• Journal of Microbiology
• /
• 제39권3호
• /
• pp.154-161
• /
• 2001

In recent years, colon cancer has been reported to be one of the most important causes of cancer morbidity and mortality in Korea. Epidemiological and experimental studies suggest that lactic acid bacteria (LAB) used to ferment dairy products inhibits colon carcinogenesis. The present study was designed to determine whether the colon cancer inhibitory effect of LAB (Bifidobacterium longum Hy8001; Bif and Lactobacillus acidophilus HY2l04; Lac) of Korean origin, is associated with intestinal microflora composition and certain enzyme activity in rats treated with azoxymethane (AOM). At five weeks of age, SD rats were divided at random into four (AOM alone, Bif, Lac, and Bif+Lac) groups. Oral administration of lactic acid bacteria cultures were performed daily until the termination of the study. Two weeks later all animals were given a subcutaneous injection of AOM dissolved in normal saline at a dose of 15 mg/kg of body weight once weekly for 2 weeks. Every two weeks for 10 weeks, five of the rats in each group were randomly chosen for fecal specimen collection. The fecal specimens were used for assay of $\beta$-glucuronidase and nitroreductase, and analysis of intestinal microflora composition. The activity of $\beta$-glucuronidase which plays an important role in the production of the carcinogenic metabolite of azoxymethane was remarkably increased in the AOM alone group after AOM injection and maintained the high level during the experiment. However, LAB inhibited the AOM-induced increase in $\beta$-glucuronidase activity. Nitroreductase activity decreased by 30-40% in LAB treated groups in comparison with that of the AOM alone group. The results of the present study suggest that LAB inhibits colon carcinogenesis by modulating the metabolic activity of intestinal micro-flora and improving the composition of intestinal microflora.

• Archives of Pharmacal Research
• /
• 제22권6호
• /
• pp.533-541
• /
• 1999

Many conventional anticancer drugs display relatively poor selectivity for neoplastic cells, in particular for solid tumors. Furthermore, expression or development of drug resistance, increased glutathione transferases as well as enhanced DNA repair decrease the efficacy of these drugs. Research efforts continue to overcome these problems by understanding these mechanisms and by developing more effective anticancer drugs. Cyclophosphamide is one of the most widely used alkylating anticancer agents. Because of its unique activation mechanism, numerous bioreversible prodrugs of phosphramide mustard, the active species of cyclophosphamide, have been investigated in an attempt to improve the therapeutic index. Solid tumors are particularly resistant to radiation and chemotherapy. There has been considerable interest in designing drugs selective for hypoxic environments prevalent in solid tumors. Much of the work had been centered on nitroheterocyclics that utilize nitroreductase enzyme systems for their activation. In this article, recent developments of anticancer prodrug design are described with a particular emphasis on exploitation of selective metabolic processes for their activation.

• 한국식품영양과학회지
• /
• 제37권5호
• /
• pp.671-675
• /
• 2008

대다수 숙성 김치의 미생물 조성이 L. mesenteroides와 L. sakei로 구성되며, 이러한 혼합조성을 가진 김치가 맛이 있다는 점을 바탕으로 김치 맛을 가장 좋게 하며 김치 미생물을 조절하는 능력을 가진 두 균주 L. mesenteroides K2M5와 L. sakei K5M3을 각각 김치스타터로 선정하였다. 선정된 두 가지 균주들은 베타 용혈현상을 보이지 않았고, 암모니아나 인돌을 생성하지 않았으며, 젤라틴을 용해하지 않았고, phenylalanine deaminase, ${\beta}$-glucuronidase, ${\beta}$-glucosidase, 7${\alpha}$-dehydroxylase, nitroreductase 등의 효소 활성에서 음성을 보여 산업적으로 사용하여도 안전한 것으로 나타났다. 선정된 두 가지 균주를 첨가하여 제조한 김치는 비첨가 김치에 비해 실험실 평가와 다수의 일반인을 상대로 한 비교평가에서 맛이 더 우수하였고, 미생물 조성은 오직 첨가한 균주로만 구성되어 선정한 균주들은 김치 맛을 좋게 하고 미생물 조성을 일정하게 조절하는 능력이 있는 스타터로 사용될 수 있음을 보여주었다. 스타터를 첨가한 김치는 대조김치에 비해 젖산 등의 유기산 함량이 특이하게 높았으나 산도, 염도, 당 함량 등에서는 큰 차이를 나타내지 않았다.

