Preventive effect of oral administration of 6-(methylsulfinyl)hexyl isothiocyanate derived from wasabi (Wasabia japonica Matsum) against pulmonary metastasis of B16-BL6 mouse melanoma cells

AIM: Effect of oral administration of 6-(methylsulfinyl)hexyl isothiocyanate (6-MITC) or a 6-MITC-containing T-wasabi fraction from wasabi root (Wasabia japonica Matsum) to inhibit the macroscopic pulmonary metastasis was studied with a murine B16-BL6 melanoma model. METHOD: Two administration routes, subcutaneous or intravenous, and two administration times, prior to or concomitant with tumor inoculation, of 6-MITC or T-wasabi against the metastatic foci formation in C57BL/6J mouse lungs were compared. RESULTS: The number of metastasized foci per lung in either subcutaneous or intravenous injection was significantly reduced by intake of 6-MITC or a T-wasabi fraction. The maximum reduction by a T-wasabi fraction reached to 82%. Fifty-six percent of foci formation was inhibited by a 2 week-prior administration of 6-MITC (200 microM), whereas only 27% inhibition was obtained by a concomitant administration with tumor inoculation. Neither 6-MITC nor T-wasabi at tested concentrations showed any toxic effects. DISCUSSION: Together with our previous results, a component of the Japanese pungent spice, wasabi appears to inhibit not only tumor cell growth but also tumor metastasis. Therefore, 6-MITC from wasabi is apparently a useful dietary candidate for controlling tumor progression.     

Adjuvant chemotherapy with TS-1 for head and neck cancer--side effect of two-week application followed by one-week rest regimen

Multimodality therapy incorporated with radiotherapy, surgery and chemotherapy are used in the treatment of head and neck cancer in order to improve the local control and survival rate. TS-1, a newly developed oral antitumor agent which could achieve the same therapeutic concentration as that of 5-FU under continuous and intravenous treatment, has been used as adjuvant therapy for carcinomas in recent years. We presented our experience applying a new regimen of TS-1 and its side effects. TS-1 has been applied for head and neck carcinomas since 2001. The oral application of TS-1 has been used in 32 cases of head and neck cancer in our department since 2003, and the agent has been applied in 22 of 32 cases as adjuvant therapy. The primary sites of malignancy included hypopharyngx (7 cases), larynx (6 cases), maxillary sinus (2 cases), oropharynx (2 cases), oral cavity (4 cases), submandibular gland (1 case) and one case in which the primary site was unknown. A regimen of four-week application followed by two-week rest had been used in 6 cases in the first part of this trial. However, a high frequency of blood toxicity was found from the third week, requiring alteration of the protocol. Thus, a new regimen of two-week application followed by one week rest was thereafter used in the other 16 cases. Blood toxicity was found in 66.7% of those cases receiving a four-week application followed by two-week rest regimen. In the 16 cases receiving the two-week application followed by one-week rest regimen, only one case showed grade 2 leucopenia while continuous application for more than eight weeks was possible in 9 cases. Mild macrocytic anemia was found in some of these cases, however none of which required any necessary interruption of the treatment. Side effects other than blood toxicity, such as edema or pigmentation of lower limbs, erythema of skin and diarrhea, were found in the other cases, requiring suspension of the treatment. But the subsequent application was possible after a break or decreasing the dosage. We concluded that the new regimen of two-week application followed by one-week rest is less likely to be interrupted by the side effects and is safer to be used outpatiently, compared with the four-week application followed by two-week rest.     

A case of high-dose rate interstitial brachytherapy for locally recurrent rectal cancer

The patient was a 55-year-old female who underwent an abdomino-perineal resection for advanced lower rectal cancer. The tumor was a well differentiated adenocarcinoma, type 2 in the Japanese classification of colorectal carcinoma, and was measured 2.3 cm in size. Histologically, the tumor was considered to be stage IIIb (mp, n3(+), P0, H0, M(-)). She received adjuvant chemotherapy with 5'-DFUR. After 13 months from the surgery, the patient developed a hip pain. After 16 months from the surgery, a pelvic MRI scan revealed a 3 cm tumor in the perineum. Biopsy from the tumor revealed adenocarcinoma. Consequently, we diagnosed local recurrence in the perineum. Chemotherapy with CPT-11 (230 mg/body) and 5'-DFUR (800 mg/body) was administered for 2 cycles. Because the tumor was enlarged, high-dose rate interstitial brachytherapy was given to the recurrent site at a total dose of 54 Gy/9 fractions/5 days. There were no severe complications. CEA was decreased within normal range from a maximum of 9.3. No progress was detected on CT and MRI, and the hip pain had disappeared. The tumor marker is within normal range for about 2 years and QOL was improved. Hence, high dose rate interstitial brachytherapy appears to be effective for locally recurrent rectal cancer.     

Evaluation of weekly low-dose CPT-11 combined with 5-FU/l-LV therapy for advanced and recurrent colorectal cancer--preliminary study

In Japan, cancer chemotherapy for advanced and recurrent colorectal cancer has not been adequately developed in comparison with the USA and Europe. However, the number of patients with advanced colorectal cancer has increased dramatically in this decade. Therefore, effective and feasible regimens against colorectal cancer are urgently needed. We designed a new regimen to evaluate the efficacy and feasibility of weekly low dose CPT-11 combined with 5-FU/l-LV therapy based on an RPMI regimen against advanced and recurrent colorectal cancer. Twenty patients were enrolled in this study. Weekly administration (CPT-11; 60 mg/m(2) div for 1st-line chemotherapy, 40 mg/m(2) div for 2nd-or 3rd-line chemotherapy, l-LV; 200 mg/m(2) div, 5-FU; 500 mg/m(2) iv, 3 consecutive weeks, 1-week break) was performed on an ambulatory basis. The treatment cycles were repeated every 4 weeks until disease progression and/or severe toxic events occurred. The overall response rate was 31.6% with 5.3% complete response and 26.3% partial response in addition to 42.1% with no changes beyond 3 months. These results suggested that the clinical benefit was shown in 73.7% of patients. Furthermore, median TTF (time to failure) of this regimen was 6.5 months and MST was 20.4 months, respectively. On the other hand, adverse events were restricted to grade 3 with 30.0% neutorocytopenia and 5.0% thrombocytopenia. Therefore, weekly low-dose CPT-11 combined with 5-FU/l-LV therapy seems to be extremely useful, with excellent anti-tumor effect and tolerable adverse reactions, for the treatment of advanced and recurrent colorectal cancer on an ambulatory basis.     

