Anti-aging Effect Of Extract Of Maize Plumule On Fruitflies And Its Anti-oxidative Effect On Mice Cardiac Muscles

Anti-aging effect of Extract of Maize Plumule (EMP) on fruitflies and its anti-oxidative effect on mice cardiac muscles were studied respectively at the whole-body level, tissue-organ level and cellular level.1. Anti-aging effect of EMP on fruitflies: Effects of EMP on productivity ability, anti-heat stress ability, food intake content, body water content and life span in fruit flies were investigated. Also, its effects on SOD activity and MDA level in aging fruit flies induced by D-Galactose were tested. The datas showed: (1) Compared with control group, 40 mg/kg EMP could obviously increase the productivity ability, anti-heat stress ability (female: 75.250±4.031 %, +33.78 %, P<0.01; male: 63.750±3.500 %, +19.72 %, P<0.01), food intake content (female: 0.043±0.003 g,+22.86 %, P<0.05; male: 0.048±0.002 g, +23.08 %, P<0.05), body water content (female: 0.065±0.004 g, +14.04 %, P<0.05; male: 0.059±0.002 g, +20.41 %, P<0.01), average life span (female: 66.23±13.37 d, +10.79 %, P<0.01; male: 63.96±12.66 d, +15.64 %, P<0.05) and maximum life span (female: 80.67±2.08 d, +14.15 %, P<0.01; male: 75.67±1.53 d, +10.74 %, P<0.05); (2) Flies treated with both D-galactose and 40 mg/kg EMP apparently had a higher SOD activity (female: 40 d P<0.01; male: 30 d, 40 d P<0.05) and lower MDA level (female: 30 d, 40 d P<0.01; male: 30 d, 40 d P<0.01) versus the age matched aging model group. These datas indicate that 40 mg/kg can increase productivity ability, anti-heat stress ability, food intake content, water content and life span in fruit flies and can provide a protection against oxidative stress caused by D-Galactose through improving the SOD activity and MDA level.2. Effects of EMP on free radical metabolism and ultrastructure of myocardium in aging mice: Effects of EMP on anti-oxidative enzyme activity, free radical content and lipid peroxidation product level in aging mice induced by D-galactose were studied. Meanwhile, its protective effect on morphological changes of myocardium in aging mice was observed. The results showed: (1) All the differences of biochemical markers beween 20 mg/kg EMP group and aging model group were extreamly significant (SOD: 87.241±3.849 U/mg, +18.8 %, P<0.01; CAT: 47.313±2.195 U/mg, +36.4 %, P<0.01; GSH-Px: 28.038±1.583 U/mg, +37.6%, P<0.01; MDA: 11.300±1.529 nmol/mg, -34.7 %, P<0.01; NO: 6.438±0.637μmol/L, -47.1 %, P<0.01); (2) HE staining showed that cardiac muscular fibers were deranged, distorted, dissolved and broken in aging group. Under transmission electron microscope, Z-line broadening and illegibility, myofilament fragmentation, dissolution and agglutination, mitochondrion swelling, vacuolization and cristae vanishing were observed in aging model group. These pathological changes were aparently improved in 20 mg/kg EMP group. All these results show that 20 mg/kg EMP has an action on increasing the activity of anti-oxidation enzymes, improving free radical metabolism and protecting ultrastructure of myocardium against oxidative stress in aging mice.3. Protective effect of EMP on oxidative stress induced by H2O2 in cardiomyocytes: Effects of EMP on morphology, cell viability, LDH activity, NO content, SOD and GSH-Px activity and MDA level in H2O2-damaged cardiomyocytes were examined. Its effects on the expression of apoptosis associated gene Bcl-2 and translocation of NF-κB were detected by immunocytochemical staining to preliminarily study the mechanism. The results showed: (1) 20 mg/L EMP could inhibit the typical features of cell apoptosis, increase cell viability (79.700±2.741%, +48.3%, P<0.01), decrease LDH activity (718.274±21.982 U/L, -24.0%, P<0.01) and NO content (71.329±3.504μmol/L, -19.8%, P<0.01) in cultural supernanant, and improve intracellular SOD (24.267±2.119 KU/L, +36.3%, P<0.01), GSH-Px (17.294±1.473 U/L, +49.2%, P<0.01) activity and MDA level (1.192±0.338μmol/L, -65.5%, P<0.01); (2) Immunofluorescence staining showed that 20 mg/L EMP could promote the expression of anti-apoptotic gene Bcl-2 and supress the translocation of NF-κB into cell nuclear. All these results show that 20 mg/L EMP could protect the cardiomyocytes against oxidative stress induced by H2O2; its mechanism is associated with the expression promotion of the antiapoptotic gene Bcl-2 and translocation supression of NF-κB into cell nuclear.