Promotion of hair growth by Rosmarinus officinalis leaf extract.

Topical administration of Rosmarinus officinalis leaf extract (RO-ext, 2 mg/day/mouse) improved hair regrowth in C57BL/6NCrSlc mice that experienced hair regrowth interruption induced by testosterone treatment. In addition, RO-ext promoted hair growth in C3H/He mice that had their dorsal areas shaved. To investigate the antiandrogenic activity mechanism of RO-ext, we focused on inhibition of testosterone 5α-reductase, which is well recognized as one of the most effective strategies for the treatment of androgenic alopecia. RO-ext showed inhibitory activity of 82.4% and 94.6% at 200 and 500 µg/mL, respectively. As an active constituent of 5α-reductase inhibition, 12-methoxycarnosic acid was identified with activity-guided fractionation. In addition, the extract of R. officinalis and 12-methoxycarnosic acid inhibited androgen-dependent proliferation of LNCaP cells as 64.5% and 66.7% at 5 µg/mL and 5 µM, respectively. These results suggest that they inhibit the binding of dihydrotestosterone to androgen receptors. Consequently, RO-ext is a promising crude drug for hair growth.

Inhibitory activities of Puerariae Flos against testosterone 5α-reductase and its hair growth promotion activities.

Crude drugs expected to have an estrogenic effect were screened for their inhibitory activity on testosterone 5α-reductase. Testosterone 5α-reductase is an enzyme catalyzing the conversion of testosterone to dihydrotestosterone, which possesses high affinity for the androgen receptor. Among the crude drugs tested, we focused on Puerariae Flos (the flowers of Pueraria thomsonii) due to its potent inhibitory activity and suitability for commercial use. The 50% ethanolic extract of Puerariae Flos (PF-ext) showed inhibitory activity of 60.2% at 500 µg/ml against testosterone 5α-reductase. Interestingly, it was more potent than that of Puerariae Radix (roots of Pueraria lobata). PF-ext also showed in vivo anti-androgenic activity using a hair growth assay in testosterone-sensitive male C57Black/6NCrSlc strain mice. We demonstrated saponins, including soyasaponin I and kaikasaponin III, to be active components in PF-ext. In addition, hair growth promotion activity in C3H/He mice at 2 mg/mouse/day of the topical administration of PF-ext was demonstrated. Thus, Puerariae Flos is a promising crude drug for treating androgenic alopecia.

Numerical changes in the mitochondrial DNA displacement loop in lung lesions induced by N-nitrosobis(2-hydroxypropyl)amine in rats.

Mutations in the mitochondrial DNA (mtDNA) displacement loop (D-loop) region were investigated to clarify the possible molecular mechanisms underlying the development of lung tumors induced by N-nitrosobis(2-hydroxypropyl)amine (BHP) in rats. Male Wistar rats, 6 weeks of age, were given 2000 ppm BHP in their drinking water for 12 weeks and then maintained without further treatment until sacrifice at 25 weeks. Genomic DNA was extracted from paraffin-embedded tissues and polymerase chain reaction (PCR)-single strand conformation polymorphism (SSCP) analysis, followed by nucleotide sequencing, was performed. Eleven out of 24 hyperplasias (45.6%), 8 out of 16 adenomas (50.0%), and 14 out of 21 adenocarcinomas (66.7%) showed numerical changes, in a polymeric C-tract at positions 16,086-16,092 of the mtDNA D-loop, with a one base insertion of cytosine increasing the length of the C-tract, from the seven nucleotides observed in normal lung tissues from non-BHP treated rats, to eight. These changes were all homoplasmic and no changes were found in lung lesions when the length of the C-tract in the normal lung tissues adjacent to the lesions was seven. These results suggest that alterations in the mtDNA D-loop may occur in an early phase of lung carcinogenesis induced in rats by BHP.

Different mutation patterns of mitochondrial DNA displacement-loop in hepatocellular carcinomas induced by N-nitrosodiethylamine and a choline-deficient l-amino acid-defined diet in rats.

