[Effects of octadecadienoic acid on proliferation and apoptosis of glioma cells and its mechanisms].

OBJECTIVE: To study the effects of octadecadienoic acid (ODA) on the proliferation and apoptosis of glioma cells and its mechanisms. METHODS: Cultured human glioma cells (cell density 2×106 cells/L) were divided into solvent control group (DMSO, 30 µl/L), 5-FU group (10 mg/L) and octadecadienic acid groups (0.3, 0.6 and 1.2 mg/L groups). The toxicity of ODA on glioma cells was detected by trypan blue and thiazolium blue (MTT). The expression levels of P53, PI3K, P21, PKB/Akt and Caspase-9 in glioma cells were determined by enzyme-linked immunosorbent assay (ELISA). RESULTS: ① Cell count under optical microscope showed that the inhibition rate of cell proliferation in ODA low, medium and high dose groups and 5-FU group was significantly higher than that in the solvent control group (P＜0.01), but there was no statistical significance compared with the 5-FU group (P＞0.05). ② MTT assay showed that the inhibition rate of cell proliferation was increased significantly in ODA low, medium and high dose groups and 5-FU groups (P＜0.01), compared with the solvent control group. Compared with 5-FU group, the inhibition rate of cell proliferation was increased significantly only in ODA high dose group (P＜0.01). ③ The number of G0/G1 phase cells in ODA low, medium and high dose groups and 5-FU group were increased significantly (P＜0.05, P＜0.01), the number of G2/M phase cells were decreased significantly (P＜0.01), and the apoptosis rate was increased significantly (P＜0.01),compared with the solvent control group. Compared with the 5-FU group, the number of cells in G2/M phase was decreased significantly (P＜0.01) and the apoptosis rate was increased significantly (P＜0.01) in ODA high dose group. ④ ELISA test results showed that the protein expression levels of P53, PI3K and PKB/Akt in ODA low , medium and high dose groups and 5-FU group were significantly lower than those in solvent control group (all P＜0.01), but the protein expression levels in ODA high dose group were significantly lower than those in 5-FU group (P＜0.01). The protein expression levels of P21 and caspase-9 in ODA low , medium and high dose groups and 5-FU group were significantly higher than those in solvent control group (P＜0.05, P＜0.01), but the protein expression levels in ODA high dose group were significantly higher than those in 5-Fu group (P＜0.01). CONCLUSION: ODA can significantly inhibit the proliferation and promote apoptosis of glioma cells. The mechanisms are related to up-regulating the levels of P21 and caspase-9 to promote apoptosis, down-regulating the levels of P53, PI3K and PKB/Akt to inhibit the cell division cycle, and reducing the activity of PI3K-Akt signal transduction pathway.

[Effects of the maca extract on the ultrastructures of mitochondria in the spinal nerve cell and exercise endurance].

OBJECTIVE: To investigate the effects of maca extract on the ultrastructures of mitochondria in the spinal nerve cell and exercise endurance. METHODS: The Wistar rats were randomly divided into 5 groups, including the control group (no swimming), the swimming group (free swimming), and 3 treatment groups treated with the maca extract at the doses of 4.0, 5.3 and 8.0 g/kg body weight. The animals in swimming and treatment groups were then for free swimming in the circulating water flow daily for 15 days. On the 16th day after swimming endurance, the spinal and muscular tissues were collected from all groups. The mitochondrial ultrastructures of the neurons of the spinal cells were observed with the projection electron microscope, and the levels of the glycogen, malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and Ca2+ in muscle tissues were determined by the RIA method. RESULTS: When rats were treated with maca extract (at 4.0, 5.3, 8.0 g/kg body weight), the total swimming time and the swimming duration before sinking were increased by 19.83%, 60.28%, 77.55%, and 55.34%, 73.91%, 94.47%, respectively, compared with the simple swimming group(P<0.01), while the sinking times were decreased by 34.35%, 51.18% and 57.96%, compared with those of the swimming group. Also, the levels of SOD, GSH-Px, and muscle glycogen in three treatment groups were enhanced by 5.12%, 22.74%, 52.53%, 44.22%, 77.79%, 98.45%(P<0.01), and 35.08%, 47.83%,81.88% (P<0.01)respectively over the swimming rats without treatment, but the MDA content and the Ca2+ levels were reduced by 20.10%, 31.49% 38.72%, and 6.42%, 17.58%, 26.35%,compared with the simple swimming group(P<0.01). In addition, compared to the swimming group, the mitochondrial densities of volume (VD), surface (SD) and numbers (ND) of spinal nerve cells in rats treated with maca extract (4.0, 5.3, 8.0 g/kg body weight) were reduced by 7.79%, 18.18%, 31.17%, 16.95%, 27.34%, 43.31% and 13.51%, 23.19%, 43.15%, respectively. CONCLUSIONS: Our results demonstrated the protective effects of maca extract on the mitochondria of spinal cell and suggested that maca extract could improve the muscle antioxidant activity by increasing the levels of SOD, GSH-Px, and muscle glycogen.

