Anti-inflammatory effect of longan seed extract in carrageenan stimulated Sprague-Dawley rats.

OBJECTIVES: Longan seeds have been used as a folk medicine in China. Longan seed extract (LSE) is known for antioxidative, antiproliferative, hypoglycemic, and hypouremic effects. However, its anti-inflammatory effect has not been shown. MATERIALS AND METHODS: In this study, Sprague-Dawley (SD) rats were given LSE orally (vehicle, 10, and 30 mg/kg) for 3 days to its test anti-inflammatory effect by injecting λ-carrageenan (CARR) in the right hind paw or lipopolysaccharide (LPS), IP. For the positive control, animals were given aspirin (20 mg/kg) orally and treated likewise. Serum or tissue samples from treated rats were collected after 3 hr of stimulation. Regarding the in vitro study, BV2 microglial cells were stimulated with LPS in the presence of LSE or normal saline for 10 min or 24 hr for Western blot and ELISA assay, respectively. RESULTS: LSE reduced CARR-induced edema in the experimental animals. LSE also reduced LPS/CARR-induced nitric oxide (NO), interleukin-1ß (IL1ß), IL6, and COX2 productions. These inflammatory factors were also reduced dose dependently by LSE in LPS-stimulated BV2 cells. Furthermore, Western blot analysis revealed that LSE inhibited LPS activated c-Jun NH2-terminal protein kinase (JNK), extracellular signal-regulated kinases (ERKs), and p38 MAP kinases signaling pathways, caspase-3, inducible NO synthase, and COX2 expressions. CONCLUSION: LSE pretreatment suppressed CARR- and LPS-induced inflammations and these effects might be through the inhibition of MAP kinases signaling pathways and inflammatory factors.

Longan seed extract reduces hyperuricemia via modulating urate transporters and suppressing xanthine oxidase activity.

Hyperuricemia causes gouty arthritis, kidney disease, heart disease, and other diseases. Xanthine oxidase (XOD) and urate transporters play important roles in urate homeostasis. Numerous plants have been identified as XOD inhibitors. Longan seeds are known to contain high levels of polyphenols such as corilagin, gallic acid and ellagic acid. We examined the effect of longan seed extract on XOD inhibition and urate transporters GLUT1 and GLUT9 using both in vitro and in vivo assays. The results showed that dried longan seed extract (LSE) and its active components inhibited XOD dose-dependently in vitro. LSE inhibited uric acid production and XOD activity in normal liver cells (clone-9 cells) and was not cytotoxic under the concentration of 200 µg/ml. For the in vivo study, Sprague-Dawley (SD) rats were given intraperitoneally for thirty minutes with or without allopurinol (a XOD inhibitor, 3.5 mg/kg) or LSE (80 mg/kg) and then injected intraperitioneally with 250 mg/kg of oxonic acid and 300 mg/kg of hypoxanthine intragastrically. LSE was able to reduce serum uric acid level and XOD activity in hyperuricemic rats. However, LSE or allopurinol did not inhibit the liver XOD activities. On the other hand, GLUT1 protein was suppressed in kidney and GLUT9 was induced in liver from experimental rats and LSE or allopurinol decreased GLUT9 but increased GLUT1 protein level in the liver and kidney, respectively. These results confirmed the claimed effect of longan seeds on gout and other complications and suggested that its urate reducing effect might be due to modulation of urate transporters and inhibition of circulating xanthine oxidase.

Fresh green tea and gallic acid ameliorate oxidative stress in kainic acid-induced status epilepticus.

Green tea is one of the most-consumed beverages due to its taste and antioxidative polyphenols. However, the protective effects of green tea and its constituent, gallic acid (GA), against kainic acid (KA)-induced seizure have not been studied. We investigated the effect of fresh green tea leaf (GTL) and GA on KA-induced neuronal injury in vivo and in vitro. The results showed that GTL and GA reduced the maximal seizure classes, predominant behavioral seizure patterns, and lipid peroxidation in male FVB mice with status epilepticus (SE). GTL extract and GA provided effective protection against KA-stressed PC12 cells in a dose-dependent manner. In the protective mechanism study, GTL and GA decreased Ca(2+) release, ROS, and lipid peroxidation from KA-stressed PC12 cells. Western blot results revealed that mitogen-activated protein kinases (MAPKs), RhoA, and COX-2 expression were increased in PC12 cells under KA stress, and expression of COX-2 and p38 MAPK, but not RhoA, was significantly reduced by GTL and GA. Furthermore, GTL and GA were able to reduce PGE(2) production from KA-stressed PC12 cells. Taken together, the results showed that GTL and GA provided neuroprotective effects against excitotoxins and may have a clinical application in epilepsy.