Mutations of the mitochondria DNA (mtDNA) displacement loop (D-loop) were investigated to clarify different changes of exogenous and endogenous liver carcinogenesis in rats. We induced hepatocellular carcinomas (HCCs) in rats with N-nitrosodiethylamine (DEN) and a choline-deficient l-amino acid-defined (CDAA) diet. DNAs were extracted from 10 HCCs induced by DEN and 10 HCCs induced by the CDAA diet. To identify mutations in mtDNA D-loop, polymerase chain reaction (PCR)-single strand conformation polymorphism (SSCP) analysis, followed by nucleotide sequencing, was performed. Mutations were detected in 5 out of 10 HCCs (50%) induced by DEN. Four out of 5 mutations were G/C to A/T transitions at positions 15707, 15717, 15930, and 16087, and one T/A to C/G transition at position 15559. By contrast, no mutations were found in 10 HCCs induced by the CDAA diet. These results demonstrated that mutations in mtDNA D-loop occur in rat HCCs induced by DEN but not by the CDAA diet, suggesting that mtDNA D-loop is a target of exogenous liver carcinogenesis in rats.

Disturbance of DNA methylation patterns in the early phase of hepatocarcinogenesis induced by a choline-deficient L-amino acid-defined diet in rats.

The authors investigated the DNA methylation patterns of the E-cadherin, Connexin 26 (Cx26), Rassf1a and c-fos genes in the early phase of rat hepatocarcinogenesis induced by a choline-deficient L-amino acid-defined (CDAA) diet. Six-week-old F344 male rats were continuously fed with the CDAA diet, and three animals were then killed at each of 4 and 8 days and 3 weeks. Genomic DNA was extracted from livers for assessment of methylation status in the 5' upstream regions of E-cadherin, Cx26, Rassf1a and c-fos genes by bisulfite sequencing, compared with normal livers. The livers of rats fed the CDAA diet for 4 and 8 days and 3 weeks were methylated in E-cadherin, Cx26 and Rassf1a genes, while normal livers were all unmethylated. In contrast, normal livers were highly methylated in c-fos gene. Although the livers at 4 days were weakly methylated, those at 8 days and 3 weeks were markedly unmethylated. Methylation patterns of CpG sites in E-cadherin, Cx26 and Rassf1a were sparse and the methylation was not associated with gene repression. These results indicate that gene-specific DNA methylation patterns were found in livers of rats after short-term feeding of the CDAA diet, suggesting gene-specific hypermethylation might be involved in the early phase of rat hepatocarcinogenesis induced by the CDAA diet.

Hypermethylation of the Dal-1 gene in lung adenocarcinomas induced by N-nitrosobis(2-hydroxypropyl)amine in rats.

DAL-1 (differentially expressed in adenocarcinoma of the lung) is an actin-binding protein that has been shown to suppress growth in lung cancer cells. Recently, inactivation of the gene encoding DAL-1 due to hypermethylation has been found in several human malignancies, including lung cancers. To assess the involvement of the Dal-1 gene in rat lung carcinogenesis, we investigated the expression of Dal1 and its methylation status in rat lung adenocarcinomas induced by N-nitrosobis(2-hydroxypropyl)amine (BHP). Six-week old male Wistar rats (n = 11) were given 2,000 ppm BHP in their drinking water for 12 wk and maintained without further treatment until they were sacrificed at 25 wk. Total RNA was extracted from 11 lung adenocarcinomas, one from each BHP treated rat, and Dal-1 gene expression was analyzed using real-time quantitative reverse transcription-polymerase chain reaction. Dal-1 expression was significantly reduced in the lung adenocarcinomas compared with three normal lung tissues (P < 0.05). For methylation analysis, bisulfite sequencing was performed using normal lung tissue and tissue from 4 tumors, all of which showed reduced expression of Dal-1. The 5' upstream region was highly methylated in all four adenocarcinomas, whereas this region was unmethylated in normal lung tissue. These results suggest that aberrant methylation of the Dal-1 gene might be involved in the development of lung adenocarcinomas induced in rats by BHP.

