A mixture of extracts from Peruvian plants (black maca and yacon) improves sperm count and reduced glycemia in mice with streptozotocin-induced diabetes

Abstract

We investigated the effect of two extracts from Peruvian plants given alone or in a mixture on sperm count and glycemia in streptozotocin-diabetic mice. Normal or diabetic mice were divided in groups receiving vehicle, black maca (Lepidium meyenii), yacon (Smallanthus sonchifolius) or three mixtures of extracts black maca/yacon (90/10, 50/50 and 10/90%). Normal or diabetic mice were treated for 7?d with each extract, mixture or vehicle. Glycemia, daily sperm production (DSP), epididymal and vas deferens sperm counts in mice and polyphenol content, and antioxidant activity in each extract were assessed. Black maca (BM), yacon and the mixture of extracts reduced glucose levels in diabetic mice. Non-diabetic mice treated with BM and yacon showed higher DSP than those treated with vehicle (p?<?0.05). Diabetic mice treated with BM, yacon and the mixture maca/yacon increased DSP, and sperm count in vas deferens and epididymis with respect to non-diabetic and diabetic mice treated with vehicle (p?<?0.05). Yacon has 3.05 times higher polyphenol content than in maca, and this was associated with higher antioxidant activity. The combination of two extracts improved glycemic levels and male reproductive function in diabetic mice. Streptozotocin increased 1.43 times the liver weight that was reversed with the assessed plants extracts. In summary, streptozotocin-induced diabetes resulted in reduction in sperm counts and liver damage. These effects could be reduced with BM, yacon and the BM+yacon mixture.     

The transillumination technique as a method for the assessment of spermatogenesis using medicinal plants: the effect of extracts of black maca (Lepidium meyenii) and camu camu (Myrciaria dubia) on stages of the spermatogenic cycle in male rats

Abstract

Transillumination technique for assessment of stages of spermatogenic cycle is a useful tool for toxicological studies. This study was designed to determine the effect of two medicinal plants on spermatogenesis in male rats using the transillumination technique. For this, the effect of the combination of a fruit with highest content of ascorbic acid (Myrciaria dubia, camu camu) and extract of black maca (Lepidium meyenii) on seminiferous tubule stages scored by transillumination on intact tubules in adult male rats was assessed. Animals were treated during seven days with vehicle, black maca, camu camu or a mixture of black maca?+?camu camu and assessed for daily sperm production (DSP), stages of spermatogenic cycle as well as antioxidant activity and levels of flavonoids and polyphenols. Black maca increased stages of spermiation (VII–VIII) and mitosis of germ cells (IX–XI), whereas camu camu increased stages of mitosis (IX–XI) and meiosis (XII). Mixture of maca?+?camu camu increased stages of spermiation, mitosis and meiosis. All treatments increased DSP (p?<?0.05) and epididymal sperm count (p?<?0.05). Total polyphenols, flavonoids levels and antioxidant activity were higher in camu camu (p?<?0.001) than in black maca. In conclusion, M. dubia (camu camu) has potential effects improving spermatogenesis and co-administered with maca increase stages of mitosis, meiosis and spermiation of the spermatogenic cycle as assessed by the transillumination technique. This technique is becoming increasingly a useful tool for assessment spermatogenesis.     

Effect of gamma irradiation on phenol content,antioxidant activity and biological activity of black maca and red maca extracts (Lepidium meyenii walp)

This study was performed to determine the effects of gamma irradiation on UV spectrum on maca, total content of polyphenols, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activities and in vivo biological activities of red and black maca extracts (Lepidium meyenii).

Adult mice of the strain Swiss aged 3 months and weighing 30–35?g in average were used to determine biological activities. Daily sperm production, effect on testosterone-induced prostate hyperplasia and forced swimming test were used to determine the effect of irradiation on biological activities of maca extracts.

Irradiation did not show differences in UV spectrum but improves the amount of total polyphenols in red maca as well as in black maca extracts. In both cases, black maca extract has more content of polyphenols than red maca extract (p?<?0.01). Gamma irradiation significantly increased the antioxidant capacity (p?<?0.05).

