• Preventive Nutrition and Food Science
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• 제16권2호
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• pp.104-109
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• 2011

Recently, we have demonstrated that green tea extract (GTE) decreases the intestinal absorption of benzo[a]pyrene (BAP), which is an extremely lipophilic food contaminant. The present study was conducted to examine if an enteral infusion of GTE would influence the biliary secretion of BAP and lipids in rats. Female rats were fed an AIN-93G diet with or without (control) GTE at 5 g/kg diet for 4 week. Following the 4-week dietary treatment, rats with bile duct cannula were infused continuously for 8 hr at 3.0 mL/hr via a duodenal catheter with a lipid emulsion containing $4.0\;{\mu}mol$ BAP labeled with $^{14}C$ ($^{14}C$-BAP), $20.7\;{\mu}mol$ cholesterol, $452\;{\mu}mol$ triolein, and $3.1\;{\mu}mol$ ${\alpha}$-tocopherol, and $396.0\;{\mu}mol$ Na-taurocholate with or without 76.1 mg GTE powder in PBS buffer (pH, 6.4). Bile was collected hourly via bile cannula for an 8 hr period. Our results showed that bile flow did not differ between groups. However, the biliary secretion of $^{14}C$-BAP was significantly enhanced by GTE infusion, compared with those infused with the lipid emulsion alone. However, GTE did not affect the biliary outputs of cholesterol, fat, phospholipid and ${\alpha}$-tocopherol. These findings indicate that GTE has a profound stimulatory effect on the biliary excretion of BAP in rats, without affecting other biliary lipids. The mechanism(s) by which GTE enhances the biliary secretion of BAP remains to be investigated.

• 한국식품영양과학회지
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• 제25권4호
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• pp.627-631
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• 1996

참치 가수분해물을 항산화제인 BHT 0.02% 첨가구와 rosemary 0.01% 및 0.02%를 첨가한 제품을 대조구와 함께 $30^{\circ}C에서$ 저장하면서 검사한 결과 색도에서 대조구 및 항산화제 처리한 4제품 모두 명도는 감소하는 반면에 적색도는 증가하는 경향이었다. 그리고 수용성 갈변물질이 지용성 갈변물질 보다 함량이 많았으며 저장 중 증가폭도 컸다. 지방산화 억제능에서는 0.02% BHT 첨가구 보다 0.02% rosemary 첨가구에서 효과가 있었고, ACE 저해능에서는 생시료에서 3% 미만의 낮은 효율을 보인 반면에 가수분해물에서는 72.2%를 나타내었으며, $IC_{50}$/은 1.124mg이었다.

• 한국응용과학기술학회지
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• 제22권3호
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• pp.219-227
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• 2005

Competitive solvent extraction of the mixure of alkali metal and alkaline earth cation from water into organic solvent containing the crown ether carboxylic acid and anlogous crown ether phosphonic acid was investigated as follows. The lipophilic group is found to strongly influence to the selective extraction in the mixed systems from only alkali metal cation for sym-(n-decyldibenzo)-16-crown-5-oxyacetic acid $\underline{1}$ to mostly alkaline earth metal cation for sym-bis[4(5)-tert-butylbenzo]-16-crown-5-oxyacetic acid $\underline{3}$. Monoethyl sym-(n-decyldibenzo)-16-crown-5-oxymethylphosphonic acid $\underline{2}$. and monoethyl-sym- bis]4(5)-tert-butylbenzo]-16-crown-5-oxymethylphosphonic acid $\underline{4}$ showed good selectivity for $Na^+$ over $Mg^{2+}$, the second extracted ion. Structural variation in the crown ether phosphonic acid somewhat was influenced to the extraction selectivity in the mixed systems. when variation of the ionized group is influenced in the mixed systems, the selectivity of $Na^+$ as the second extracted ion was much better crown ether carboxylic acid $\underline{1}$ than crown ether phosphonic acid $\underline{2}$, while the efficiency of $Na^+$ extraction was better $\underline{2}$ (83% total loading) than $\underline{1}$ (32%).

• 대한핵의학회지
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• 제26권1호
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• pp.133-139
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• 1992

To improve the quality of $^{99m}Tc-methylenediphonate$ $(^{99m}Tc-MDP)$ for skeletal imaging, different composed $^{99m}Tc-MDP$ complexes were prepared with addition of antioxidants such as ascorbic acid, getisic acid, and p-aminobenzoic acid. To characterize the different $^{99m}Tc-MDP$ preparations, some physical and biochemical properties of $^{99m}Tc-MDP$ such as thermal stability, lipophilicity and bindability to serum protein were studied and organ distribution pattern of these complexes also compared. The thermal stabilities of $^{99m}Tc-MDP$ contained antioxidants were dependant mainly on pH, temperature, and elapsed time after the preparation. $^{99m}Tc-MDP$ complex contained gentisic acid as antioxidant was extremely unstable at alkaline condition. The most stable $^{99m}Tc-MDP$ was found in the presence of p-aminobenzoic acid. $^{99m}Tc-MDP$ complexes with antioxidants were very lipophilic but lipophilicity differences in antioxidants were not observed. The bindability of $^{99m}Tc-MDP$ to serum protein was not affect at pH $5.0\sim9.0$ by the different antioxidants. However, protein binding percentage of $^{99m}Tc-MDP$ with ascorbic acid was relatively low (22.7%) at pH 9.0. In biodistribution studies in mice, bone to muscle ratios of $^{99m}Tc-MDP$ preparations containing ascorbic acid, gentisic acid, and p-aminobenzoic acid were 15.3, 24.5, and 30.1, respectively. Im to our results, p-aminobenzoic acid is fond to be the most promising antioxidant.