[Role of catecholamine hormone in heroin addicts].

OBJECTIVE: To investigate the effects of catecholamine hormone on the blood and brain of heroin addicts. METHODS: Rats were divided into three groups and treated with the glucose (control group), the heroin (im) (heroin group), and the combination of the intramuscular injection of reserpine and heroin (reserpine group). Changes in the levels of the dopamine (DA), cAMP, and cGMP were detected by the radioimmunoassay (RIA) method in the blood and brain tissue. RESULTS: No significant withdrawal symptoms were observed in the reserpine group. Compared with the control and heroin groups, the blood cAMP levels were increased by 35.36% and 15.53% in the reserpine group, respectively; the cAMP levels in the midbrain ventral tegmental area (VTA), prefrontal cortex (PFC), and hippocampus (Hipp) were increased by 24.08% & 8.53%, 15.66% & 8.13%, and 21.95% & 8.40%, respectively. While compared to the control and heroin groups, the DA levels of the PFC, Hipp, striatum, and nucleus accumbens (NAc) were significantly reduced in the reserpine group, decreasing by 74.09% & 82.86%, 81.06% & 82.23%, 91.62% & 86.55% and 84.35% & 90.63%, respectively. The concentrations of cGMP of the brain tissues in the reserpine group were lower than those in the control group. In addition, the neural electrophysiological testing showed that the electroencephalogram (EEG), electrocardiogram (ECG), and muscle spindle discharge diagram of rats in both the reserpine and heroin groups were apparently changed. CONCLUSION: Catecholamine hormone plays an important role in heroin addiction.

Effects of a flavonoid extract from Cynomorium songaricum on the swimming endurance of rats.

The present study investigated the effects of a flavonoid extract from Cynomorium songaricum on the swimming endurance of rats by measuring changes of free radical scavenging enzymes, such as CuZn-SOD (copper, zinc-superoxide dismutase) and GSH-px (glutathione peroxidase), and body weights. Significant and dose-dependent antioxidant and anti-fatigue effects of flavonoids (rutin, catechin and isoquercitrin) on swimming rats were observed during 10 days of swimming exercise. After treatment with the flavonoid extract at doses of 0.5, 1.0, and 2.0 g/kg body weight, the CuZn-SOD and GSH-px activities in swimming rats were increased by 1.4%, 3.3%, 4.1% and 112.2%, 208.7%, 261.7%, respectively, while the levels of MDA (malondialdehyde) were decreased by 64.7%, 79.4%, and 86.4% respectively. Furthermore, the average body weight and the total swimming time were increased by 3.1%, 8.8%, 10.6%, and 7.7%, 34.5%, 61.5%, respectively. Our experimental results suggest that flavonoid supplementation could not only reduce free radical formation and scavenge free radicals, but also enhance endurance exercise performance by reducing muscle fatigue.

Isolation and characterization of methyl esters and derivatives from Euphorbia kansui (Euphorbiaceae) and their inhibitory effects on the human SGC-7901 cells.

PURPOSE: In this study, the inhibitory activity of the methyl esters and derivatives extracted from Euphorbia kansui (Euphorbiaceae) and their effect on apoptosis and cell cycle distribution in the human gastric cancer cell line (SGC-7901) were evaluated. METHODS: The inhibitory activity of the methyl esters and derivatives was evaluated by using trypan-blue, MTT (3-(4, 5-dimethyl thiazol-2yl) - 2, 5-diphenyltetrazolium bromide), and FCM (flow cytometry) assays. 5-fluorouracile (5-FU) was used for a positive control. RESULTS: Six new methyl esters and derivatives were extracted from the root of E. kansui. Subjecting the SGC-7901 cell line to the extract indicated that methyl ester derivatives could initiate growth inhibition and induce apoptosis in these tumor cells. The inhibitory rates as measured from trypan-blue and MTT assays were significantly increased and are comparable to those of the common antitumor agent 5-FU. In addition, the methyl ester extract effectively inhibited the proliferation of SGC-7901 cells by interfering with the progression of the cells through the G1 phase of the cell cycle. CONCLUSION: The current study indicates that methyl esters might be a promising chemopreventive and chemotherapeutic agent for treating various forms of cancer by causing apoptosis and proliferation inhibition.