Cardiovascular effects of KUR-1246, a new tetrahydronaphthalen derivative beta2-adrenoceptor agonist and a selective uterine relaxant

The aim of this study was to assess the cardiovascular effects of KUR-1246 (CAS 194785-31-4, (-)-bis(2-{[(2S)-2-({(2R)-2-hydroxy-2-[4-hydroxy-3-(2-hydroxyethyl) phenyl] ethyl}amino)-1,2,3,4-tetrahydronaphthalen-7-yl]oxy}-N,N-dimethylacetamide)monosulfate), a new beta2-adrenoceptor agonist tocolytic agent. In conscious dogs, the intravenous administration of KUR-1246 at 0.1 and 1 microg/kg had no effects on blood pressure, heart rate or femoral artery blood flow. KUR-1246 at 10 and 100 microg/kg significantly decreased blood pressure and increased heart rate. In the electrocardiograms, KUR-1246 did not affect QT intervals or QTc. In addition, the cardiac effects of KUR-1246 were evaluated in in vitro electrophysiological studies. KUR-1246 at 10 micromol/L did not affect action potential parameters (the maximal upstroke velocity, resting membrane potential, action potential amplitude and action potential durations) in isolated papillary muscles of guinea pigs or in the human ether-a-go-go related gene (HERG) tail current recorded from stably transfected human embryonic kidney (HEK) 293 cells. On the basis of these results, the effects of KUR-1246 in conscious dogs on the cardiovascular system appear to be limited to changes in blood pressure and heart rate. Therefore, KUR-1246 is unlikely to provoke ventricular arrhythmias by delaying the ventricular repolarization.     

Stereospecific recognition of a spirosuccinimide type aldose reductase inhibitor (AS-3201) by plasma proteins: a significant role of specific binding by serum albumin in the improved potency and stability

AS-3201 [(3R)-2'-(4-bromo-2-fluorobenzyl)spiro[pyrrolidine-3,4'(1'H)-pyrrolo[1,2-a]pyrazine]-1',2,3',5(2'H)-tetrone] is a structurally novel and stereospecifically potent aldose reductase (AKR1B; EC 1.1.1.21) inhibitor, which contains a succinimide ring that undergoes ring-opening at physiological pH levels. To delineate intermolecular interactions governing its favorable pharmacokinetic profile, the interaction of AS-3201 (R-isomer) with plasma proteins, especially human serum albumin (HSA), was examined in comparison with that of the optical antipode (S-isomer). Fluorescence, kinetic, and high-performance frontal analyses showed that the R-isomer is more strongly bound than the S-isomer to sites I and II on HSA, and the R-isomer is particularly protected from hydrolysis, suggesting that the stable HSA-R-isomer complex contributes to its prolonged activity. The thermodynamic parameters for the specific binding indicated that in addition to hydrophobic interactions, hydrogen bonds contribute significantly to the R-isomer complex formation. (13)C NMR observations of the succinimide ring (5-(13)C enriched), which are sensitive to its ionization state, suggested the presence of a hydrogen bond between the R-isomer and HSA, and (19)F NMR of the pendent benzyl ring (2-(19)F) evaluated the equilibrium exchange dynamics between the specific sites. Furthermore, fatty acid binding or glycation (both are site II-oriented perturbations) inhibited the binding to one of the specific sites and reduced the stereospecificity of HSA toward the isomers, although the clinical influence of these perturbations on the R-isomer binding ratio seemed to be minor. Thus, the difference in the interaction mode at site II might be a major cause of the stereospecificity; this is discussed on the basis of putative binding modes. The present results, together with preliminary absorption and distribution profiles, provide valuable information on the stereospecific pharmacokinetic and pharmacodynamic properties of the R-isomer relevant for the therapeutic treatment of diabetic complications.     

Standardization of habu (Trimeresurus flavoviridis) snake-venom toxoid.

Of the multiple toxic principles contained in the venom of the crotalid Habu (Trimeresurus flavoviridis), two hemorrhagic principles, HR1 and HR2, are known to play the most important role in envenomation. HR1 and HR2 were treated separately with formalin to make individual toxoids. The mixed toxoid composed of HR1- and HR2-toxoids was highly immunogenic for various animals and human beings. The potency of the mixed toxoid was determined relative to a reference toxoid, by titrating the circulating antitoxin in guinea-pigs, and was expressed in terms of guinea-pig immunizing units. It is of vital importance to determine whether or not the potency of toxoid preparations for human use can be expressed in guinea-pig immunizing units. Since the immune response of men and monkeys to HR1-toxoid was shown to be similar to each other, we studied the immune response of monkeys to the mixed toxoid, as a model system for that of humans. We demonstrated a linear relationship between the immune response of monkeys and the injected dose of the toxoid as expressed in guinea-pig immunizing units for HR1-antigen. The present findings enabled us to determine, in guinea-pigs, the potency of the toxoid preparations for human use relative to that of the reference toxoid.