Herpes Simplex virus type 1(HSV-1) is a neurotropic double-stranded DNA virus that belongs to the herpes virus family that establishes life-long latency infection in the human nervous system. HSV-1 infection can cause various of human diseases, such as gingivo-stomatitis, herpes labialis, meningitis, as well as eye and genital infection. Among these diseases, herpes simplex encephalitis (HSE) is a rare disease with high mortality and significant morbidity. Though some patients with severe viral encephalitis after treatment can survive, neural function defect symptoms always result to differing extents. Therefore, it much research has focused on identification of drugs that may inhibit or reduce nerve damage caused by HSV-1 infection.
Ginseng, the root of Panax ginseng C.A. Meyer, has been widely used in traditional oriental medicine for over two thousand years in the prevention and treatment of aging-associated disorders in Asia. Ginsenosides, as the main bioactive components of ginseng, play an important role in the central nervous system (CNS). Ginsenoside Rb1 (GRb1)(Fig. 1), one of the saponin components of ginseng, has been widely reported to exert neurotrophic and neuroprotective activities on the CNS. It has been known that GRb1 enhances the stimulatory effect of neurite outgrowth. Recent studies have also revealed that GRb1 can reduce neural cell apoptosis. Later, it has been demonstrated that GRb1 can promote the proliferation and expression of neurotrophic factors in primary Schwann cell cultures. Furthermore, recent studies have proved that ginseng can inhibit virus infection[14, 18, 22].
In spite of these many investigations into the properties of GRb1, there has been no report about the effect of GRb1 in HSV-1 infections. In this study, human glioma Cell line U251 was selected to investigate the effects of GRb1 on the apoptosis caused by HSV-1, and we illustrate the potential neuroprotective effect of GRb1 after HSV-1 infection. This study provides theoretical and experimental evidence to support the further study of ginsenoside on HSV-1 infection.
Inhibitory Effects of Ginsenoside Rb1 on Apoptosis Caused by HSV-1 in Human Glioma Cells
- Received Date: 05 September 2011
- Accepted Date: 05 December 2011
Abstract: To investigate the inhibitory effects of Ginsenoside Rb1 (GRb1) on apoptosis caused by Herpes Simplex Virus-1(HSV-1) in Human Glioma Cells (U251), U251 cells were infected by HSV-1 at a multiplicity of infection of 5 and GRb1, GRb1+HSV-1, HSV-1 and control groups. MTT and cell apoptosis assays were used to detect the inhibitory effects of GRb1 on the apoptosis of U251 cells that caused by HSV-1 infection for various concentrations of drug and virus treatments by MTT assay. We found that in the 400 μg/mL GRb1 and 400 μg/mL GRb1+HSV-1 groups, MTT values were higher than control group at all times (P<0. 05). Moreover, the apoptosis rate in the 400 μg/mL GRb1+HSV-1 group was lower than the HSV-1 group (P<0. 05). These results confirmed that, at appropriate concentrations, GRb1 could inhibit nerve cell apoptosis in HSV-1 infections.