No difference was observed in daily sperm production when irradiated and nonirradiated maca extract were administered to mice (p?>?0.05). Black maca extract but not red maca extract has more swimming endurance capacity in the forced swimming test. Irradiation of black maca extract increased the swimming time to exhaustion (p?<?0.05). This is not observed with red maca extract (p?>?0.05). Testosterone enanthate (TE) increased significantly the ventral prostate weight. Administration of red maca extract in animals treated with TE prevented the increase in prostate weight. Irradiation did not modify effect of red maca extract on prostate weight (p?>?0.05).

In conclusion, irradiation does not alter the biological activities of both black maca and red maca extracts. It prevents the presence of microorganisms in the extracts of black or red maca, but the biological activities were maintained.     

硫化氢抑制葡萄糖调节蛋白78减轻6-OHDA诱导的PC12细胞损伤

目的：探讨硫化氢（H2S）是否通过改变葡萄糖调节蛋白78（GRP78）的表达参与其对抗6-羟基多巴胺（6-OHDA）诱导PC12细胞损伤的保护作用。方法应用具有神经毒性的6-OHDA损伤PC12细胞为帕金森病细胞模型,以硫氢化钠（NaHS）作为H2S的供体;应用CCK-8比色法检测细胞存活率;DFCH-DA染色检测细胞内活性氧（ROS）的水平;Rh123染色检测细胞线粒体膜电位（MMP）;Western blot检测GRP78的表达。结果200μmol/L的6-OHDA引起PC12细胞的存活率显著降低,ROS生成增加及MMP降低,且诱导了GRP78的高表达。应用25~400μmol/L的NaHS预处理30 min,呈浓度依赖性抑制6-OHDA引起的细胞存活率降低,其中400μmol/L的NaHS作用最明显,此浓度也可以显著减少6-OHDA引起的ROS增多,提高MMP,同时明显抑制6-OHDA诱导的GRP78高表达。结论 H2S具有抗6-OHDA氧化应激损伤的PC12细胞保护作用,抑制内质网应激分子GRP78的表达可能是其机制之一。     

Attenuation of 6-hydroxydopamine (6-OHDA)-induced nuclear factor-kappaB (NF-kappaB) activation and cell death by tea extracts in neuronal cultures.

Antioxidant and anti-inflammatory therapy approaches have been in the focus of attention in the treatment of neurodegenerative Parkinson's and Alzheimer's diseases where oxidative stress has been implicated. Tea extracts have been previously reported to possess radical scavenger, iron chelating and anti-inflammatory properties in a variety of tissues. The purpose of this study was to investigate potential neuroprotective effects of tea extracts and possible signal pathway involved in a neuronal cell model of Parkinson's disease. We demonstrated highly potent antioxidant-radical scavenging activities of green tea (GT) and black tea (BT) extracts on brain mitochondrial membrane fraction, against iron (2.5 microM)-induced lipid peroxidation. Both extracts (0.6-3 microM total polyphenols) were shown to attenuate the neurotoxic action of 6-hydroxydopamine (6-OHDA)-induced neuronal death. 6-OHDA (350 and 50 microM) activated the iron dependent inflammatory redox sensitive nuclear factor-kappaB (NF-kappaB) in rat pheochromocytoma (PC12) and human neuroblastoma (NB) SH-SY5Y cells, respectively. Immunofluorescence and electromobility shift assays showed increased nuclear translocation and binding activity of NF-kappaB after exposure to 6-OHDA in NB SH-SY5Y cells, with a concomitant disappearance from the cytoplasm. Introduction of GT extract (0.6, 3 microM total polyphenols) before 6-OHDA inhibited both NF-kappaB nuclear translocation and binding activity induced by this toxin in NB SH-SY5Y cells. Neuroprotection was attributed to the potent antioxidant and iron chelating actions of the polyphenolic constituents of tea extracts, preventing nuclear translocation and activation of cell death promoting NF-kappaB. Brain penetrating property of polyphenols may make such compounds an important class of drugs for treatment of neurodegenerative diseases.     

