Protective effect of wild ginseng cambial meristematic cells on d-galactosamine-induced hepatotoxicity in rats

Abstract

Background: Panax ginseng has a wide range of biological activities including anti-inflammatory, antioxidant, and immunomodulatory functions. Wild ginseng cambial meristematic cells (CMCs) were obtained from P. ginseng cambium. This study examined the protective mechanism of wild ginseng CMCs against d-galactosamine (GalN)-induced liver injury. GalN, a well-known hepatotoxicant, causes severe hepatocellular inflammatory damage and clinical features similar to those of human viral hepatitis in experimental animals.

Methods: Hepatotoxicity was induced in rats using GalN (700 mg/kg, i.p.). Wild ginseng CMCs was administered orally once a day for 2 wks, and then 2 h prior to and 6 h after GalN injection.

Results: Wild ginseng CMCs attenuated the increase in serum aminotransferase activity that occurs 24 h after GalN injection. Wild ginseng CMCs also attenuated the GalN-induced increase in serum tumor necrosis factor-α, interleukin-6 level, and hepatic cyclooxygenase-2 protein and mRNA expression. Wild ginseng CMCs augmented the increase in serum interleukin -10 and hepatic heme oxygenase-1 protein and mRNA expression that was induced by GalN, inhibited the increase in the nuclear level of nuclear factor-kappa B, and enhanced the increase in NF-E2-related factor 2.

Conclusion: Our findings suggest that wild ginseng CMCs protects liver against GalN-induced inflammation by suppressing proinflammatory mediators and enhancing production of anti-inflammatory mediators.

Keywords: Panax ginseng; d-galactosamine; heme oxygenase-1; hepatitis; wild ginseng cambial meristematic cells.

Fig. 1

HPLC chromatogram of ginsenosides detected from the wild ginseng CMCs. Numbers on the HPLC chromatogram indicate: (1) ginsenoside 20(S)-Rg3, (2) ginsenoside 20(R)-Rg3, (3) ginsenoside Rk1, (4) ginsenoside Rg5, (5) ginsenoside 20(S)-Rh2, and (6) ginsenoside 20(R)-Rh2. CMC, cambial meristematic cells. CMCs, cambial meristematic cells.

Fig. 2

Effects of wild ginseng CMCs on serum ALT, AST levels (A) and histological changes (B) in the rat liver after GalN (700 mg/kg) injection (original magnification ×400). All values are means ± SD of 10 rats per group. Rats received oral injection of vehicle or wild ginseng CMCs (75, 150, and 300 mg/kg) once daily for 2 wks and 2 h prior to and 6 h after GalN (700 mg/kg) treatment. **p < 0.05, significantly different from control group. ^†p < 0.05, ^††p < 0.01, significantly different from GalN group. Histological features of liver sections stained with H&E at 24 h after GalN injection. Typical images were chosen from each experimental group (original magnification, ×400). Arrow and arrowhead indicate hemorrhagic necrosis and inflammatory cell infiltration, respectively. ALT, alanine aminotransferase; AST, aspartate aminotransferase; CMCs, cambial meristematic cells; H&E, hematoxylin and eosin; GalN, d-galactosamine; SD, standard deviation.

Fig. 3

Effects of wild ginseng CMCs (300 mg/kg) on levels of serum TNF-α and hepatic mRNA expression (A), and serum IL-10 and hepatic mRNA expression (B) after GalN (700 mg/kg) treatment. All values are means ± SD of 10 rats per group. *p < 0.05, **p < 0.01, significantly different from control group. ^†p < 0.05, ^††p < 0.01, significantly different from GalN group. CMCs, cambial meristematic cells; GalN, d-galactosamine; IL, interleukin; TNF-α, tumor necrosis factor alpha; SD, standard deviation

Fig. 4

Effects of wild ginseng CMCs (300 mg/kg) on levels of hepatic COX-2 protein and mRNA expression (A), and hepatic HO-1 protein and mRNA expression (B) after GalN (700 mg/kg) treatment. All values are means ± SD of 10 rats per group. *p < 0.05, **p < 0.01, significantly different from control group. ^†p < 0.05, ^††p < 0.01, significantly different from GalNgroup. CMCs, cambial meristematic cells; COX-2, cyclooxygenase-2; GalN, d-galactosamine; HO-1, heme oxygenase-1; SD, standard deviation.

Fig. 5

Effects of wild ginseng CMCs (300 mg/kg) on hepatic levels of nuclear NF-κB (A), p-cJun (B), and Nrf2 (C), and cytosolic Keap1 (D) protein expression. All values are means ± SD of 10 rats per group. *p < 0.05, **p < 0.01, significantly different from control group. ^†p < 0.05, ^††p < 0.01, significantly different from GalN group. CMCs, cambial meristematic cells; GalN, d-galactosamine; Keap1, kelch-like ECH-associated protein 1; NF-κB, nuclear factor-kappa B; Nrf2, NF-E2-related factor 2; TNF, tumor necrosis factor.