Gatifloxacin induces augmented insulin release and intracellular insulin depletion of pancreatic islet cells.

Many hypoglycemic and hyperglycemic episodes associated with clinical use of gatifloxacin (GFLX), a novel fluoroquinolone antimicrobial agent, have been reported in recent years. Some have reported hypoglycemia induced by fluoroquinolones, indicating that these agents may stimulate insulin secretion from pancreatic islet cells. In this study, we investigated the effect of GFLX on insulin homeostasis in islet cells using the insulin secreting cell line, HIT-T15. After 1 h incubation with over 100 microM of GFLX, insulin secretion from the cells was significantly augmented. However, the augmentation of insulin release induced by GFLX subsequently reached a plateau. Coincidentally, cellular insulin was decreased by 120 h incubation, and reactivity to re-stimulation by sulfonylurea was suppressed. The GFLX insulin depletion effect was stronger than the effects produced by such other fluoroquinolones as levofloxacin and ciprofloxacin. This study suggests that GFLX should induce insulin oversecretion from pancreatic islet cells in the short-term, and decrease insulin productivity or increase insulin disintegration in the long-term. These results are consistent with the clinical results of GFLX finding that hypoglycemic episodes were seen after a first single administration, and most hyperglycemic episodes were seen more than 2 d after the start of administration.

Expression and DNA methylation patterns of Tslc1 and Dal-1 genes in hepatocellular carcinomas induced by N-nitrosodiethylamine in rats.

To assess the involvement of the TSLC cascade in hepatocarcinogenesis, we investigated the expression and DNA methylation patterns of the genes Tslc1 and Dal-1 in hepatocellular carcinomas (HCC) induced using N-nitrosodiethylamine (DEN) in rats. Six-week-old male F344 rats received a single intraperitoneal injection of DEN at a dose of 10 mg/kg body weight, followed by combined treatment with partial hepatectomy and colchicine to induce cell-cycle disturbance and a selection procedure consisting of 2-acetylaminofluorene and carbon tetrachloride. Total RNA was extracted from 10 HCC, and the expression levels of Tslc1 and Dal-1 were measured using semiquantitative reverse transcription-polymerase chain reaction (RT-PCR) analysis. Three of 10 HCC showed reduced expression of Tslc1, compared with normal liver tissues, but no changes in the expression level of Dal-1 were found. For DNA methylation analysis, bisulfite sequencing was performed. The 5' upstream region of Tslc1 was methylated in the three HCC in which its expression was reduced, but was unmethylated in normal liver tissue. Western blot analysis also revealed reduced expression of Tslc1 protein in the three HCC. These results suggest that alterations to the TSLC cascade might have a role in hepatocarcinogenesis using DEN in rats.

CpG site hypermethylation of E-cadherin and Connexin26 genes in hepatocellular carcinomas induced by a choline-deficient L-Amino Acid-defined diet in rats.

We investigated DNA methylation patterns of E-cadherin and Connexin26 (Cx26) genes in rat hepatocellular carcinomas (HCCs) induced by a choline-deficient L-Amino Acid-defined (CDAA) diet. Six-wks-old F344 male rats were continuously fed with a CDAA diet for 75 wks, and were then killed. A total of five HCCs were obtained, and genomic DNA was extracted from each HCC for assessment of methylation status in the 5' upstream regions of E-cadherin and Cx26 genes by bisulfite sequencing, comparing to two normal liver tissues. The five HCCs showed highly methylated E-cadherin and Cx26 genes, while these genes in two normal liver tissues were all unmethylated. For analysis of gene expression, real-time quantitative reverse transcription (RT)-polymerase chain reaction (PCR) was performed. Expressions of E-cadherin and Cx26 genes were significantly reduced in the five HCCs (P < 0.0001 and P < 0.001, respectively) compared to normal liver tissues, correlating with their methylation statuses. These results suggested that hypermethylation of E-cadherin and Cx26 genes may be involved in the development of HCCs induced by a CDAA diet in rats.