IGF-1对6-OHDA诱导神经元氧化损伤的保护作用

目的 探讨胰岛素样生长因子-1（IGF-1）对6-羟基多巴胺（6-OHDA）诱导的PC12细胞氧化损伤的保护作用。方法 以25、50、100、150、200 μmol/L 的6-OHDA 处理PC12细胞,在12、24、48 h用MTT 法检测6-OHDA 对PC12细胞活性的影响,筛选最佳的实验浓度和观察时间。实验分为3组：对照组、6-OHDA组（150 μmol/L处理24 h）和IGF-1+6-OHDA组（IGF-1 100 nmol/L预处理2 h,后加入150 μmol/L 6-OHDA处理24 h）,MTT法检测各组细胞活性;免疫荧光染色法检测细胞活性氧（ROS）水平;Hoechst33342/PI双染法检测细胞凋亡。结果 随6-OHDA浓度的增加和作用时间的延长,PC12细胞的活性呈梯度降低,150 μmol/L 6-OHDA浓度和处理后24 h作为本研究的最佳的实验浓度和观察时间。与6-OHDA组比较,IGF-1+6-OHDA组PC12细胞活力增强、ROS水平下降、细胞凋亡减少。结论 IGF-1预处理能减少6-OHDA引起的PC12细胞氧化损伤及凋亡,增加细胞活性,为防治帕金森病提供了潜在的治疗策略。     

玛咖的化学成分、药理作用及质量评价研究进展

玛咖又名迈恩独行菜Lepidium meyenii,含有丰富的营养成分和具有多种生物活性的次级代谢产物,玛咖烯和玛咖酰胺被认为是玛咖特有的标志性物质。玛咖具有多方面的药理作用,包括抗疲劳、抗氧化、改善性功能等,这些都预示着玛咖在保健品和药用方面具有广阔的开发前景。对玛咖的化学成分、药理作用和质量评价方法的国内外研究现状进行综述。     

Neuroprotective effects of dimerumic acid and deferricoprogen from Monascus purpureus NTU 568-fermented rice against 6-hydroxydopamine-induced oxidative stress and apoptosis in differentiated pheochromocytoma PC-12 cells

Context Oxidative stress plays a key role in neurodegenerative disorders, including Parkinson’s disease (PD). Rice fermented with Monascus purpureus Went (Monascaceae) NTU 568 (red mould rice) was found to contain antioxidants, including dimerumic acid (DMA) and deferricoprogen (DFC).

Objective The effects of DMA and DFC on 6-hydroxydopamine (6-OHDA)-induced cytotoxicity and potential protective mechanisms in differentiated PC-12 pheochromocytoma cells were investigated.

Materials and methods DMA (0–60?μM) or DFC (0–10?μM) was co-treated with 6-OHDA (200?μM, 24?h exposure) in differentiated PC-12 cells. Cell viability and intercellular reactive oxygen species (ROS) were measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) and 2′,7′-dichlorofluorescein-diacetate (DCFH-DA) assays, respectively. Cell apoptosis was determined by DNA fragmentation analysis and propidium iodide staining by flow cytometry. Western blot analysis was used to measure the levels of cell protein expression.

Results DMA and DFC significantly increased cell viability to 72% and 81% in 6-OHDA-induced differentiated PC-12 cell cultures, respectively. Furthermore, DMA and DFC reduced 6-OHDA-induced formation of extracellular and intercellular ROS by 25% and 20%, respectively, and decreased NADPH oxidase-2 expression in differentiated PC-12 cells. DMA and DFC inhibited 6-OHDA-induced apoptosis and decreased activation of caspase-3 via regulation of Bcl-2-associated X protein (Bax) and Bcl-2 protein expression in differentiated PC-12 cells.

Conclusion DMA and DFC may protect against 6-OHDA toxicity by inhibiting ROS formation and apoptosis. These results showed that the metabolites from M. purpureus NTU 568 fermentation were potential therapeutic agents for PD induced by oxidative damage and should be encouraged for further research.     

Retracted: Larvicidal activity of 4-hydroxycoumarin derivatives against Aedes aegypti

Context: Apoptotic neuronal cell death plays an important role in Parkinson’s disease (PD), a progressive neurodegenerative disorder. Luteolin, a flavonoid, has been shown to possess various pharmacological properties including strong antioxidant capacity.