Pu-Erh tea and GABA attenuates oxidative stress in kainic acid-induced status epilepticus.

BACKGROUND: Pu-Erh tea is one of the most-consumed beverages due to its taste and the anti-anxiety-producing effect of the gamma-aminobutyric acid (GABA) if contains. However the protective effects of Pu-Erh tea and its constituent, GABA to kainic acid (KA)-induced seizure have not been fully investigated. METHODS: We analyzed the effect of Pu-Erh tea leaf (PETL) and GABA on KA-induced neuronal injury in vivo and in vitro. RESULTS: PETL and GABA reduced the maximal seizure classes, predominant behavioral seizure patterns, and lipid peroxidation in male FVB mice with status epilepticus. PETL extracts and GABA were effective in protecting KA-treated PC12 cells in a dose-dependent manner and they decreased Ca(2+) release, ROS production and lipid peroxidation from KA-stressed PC12 cells. Western blot results revealed that mitogen-activated protein kinases (MAPKs), RhoA and cyclo-oxygenase-2 (COX-2) expression were increased in PC12 cells under KA stress, and PETL and GABA significantly reduced COX-2 and p38 MAPK expression, but not that of RhoA. Furthermore, PETL and GABA reduced PGE(2) production from KA-induced PC12 cells. CONCLUSIONS: Taken together, PETL and GABA have neuroprotective effects against excitotoxins that may have clinical applications in epilepsy.

Elephantopus scaber inhibits lipopolysaccharide-induced liver injury by suppression of signaling pathways in rats.

Elephantopus scaber (ES, Teng-Khia-U) has been traditionally used for the treatment of nephritis, pain, and fever; however, the direct evidence is lacking. We investigated the effect of ES on lipopolysaccharide (LPS) induced inflammation of BV-2 microglial cells and acute liver injury in Sprague-Dawley (SD) rats. Our results showed that ES reduced LPS-induced nitric oxide (NO), interleukin (IL)-1, IL-6, reactive oxygen species (ROS), and prostaglandin (PGE(2)) production in BV-2 cells. ES significantly decreased serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels in LPS-treated rats. Furthermore, the water extract, but not the ethanol extract, of ES dose-dependently inhibited LPS-induced JNK, p38 mitogen-activated protein kinases (MAPK), and slightly inhibited cyclooxygenase (COX-2) in BV-2 cells but decreased p38 MAPK and COX-2 expressions in the liver of LPS-treated rats. Taken together, these results indicate that the protective mechanism of ES involves an antioxidant effect and inhibition of p38 MAP kinase and COX-2 expressions in LPS-stressed acute hepatic injury in SD rats.

Effect of Cordyceps militaris supplementation on sperm production, sperm motility and hormones in Sprague-Dawley rats.

Cordyceps species have been traditionally used as for the enhancement of sexual function, but its direct evidence is lacking. We investigated the spermatogenic effect of Cordyceps militaris (CM) as supplementation with CM mycelium to 7-week-old male Sprague-Dawley (SD) rats. Ninety rats (30 for each group) were selected to regular diet or diet supplemented with CM mycelium (1% and 5%) for 6 weeks. Epididymal sperm were collected from 6 animals per group at each interval of observation. They were allowed to recover for one week. The quality and quantity of sperm were compared in these rats. The CM supplementation resulted in an increase of serum cordycepin concentration (n = 6, each group) that correlated with treatment time and the cordycepin level was significantly higher (p < 0.05) in 5% group as compared to 1% group at the 5th and 6th week. Epididymal sperm count was enhanced significantly from the control, at the 5th week and peaked at the 6th week in both groups supplemented with CM (each time point, n = 6; p < 0.05) and maintained for 2 weeks after stopping the treatment. Increased serum testosterone and estradiol-17 (E2) concentrations were found in rats with the CM supplementation (p < 0.05), but not other hormones such as follicle stimulating hormone (FSH), luteinizing hormone (LH) or prolactin. Importantly, percentages of motile sperm cells were also enhanced significantly (p < 0.05) paralleled the serum testosterone pattern from the supplement groups as compared to the control group. Taken together, these results indicate that supplementation with CM improves sperm quality and quantity in rats.