Metabolism of puerarin and daidzin by human intestinal bacteria and their relation to in vitro cytotoxicity

When puerarin or daidzin were incubated for 24 h with human intestinal bacteria, two metabolites, daidzein and calycosin, were produced from them, respectively. The metabolic time course of puerarin was as follows: at an early time, puerarin was converted to daidzin, and then calycosin. The metabolic time course of daidzin by human intestinal bacteria was also similar to that of puerarin. The in vitro cytotoxicities of these metabolites, calycosin and daidzein, were superior to those of puerarin and daidzein.

Inhibitory effects of Bifidobacterium spp. isolated from a healthy Korean on harmful enzymes of human intestinal microflora

Five hundreds of bifidobacteria were isolated from a healthy Korean and the inhibitory effects of these isolated bacteria on harmful enzymes of human intestinal microflora were examined by cocultivation of the isolated bifidobacteria with E. coli or total human intestinal microflora. In comparison with the results of E. coli or intestinal microflora cultivation, Bifidobacterium breve K-110, B. breve K-111 and B. infantis K-525 effectively inhibited harmful enzymes (beta-glucuronidase and tryptophanase) of E. coli and lowered the pH of the culture media. Also they inhibited the harmful enzymes (beta-glucosidase, beta-glucuronidase, tryptophanase and urease) and ammonia production of intestinal microflora, and lowered pH of the culture media by increasing lactic acid bacteria of intestinal microflora. When these isolated bifidobacteria were administered on mice, fecal harmful enzymes were also inhibited. Among tested bifidobacteria, B. breve K-110 had the highest inhibitory effect of fecal harmful enzymes.

Intestinal bacterial metabolism of flavonoids and its relation to some biological activities

Flavonoid glycosides were metabolized to phenolic acids via aglycones by human intestinal microflora producing alpha-rhamnosidase, exo-beta-glucosidase, endo-beta-glucosidase and/or beta-glucuronidase. Rutin, hesperidin, naringin and poncirin were transformed to their aglycones by the bacteria producing alpha-rhamnosidase and beta-glucosidase or endo-beta-glucosidase, and baicalin, puerarin and daidzin were transformed to their aglycones by the bacteria producing beta-glucuronidase, C-glycosidase and beta-glycosidase, respectively. Anti-platelet activity and cytotoxicity of the metabolites of flavonoid glycosides by human intestinal bacteria were more effective than those of the parental compounds. 3,4-Dihydroxyphenylacetic acid and 4-hydroxyl-phenylacetic acid were more effective than rutin and quercetin on anti-platelet aggregation activity. 2,4,6-Trihydroxybenzaldehyde, quercetin and ponciretin were more effective than rutin and ponciretin on the cytotoxicity for tumor cell lines. We insist that these flavonoid glycosides should be natural prodrugs.

Partial splenic embolization for hypersplenism concomitant with or after arterial embolization of hepatocellular carcinoma in 30 patients

PURPOSE

To study the value of partial splenic embolization (PSE) for the treatment of hypersplenism in patients undergoing embolization of hepatocellular carcinoma (HCC).

METHODS

Transcatheter hepatic arterial embolization (THAE) combined with PSE was performed in 30 patients with HCC complicating liver cirrhosis, portal hypertension, and hypersplenism. Gelfoam sponge was used as the embolic material for PSE and limited to 100-150 pieces.

RESULTS

More than 50% of splenic parenchyma was infarcted in 27 patients. Leukopenia and thrombocytopenia were corrected by PSE in 25 of 27 patients with hypersplenism. In 26 patients with esophageal varices, including 5 patients with bleeding, no rebleeding occurred during a 6-17 month follow-up. Hypersplenism was not corrected in 2 of 3 patients whose infarcted splenic parenchyma was less than 50%. No splenic abscesses or other severe complications were observed. Of the 30 patients treated, 19 are still alive after 1 year.

CONCLUSIONS

THAE combined with PSE is a safe and effective measure for patients with HCC.

Purification and characterization of beta-glucosidase from Bacteroides JY-6, a human intestinal bacterium

A beta-glucosidase (EC 3.2.1.21.) was purified 2500-fold from Bacteroides JY-6, an intestinal anaerobic bacterium of human. The specific activity of the homogeneously purified enzyme was 210 mumol/min/mg protein. The enzyme (M(r) 75kDa) was an monomer whose pI and optimal pH values were 4.6 and 5.5-6, respectively. The best substrates were p-nitrophenyl beta-D-glucopyranoside and natural beta-bound glucosides, such as prunin and poncirenin. Puerarin, which is a C-glycoside, was weakly effective. However, cellobiose, alpha-bound glycosides and rhamnoglucosides were not effective. The apparent Kms for prunin and p-nitrophenyl-beta-D-glucopyranoside were determined to be 0.08 and 0.19 mM, respectively. The enzyme was strongly inhibited by p-chloromercuriphenylsulfonic acid and reaction products such as p-nitrophenol and glucose.

