Improvements of doxorubicin-induced antitumor activity and adverse reaction by combined citrulline.

Citrulline is an amino acid with antioxidant activity. In this study, effects of citrulline on the adverse effects of doxorubicin (DOX) and DOX-induced antitumor activity were examined. Citrulline significantly inhibited DOX-induced increases in lipid peroxide (LPO) in the heart as adverse reaction. Combined treatment with DOX and citrulline increased DOX levels in tumor cells and enhanced cytotoxicity in vitro by significantly increasing DOX uptake compared with DOX treatment alone. In simultaneous in vivo treatments, combination treatment with DOX and citrulline decreased tumor weight and increased DOX concentrations in tumors. Promotion of DOX uptake by citrulline enhanced the antitumor activity of DOX through the action of energy-independent and Na(+)-independent transporters. This effect of citrulline on DOX influx is identical to that of S-(4-nitrobenzyl)-6-thioinosine, promoting DOX influx through the equilibrative nucleoside transporter 1. Therefore, it is anticipated that citrulline as a food component may enhance DOX efficacy.

Effect of linalool as a component of Humulus lupulus on doxorubicin-induced antitumor activity.

As malignant neoplasm is a major public health problem, there is a need for the development of a novel modulator that enhances antitumor activity and reduces adverse reactions to antitumor agents. In this study, the effects of some volatile oil components in Humulus lupulus on doxorubicin (DOX) permeability in tumor cells and DOX-induced antitumor activity were examined. In vitro, DOX levels in tumor cells by combined linalool as its component significantly increased in the DOX influx system, and the increased effect by linalool on DOX cytotoxicity was shown. In vivo, the combination of DOX with linalool significantly decreased tumor weight compared with that of DOX alone treated group. The promotion of DOX influx level by combined linalool did not depend on energy, whereas it was suppressed by the absence of Na(+). This promoting effect was suppressed by the presence of S-(4-nitrobenzyl)-6-thioinosine and inhibited dependently on phlorizin concentration. It is considered that linalool promoted DOX influx in tumor cells because of its action on DOX transport through concentrative Na(+)-dependent nucleoside transporter 3, which increased DOX concentration in tumor cells and thus enhanced the antitumor activity of DOX. Therefore, linalool as a food component is anticipated to be an effective DOX modulator.

Beneficial effects by intake of Euphausiacea pacifica on high-fat diet-induced obesity.

Obesity is a major health problem showing increased incidence in developed and developing countries. We examined the effect of Euphausia pacifica (E. pacifica) (Pacific Krill) on high-fat diet (HFD)-induced obesity in C57BL/6 mice. No significant differences were observed in average food intake between the HFD and HFD with E. pacifica group, or the low-fat diet (LFD) and LFD with E. pacifica group for 18 weeks. The increased ratio of body weight in the HFD containing E. pacifica group was significantly reduced, being 10% lower than that with HFD group in the 18th week (HFD, 298.6±18.8% vs. HFD with E. pacifica, 267.8±16.2%; p<0.05), while the ratio for the LFD containing E. pacifica group was reduced by 4% compared with LFD group (LFD, 244.2±11.6% vs. LFD with E. pacifica, 234.1±18.0%). There were no effects of E. pacifica on total cholesterol levels in serum and liver, whereas the supplement of E. pacifica tended to decrease triglyceride levels in the HFD groups. The leptin level in serum was significantly decreased in the HFD group (p<0.01) by E. pacifica. The adipocyte area (1926±1275 µm(2)) in the HFD containing E. pacifica group was significantly reduced by 20% (p<0.001) compared with the HFD group. These results suggested that E. pacifica supplementation in the diet is beneficial for the prevention of HFD-induced obesity.

Oral and cervical human papillomavirus infection among female sex workers in Japan.

It has been reported recently that oral human papillomavirus (HPV) infection is associated with oropharyngeal squamous cell carcinomas. The aim of this study was to determine the prevalence of HPV infection and HPV types in the oral cavity and cervix of female sex workers in Japan. Oral and cervical swabs were taken from 196 female sex workers who visited a clinic for regular medical checkups in 2007, and genomic DNA was extracted from those specimens. The HPV L1 gene was amplified by polymerase chain reaction (PCR) using original and modified GP5(+)/6(+) primers, and genotyping was performed using the Kurabo GeneSquare Microarray or by sequencing cloned PCR products. HPV DNA was detected in the oral cavity of 12 (6.1%) women, with HPV-56 being the most common type (7/12). Likewise, HPV DNA was detected in the cervix of 103 (52.6%) women, with HPV-52 (30/103, 29.1%), followed by HPV-16 (24.3%) and HPV-56 (18.4%), being the most common. Of the 12 women with oral HPV infection, only two were infected with the concordant HPV genotype in the cervix. These findings suggest that oral HPV infection occurs independently of cervical HPV infection in this population, and that oral HPV infection may play a role in HPV transmission in Japan.

High-risk HPV types in lesions of the uterine cervix of female commercial sex workers in the Philippines.

