Advances in fluorosis-induced nervous system injury and antagonistic protection / 中华地方病学杂志

The damage of nervous system caused by fluorosis has been paid more and more attention. Fluorosis can lead to memory loss, mental retardation and cognitive deficits in children. Advance in the understanding of the mechanism of fluorosis induced nervous system damage will be summarized here from several aspects, including oxidative stress, signal transduction and neurotransmitters and receptors. Oxidative stress is the central link in the mechanism of fluorotoxic nerve damage. Studies have suggested that in addition to some antioxidant drugs and preparations, black garlic, which is a food, has many biological effects such as antioxidants. It suggested that black garlic may have protective effects on fluorosis nerve injury through analyzing the antioxidant property and neuroprotective effects of black garlic, further studies are needed to address the effect and the underlying mechanism of black garlic.

In vitro and in vivo antioxidant activities of polyphenol extracted from black garlic

Abstract This study investigated the in vitro and in vivo antioxidant activities of polyphenol extracted from black garlic. Black garlic polyphenol (BGP) was extracted from black garlic. The in vitro antioxidant activities of BGP were determined using DPPH·, OH and O2- radical scavenging assays. The in vivo antioxidant activities were determined by detecting the malondialdehyde (MDA) content and superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities in mice. Results showed that, the DPPH· radical inhibition rate of 200 and 250 μg/mL BGP was equivalent with Vc (P > 0.05). With concentration of 400 and 500 μg/mL, the OH radical inhibition rate of BGP was slightly lower than Vc (P > 0.05). The O2- radical inhibition rates of 200, 400, 600, 800 and 1000 μg/mL BGP were significantly lower than Vc (P < 0.05). In the groups treated with BGP with suitable dose, the serum MDA content was significantly decreased compared with model group (P < 0.05), and the serum SOD and GSH-Px activities were significantly increased (P < 0.05). BGP has obvious DPPH· and ·OH radical scavenging activities, and can significantly decrease the serum MDA content in mice with oxidative damage, and increase the serum SOD and GSH-Px activities.

The effects of black garlic (Allium satvium) extracts on lipid metabolism in rats fed a high fat diet

BACKGROUD/OBEJECTIVES: The mechanism of how black garlic effects lipid metabolism remains unsolved. Therefore, the objectives of this study were to determine the effects of black garlic on lipid profiles and the expression of related genes in rats fed a high fat diet. MATERIALS/METHODS: Thirty-two male Sqrague-Dawley rats aged 4 weeks were randomly divided into four groups (n=8) and fed the following diets for 5 weeks: normal food diet, (NF); a high-fat diet (HF); and a high-fat diet + 0.5% or 1.5% black garlic extract (HFBG0.5 or HFBG1.5). Body weights and blood biochemical parameters, including lipid profiles, and expressions of genes related to lipid metabolism were determined. RESULTS: Significant differences were observed in the final weights between the HFBG1.5 and HF groups. All blood biochemical parameters measured in the HFBG1.5 group showed significantly lower values than those in the HF group. Significant improvements of the plasama lipid profiles as well as fecal excretions of total lipids and triglyceride (TG) were also observed in the HFBG1.5 group, when compared to the HF diet group. There were significant differences in the levels of mRNA of sterol regulatory element binding protein-1c (SREBP-1c), acetyl-CoA carboxylase (ACC), fatty acid synthase (FAS), and glucose-6-phosphate dehydrogenase (G6PDH) in the HFBG1.5 group compared to the HF group. In addition, the hepatic expression of (HMG-CoA) reductase and Acyl-CoA cholesterol acyltransferase (ACAT) mRNA was also significantly lower than the HF group. CONCLUSIONS: Consumption of black garlic extract lowers SREBP-1C mRNA expression, which causes downregulation of lipid and cholestrol metahbolism. As a result, the blood levels of total lipids, TG, and cholesterol were decreased.

Induction of apoptosis by a hexane extract of aged black garlic in the human leukemic U937 cells

BACKGROUND/OBJECTIVES: In this study, the apoptogenic activity and mechanisms of cell death induced by hexane extract of aged black garlic (HEABG) were investigated in human leukemic U937 cells. MATERIALS/METHODS: Cytotoxicity was evaluated by MTT (3-(4, 5-dimethyl-thiazol-2-yl)-2, 5-diphenyl tetrazoliumbromide) assay. Apoptosis was detected using 4,6-diamidino-2-phenyllindile (DAPI) staining, agarose gel electrophoresis and flow cytometry. The protein levels were determined by Western blot analysis. Caspase activity was measured using a colorimetric assay. RESULTS: Exposure to HEABG was found to result in a concentration- and time-dependent growth inhibition by induction of apoptosis, which was associated with an up-regulation of death receptor 4 and Fas legend, and an increase in the ratio of Bax/Bcl-2 protein expression. Apoptosis-inducing concentrations of HEABG induced the activation of caspase-9, an initiator caspase of the mitochodrial mediated intrinsic pathway, and caspase-3, accompanied by proteolytic degradation of poly(ADP-ribose)-polymerase. HEABG also induced apoptosis via a death receptor mediated extrinsic pathway by caspase-8 activation, resulting in the truncation of Bid, and suggesting the existence of cross-talk between the extrinsic and intrinsic pathways. However, pre-treatment of U937 cells with the caspase-3 inhibitor, z-DEVD-fmk, significantly blocked the HEABG-induced apoptosis of these cells, and increased the survival rate of HEABG-treated cells, confirming that HEABG-induced apoptosis is mediated through activation of caspase cascade. CONCLUSIONS: Based on the overall results, we suggest that HEABG reduces leukemic cell growth by inducing caspase-dependent apoptosis through both intrinsic and extrinsic pathways, implying its potential therapeutic value in the treatment of leukemia.

Antioxidant effect of garlic and aged black garlic in animal model of type 2 diabetes mellitus

Hyperglycemia in the diabetic state increases oxidative stress and antioxidant therapy can be strongly correlated with decreased risks for diabetic complications. The purpose of this study is to determine antioxidant effect of garlic and aged black garlic in animal model of type 2 diabetes. The antioxidant activity of garlic and aged black garlic was measured as the activity in scavenging free radicals by the trolox equivalent antioxidant capacity (TEAC) assay. Three week-old db/db mice were fed AIN-93G diet or diet containing 5% freeze-dried garlic or aged black garlic for 7 weeks after 1 week of adaptation. Hepatic levels of lipid peroxides and activities of antioxidant enzymes were measured. TEAC values of garlic and aged black garlic were 13.3 +/- 0.5 and 59.2 +/- 0.8 micromol/g wet weight, respectively. Consumption of aged black garlic significantly decreased hepatic thiobarbituric acid reactive substances (TBARS) level compared with the garlic group which showed lower TBARS level than control group (p<0.05). Activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) of garlic and aged black garlic group were significantly elevated compared to the control group. Catalase (CAT) activity of aged black garlic group was increased compared with the control group. These results show that aged black garlic exerts stronger antioxidant activity than garlic in vitro and in vivo, suggesting garlic and aged black garlic, to a greater extent, could be useful in preventing diabetic complications.