-ray irradiation to high dose γ-ray irradiation, was able to inhibit the induction of adaptive response, which is the reduction of the extent DNA fragmentation in irradiated EL4 cells. These data suggest that the induction of adaptive response to ionizing radiation in EL4 cells required both protein and RNA synthesis.