Objective: This study investigated the neuroprotective effect of luteolin against cytotoxicity induced by 6-hydroxy-dopamine (6-OHDA) (250 µM) in rat pheochromocytoma (PC12) cell line.

Materials and methods: The neuroprotective effect of luteolin against 6-OHDA-induced cytotoxicity in PC12 was evaluated by using cell viability test, nuclear staining and flow cytometry. In addition, the apoptotic role of luteolin was unveiled by monitoring mRNA expression of proapoptotic and anti-apoptotic genes.

Results: Pretreatment with luteolin (3.13, 6.25, 12.5, 25 or 50 µM) could markedly attenuate 6-OHDA-induced PC12 cell viability loss in a concentration-dependent manner. Cell morphologic analysis and nuclear staining assays showed that luteolin (3.13, 12.5 or 50 µM) protected the cells from 6-OHDA-induced damage. As shown in the flow cytometry assay, the increased apoptotic rate induced by 6-OHDA could be significantly (p < 0.001) suppressed by luteolin (12.5 or 50 µM) pretreatment. The protection of luteolin (50 µM) against 6-OHDA-induced cell damage was shown to be through suppressing the over-expression of Bax gene (p < 0.01), inhibiting the reduction of Bcl-2 gene expression (p < 0.05) and markedly depressing the enhanced Bax/Bcl-2 ratio. Luteolin also downregulated the gene expression level of p53.

Discussion and conclusion: Luteolin has protective effects against 6-OHDA-induced cell apoptosis and might be a potential nutritional supplement which could be used to prevent neurodegenerative diseases such as PD.     

6-羟基多巴的细胞毒作用与谷氨酸转运的关系

目的探讨6-羟基多巴(6-OHDA)导致细胞毒性与谷氨酸(glutamate,Glu)递质水平和谷氨酸转运体的相关性。方法大鼠脑黑质内定位注射6-OHDA,制备帕金森病(Parkinson's disease,PD)动物模型;用在体微透析技术收集大鼠纹状体细胞外液;用高效液相色谱法测定PD大鼠纹状体和PC12细胞的细胞外液中Glu的水平;用流式细胞仪和酶标仪检测细胞凋亡率和细胞活性;通过测定L-［³H］-Glu的摄取能力确定谷氨酸转运体的功能。结果6-OHDA诱导PC12细胞和大鼠损毁侧纹状体释放Glu增加,使PC12细胞凋亡和活性降低,而PC12细胞和突触体上的谷氨酸转运体功能显著下降。结论6-OHDA引起的神经毒性与其增加Glu释放和降低谷氨酸转运体功能有关。     

Ⅱ、Ⅲ组亲代型谷氨酸受体激动剂对6-羟基多巴诱导的PC12细胞毒性无保护作用

阐明Ⅱ、Ⅲ组亲代谢型谷氨酸受体(metabotropic glutamate receptors,mGluRs)激动剂对6—羟基多巴(6-hydroxydopamine,6-OHDA)诱导的PC12细胞毒性是否具有保护作用。方法：应用高效液相色谱仪联用荧光检测技术测定谷氨酸浓度，应用四甲基偶氮唑盐(MTT)比色法测定PC12细胞活性。结果：6—OHDA剂量依赖性地诱导PC12细胞释放谷氨酸、减低细胞活性，Ⅱ组mGluRs激动剂DCG—IV和Ⅲ组mGluRs激动剂L-AP4对6—0HDA诱导的PC12细胞释放谷氨酸和细胞活性的降低均无显影响。结论：6—OHDA对多巴胺神经元的损伤作用与其诱导谷氨酸过度释放及其继发的兴奋性神经毒性有关，Ⅱ、Ⅲ组亲代谢型谷氨酸受体激动剂对6—OHDA诱导的PC12细胞毒性无保护作用。     

Quebrachitol (2-O-methyl-L-inositol) attenuates 6-hydroxydopamine-induced cytotoxicity in rat fetal mesencephalic cell cultures.