In order to prevent cervical cancer, vaccines against human papilloma virus types 16 (HPV-16) and 18 (HPV-18) have been implemented worldwide. However, the HPV types that cause cancer can differ according to geographical area and ethnicity. In this new era of the HPV vaccine, it is important to elucidate the prevalent HPV types in each area. Therefore, the prevalence of HPV infection and cervical abnormalities among 369 female commercial sex workers in the Philippines were examined. HPV L1 gene was amplified by polymerase chain reaction (PCR) using modified GP5+/6+ primers, and genotyping was performed by sequencing cloned PCR products. HPV DNA was detected in 211 (57.2%) women, among whom 46 HPV types were identified. HPV-52 was most common and multiple-type infection was observed in 44.5%. Among 56 women with abnormal cervical cytology (low- and high-grade squamous intraepithelial lesions and adenocarcinoma in situ), HPV-52 was most common (23.2%), followed by HPV-16 (19.6%), -58 (10.7%), and -67 (10.7%). Only 27% of these women were positive for HPV-16 and -18. Multivariate analysis revealed that HPV-16, -39, -52, -67, and -82 were significantly associated with abnormal cytology. Repeated analysis of HPV-52 single-positive samples using the original GP5+/6+ PCR primers produced negative results in 57% of cases, suggesting that the prevalence of HPV-52 infection may have been underestimated in previous studies, and the current vaccines may not be sufficient for preventing infection and the development of premalignant lesions of the cervix in women in the Philippines.

RANTES -28G delays and DC-SIGN - 139C enhances AIDS progression in HIV type 1-infected Japanese hemophiliacs.

The relationships between host immune factors and HIV-1 disease progression are still in dispute. Unlike CCR5Delta32, which has been found to delay disease progression of HIV-1, there still remain several factors whose effect on the clinical course is unconfirmed. To clarify the relationships, we selected seven single-nucleotide polymorphisms (SNPs) out of the previously reported factors, namely, RANTES promoter -28G/-403A, RANTES In1.1C, SDF-1 3'A, IL-4 promoter -589T, and DC-SIGN promoter -139C/-336C, and examined these in Japanese HIV-1-infected hemophiliacs (n = 102). The genotypes were examined by the direct sequencing method, and the distributions of genotype and allelic frequencies were compared between two groups, slow progressors (n = 54) who did not develop AIDS more than 10 years after intravenous infection and others (progressors) (n = 48). The allelic frequency of RANTES -28G was significantly higher in slow progressors (0.185) than in the progressor group (0.074) [p = 0.023, OR = 0.35, 95% CI (0.142, 0.880)]. DC-SIGN promoter -139C, and appeared in progressors with significantly higher allelic frequency (0.333) than slow progressors [0.204, p = 0.040, OR = 1.95, 95% CI (1.039, 3.677)]. With RANTES -403A, RANTES In1.1C, SDF-1 3' A, IL-4 -589T, and DC-SIGN -336C, no significant difference was observed in allelic frequencies between the two groups. These results suggest that RANTES -28G was associated with delayed AIDS progression, while DC-SIGN -139C was associated with accelerated AIDS progression in HIV-1-infected Japanese hemophiliacs.

Emergence of antiretroviral therapy resistance-associated primary mutations among drug-naive HIV-1-infected individuals in rural western Cameroon.

The prevalence of antiretroviral therapy (ART) resistance-associated mutations among HIV-1 strains in western Cameroon was evaluated by genotypically analyzing strains isolated from drug-naive individuals. Proviral DNA was extracted from 54 blood samples and amplified by polymerase chain reaction of protease, reverse transcriptase, integrase, and envelope genes. At least 4 clones per sample were analyzed. Of 54 HIV-1 strains, 45 (83.3%) had a concordant subtype or circulating recombinant form (CRF) designation: 40 CRF02_AG, 2 subtype A1, 2 G, and 1 F2. The remaining 9 (16.7%) had a discordant subtype: 6 subtype A1/CRF02_AG, 2 D/CRF02, and 1 G/CRF02. Protease inhibitor-associated primary resistance mutations were found in 4 (7.4%) cases: M46L with full clones in 1 case, and M46I, M46L, and V82A as minor populations in 1 case each. Reverse transcriptase inhibitor-associated primary resistance mutations were found in 5 (9.8%) samples: Y188C in 2 cases, and L100I, M184V, and V75I in 1 case each, although all of these mutations were found as minor populations. This is one of the first reports of the emergence of primary ART resistance mutations among drug-naive, non-B subtype HIV-1-infected individuals in Cameroon. Follow-up studies should be conducted to assess whether these drug-resistant mutants found as minor populations might impact future ART.

Drug release properties of a gel bead prepared with pectin and hydrolysate.

A calcium-induced pectin gel bead (PB) containing pectin hydrolysate was prepared, and the drug release profiles and degradation properties of the PB were investigated in aqueous media. The stiff PB swelled in physiological saline and its drug release rate decreased with exposure to increasing concentrations of CaCl2 during preparation. And erosion of the PB was not observed in physiological saline. However, the PB did disintegrate in phosphate buffer (pH 6.8) and the rate of disintegration depended on the calcium chloride concentration used to prepare the PB. In addition, the drug release rate of the PB in buffer solution decreased as the rate of gel erosion declined. Consequently, it appears that the PB gel matrix is an effective medium by which to control the release of drug within the gastrointestinal tract.

Derivation of hydroxamic acid from pectin and its applications in colorimetric determination.

A hydroxamic acid (HX) derivative of pectin was prepared, and its potential application to simple colorimetric determination of polysaccharides was investigated. The coupling reaction between pectin and hydroxylamine (HA) progresses in the presence of 1-cyclohexyl-3-(2-morpholinoethyl) carbodiimide metho-p-toluenesulfonate (CMEC). The calibration curve for pectin showed good agreement and the lower limit of detection was 0.5 mg. This is a very simple and rapid determination method, which does not require tedious pre-treatment, for polysaccharides containing carboxyl groups.