Budd-Chiari syndrome caused by obstruction of the hepatic inferior vena cava: immediate and 2-year treatment results of transluminal angioplasty and metallic stent placement

PURPOSE

To assess the usefulness of percutaneous transluminal angioplasty (PTA) and expandable metallic stent (EMS) placement for treatment of Budd-Chiari syndrome (BCS).

METHODS

Thirty-two patients with BCS were treated by PTA alone or by PTA and EMS placement. Among the 32 patients, a membranous obstruction was found in 24 and a segmental stenosis or occlusion in 8 patients. The follow-up period for PTA was 38-68 months (mean 52.2 months); for EMS it was 20-36 months (mean 24.3 months).

RESULTS

Twenty-one patients underwent PTA as the primary treatment. Of these, one patient died of disseminated intravascular coagulation shortly after the procedure; 20 had good to excellent initial angiographic and clinical results. Of the 20, restenosis or reocclusion developed in 10 patients (48%), all before 27 months; 8 patients (38%) became symptomatic, and 2 remained symptom-free for a total recurrent obstruction rate of 50%. The EMS group of 17 patients included 11 patients who underwent primary stenting and 6 patients with secondary stenting after recurrence following primary PTA; restenosis was demonstrated in only 2 patients (12%).

CONCLUSIONS

We conclude that PTA alone produces excellent short-term results and about 50% sustained patency after 2 years in patients with BCS; therefore it should remain the procedure of first choice. Stents should be reserved for primary or secondary PTA failures.

Purification and characterization of beta-glucuronidase from Escherichia coli HGU-3, a human intestinal bacterium

beta-Glucuronidase was purified 360-fold from Escherichia coli HGU-3, an human intestinal bacterium. The specific activity of the purified enzyme was 17.78 units/mg protein. The enzyme (M.W. 290000) is composed of four subunits (M.W. 72000) with a pI and optimal pH of 4.8 and 6-7, respectively. The apparent Km for p-nitrophenyl-beta-D-glucuronide was found to be 0.22 mM. The enzyme was inhibited by saccharic acid 1,4-lactone, glycyrrhizin, N-ethylmaleimide (NEM) and p-chloromercuriphenylsulfonic acid (PCMS). Using the bile containing bilirubin diglucuronide as a substrate, the purified beta-glucuronidase was able to hydrolyze it to bilirubin. This hydrolyzed bilirubin formed calcium bilirubinate with a reaction mixture containing CaCl2.

Chlorophyll derivatives (CpD) extracted from silk worm excreta are specifically cytotoxic to tumor cells in vitro

Among chlorophyll derivatives (CpD-A, -B, -C, and -D) extracted from silk worm (Bombyx mori) excretas, CpD-A was extensively studied to clarify its role as a "photosensitizer" for photodynamic therapy (PDT) of tumors in vitro. It was found that CpD-A was photoreactive both in itself and also in its cell bound forms. The cell bound CpD-A produced fluorescent light and singlet oxygen following the exposure to lights of varied wave length. Among them, lights of near 650 nm, which was the maximum absorbance band, efficiently activated CpD-A following the application of only 10 minutes of irradiation. CpD-A was found to have specificity for the human and mouse tumor cells regardless of their species difference. A higher intensity of fluorescence and a larger amount of CpD-A were found in the tumor cells as opposed to the intensity found in normal cells. Only 10 minutes of light irradiation of the CpD-A treated tumor cells resulted in their rapid and complete destruction within 2 hours of irradiation. Simultaneously, more than 80% of the normal human and mouse control cells remained alive after receiving treatment. These findings suggested that CpD-A produced by use of silkworm excreta could be used as a photosensitizer for PDT of tumors by the use of lights of near 650 nm.

Chlorophyll derivatives--a new photosensitizer for photodynamic therapy of cancer in mice

The in vivo photosensitizing efficacy of chlorophyll derivatives (CpD), which had been developed as a new photosensitizer, was compared with that of hematoporphyrin derivatives (HpD). A murine tumor model implanted subcutaneously with S-180 cells on the abdomen was used. The CpD or HpD was administered by intratumoral injection, and light of appropriate wavelength was irradiated on the tumor areas for 10 minutes at 1h and 24h or 24h and 48h after the injection of photosensitizer. When CpD was injected, the early irradiation group (1h and 24h) showed a 100% tumor cure rate; however, the late irradiation group (24h and 48h) showed a 60% tumor cure rate (p less than 0.01). This showed that the early irradiation with light after injection of CpD was an important factor for obtaining better results. With HpD, there was no difference in tumor cure rate between early (1h and 24h, 80%) and late irradiation (24h and 48h, 80%) groups. Thus, in early irradiation groups, the tumor cure rate using CpD (100%) was superior to that of HpD (80%) (p less than 0.05). However, in late irradiation groups, the tumor cure rate using CpD (60%) was inferior to that of HpD (80%), but this difference was not statistically significant (p greater than 0.1). Pathologic sections of these tumors were made before treatment and 48h and 3 weeks after treatment. These showed geographic necrosis at 48h after treatment and no viable tumor tissue at 3 weeks after treatment. Our results showed that CpD was as effective as HpD as a photosensitizer for in vivo photodynamic therapy.