• Biomolecules & Therapeutics
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• 제15권1호
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• pp.65-72
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• 2007

Flax seed(Linseed, Linum usitatissimum L.) and its oil, a richest source of alpha-linolenic acid(ALA)(${\omega}-3$), contain saturated fatty acids, neurotoxic cyanogen glycosides and immuno-suppressive cyclic-nonapeptides. Present paper describes the development of two chemical processes, Process-A and -B, to remove saturated fatty acids and to destroy cyclic nonapeptides and cyanogen glycosides from flax seed oil. Process-A consists of three major steps, i.e., extraction of fatty acid mixture by alkaline saponification, removal of saturated fatty acid by urea-complexation, and triglyceride reconstruction of unsaturated fatty acid via fatty acyl-chloride activation using oxalyl chloride. Process-B consists of preparation of fatty acid ethyl ester by transesterification, elimination of saturated fatty acid ester by urea-complexation, and reconstruction of triglyceride by interesterification with glycerol-triacetate (triacetin). The destruction of lipophilic cyclic nonapeptide during saponification or transesterification processes could be demonstrated indirectly by the disappearance of antibacterial activity of bacitracin, an analogous cyclic-decapeptide. The cyanogen glycosides were found only in the dregs after hexane extraction, but not in the flax seed oil. The reconstructed triglyceride of flax seed oil, obtained by these two different pathways after elimination of saturated fatty acid and toxic components, showed agreeable properties as edible oil in terms of taste, acid value, iodine and peroxide value, glycerine content, and antioxidant activity.

• Toxicological Research
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• 제17권
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• pp.271-280
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• 2001

We report on the applicability oj a method recently developed in our laboratory for measuring the antioxidant potential of isolated chemicals and extracts derived from natural products. Peroxyl radicals generated by thermal homolysis of 2,2'-azobis-amidinopropane (ABAP) oxidize $\alpha$-keto-${\gamma}$-methiolbutyric acid (KMBA) to ethylene, which is monitored by gas chromatography. Inhibition of ethylene formation in the presence of antioxidants that compete with KMBA for peroxyl radicals is the basis of the Total Oxyradical Scavenging Capacity Assay (TOSCA; Winston et al., 1998). Antioxidative activities of water-soluble extracts of American green tea, the anti-hepatotoxic flavonolignan from milk thistle (Silybum marianum) silybin, Ginkgo biloba extract EGb 761, and a series of naturally occuring sesquiterpene lactones (all ger-macranolides found in in fungi, liverworts, and plants) were studied. The specific TOSC value per $\mu$M silybin was 5.2, which is essentially comparable to that of Trolo $x^{ⓡ}$, a water-soluble vitamine E analog. Tea and Ginkgo extracts exhibited potent peroxyl radical scavenging capacity with values, respectively of =1700 and 1000 $\mu$mols Trolo $x^{ⓡ}$ equivalent per gram dry matter. The known anti-inflammatory activity of some germacranolides prompted study of their antioxidant capacity. None of the lactones exhibited antioxidant capacity toward peroxyl radicals comparable to Trolo $x^{ⓡ}$; costunilide, the most lipophilic, had a TOSC value = to glutathione. The potential role of peroxyl radicals in lipidperoxidation, other cellular damage, and var-ious disease states suggest a possible preventive role for silybin, green tea and Ginkgo biloba in oxidative stress caused by these free radical species.ecies.

• Journal of Microbiology and Biotechnology
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• 제23권8호
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• pp.1107-1115
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• 2013

