Hydrolysis of ochratoxin A by the microbial activity of digesta in the gastrointestinal tract of rats

Abstract

This study established the influence of dietary neomycin sulphate on the rate of hydrolysis of ochratoxin A (OA) by digesta from the intestine, and its effect on the excretion of OA and its hydrolyzed metabolite, alpha ochratoxin (O alpha), in the urine and feces of the rat. The first in vitro study demonstrated that digesta from the cecum and the large intestine were able to hydrolyze OA whereas digesta from the small intestine and stomach had very low hydrolytic activity against this substrate. Homogenates of the liver had no hydrolytic activity. The second in vivo study demonstrated that digesta from the large intestine and cecum of the neomycin treated rats was much less effective (P < 0.001) in promoting the hydrolysis of OA than digesta from the control rats. Neomycin when added directly to the in vitro system, however, did not affect the rate at which OA was hydrolyzed. In a third study, OA was administered in vivo to control and neomycin-treated rats. Rats fed the neomycin containing diet compared to those fed the control diet had a higher concentration (P < 0.005) of blood OA, and a greater cumulative excretion of OA plus O alpha over the entire 5 day collection period in the feces (P < 0.0001) and a corresponding decrease in the cumulative excretion of OA plus O alpha in the urine (P < 0.0001). Individually, there was a marked increase in cumulative fecal excretion of OA (P < 0.05) and a corresponding decrease in excretion of O alpha (P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Species-, Sex-, and Cell Type-Specific Effects of Ochratoxin A and B

“…In contrast, the observations of the study presented here were obtained in both cell lines and in primary cells and furthermore, in the presence of serum. Variations in metabolism and detoxification of OTA were not investigated in this study but are unlikely to account for the observed toxicity differences between cell types as the hydrolysis of OTA to OTA␣ in vitro by kidney and liver homogenates has been demonstrated to be insignificant (Madhyastha et al, 1992;Stormer et al, 1983). Previously observed effects on phenylalanine metabolism are also unlikely to be involved in the differences noted in this sudy, as these effects first become apparent following exposure to M concentrations of OTA (Creppy et al, 1995).…”

Species-, Sex-, and Cell Type-Specific Effects of Ochratoxin A and B

“…In contrast, the observations of the study presented here were obtained in both cell lines and in primary cells and furthermore, in the presence of serum. Variations in metabolism and detoxification of OTA were not investigated in this study but are unlikely to account for the observed toxicity differences between cell types as the hydrolysis of OTA to OTA␣ in vitro by kidney and liver homogenates has been demonstrated to be insignificant (Madhyastha et al, 1992;Stormer et al, 1983). Previously observed effects on phenylalanine metabolism are also unlikely to be involved in the differences noted in this sudy, as these effects first become apparent following exposure to M concentrations of OTA (Creppy et al, 1995).…”

Isolation, Screening and Identification of Swine Gut Microbiota with Ochratoxin A Biodegradation Ability

“…Several studies have demonstrated the OTA-degrading activity of microbiota from the mammalian gastrointestinal tract, including the rumen of cow and sheep (Hult et al, 1976; Galtier et al, 1976; Xiao et al, 1991), and the intestine of rats (Madhyastha et al, 1992). This led us to investigate and isolate bacteria from swine intestinal fluid.…”

“…Other reports have indicated that gut microbes from monogastric animals as well as other mammalian guts contain OTA-degrading capacity. For instance, microbes living mainly in the intestines of rats (Madhyastha et al, 1992) and bacteria from swine including Eubacterium callanderi from the large intestine and Eubacterium ramulus from the small intestine were reported to be OTA-degrading strains, degrading almost 100% OTA over a 6 h incubation (Schatzmayr et al, 2006). In this study, one isolate designated as MM11, among the screened isolates had the highest OTA degradation level of 77% initially in liquid medium supplemented with 100 ppb OTA.…”

Isolation of Bacillus spp. from Thai fermented soybean (Thua-nao): screening for aflatoxin B1and ochratoxin A detoxification

“…1976; Park et al. 1988) and microbes living mainly in the caecum and large intestine of rats (Madhyastha et al. 1992).…”

“…Regarding OTA, several reports describe OTA degrading activities of the microbial flora of the mammalian gastrointestinal tract including rumen microbes of cow and sheep (Galtier and Alvinerie 1976;Hult et al 1976;Park et al 1988) and microbes living mainly in the caecum and large intestine of rats (Madhyastha et al 1992). The human intestinal microflora can also partially degrade OTA (Akiyama et al 1997).…”