Naturally occurring plant substances have the potential to prevent oxidative damage in various pathophysiological conditions including neurodegenerative disorders. Recent findings indicate that impaired energy metabolism plays a prominent role in neurodegeneration. The present study investigated whether quebrachitol (2-O-methyl-L-inositol) (QCT), a sugar like natural compound that was suggested to have both antioxidant and membrane stabilization activity prevents the cytotoxic effect of 6-hydroxydopamine (6-OHDA, 200 microM) on cultured rat fetal mesencephalic cells. While QCT (0.1-100 microg/ml) produced no effect per se on cell viability as measured in the 3[4,5-dimethylthiazole-2il]-2,5-diphenyltetrazolium bromide (MTT) test, it offered concentration-related protection against cell death induced by 6-OHDA. In addition, QCT demonstrated an antioxidant activity against 6-OHDA-induced oxidative stress as evidenced by reduced formation of nitrite-nitrate and thiobarbituric acid-related substances. Fluorescence microscopy using acridine orange/ethidium bromide double staining further affirmed the absence of 6-OHDA (200 microM)-induced morphological changes characteristic of apoptosis/necrosis in cultures pretreated with QCT (100 microg/ml). Also, results of tyrosine hydroxylase immunoreactivity indicated that 6-OHDA induces cell death in mesencephalic cultures affecting both TH+ positive and TH- negative (TH+ and TH-, respectively) and QCT pretreatment protects them from cell death, in a non-specific manner. Our data indicate that QCT has a cytoprotective role due, at least in part, to an antioxidant and free radical scavenging mechanism. Furthermore, the study suggests that inositol compounds might serve as leads in developing drugs for the treatment of various neurodegenerative disorders.     

6-羟基多巴胺诱导PC12细胞释放谷氨酸及死亡不受Ⅰ组亲代谢型谷氨酸受体配基的影响(英文)

目的:探讨Ⅰ组亲代谢型谷氨酸受体(mGluR)配基对6-羟基多巴胺(6-OHDA)诱导的PC12细胞死亡及谷氨酸(Glu)释放的影响。方法:培养PC12细胞,以100μmol/LⅠ组mGluR激动剂(RS)-3,5-dihydroxyphenylglycine(DHPG)和拮抗剂DL-2-amino-3-phosphonopropionic acid(DL-AP3)预先剌激细胞1h,再加入6-OHDA100μmol/L共孵育24h,显微镜下观察细胞形态变化,用TUNEL法检测凋亡细胞,用噻唑蓝(MTT)法检测细胞存活率,并用高效液相色谱检测Glu的释放量。结果:6-OHDA 降低PC12细胞存活率(P<0.01),其诱导的Glu释放呈浓度和时间依赖性。Ⅰ组mGluR配基不能减少6-OHDA引起的PC12细胞死亡,也不影响6OHDA引起的Glu释放量。结论:Ⅰ组mGluR配基对6-OHDA引起死亡的PC12细胞无保护作用。     

Protective effect of Lepidium sativum seed extract against hydrogen peroxide-induced cytotoxicity and oxidative stress in human liver cells (HepG2)

Context: Garden cress [Lepidium sativum (Brassicaceae)] has been widely used to treat a number of ailments in traditional medicine. The pharmacological and preventive potential of Lepidium sativum, such as anti-inflammatory, antipyretic, antihypertensive, anti-ashthamatic, anticancer, and anti-oxidant, are well known.

Objective: The present investigation was designed to study the protective effects of chloroform extract of Lepidium sativum seed (LSE) against oxidative stress and cytotoxicity induced by hydrogen peroxide (H₂O₂) in human liver cells (HepG2).

Materials and methods: Cytotoxicity of LSE and H₂O₂ was identified by (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT), neutral red uptake (NRU) assays, and morphological changes in HepG2. The cells were pre-exposed to biologically safe concentrations (5–25?μg/ml) of LSE for 24 h, and then cytotoxic (0.25 mM) concentration of H₂O₂ was added. After 24 h of the exposures, cell viability by MTT, NRU assays, and morphological changes in HepG2 were evaluated. Further, protective effects of LSE on reactive oxygen species (ROS) generation, mitochondrial membrane potential (MMP), lipid peroxidation (LPO), and reduced glutathione (GSH) levels induced by H₂O₂ were studied.