• Journal of Dairy Science and Biotechnology
• /
• 제17권1호
• /
• pp.58-71
• /
• 1999

This study was designed to investigate the health promotion effect of fermented milk and historical story of Korean dairy products from the ancient period to present. Although the origin of fermented milk is Europe, the recede of fermented milk was founded in far-east and middle east areas at BC 4C. After the spread of fermented milk to Korea and Japan. The consumption of fermented milk in Korea was dramatically increased to 14.2 kg per person in 1997. Health promotion effect of fermented milk can be devided to 5 major effected improvements of intestinal microflora, anticancer, cholesterol assimilation anti-pathogenic activity. Fermented milk reduced the level of ${\beta}$-glucornidase and nitroreductase to 50% and it provides anticancer activity by cell wall an polysaccharides. Fermented milk has cholesterol assimilation activity ca. 54${\sim}$40% (B. longum, Str. thermophillus). Anti-pathogenic activity of fermented milk was significant. It appeared that Sal. ser. typhimurium was more susceptible than 5. coli 0157 at low pH fermented milk. Viable cells of E. coli 0157 were not dramatically decreased in most of fermented milks tested, but in general, Sal. ser. typhimurium was drastically decreased in most of the fermented milks.

• Journal of Microbiology and Biotechnology
• /
• 제29권8호
• /
• pp.1221-1229
• /
• 2019

Mycobacterium tuberculosis, a causative pathogen of tuberculosis (TB), still threatens human health worldwide. To find a novel drug to eradicate this pathogen, we tested taurine-5-bromosalicylaldehyde Schiff base (TBSSB) as an innovative anti-mycobacterial drug using Mycobacterium smegmatis as a surrogate model for M. tuberculosis. We investigated the antimicrobial activity of TBSSB against M. smegmatis by plotting growth curves, examined the effect of TBSSB on biofilm formation, observed morphological changes by scanning electron microscopy and transmission electron microscopy, and detected differentially expressed proteins using two-dimensional gel electrophoresis coupled with mass spectrometry. TBSSB inhibited mycobacterial growth and biofilm formation, altered cell ultrastructure and intracellular content, and inhibited cell division. Furthermore, M. smegmatis adapted itself to TBSSB inhibition by regulating the metabolic pathways and enzymatic activities of the identified proteins. NDMA-dependent methanol dehydrogenase, NAD(P)H nitroreductase, and amidohydrolase AmiB1 appear to be pivotal factors to regulate the M. smegmatis survival under TBSSB. Our dataset reinforced the idea that Schiff base-taurine compounds have the potential to be developed as novel anti-mycobacterial drugs.

• 고려인삼학회:학술대회논문집
• /
• 고려인삼학회 1990년도 Proceedings of International Symposium on Korean Ginseng, 1990, Seoul, Korea
• /
• pp.111-122
• /
• 1990

The growth responses of a variety of human Intestinal bacteria to extracts of Pun(1.vKy'n.ieny and five other oriental medicinal Araliaceae were evaluated in vitro and in vivo. The extracts enhanced the growth of Bifidobncterilim breve and B. longum in Media with or without carbon sources, suggesting the bifid factor (5) might be involved in the phenomenon. This effect was most pronounced with water extract of p. ginseng, the growth of 27 bifidobacteria strains belonging to B. ndolexcentium, H. longlrm, and 1. breve and B. iniuntis being greatly stimurated, whereas seven B. bifidum strains and other bacteria such as clostridia and 5.fcherirhia coli had little or no ability to utilizes it (or growth. Methanol extracts of p, ginseng were found to selectively inhibit growth of various clostridia including C. perfringens and C. Paraputrificum, but this effect was not observed on other bacteria including bifidobacteria. The effect of ginseng extract intake(600 mg/day for two weeks) on the fecal microflora, pH, volatile fatty acids, ammonia, putrefactive products, and -glucuronidase, -glucosidase and nitroreductase activities, and on the blood components (triglyceride, total cholesterol and ammonia) were investigated using seven healthy human volunteers. The total concentration of fecal microflora including Bri'idobucterilim app. during the period of ginseng extract intake was significantly unaffected from the proceeding and sub sequent control periods. However, the frequency of occurrence of subjects having C. perfringens was significantly decreased. The fecal pH value was also significantly decreased, suggesting that the intake might increase the activity of Bifidobacterium spp. Other biochemical properties in faces did not changed significantly. The levels of ammonia and triglycerid in blood were decreased with ginseng extract intake. These results may be an indication of at least one of the pharmacological actions of P ginseng as an adaptogen.