Aberrant DNA methylation of the 5' upstream region of Tslc1 gene in hamster pancreatic tumors.

To determine if the Tslc1 gene is involved in pancreatic carcinogenesis, the expression level of Tslc1 and the DNA methylation status of its 5' upstream region were investigated in pancreatic duct adenocarcinomas (PDAs) induced in hamsters by N-nitrosobis(2-oxopropyl)amine (BOP). Female Syrian golden hamsters received 70 mg/kg of BOP followed by repeated exposure to an augmentation pressure regimen consisting of a choline-deficient diet combined with ethionine-methionione-BOP injection. Total RNA was extracted from 11 PDAs and the level of Tslc1 expression was measured in each by real-time quantitative reverse transcription (RT)-polymerase chain reaction (PCR). The expression level of Tslc1 was significantly reduced in PDAs (p < 0.05) compared with normal pancreatic tissues. In order to assess the DNA methylation status of the 5' upstream region of Tslc1, bisulfite sequencing was performed. Although this region was unmethylated in normal pancreatic tissue, it was highly methylated in four PDAs, correlating with reduced Tslc1 expression. These results suggest that a reduction in the expression of Tslc1 due to aberrant DNA methylation might be involved in the development of PDAs induced in hamsters by BOP.

Involvement of aberrant DNA methylation on reduced expression of lysophosphatidic acid receptor-1 gene in rat tumor cell lines.

Lysophosphatidic acid (LPA) is a bioactive phospholipid that stimulates cell proliferation, migration, and protects cells from apoptosis. It interacts with specific G protein-coupled transmembrane receptors. Recently, it has been reported that alterations of LPA receptor expression might be important in the malignant transformation of tumor cells. Therefore, to assess an involvement of DNA methylation in reduced expression of the LPA receptor-1 (lpa1) gene, we investigated the expression of the lpa1 gene and its DNA methylation patterns in rat tumor cell lines. Both rat brain-derived neuroblastoma B103 and liver-derived hepatoma RH7777 cells used in this study indicated no expression of lpa1. For the analysis of methylation status, bisulfite sequencing was performed with B103 and RH7777 cells, comparing with other lpa1 expressed cells and normal tissues of brain and liver. The lpa1 expressed cells and tissues were all unmethylated in this region of lpa1. In contrast, both B103 and RH7777 cells were highly methylated, correlating with reduced expression of the lpa1. Treatment with 5-aza 2'-deoxycytidine induced expression of lpa1 gene in B103 and RH7777 cells after 24h. In RH7777 cells treated with 5-aza 2'-deoxycytidine, stress fiber formation was also observed in response to LPA in RH7777 cells, but not in untreated RH7777 cells. These results suggest that aberrant DNA methylation of the lpa1 gene may be involved in its reduced expression in rat tumor cells.

Reduced expression of the Tslc1 gene and its aberrant DNA methylation in rat lung tumors.

TSLC1 gene inactivation due to promoter methylation has been reported in several human cancers. Here, we investigated the expression of the Tslc1 gene and its methylation pattern in lung adenocarcinomas induced by N-nitrosobis(2-hydroxypropyl)amine (BHP). Six-week-old male Wistar rats were given 2000 ppm BHP in their drinking water for 12 weeks and maintained without further treatment until they were sacrificed at 25 weeks. Total RNA was extracted from a total of 11 lung adenocarcinomas and their Tslc1 gene expressions were analyzed by real-time quantitative reverse transcription-polymerase chain reaction. Tslc1 expression was significantly reduced in the lung adenocarcinomas compared with three normal lung tissues (p < 0.05). Bisulfite sequence analysis of four lung adenocarcinomas and two normal lung tissues revealed that the 5' upstream region of the Tslc1 gene was highly methylated in the four lung adenocarcinomas, but unmethylated in the two normal lung tissues. These results suggest that aberrant Tslc1 gene methylation may be involved in BHP-induced development of lung adenocarcinomas in rats.