Bamboo salt attenuates CCl4-induced hepatic damage in Sprague-Dawley rats

Abstract

Bamboo salt, a Korean folk medicine, is prepared with solar salt (sea salt) and baked several times at high temperatures in a bamboo case. In this study, we compared the preventive effects of bamboo salt and purified and solar salts on hepatic damage induced by carbon tetrachloride in Sprague-Dawley rats. Compared with purified and solar salts, bamboo salts prevented hepatic damage in rats, as evidenced by significantly reduced serum levels of aspartate aminotransferase, alanine aminotransferase, and lactate dehydrogenase (P < 0.05). Bamboo salt (baked 9×) triggered the greatest reduction in these enzyme levels. In addition, it also reduced the levels of the proinflammatory cytokines interleukin (IL)-6, interferon (IFN)-γ, and tumor necrosis factor (TNF)-α. Histopathological sections of liver tissue demonstrated the protective effect of bamboo salt, whereas sections from animals treated with the other salt groups showed a greater degree of necrosis. We also performed reverse transcription-polymerase chain reaction and western blot analyses of the inflammation-related genes iNOS, COX-2, TNF-α, and IL-1β in rat liver tissues. Bamboo salt induced a significant decrease (~80%) in mRNA and protein expression levels of COX-2, iNOS, TNF-α, and IL-1β, compared with the other salts. Thus, we found that baked bamboo salt preparations could prevent CCl4-induced hepatic damage in vivo.

Keywords: Bamboo salt; CCl4; cytokines; hepatic damage; inflammation.

Fig. 1

Effect of various salt samples on serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), and lactate dehydrogenase (LDH) levels in CCl₄-induced hepatic damage (n = 10 Sprague-Dawley rats in each group, 400 mg/kg b.w. of salt). P, purified salt; S, solar salt; BS, bamboo salt. Mean values with different letters over the bars indicate significant differences (P < 0.05) according to Duncan's multiple range test.

Fig. 2

Effect of salt samples on serum triglyceride (TG) and total cholesterol (TC) levels in CCl₄-induced hepatic damage (n = 10 Sprague-Dawley rats in each group, 400 mg/kg b.w. of salt). P, purified salt; S, solar salt; BS, bamboo salt. Mean values with different letters over the bars indicate significant differences (P < 0.05) according to Duncan's multiple range test.

Fig. 3

Effect of salt samples on serum IL-6, IFN-γ, and TNF-α levels in CCl₄-induced hepatic damage (n = 10 Sprague-Dawley rats in each group, 400 mg/kg b.w. of salt). P, purified salt; S, solar salt; BS, bamboo salt. Mean values with different letters over the bars indicate significant differences (P < 0.05) according to Duncan's multiple range test.

Fig. 4

Histology images of liver tissues in rats with CCl₄-induced hepatic damage (×200 magnification).

Fig. 5

Effects of bamboo salt (400 mg/kg b.w.) on mRNA expression levels of iNOS, COX-2, TNF-α, and IL-1β in liver tissues of rats treated with CCl₄. P, purified salt; S, solar salt; BS, bamboo salt. The intensity of the band was measured by densitometry and expressed as fold ratios compared with the control. Fold ratio: gene expression/GAPDH × control numerical value (control fold ratio: 1). Mean values with different letters over the bars indicate significant differences (P < 0.05) according to Duncan's multiple range test.

Fig. 6

Effects of bamboo salt (400 mg/kg b.w.) on protein expression levels of iNOS, COX-2, TNF-α, and IL-1β in liver tissues of rats treated with CCl₄. P, purified salt; S, solar salt; BS, bamboo salt. The intensity of the band was measured using a densitometer and expressed as fold ratios compared with the control. Fold ratio: gene expression/GAPDH × control numerical value (control fold ratio: 1). Mean values with different letters over the bars indicate significant differences (P < 0.05) according to Duncan's multiple range test.