Results: Pre-exposure of LSE significantly attenuated the loss of cell viability up to 48% at 25?µg/ml concentration against H₂O₂ (LD₅₀ value?=?2.5?mM). Results also showed that LSE at 25?µg/ml concentration significantly inhibited the induction of ROS generation (45%) and LPO (56%), and increases the MMP (55%) and GSH levels (46%).

Discussion and conclusion: The study suggests the cytoprotective effects of LSE against H₂O₂-induced toxicity in HepG2. The results also demonstrate the anti-oxidative nature of LSE.     

Characterization of myrtle seed (Myrtus communis var. baetica) as a source of lipids,phenolics, and antioxidant activities

This study aimed to characterize the chemical composition and antioxidant activity of the oil and the methanolic extract of Myrtus communis var. baetica seed. The oil yield of myrtle seed was 8.90%, with the amount of neutral lipid, especially triacylglycerol, being the highest, followed by phospholipids and glycolipids. Total lipids and all lipid classes were rich in linoleic acid. The content of total phenols, flavonoids, tannins, and proanthocyanidins of the methanolic extract and the oil from myrtle seed was determined using spectrophotometric methods. Antioxidant activities of the oil and the methanolic extract from myrtle seed were evaluated using 1,1-diphenyl-2-picrylhydrazyl radical scavenging, β-carotene–linoleic acid bleaching, and reducing power and metal chelating activity assays. In all tests, the methanolic extract of myrtle seed showed better antioxidant activity than oil. This investigation could suggest the use of myrtle seed in food, industrial, and biomedical applications for its potential metabolites and antioxidant abilities.     

In vitro hepatoprotective and antioxidant activities of crude extract and isolated compounds from Ficus gnaphalocarpa

The in vitro hepatoprotective effect of the methanolic extract from Ficus gnaphalocarpa (Miq.) Steud. ex A. Rich (Moraceae) on the CCl?-induced liver cell damage as well as the possible antioxidant mechanisms involved in this protective effect, were investigated. The phytochemical investigation of this methanolic extract led to the isolation of six compounds identified as: betulinic acid (1); 3-methoxyquercetin (2); catechin (3); epicatechin (4); quercetin (5); and quercitrin (6). The hepatoprotective activity of these compounds was tested in vitro against CCl?-induced damage in rat hepatoma cells. In addition, radical-scavenging activity, β-carotene-linoleic acid model system, ferric-reducing antioxidant parameter and microsomal lipid peroxidation assays were used to measure antioxidant activity of crude extract and isolated compounds. Silymarin and trolox were used as standard references and, respectively, exhibited significant hepatoprotective and antioxidant activities. (5), (6) and (2) showed significant antioxidant and hepatoprotective activities as indicated by their ability to prevent liver cell death and lactate dehydrogenase leakage during CCl? intoxication. These results suggest that the protective effects of crude extract of F. gnaphalocarpa against the CCl?-induced hepatotoxicity possibly involve the antioxidant effect of these compounds.     

Effects of macamides on endurance capacity and anti-fatigue property in prolonged swimming mice

Context: Lepidium meyenii Walp. (Brassicaceae), most commonly known as “maca”, has been used as a food or folk medicine to improve vitality in Peru. Previous research demonstrated that lipid-soluble extract from maca improved swimming endurance capacity. Macamides are considered the typical lipid-soluble markers for maca and proved to have several pharmacological properties, such as improving sexual performance and neuroprotective activies.

Objective: The present study investigates the effects of macamides on endurance capacity and anti-fatigue property in prolonged swimming mice.

Materials and methods: The Balb/c mice were divided into seven groups: a control group, low-dose groups of N-benzyllinoleamide, N-benzyloleamide, and N-benzylpalmitamide, high-dose groups of these macamides. The macamides groups received the commercial products (12 and 40?mg/kg, ig), while the control group received vehicle for 21 d. On the 14th day, the mice were given the weight-loaded swimming test. On the 21st day, the mice were sacrificed immediately after 90?min swimming, and some biochemical parameters were measured.