The Cyt1Aa protein of Bacillus thuringiensis susbp. israelensis elaborates demonstrable toxicity to mosquito larvae, but more importantly, it enhances the larvicidal activity of this species Cry proteins (Cry11Aa, Cry4Aa, and Cry4Ba) and delays the phenotypic expression of resistance to these that has evolved in Culex quinquefasciatus. It is also known that Cyt1Aa, which is highly lipophilic, synergizes Cry11Aa by functioning as a surrogate membrane-bound receptor for the latter protein. Little is known, however, about whether Cyt1Aa can interact similarly with other Cry proteins not primarily mosquitocidal; for example, Cry2Aa, which is active against lepidopteran larvae, but essentially inactive or has very low toxicity to mosquito larvae. Here we demonstrate by ligand binding and enzyme-linked immunosorbent assays that Cyt1Aa and Cry2Aa form intermolecular complexes in vitro, and in addition show that Cyt1Aa facilitates binding of Cry2Aa throughout the midgut of C. quinquefasciatus larvae. As Cry2Aa and Cry11Aa share structural similarity in domain II, the interaction between Cyt1Aa and Cry2Aa could be a result of a similar mechanism previously proposed for Cry11Aa and Cyt1Aa. Finally, despite the observed interaction between Cry2Aa and Cyt1Aa, only a 2-fold enhancement in toxicity resulted against C. quinquefasciatus. Regardless, our results suggest that Cry2Aa could be a useful component of mosquitocidal endotoxin complements being developed for recombinant strains of B. thuringiensis subsp. israelensis and B. sphaericus aimed at improving the efficacy of commercial products and avoiding resistance.

• Journal of Pharmaceutical Investigation
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• 제35권1호
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• pp.33-38
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• 2005

Recently increasing attention has been focused on solid lipid nanoparticles (SLN) as a parenteral drug carrier due to its numerous advantages that can come from both polymeric particle and fat emulsions, together with the possibility of controlled release and increasing drug stability. Lipophilic drugs such as paclitaxel, cyclosporin A, and all-trans retinoic acid have been successfully entrapped in SLN but the incorporation of hydrophilic drugs in SLN is very limited because of their very low affinity to the lipid. Therefore, as a new approach to improve the loading of hydrophilic drugs, a w/o/w emulsion technique has been developed. The primary objective of the current study was to improve the loading efficiency of a model hydrophilic drug, glycine (Log P = -3.44) into SLN. The proposed preparation process is as follows: A heated aqueous phase consisting of 0.1 ml of glycine solution in water (100 mg/ml), and poloxamer 188 (5 mg) were then added to a molten oil phase containing precirol (100 mg) and lecithin (5 mg). This mixture was dispersed by sonicator, leading to a w/o emulsion. A double emulsion (w/o/w) was formed after the addition of 2% poloxamer solution to the above dispersed system. After cooling the double emulsion, solid lipid nanosuspensions were successfully formed. The lipid nanoparticles had the mean particle size of 441.25 nm, and the average zeta potential of -20.98 mV. The drug loading efficiency was measured to be 8.54% and the drug loading amount was measured to be 0.92%. The w/o/w emulsion method showed an increased loading efficiency compared to conventional o/w emulsion method.

• Journal of Pharmaceutical Investigation
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• 제31권3호
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• pp.143-150
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• 2001

Butyrolactone ester of ceftezole (CFZ-BL) was synthesized by esterification of ceftezole (CFZ) with ${\alpha}-bromo-{\gamma}-butyrolactone$. The synthesis was confirmed by spectroscopic analysis. CFZ-BL was more lipophilic than CFZ when the lipophilicity was assessed by partition coefficients between n-octanol and water at various pH. CFZ-BL itself did not show any microbiological activity in vitro, but serums taken after oral administration of CFZ-BL showed substaintial microbiological activity indicating that CFZ-BL is converted to microbiologically active metabolite, probably CFZ, in the body. The conversion was confirmed by in vitro incubation study, in which CFZ-BL was incubated in some body tissues of rabbit. Liver homogenate showed fastest conversion of CFZ-BL among the tissues tested (blood and intestine). Thus, CFZ-BL appeares to be rapidly metabolized in the liver to CFZ following oral administration. The metabolism process appears to be hydrolysis of the ester to CFZ, the parent drug of CFZ-BL. In vivo metabolism of CFZ-BL to CFZ was confirmed by analying CFZ by HPLC. CFZ concentration in the serum samples taken after oral administration of CFZ-BL were higher than those in the serum samples taken after oral administration of equivalent amount of CFZ. Oral bioavailability of CFZ-BL, a prodrug of CFZ, was 1.45-fold higher than that of CFZ in rabbits possibly due to enhanced lipophility and absorption of the prodrug.

• Journal of Pharmaceutical Investigation
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• 제32권3호
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• pp.165-172
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• 2002

Injectable gel composed of egg phosphatidylcholine (egg PC), hyaluronate (HA) and water was formulated for local drug delivery. The lamellar liquid crystalline structure of the egg PC/water system did not change by adding HA in the formulation. However, egg PC/HA/water gel was more resistant to erosion than the egg PC/water gel. The egg PC/HA/water and egg PC/water gels containing model drugs, tetracycline and sudan IV were prepared to perform in vitro and in vivo drug release experiments. In vitro release of tetracycline was sustained in the gel type formulations. The release rate of hydrophobic sudan IV was extremely slow. More than 99% of sudan IV remained inside the gel after 5 days. In vivo release of drugs from the air pouch model in Balb/c mice shows that lipophilic sudan IV remained for more than 10 days whereas tetracycline remained for 1 day in the pouch. The compatibility of the gels was also examined by histopathology. The gels did not cause any adverse inflammatory effect in the air pouch.