Evaluation of Citrinin Occurrence and Cytotoxicity in Monascus Fermentation Products

Abstract

Monascus purpureus and its fermentation products have been used in food coloring and meat preservation in Asia for centuries and have also been recently used as dietary supplements because of their cholesterol-lowering ability. However, the presence of the mycotoxin citrinin (CTN), a secondary metabolite of Monascus species, in fermentation products is a potential threat to public health. In the present study, HPLC was used to analyze CTN levels in lipid and aqueous extracts of commercialized Monascus products. CTN was detected in lipid extracts of all examined samples at concentrations varying between 0.28 and 6.29 microg/g, but was not found in aqueous extracts. When human embryonic kidney cells (HEK293) were incubated for 72 h with Monascus extracts, the concentrations causing 50% cell death by all lipid extracts were in the range of 1.8-4.7 mg/mL, whereas aqueous extracts showed a lower cytotoxicity. Incubation of HEK293 cells with 60 microM pure CTN for 72 h caused cell viability to fall to 50% of control levels. In addition, coadministration of pure CTN and lipid extracts from Monascus samples significantly enhanced CTN cytotoxicity for HEK293 cells using the MTT assay. These results provide the first information about the cytotoxic effects of various Monascus samples and CTN-Monascus mixtures on a human cell line.

Citrinin induces apoptosis via a mitochondria-dependent pathway and inhibition of survival signals in embryonic stem cells, and causes developmental injury in blastocysts

“…CTN contamination has additionally been reported in Monascus fermentation products [29,37] used as food colourants and flavour enhancers in the Orient, and as dietary supplements believed to prevent heart disease and decrease plasma triacylglycerol and cholesterol levels [38]. One recent study identified 0.28-6.29 µg/g CTN in lipid extracts from commercialized Monascus products [29], while another showed that treatment of human HEK-293 cells (human embryonic kidney cells) with lipid extracts of Monascus products (60 µM CTN) for 72 h induced over 50 % cell death [29]. As these and other studies have shown that CTN can induce apoptosis, I examined the effects of 30 µM CTN (∼ 3.75 µg/g in culture medium) on blastocysts in vitro and in vivo.…”

“…While CTN clearly induces apoptosis in mammalian cells [28,29], its effects on embryonic development and the precise regulatory mechanisms governing these effects are currently unclear. To identify the apoptotic signalling pathway(s) involved in CTNinduced cell death in embryonic cells, I initially analysed the effects of the toxin on embryonic stem cells (ESC-B5) in vitro.…”

Low doses of the mycotoxin citrinin protect cortical neurons against glutamate-induced excitotoxicity

“…The toxic effects of citrinin observed in vitro were reported in HEK 293 cells (Liu et al, 2005), mouse embryonic stem cells (Chan, 2008), CHO-K1 cells (Liu et al, 2003), and V79 cells (Pfeiffer et al, 1998). These studies used 10-100 μM citrinin to assess the toxic effects, with lower concentrations having no signifi cant effect (Pfeiffer et al, 1998).…”

Effects of red monascal rice supplementation on growth, digestive function and oocyte maturation in Siamese fighting fish (Betta splendens Regan, 1910)

“…Toxicological effects of citrinin, a secondary metabolite produced by several fungal species including Monascus sp. and Penicillium sp., have been reported, including increasing apoptosis and decreasing the number and viability of treated cells (Liu et al, 2005;Chan and Shiao, 2007). Citrinin increased DNA fragmentation in HL-60 cells (Yu et al, 2006), which might lead to a reduction of the muscle RNA (Table 3) thereby inducing lower cell proliferation (Chan and Shiao, 2007).…”

“…This compound has been found to induce reproductive abnor-malities in male gametes (Qingqing et al, 2012), and to reduce the rate of oocyte maturation and fertilization (Chan, 2008); it also has a teratogenic effect (Chan and Shiao, 2007;Singh et al, 2007a;Chan, 2008), and has induced maternal toxicity in pregnant rats (Singh et al, 2007b). Moreover, it has been associated with cytoto-xicity (Liu et al, 2005) and the activation of apoptosis by the mitochondrial pathway (Yu et al, 2006).…”