Effects of dietary bamboo (Phyllostachys pubescens Mazel) culm powder on blood properties and intestinal environment of rabbits.

This study investigated the effects of bamboo powder as an alternative feed for rabbits. The normal hay diet of rabbits was replaced with bamboo culm powder (10% and 20%) and fed to the rabbits until they were 90 days old. The blood samples were collected when the rabbits were 46, 66, and 90 days old to assess the effects of bamboo powder on blood parameters. The organs and intestinal contents were harvested at the age of 90 days, and the functions and morphologies of different organs were evaluated. The concentration of short-chain fatty acids (SCFAs) and the composition of microbiota in the cecum were measured. Substituting bamboo powder did not affect the growth, hematology profile, intestinal morphologies, and cecum SCFA concentration in rabbits. In contrast, it significantly altered the cecum microbiota composition, particularly the abundance of Ruminococcus and Bacteroides related to fiber degradation and Tyzzerella spp., associated with large intestine inflammation. These findings suggest that the substitution of hay with bamboo powder in rabbit diets does not negatively affect the overall health of rabbits and could be considered an alternative feed for rabbits; nevertheless, the protein and lipid deficiency in the bamboo powder should be taken into account.

Evaluation of human hepatocytes cultured by three-dimensional spheroid systems for drug metabolism.

We investigated the utility of three-dimensional (3D) spheroid cultures of human hepatocytes in discovering drug metabolites. Metabolites of acetaminophen, diclofenac, lamotrigine, midazolam, propranolol and salbutamol were analyzed by liquid chromatography-tandem mass spectrometry (LC/MS/MS) to measure enzyme activities in this system cultured for 2 and 7 days. Sequential metabolic reactions by Phase I and then Phase II enzymes were found in diclofenac [CYP2C9 and UDP-glucuronyltransferases (UGTs)], midazolam (CYP3A4 and UGTs) and propranolol (CYP1A2/2D6 and UGTs). Moreover, lamotrigine and salbutamol were metabolized to lamotrigine-N-glucuronide and salbutamol 4-O-sulfate, respectively. These metabolites, which are human specific, could be observed in clinical studies, but not in conventional hepatic culture systems as in previous reports. Acetaminophen was metabolized to glucuronide and sulfate conjugates, and N-acetyl-p-benzo-quinoneimine (NAPQI) and its metabolites were not observed. In addition, mRNA of drug-metabolism enzymes [CYP1A2, CYP2C9, CYP2C19, CYP2D6, CYP2E1, CYP3A4, UGT1A1, UGT2B7, sulfotransferase 1A1 (SULT1A1) and glutathione S-transferase pi 1 (GSTP1)], which were measured by qRT-PCR, were expressed in the human hepatocyte spheroids. In conclusion, these results suggest that human hepatocyte spheroids are useful in discovering drug metabolites.