• Journal of Ginseng Research
• /
• 제14권2호
• /
• pp.253-264
• /
• 1990

The growth responses of a variety of human intestinal bacteria to extracts of Panax ginseng and five other oriental medicinal Araliaceae were elraluattd in vitro and in vivo. The extracts enhanced the growth of Brifidobnnerilrm breve and B. longlim in media with or without carbon sources, suggesting that bifidus factors) might be involved in the phenomenon. This effect was most pronounced with water extract of P. ginseng, the growth of 27 bifidobacteria strains belonging to B adolescentis, B. longum, B. brim and B. infantis being greatly stimurated, whereas seven B. bifidum strains and other bacteria such as clostridia and Escherichin soli had little or no ability to utilise it for growth. Methanol extracts of p. ginseng were found to selectively inhibit growth of various clostridia including bifidobacteria. Paraputrificum, but this effect was not observed on other bacteria including bifidobacteria. The effect of ginseng extract intake (600 mg/day for two weeks) on the faecal microflora, pH, volatile fatty acids, ammonia, putrefactive products, and -glucuronidase, -glucosidase and nitroreductase activities, and on the blood components (triglyceride, total cholesterol and ammonia) were investigated using seven healthy human volunteers. The total concentration of faecal microflora including Bifidnkaderiifm app. during the period of ginseng extract intake %twas significantly unaffected from the preceding and subsequent control peroids. However, the frequency of occurrence of subjects having C. perfringens was significantly decreased. The faecal pH value was also significantly decreased, suggesting that the intake might increase the activity of Bifidobncterium spry. Other biochemical properties in faeces did not changed significantly. The levels of ammonia and triglycerid in blood were decreased with ginseng extract intake. These results may be an indication of at least one of the Pharmacological actions of p. ginseng as an adaptogen.

• 생명과학회지
• /
• 제17권5호
• /
• pp.723-727
• /
• 2007

본 연구는 H. pylori에서 metronidazole내성에 관여하는 유전자를 발견하고 이들 유전자들의 상호 조절 기전을 밝힘으로서 위장질환의 원인균인 H. pylori를 퇴치하기 위한 기본바탕을 마련하고자 수행되었다. 우선적으로 metronidazole 내성을 조절하는 유전자인 fdxA(ferredoxin)에 의한 metronidazole 내성 조절 기전을 밝히기 위하여 다음의 연구를 수행하였다. Type I 균주인 26695균주의 fdxA 유전자에 chloramphenicol 내성 유전자를 삽입하여 결손돌연변이주를 구축하였다. fdxA의 비활성화에 의한 rdxA 및 frxA 유전자의 발현을 알아보기 위하여 2-D electrophoresis와 MALDI-TOP-MS을 이용하여 fdxA 유전자의 비활성화에 의해 over-expressed protein과 under-expressed protein을 검색하였다. 본 실험의 결과로 type I 균주인 26695에서 fdxA 유전자를 비활성화시킨 결과 frxA 유전자의 발현양이 증가함을 northern으로 확인하였으며, 또한 fdxA유전자의 downstream에 위치한 유전자들이 H. pylori의 생존에 중요한 역할은 한다는 것을 알 수 있었다. 또한 2-D electrophoresis와 MALDI-TOP-MS을 이용하여 fdxA 유전자의 inactivation에 의해 over-expressed protein으로 nifU-like protein(HP0221), frxA(HP0642), nonheme ferritin(HP0653)와 아직 기능이 밝혀지지 않은 hypothetical protein(HP0902) 등이 발견되었다. 그리고 5'-methylthioadenosine/S-adenosylhomocysteine nucleosidase(HP0089), (3R)-hydroxymyristoyl ACP dehydratase(HP1376)과 thioredoxin(HP1458)등이 under-expressed protein으로 발견되었다.