benzofurans and Precancerous-Conditions

Topics: Animals; Anticarcinogenic Agents; Benzofurans; CHO Cells; Colonic Neoplasms; Cricetinae; Cricetulus; Genomic Instability; Mutagenicity Tests; Precancerous Conditions

Salvianolic acid B (SalB) was demonstrated to be a promising chemopreventive agent for head and neck squamous cell carcinoma (HNSCC) in the previous studies by our and other research institution, but the properties like low efficacy, poor systemic delivery, and low bioavailability has hampered its clinical applications. To continue our research program focused on the use of natural compounds on cancer chemoprevention, we propose a first example of phospholipid complex loaded nanoparticles (PLC-NPs) encapsulating SalB as a potential carrier for intervention of HNSCC (HN13, HN30) cells and precancer Leuk1 cells in this study. Qualitative and quantitive studies of cellular uptake showed that intracellular accumulation of SalB was significantly higher when HN13, HN30 and Leuk1 cells were incubated with SalB-PLC-NPs complex (nano-SalB) as against free-SalB. Cell viability assay revealed that the cell growth of HN13 and HN30 cells was significantly inhibited of 56.1% and 29.3%, respectively, for nano-SalB compared to an equivalent amount of free-SalB (P<0.001). Moreover, cell cycle and apoptosis assay showed that a clear trend of cell cycle arrest and induction of apoptosis was also observed within the HNSCC cells treated with nano-SalB. Collectively, this study demonstrated that nano-SalB was significantly more potent had an anticancer effect against HNSCC cells, which serves as the first step toward establishing SalB nano-formulations as promising cancer chemopreventive agents. The current study could pave a new way for the development of drugs that target HNSCC in the future.

Topics: Antineoplastic Agents; Apoptosis; Benzofurans; Carcinoma, Squamous Cell; Cell Cycle; Cell Proliferation; Drugs, Chinese Herbal; Head and Neck Neoplasms; Humans; Nanoparticles; Precancerous Conditions; Tumor Cells, Cultured

Salvia miltiorrhiza (SM) has been used clinically in Asian countries to improve the microcirculation in the human body. Salvianolic acid B (Sal B), a pure compound extracted from SM, has been reported to be effective against fibrosis and ischemia-reperfusion injury, possibly through its anti-lipid peroxidation action. But the effect of Sal B on oral premalignant lesion and oral carcinogenesis remains unexplored. It is our interest to investigate the chemopreventive effect of Sal B on 7,12-dimethylbenz[a]anthracene (DMBA)-induced oral carcinogenesis in hamsters with respect to angiogenesis. Seventy male Syrian golden hamsters were randomly divided into five groups, with two of 20 and three of 10. DMBA solution (0.5% in acetone) was applied topically to the left cheek pouch of male Syrian golden hamsters in Groups A and B, while animals in Group C were painted with acetone, three times a week for 6 weeks. For the next 18 weeks, animals in Groups B and D received Sal B daily (10 mg/kg body wt/day) by gavage, animals in Groups A and C received same volume of saline. Animals in Group E received no treatment and served as blank control. At the end of the experiment, animals were killed and tissue samples were collected for histopathological and immunohistochemical examinations. The results showed that Sal B significantly decreased the squamous cell carcinoma (SCC) incidence from 64.7 (11/17) to 16.7% (3/18) (P=0.004); angiogenesis was inhibited in dysplasia and SCC (P<0.01), with a simultaneous decrease in the immunostaining of hypoxia-inducible factor 1alpha and vascular endothelium growth factor protein (P<0.05). The results suggested that Sal B had inhibitory effect against the malignant transformation of oral precancerous lesion and such inhibition may be related to the inhibition of angiogenesis.

Topics: 9,10-Dimethyl-1,2-benzanthracene; Administration, Oral; Animals; Benzofurans; Carcinogens; Carcinoma, Squamous Cell; Cell Transformation, Neoplastic; Chemoprevention; Cricetinae; Male; Mesocricetus; Mouth Neoplasms; Neovascularization, Pathologic; Precancerous Conditions; Random Allocation

The hepatic tumor-promoting activity of a mixture of polyhalogenated aromatic hydrocarbons (PHAHs) was studied in a medium term two-stage initiation/promotion bioassay in female Sprague-Dawley rats. The PHAH mixture contained 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), 1, 2,3,7,8-pentachlorodibenzo-p-dioxin (PeCDD), 2,3,4,7, 8-pentachlorodibenzofuran (PeCDF), 3,3',4,4',5-pentachlorobiphenyl (PCB 126), 2,3',4,4',5-pentachlorobiphenyl (PCB 118), 2,3,3',4,4', 5-hexachlorobiphenyl (PCB 156), 2,2',4,4',5,5'-hexachlorobiphenyl (PCB 153) and covered >90% of the total toxic equivalents (TEQ) present in Baltic herring. To determine possible interactive effects of di-ortho-substituted PCBs, the PHAH mixture was tested with (PHAH+) and without (PHAH-) PCB 153. Rats were initiated by a diethylnitrosamine injection (30 mg/kg body wt i.p.) 24 h after a partial 23 hepatectomy. Six weeks after initiation, the PHAH mixtures were administered once a week by subcutaneous injections for 20 weeks. Treatment with the PHAH mixtures caused liver enlargement and an increased activity of the hepatic cytochrome P4501A1/2 and P4502B1/2. All PHAH exposure groups exhibited an increased occurrence of hepatic foci positive for the placental form of glutathione-S-transferase. In the PHAH-group dosed 1 microgram TEQ/kg body wt/week, the volume fraction of the liver occupied by foci was significantly lower compared to the TEQ equivalent dosed TCDD group (3.8 vs 8.7%). The volume fraction was significantly increased in the groups treated with 0.5, 1, or 2 micrograms TEQ/kg body wt/week of the PHAH+ mixture (4.5, 5.2, and 6.6%, respectively) compared to the corn oil group (2.0%), but to a lower extent than expected on basis of the TEQ doses. Overall, the TEQ-based administered dose overestimated the observed tumor-promoting effects of this PHAH mixture. The applicability of the toxic equivalency factor concept, the role of differences in toxicokinetic properties and interactive effects of PCB 153 on hepatic deposition of the dioxin-like congeners are discussed.

Topics: Animals; Benzofurans; Cytochrome P-450 Enzyme System; Enzyme Induction; Female; Liver; Liver Neoplasms, Experimental; Polychlorinated Biphenyls; Polychlorinated Dibenzodioxins; Precancerous Conditions; Rats; Rats, Sprague-Dawley