Investigation of anti-oxidative stress in vitro and water apparent diffusion coefficient in MRI on rat after spinal cord injury in vivo with Tithonia diversifolia ethanolic extracts treatment.

BACKGROUND: Spinal cord injury (SCI)-induced secondary oxidative stress associates with a clinical complication and high mortality. Treatments to improve the neurological outcome of secondary injury are considered as important issues. The objective of the current study is to evaluate the anti-oxidative effect of Tithonia diversifolia ethanolic extracts (TDE) on cells and apply the pharmacological effect to SCI model using a MRI imaging algorism. METHODS: The anti-oxidation properties were tested in a 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay. Rat liver cells (clone-9) were treated with various doses of TDE (0 ~ 50 µg/ml) before exposed to 250 µM H2O2 and cell survival was determined by MTT and LDH assays. We performed water apparent diffusion coefficient (ADC) map in MR techniques to investigate the efficacy of TDE treatment on SCI animal model. We performed T5 laminectomy and compression (50 g, 1 min) to induce SCI. PHILIP 3.0 T MRI was used to image 24 male Sprague-Dawley rats weighing 280-320 g. Rats were randomly divided into three groups: sham group, SCI group, SCI treated with TDE group. The MRI images were taken and ADC were acquired before and after of treatment of TDE (50 mg/kg B. W. orally, 5 days) in SCI model. RESULTS: TDE protected clone-9 cells against H2O2-induced toxicity through DPPH scavenging mechanism. In addition, SCI induced the increase in ADC after 6 hours. TDE treatment slightly decreased the ADC level after 1-week SCI compared with control animals. CONCLUSION: Our studies have proved that the cytoprotection effect of TDE, at least in part, is through scavenging ROS to eliminate intracellular oxidative stress and highlight a potential therapeutic consideration of TDE in alternative and complementary medicine.

Anti-human hepatoma Hep-G2 proliferative, apoptotic, and antimutagenic activity of tagitinin C from Tithonia diversifolia leaves.

Tagitinin C, a major sesquiterpenoid, was isolated from the leaves of Tithonia diversifolia. The high morbidity and mortality rate of hepatoma in Taiwan motivated our interest in the investigation of tagitinin C's mechanism against the human hepatocellular carcinoma. The methanolic extract of leaves of T. diversifolia (TDM) and tagitinin C were found to have cytotoxic activities against human hepatoma Hep-G2 cells in the MTT assay with IC(50) values of 40.0 ± 2.0 and 2.0 ± 0.1 µg/mL, respectively. This compound induced population increase in the sub-G(1) phase and S phase arrest. Treatment with tagitinin C isolated from TDM resulted in activation of both caspase 3 and caspase 8 which suggested that the antiproliferative effect of this compound was caspase-dependent apoptosis. Magnetic resonance techniques indicated that the tumorigenisity of xenografts derived from Hep-G2 cells was retarded by the delivery of tagitinin C (15 µg/mouse/day) relative to the control counterparts.

Effects of arginine supplementation on post-exercise metabolic responses.

This study investigated the effects of arginine supplementation on acute metabolic responses during recovery after a single bout of endurance exercise in trained athletes. Twelve healthy male judo athletes were randomly divided into two groups and performed a single bout of exercise at a speed estimated to correspond to 75%VO2max for 60 min, and then took either a placebo or arginine at 0.1 g/kg-wt. Blood samples of each athlete were collected before exercise, and 0, 15, 30, 45, 60, 90, 120 min after exercise, respectively. The experiment was repeated two weeks later, but treatments were exchanged for the two groups. The concentrations of glucose, insulin, free fatty acid (FFA), glycerol, lactate, ammonia, creatine kinase, and NOx (NO2(-) + NO3(-)) in blood were examined. No differences in the levels of glycerol, lactate, ammonia, creatine kinase, or NOx between the two groups were observed at any of the time points. However, the concentration of glucose was significantly higher in the arginine group as compared to that in the placebo group at the 15-min recovery point. The insulin concentration was also higher in the arginine group as compared to that in the placebo group at the 30-min recovery point. Furthermore, the free fatty acid levels at the 30, and 45-min recovery points were significantly lower in the arginine group compared to those in the placebo group. The results indicated that arginine supplementation during the exercise recovery period could increase glucose and insulin concentrations, and decrease FFA availability in the blood.

Gastrointestinal enhancement of MRI with melanin derived from tea leaves (Thea sinensis Linn.).

Melanin was extracted from tea leaves (Thea sinensis Linn.) for the first time. Characterization of melanin proved similarity of the original compound to standard melanin. The Langmuir adsorption isotherms for gadolinium (Gd) binding were obtained using melanin. Melanin-Gd preparation demonstrated low acute toxicity. LD(50) for this preparation was in a range of 1250-1500 mg/kg in mice. Magnetic Resonance Imaging (MRI) properties of melanin itself and melanin-Gd complexes have been estimated. Gd free melanin fractions possess slighter relaxivity compared with its complexes. The relaxivity of lower molecular weight fraction was two times higher than relaxivity of Gd(DTPA) standard. Postcontrast images demonstrate that oral administration of melanin complexes in concentration 0.1 mM provides essential enhancement to longitudinal relaxation times (T(1))-weighted spin echo image. The required contrast and delineation of the stomach wall demonstrated uniform enhancement of MRI with proposed melanin complex.