SMND-309 Antioxidant Activity In Vitro Study

Since some endogenous or exogenous factors, the body usually generates some free radicals. In normal conditions, developing and elimination of free radicals are under dynamic equilibrium. When free radicals are excessive for many abnormal factors, such as pathology changes and senescence, the equilibrium will be broken. Excessive free radicals can cause the oxidative damage of many bio-macromolecules and organelle and induce many diseases, such as angiocardiopathy, tumor, diabetes, immune system diseases et al. Therefore, cleaning excessive radicals using antioxidant can prevent many free radical-related diseases. Thus, most of artificial synthesis antioxidants are aromatic and amines and useless for their toxic and carcinogenic effects. In view of the risks of synthetic antioxidants, many researchers paid more attention to natural antioxidants and found that natural antioxidants were lower cost and higher safety.Salvia miltiorrhiza, Bge is one of traditional Chinese medicines used to treatment of cardiovascular diseases. Its major water-soluble component is salvianolic acid B with strong effect in antioxidant and scavenging free radicals. Based of salvianolic acid B, researchers in Shandong Engineering Research Center for Nature Drug developed new compounds, SMND-309 with intellectual property. Previous studies have showed that SMND-309 could prevent nerve cells and rat brain tissue from ischemic injury. But the effects in vitro of SMND-309 in antioxidant, scavenging free radicals and inhibition of liver mitochondrial oxidative damage have not been systemic studied and evaluated.The main studies consist of two parts:In order to reveal the pharmacological mechanism of SMND-309, we studied the effects of SMND-309 in antioxidant, scavenging free radicals and inhibition of liver mitochondrial oxidative damage in chemical simulation system. As follows:(1) Measured the antioxidant activity of SMND-309 in chemical simulation system in vitro. Detection of SMND-309 scavenging activity of three free radicals, DPPH·, O2-·and·OH, by using DPPH·, NBT-NADH-PMS, Fenton, Fe2+ induced yolk lipid peroxidation reaction system, Ferricyanide-Fe3+ system and (β-carotene/linoleic acid self-oxidation system. Detection of the ability to inhibit lipid peroxidation, total reducing power and total antioxidant capacity of SMND-309. Systemic preliminary identification of antioxidant activity of SMND-309.(2) Detection of protection of SMND-309 on mitochondrial oxidative injury in rat isolated liver. Generating-OH by using Fe2+-Vc (H2O2) system and inducing oxidative damage in isolated mitochondria. Identifying the protective effect of SMND-309 in isolated mitochondria through detecting swelling of mitochondria membrane, membrane lipid peroxidation, membrane protein carbonyl, ATP enzyme, CAT, SDH activity and generation of O2-·in mitochondria.The results demonstrate:(1) SMND-309 had strong ability to antioxidant and scavenging free radicals. It can scavenge DPPH·,O2-·and·OH significantly in the concentration range. Inhibitions of lipid peroxidation and oxidation fading ofβ-carotene were also significant. The IC50 of SMND-309 removing DPPH·,O2-·and inhibition of lipid peroxidation are 6.33μg/ml,260μg/ml,462.24μg/ml, respectively. In addition, SMND-309 also had strong reducing power. Reducing power of high concentrations much higher than positive control Vc and BHT. And SMND-309 had good antioxidant effect of concentration dependence.(2) SMND-309 had a significant benefit to protect the rat liver mitochondria. It could effectively inhibit the oxidative damage of mitochondrial induced by Fe2+-Vc (H2O2) system, included swelling of mitochondrial, lipid peroxidation and generating of protein carbonyl. Meanwhile it could also inhibit the oxidative damage of CAT, SDH and ATP enzyme with free radicals in mitochondria. In addition, SMND-309 could suppress the generation of various free radicals in mitochondria from the source by reducing generation of O2-·. The IC50 of SMND-309 removing O2-·and inhibition of lipid peroxidation are 95.4μg/ml and 56.4μg/ml, respectively. And protective effect of SMND-309 in hepatic mitochondrial oxidative damage within the test showed good dose-effect. The results show that SMND-309 could protect the liver mitochondria effectively.In conclusion, SMND-309 had a good antioxidant activity in vitro. Compared with positive control, antioxidant activity of SMND-309 was slightly higher than Vc in vitro and it's more safety than BHT for its natural properties. Our researches provided an important experimental basis for the use of this new compound in the field of food and drugs.