382 The Effect of Natural Products on the Metabolism of Boar Taint Compounds in Porcine Hepatocytes

Abstract

Abstract Boar taint is a meat quality issue that develops in entire male pigs resulting from the accumulation of androstenone and skatole in the fat, which is dependent on the balance between their rate of synthesis and hepatic metabolism. Prior research from our lab showed that transactivation of the nuclear receptors pregnane X receptor (PXR), constitutive androstane receptor (CAR), and farnesoid X receptor (FXR) can alter gene expression in porcine hepatocytes to increase the metabolism androstenone and skatole. Many plant species and herbal medicines contain active compounds that function as ligands for these nuclear receptors and could be developed into dietary treatments for boar taint unlike the classic agonists used in our previous work, which have known cytotoxic effects in vivo. Therefore, the purpose of this study was to evaluate the effect of different natural product (NP) treatments on the hepatic metabolism of androstenone and skatole. Hepatocytes were isolated from 5-month-old crossbred [(Yorkshire x Landrace) x Duroc] boars (n = 7) and pretreated for 24 hours with one of three NP treatments, which included the PXR agonist hyperforin (HYP) from Hypericum perforatum or St. John’s Wort, diallyl sulfide (DAS), an active ingredient found in garlic and an agonist of CAR, and oleanolic acid (OA), a selective modulator of FXR present in various plant species. Control incubations were pretreated with dimethyl sulfoxide (DMSO). Next, all pretreated hepatocytes were treated with androstenone or skatole for 3 hours. The metabolism of androstenone and skatole was evaluated using high-performance liquid chromatography and boars were classified as rapid (RM, n = 4) or slow (SM, n = 3) metabolizers according to natural threshold values established from the percentage of androstenone (< 5% RM; >5% SM) or skatole (< 50% RM; >50% SM) remaining in control incubations with DMSO. Statistical analysis was conducted using a two-way ANOVA in SAS with Dunnett’s post hoc test. NP treatments differentially regulated androstenone metabolism in SM and RM boars but had no effect (P > 0.05) on skatole metabolism. In SM boars, androstenone metabolism was increased 1.43, 1.75, and 1.67-fold by HYP, DAS, and OA, respectively, but was significantly decreased (P < 0.05) by all NPs in RM boars relative to control incubations with DMSO. These results indicate that SM boars respond more favorably to NP treatments than RM boars suggesting that these NPs may be a viable dietary treatment for boar taint if provided exclusively to SM boars. This targeted treatment approach will require additional research to identify predictive biomarkers associated with the SM profile.