Curcumin prevents bile canalicular alterations in the liver of hamsters infected with Opisthorchis viverrini

Abstract

Opisthorchis viverrini infection causes inflammation and liver injury leading to periductal fibrosis. Little is known about the pathological alterations in bile canaliculi in opisthorchiasis. This study aimed to investigate bile canalicular alterations in O. viverrini-infected hamsters and to examine the chemopreventive effects of curcumin on such changes. Hamsters were infected with O. viverrini and one group of animals was fed with 1% dietary curcumin supplement. Animals were examined during the acute infection phase, days 21 and 30 post-infection (PI) and chronic infection phase (day 90 PI). Scanning electron microscopy revealed that in the infected group fed with a normal diet, bile canaliculi became slightly tortuous by 30 day PI and more tortuous at day 90 PI. Transmission electron microscopy showed a reduction in microvilli density of canaliculi starting at day 30 PI, with a marked loss of microvilli at day 90 PI. These ultrastructral changes were slightly seen at day 21 PI, which was similar to that found in infected animals fed with 1% curcumin-supplemented diet. Notably, curcumin treatment prevented the reduction of microvilli density, reduced the dilation of bile canaliculi, and decreased the tortuosity of the bile canaliculi relative to non-infected animals on a normal diet at days 30 and 90 PI. These results suggest that curcumin reduces alteration of bile canaliculi and may be a promising agent to prevent the onset of bile duct abnormalities induced by O. viverrini infection.

Keywords: Opisthorchis viverrini; bile canaliculus; curcumin; hamster liver; ultrastructure.

Fig. 1

Scanning electron micrographs of bile canaliculi in non-infected (A-F) and O. viverrini-infected hamsters (G-L) fed with a normal diet and a 1% curcumin-supplemented diet in acute (days 21 and 30) and chronic (day 90) phases. A protective effect of curcumin against alteration of bile canaliculi was observed on day 90 PI in O. viverrini-infected hamsters fed with a 1% curcumin-supplemented diet (L). Several pits (arrowheads) were observed on the lateral surfaces of the hepatocytes.

Fig. 2

Transmission electron micrographs of bile canaliculi in non-infected (A-F) and O. viverrini-infected hamsters (G-L) fed with a normal diet and a 1% curcumin-supplemented diet in acute (day 21 and day 30) and chronic (day 90) phases. In O. viverrini-infected hamsters fed with a normal diet, few microvilli were observed within the canalicular lumen on day 90 PI (I). The density of microvilli in the bile canalicular lumen in O. viverrini-infected hamsters fed with a 1% curcumin-supplemented diet for the same period (L) was similar to that found in the control group (F).