Antioxidant enzyme activity and malondialdehyde levels can be modulated by Piper betle, tocotrienol rich fraction and Chlorella vulgaris in aging C57BL/6 mice

OBJECTIVE: The aim of this study was to determine the erythrocyte antioxidant enzyme activity and the superoxide dismutase, catalase, glutathione peroxidase, and plasma malondialdehyde levels in aging mice and to evaluate how these measures are modulated by potential antioxidants, including the tocotrienol-rich fraction, Piper betle, and Chlorella vulgaris. METHOD: One hundred and twenty male C57BL/6 inbred mice were divided into three age groups: young (6 months old), middle-aged (12 months old), and old (18 months old). Each age group consisted of two control groups (distilled water and olive oil) and three treatment groups: Piper betle (50 mg/kg body weight), tocotrienol-rich fraction (30 mg/kg), and Chlorella vulgaris (50 mg/kg). The duration of treatment for all three age groups was two months. Blood was withdrawn from the orbital sinus to determine the antioxidant enzyme activity and the malondialdehyde level. RESULTS: Piper betle increased the activities of catalase, glutathione peroxidase, and superoxide dismutase in the young, middle, and old age groups, respectively, when compared to control. The tocotrienol-rich fraction decreased the superoxide dismutase activity in the middle and the old age groups but had no effect on catalase or glutathione peroxidase activity for all age groups. Chlorella vulgaris had no effect on superoxide dismutase activity for all age groups but increased glutathione peroxidase and decreased catalase activity in the middle and the young age groups, respectively. Chlorella vulgaris reduced lipid peroxidation (malondialdehyde levels) in all age groups, but no significant changes were observed with the tocotrienol-rich fraction and the Piper betle treatments. CONCLUSION: We found equivocal age-related changes in erythrocyte antioxidant enzyme activity when mice were treated with Piper betle, the tocotrienol-rich fraction, and Chlorella vulgaris. However, Piper betle treatment showed increased antioxidant enzymes activity during aging.

Gamma-tocotrienol modulation of senescence-associated gene expression prevents cellular aging in human diploid fibroblasts

OBJECTIVE: Human diploid fibroblasts undergo a limited number of cellular divisions in culture and progressively reach a state of irreversible growth arrest, a process termed cellular aging. The beneficial effects of vitamin E in aging have been established, but studies to determine the mechanisms of these effects are ongoing. This study determined the molecular mechanism of γ-tocotrienol, a vitamin E homolog, in the prevention of cellular aging in human diploid fibroblasts using the expression of senescence-associated genes. METHODS: Primary cultures of young, pre-senescent, and senescent fibroblast cells were incubated with γ-tocotrienol for 24 h. The expression levels of ELN, COL1A1, MMP1, CCND1, RB1, and IL6 genes were determined using the quantitative real-time polymerase chain reaction. Cell cycle profiles were determined using a FACSCalibur Flow Cytometer. RESULTS: The cell cycle was arrested in the G0/G1 phase, and the percentage of cells in S phase decreased with senescence. CCND1, RB1, MMP1, and IL6 were upregulated in senescent fibroblasts. A similar upregulation was not observed in young cells. Incubation with γ-tocotrienol decreased CCND1 and RB1 expression in senescent fibroblasts, decreased cell populations in the G0/G1 phase and increased cell populations in the G2/M phase. γ-Tocotrienol treatment also upregulated ELN and COL1A1 and downregulated MMP1 and IL6 expression in young and senescent fibroblasts. CONCLUSION: γ-Tocotrienol prevented cellular aging in human diploid fibroblasts, which was indicated by the modulation of the cell cycle profile and senescence-associated gene expression.

Hot water extract of Chlorella vulgaris induced DNA damage and apoptosis

OBJECTIVES: The aim of this study was to determine the antiproliferative and apoptotic effects of hot water extracts of Chlorella vulgaris on hepatoma cell line HepG2. INTRODUCTION: The search for food and spices that can induce apoptosis in cancer cells has been a major study interest in the last decade. Chlorella vulgaris, a unicellular green algae, has been reported to have antioxidant and anti-cancer properties. However, its chemopreventive effects in inhibiting the growth of cancer cells have not been studied in great detail. METHODS: HepG2 liver cancer cells and WRL68 normal liver cells were treated with various concentrations (0-4 mg/ml) of hot water extract of C. vulgaris after 24 hours incubation. Apoptosis rate was evaluated by TUNEL assay while DNA damage was assessed by Comet assay. Apoptosis proteins were evaluated by Western blot analysis. RESULTS: Chlorella vulgaris decreased the number of viable HepG2 cells in a dose dependent manner (p < 0.05), with an IC50 of 1.6 mg/ml. DNA damage as measured by Comet assay was increased in HepG2 cells at all concentrations of Chlorella vulgaris tested. Evaluation of apoptosis by TUNEL assay showed that Chlorella vulgaris induced a higher apoptotic rate (70 percent) in HepG2 cells compared to normal liver cells, WRL68 (15 percent). Western blot analysis showed increased expression of pro-apoptotic proteins P53, Bax and caspase-3 in the HepG2 cells compared to normal liver cells WRL68, and decreased expression of the anti-apoptotic protein Bcl-2. CONCLUSIONS: Chlorella vulgaris may have anti-cancer effects by inducing apoptosis signaling cascades via an increased expression of P53, Bax and caspase-3 proteins and through a reduction of Bcl-2 protein, which subsequently lead to increased DNA damage and apoptosis.

Ginger extract (Zingiber officinale) has anti-cancer and anti-inflammatory effects on ethionine-induced hepatoma rats

OBJECTIVE: To evaluate the effect of ginger extract on the expression of NFêB and TNF-á in liver cancer-induced rats. METHODS: Male Wistar rats were randomly divided into 5 groups based on diet: i) control (given normal rat chow), ii) olive oil, iii) ginger extract (100mg/kg body weight), iv) choline-deficient diet + 0.1 percent ethionine to induce liver cancer and v) choline-deficient diet + ginger extract (100mg/kg body weight). Tissue samples obtained at eight weeks were fixed with formalin and embedded in paraffin wax, followed by immunohistochemistry staining for NFêB and TNF-á. RESULTS: The expression of NFêB was detected in the choline-deficient diet group, with 88.3 ± 1.83 percent of samples showing positive staining, while in the choline-deficient diet supplemented with ginger group, the expression of NFêB was significantly reduced, to 32.35 ± 1.34 percent (p<0.05). In the choline-deficient diet group, 83.3 ± 4.52 percent of samples showed positive staining of TNF-á, which was significantly reduced to 7.94 ± 1.32 percent (p<0.05) when treated with ginger. There was a significant correlation demonstrated between NFêB and TNF-á in the choline-deficient diet group but not in the choline-deficient diet treated with ginger extract group. CONCLUSION: In conclusion, ginger extract significantly reduced the elevated expression of NFêB and TNF-á in rats with liver cancer. Ginger may act as an anti-cancer and anti-inflammatory agent by inactivating NFêB through the suppression of the pro-inflammatory TNF-á.