Species-, Sex-, and Cell Type-Specific Effects of Ochratoxin A and B

“…In contrast, the observations of the study presented here were obtained in both cell lines and in primary cells and furthermore, in the presence of serum. Variations in metabolism and detoxification of OTA were not investigated in this study but are unlikely to account for the observed toxicity differences between cell types as the hydrolysis of OTA to OTA␣ in vitro by kidney and liver homogenates has been demonstrated to be insignificant (Madhyastha et al, 1992;Stormer et al, 1983). Previously observed effects on phenylalanine metabolism are also unlikely to be involved in the differences noted in this sudy, as these effects first become apparent following exposure to M concentrations of OTA (Creppy et al, 1995).…”

Isolation, Screening and Identification of Swine Gut Microbiota with Ochratoxin A Biodegradation Ability

“…Several studies have demonstrated the OTA-degrading activity of microbiota from the mammalian gastrointestinal tract, including the rumen of cow and sheep (Hult et al, 1976; Galtier et al, 1976; Xiao et al, 1991), and the intestine of rats (Madhyastha et al, 1992). This led us to investigate and isolate bacteria from swine intestinal fluid.…”

“…Other reports have indicated that gut microbes from monogastric animals as well as other mammalian guts contain OTA-degrading capacity. For instance, microbes living mainly in the intestines of rats (Madhyastha et al, 1992) and bacteria from swine including Eubacterium callanderi from the large intestine and Eubacterium ramulus from the small intestine were reported to be OTA-degrading strains, degrading almost 100% OTA over a 6 h incubation (Schatzmayr et al, 2006). In this study, one isolate designated as MM11, among the screened isolates had the highest OTA degradation level of 77% initially in liquid medium supplemented with 100 ppb OTA.…”

Isolation of Bacillus spp. from Thai fermented soybean (Thua-nao): screening for aflatoxin B1and ochratoxin A detoxification

“…1976; Park et al. 1988) and microbes living mainly in the caecum and large intestine of rats (Madhyastha et al. 1992).…”

“…Regarding OTA, several reports describe OTA degrading activities of the microbial flora of the mammalian gastrointestinal tract including rumen microbes of cow and sheep (Galtier and Alvinerie 1976;Hult et al 1976;Park et al 1988) and microbes living mainly in the caecum and large intestine of rats (Madhyastha et al 1992). The human intestinal microflora can also partially degrade OTA (Akiyama et al 1997).…”

Species-, Sex-, and Cell Type-Specific Effects of Ochratoxin A and B

“…In contrast, the observations of the study presented here were obtained in both cell lines and in primary cells and furthermore, in the presence of serum. Variations in metabolism and detoxification of OTA were not investigated in this study but are unlikely to account for the observed toxicity differences between cell types as the hydrolysis of OTA to OTA␣ in vitro by kidney and liver homogenates has been demonstrated to be insignificant (Madhyastha et al, 1992;Stormer et al, 1983). Previously observed effects on phenylalanine metabolism are also unlikely to be involved in the differences noted in this sudy, as these effects first become apparent following exposure to M concentrations of OTA (Creppy et al, 1995).…”

Isolation, Screening and Identification of Swine Gut Microbiota with Ochratoxin A Biodegradation Ability

“…Several studies have demonstrated the OTA-degrading activity of microbiota from the mammalian gastrointestinal tract, including the rumen of cow and sheep (Hult et al, 1976; Galtier et al, 1976; Xiao et al, 1991), and the intestine of rats (Madhyastha et al, 1992). This led us to investigate and isolate bacteria from swine intestinal fluid.…”

“…Other reports have indicated that gut microbes from monogastric animals as well as other mammalian guts contain OTA-degrading capacity. For instance, microbes living mainly in the intestines of rats (Madhyastha et al, 1992) and bacteria from swine including Eubacterium callanderi from the large intestine and Eubacterium ramulus from the small intestine were reported to be OTA-degrading strains, degrading almost 100% OTA over a 6 h incubation (Schatzmayr et al, 2006). In this study, one isolate designated as MM11, among the screened isolates had the highest OTA degradation level of 77% initially in liquid medium supplemented with 100 ppb OTA.…”

Isolation of Bacillus spp. from Thai fermented soybean (Thua-nao): screening for aflatoxin B1and ochratoxin A detoxification

“…1976; Park et al. 1988) and microbes living mainly in the caecum and large intestine of rats (Madhyastha et al. 1992).…”

“…Regarding OTA, several reports describe OTA degrading activities of the microbial flora of the mammalian gastrointestinal tract including rumen microbes of cow and sheep (Galtier and Alvinerie 1976;Hult et al 1976;Park et al 1988) and microbes living mainly in the caecum and large intestine of rats (Madhyastha et al 1992). The human intestinal microflora can also partially degrade OTA (Akiyama et al 1997).…”