Results and discussion: Compared with the control group, exhaustive swimming time was significantly prolonged in high-dose group of N-benzyloleamide (p?<?0.05); the levels of lactic acid (LD), blood ammonia (BA), and lactate dehydrogenase (LDH) were significantly decreased (p?<?0.05), whereas the levels of liver glycogen (LG) and non-esterified fatty acid (NEFA) were significantly increased (p?<?0.05) in high-dose group of N-benzyloleamide. The malondialdehyde (MDA) contents in the brain, muscle, and liver were significantly decreased (p?<?0.05), whereas superoxide dismutase (SOD) and glutathione peroxidase (GSH-PX) activities in the brain, muscle, and liver were significantly increased in high-dose group of N-benzyloleamide (p?<?0.05).

Conclusion: The results indicate that N-benzyloleamide has pharmaceutical property against exercise-induced fatigue, and this effect can be explained by the modulated energy metabolism and improved antioxidant status.     

The Raf-1 inhibitor GW5074 and the ERK1/2 pathway inhibitor U0126 ameliorate PC12 cells apoptosis induced by 6-hydroxydopamine

6-Hydroxydopamine (6-OHDA) is a widely used dopaminergic neurotoxin that leads to cell apoptosis in vivo and in vitro, and is a widely accepted experimental model of neurodegeneration in Parkinson's disease. However, the molecular mechanisms responsible for 6-OHDA-induced cell apoptosis are unclear. We found that the treatment of PC12 cells with 6-OHDA resulted in a significant decrease in cell viability and elevated apoptosis as detected by MTT assay, Hoechst 33258 staining, and flow cytometry. In addition, 6-OHDA induced a time-dependent phosphorylation of ERK1/2 at Thr-202/Tyr-204 and of Raf-1 at Ser-338, but a decreased level of Raf-1 phosphorylation at Ser-259. Phosphorylation of ERK1/2 at Thr-202/Tyr-204 and Raf-1 at Ser-338 were inhibited by the Raf-1 inhibitor GW5074, while the ERK1/2 pathway inhibitor U0126 decreased phosphorylation of ERK1/2. Furthermore, 6-OHDA-induced PC12 cells apoptosis was suppressed by GW5074 and U0126. Our results suggest that GW5074 and U0126 act as neuroprotants against 6-OHDA toxicity in PC12 cells by modulating Raf-1/ERK1/2 signaling systems.     

Effect of ethanolic extract of Lepidium meyenii Walp on serum hormone levels in ovariectomized rats

Objective:

To evaluate the effect of long-term ethanol extract of Lepidium meyenii (Maca) on serum hormone levels in ovariectomized (OVX) rats and compare them with the effect of diethylstilbestrol.

Materials and Methods:

Fifty female Sprague-Dawley rats were ovariectomized or sham operated. Both sham and OVX control groups (n = 10, respectively) received the vehicle. The remaining OVX rats were oral administrated with ethanol extract of Maca (0.096, or 0.24g/kg; n = 10, respectively) and diethylstilbestrol (0.05 mg/kg; n = 10). The treatment continued for 28 weeks. At week 12 and week 28, the blood of rats was collected and serum hormone levels, including estradiol (E2), testosterone (T) and follicle-stimulating hormone (FSH) were measured by radioimmunoassay.

Results:

At week 12, the levels of serum E2 were slightly higher in Maca groups than that in OVX group; T levels were significantly decreased; and FSH levels were advanced slightly in Maca groups than that in sham group. After 28 weeks administration, serum E2 levels in Maca-treated animals did not differ significantly from sham control, the low dose of Maca increased serum E2 levels, and Maca prevented increase in serum FSH levels compared with OVX group.

Conclusions:

Long-term Maca supply modulates endocrine hormone balance in OVX rats, especially it decreases enhanced FSH levels. It is proposed that Maca may become a potential choice for postmenopausal women.KEY WORDS: Lepidium meyenii, maca, ovariectomized rats, serum hormone