Red Mold Rice Mitigates Oral Carcinogenesis in 7,12‐Dimethyl‐1,2‐Benz[a]anthracene‐Induced Oral Carcinogenesis in Hamster

Abstract

The prevalence of oral tumor has exponentially increased in recent years; however, the effective therapies or prevention strategies are not sufficient. Red mold rice is a traditional Chinese food, and several reports have demonstrated that red mold rice had an anti-tumor effect. However, the possible anti-tumor mechanisms of the red mold rice are unclear. In this study, we examined the anti-tumor effect of red mold rice on 7,12-dimethyl-1,2-benz[a]anthracene (DMBA)-induced oral tumor in hamster. The ethanol extract of red mold rice (RMRE) treatment significantly decreases the levels of DMBA-induced reactive oxygen species, nitro oxide and prostaglandin E2 than those of the lovastatin-treated group (P < .001). Moreover, RMRE decreases the formation of oral tumor induced by DMBA. Monacolin K, monascin, ankaflavin or other red mold rice metabolites had been reported to decrease inflammation and oxidative stress and exerted anti-tumor effects. Therefore, we evaluated the anti-inflammation and anti-oxidative stress effects of monacolin K, monascin, ankaflavin and citrinin in lipopolysaccharide-treated RAW264.7 cells. We found that RMRE reduced the LPS-induced nitrite levels in RAW264.7 cells better than monacolin K, monascin, ankaflavin or citrinin (P < .05).

Red mold dioscorea-induced G2/M arrest and apoptosis in human oral cancer cells

“…Monascus ‐fermented products have been reported to inhibit tumour progression and tumour metastasis‐associated factors and to reduce angiogenesis 8. RMRE is known to exert inhibitory effects against oral carcinogenesis 15. However, in the present study, RMDE exerted stronger cell cytotoxicity than RMRE (Table 1) and was a more potent cell proliferation inhibitor than RMDW and RMRW (Fig.…”

“…As a result, apart from analysing phenol and flavonoid contents, we also used high‐performance liquid chromatography to identify the bioactive chemical constituents in RMDE. Monascin and ankaflavin were present at concentrations of 137.2 and 34.14 g kg −1 respectively in Monascus ‐fermented dioscorea,25 higher than the levels found in RMRE 15. Dioscorea has proven antitumour ability,13 and RMDE has stronger anticancer activity than RMRE, RMDW and RMRW used in this study.…”

“…Thus Monascus fermentation of dioscorea should strengthen the anticancer effects of RMD. In a previous study the ethanol extract of RMR (RMRE) was found to effectively inhibit oral cancer carcinogenesis in a hamster buccal pouch model 15. Hence Monascus fermentation of dioscorea may lead to stronger anticancer effects.…”

Anticancer properties of Monascus metabolites

“…Treatment with RMRE (22.7 mg/kg/ day) [64] or RMDE (50, 100, or 200 mg/kg/day) [65] for 6 weeks markedly reduced the number of tumors and the mean tumor volume. Treatment with RMRE (22.7 mg/kg/ day) [64] or RMDE (50, 100, or 200 mg/kg/day) [65] for 6 weeks markedly reduced the number of tumors and the mean tumor volume.…”

New Anti-Inflammatory and Anti-Proliferative Constituents from Fermented Red Mold Rice Monascus purpureus NTU 568

“…Pharmacognosy research has corroborated that Monascus species contain several bioactive secondary metabolites, such as monacolins with hypolipidemic activities, γ-aminobutyric acid (GABA) with an antihypertensive effect, dimerumic acid, which reduces the damage caused by oxidative-stress in cells, and azaphilonoid pigments with anti-inflammatory and antitumor activity [ 10 , 11 , 12 , 13 , 14 ]. In our previous studies, Monascus purpureus NTU 568 fermented RMR was examined for the regulation of obesity-related factors [ 15 ], the mitigation of oral carcinogenesis in 7,12-dimethyl-1,2-benz[a]anthracene (DMBA)-induced oral tumors [ 16 ], and the amelioration of memory impairment [ 17 ] in vivo . Recently, three new yellow pigments, monaphilones A, B and C, were isolated from RMR by our laboratory [ 18 ].…”