The use of Lepidium sativum in a plant bioassay system for the detection of microcystin-LR.

Toxin-producing cyanobacteria pose a worldwide health threat to humans and animals due to their increasing presence in both drinking and recreational waters. Detection of microcystins in water generally relies on specialised equipment and a delay of several days for transport and analysis. Little work has, however, been done on establishing a simple, cost-effective and sensitive plant bioassay for the detection of microcystin-LR (MCLR) in water at the WHO Tolerable Daily Intake guideline level of 1 microg/l. We investigated the effect of a MCLR extract at 1 and 10 microg/l on the growth of Lepidium sativum over 6 days. Exposure to 10 microg/l MCLR resulted in a significant decrease in root and leaf lengths and fresh weights of seedlings when compared to the controls. These results were consistent with seedlings exposed to pure MCLR at 10 microg/l. Seedlings exposed to 1 microg/l MCLR showed a significant decrease in root development from day 2 to day 6. Glutathione S-transferase and glutathione peroxidase activities were also significantly raised in plants from days 5 and 4, respectively, at both toxin levels investigated.     

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。     

玛咖酰胺研究进展

玛咖因其丰富的营养价值和多样的药用价值被作为食品和传统药材长期食用。玛咖酰胺为其特征性化合物,是一系列非极性长链脂肪酸的氮苄基酰胺类化合物,具有神经保护及神经系统调节等活性。综述了玛咖酰胺的种类,及其化学合成、检测方法、生物活性的国内外研究进展,为进一步研究及开发利用提供参考。     

玛咖醇提取物对小鼠的抗衰老作用

目的探讨玛咖醇提取物的抗衰老作用及其机制。方法采用自然衰老小鼠为模型,连续ig给予玛咖醇提取物60 d后,测定小鼠血清、肝脏、心脏组织中谷胱甘肽过氧化物酶(G SH-Px)、超氧化物歧化酶(SOD)活性和丙二醛(M DA)的水平以及皮肤羟脯氨酸水平,免疫功能实验采用PHA刺激淋巴细胞转化及免疫器官指数的方法。结果玛咖醇提取物能显著提高老龄小鼠心脏和肝脏中G SH-Px活性及血清和肝脏中SOD活性,降低血清及肝脏中M DA水平,增加皮肤羟脯氨酸水平,提高PHA刺激的淋巴细胞转化率。结论玛咖醇提取物可能通过改善自由基代谢、增强细胞免疫发挥其抗衰老作用。     

中国十字花科独行菜属植物的叶表皮特征研究

目的:对中国十字花科独行菜属植物进行分类鉴别研究。方法:利用光学显微镜和扫描电镜观察了中国十字花科独行菜属10种植物的叶表皮形态。结果:独行菜属植物气孔器在叶上、下表皮均有分布,气孔类型主要为不等细胞型,其次为无规则型,在少数植物种类中偶见平列型;叶表皮细胞形状为多边形或不规则形,垂周壁一般为平直或弓形、浅波、波状;独行菜属植物在叶表皮特征上具有较强的一致性,同一种植物叶上、下表皮同形或近同形,叶表面仅被单毛或无毛;扫描电镜下叶片角质层通常具有条状波纹,气孔外拱盖内缘通常为浅波状或近平滑。叶表皮细胞形态、垂周壁式样、气孔类型、气孔指数与气孔器大小以及叶片角质层特征等对该属种的区分具有重要的参考价值。结论:叶表皮特征研究可用于中国独行菜属种间分类鉴别研究,为该属药用植物资源的合理应用和开发提供了新的依据。     

Maca (Lepidium meyenii) for treatment of menopausal symptoms: A systematic review

Maca (Lepidium meyenii), an Andean plant of the brassica (mustard) family has been used for centuries in the Andes as an adaptogenic plant to manage anemia, infertility and female hormone balance. The aim of this review was to assess the evidence for and against the effectiveness of the maca plant as a treatment for menopausal symptoms. We searched 17 databases from their inception up to June 2011 and included all randomized clinical trials (RCTs) that compared any type of maca-based intervention to a placebo for the treatment of menopausal symptoms. All studies were assessed for methodological quality using the Cochrane ‘risk of bias’ assessment tool. Four RCTs met all inclusion criteria. These RCTs tested the effects of maca on menopausal symptoms in healthy perimenopausal, early postmenopausal, and late postmenopausal women. Using the Kupperman Menopausal Index and the Greene Climacteric Score, all RCTs demonstrated favorable effects of maca. There have been very few rigorous trials of maca for menopausal symptoms. The results of our systematic review provide limited evidence for the effectiveness of maca as a treatment for menopausal symptoms. However, the total number of trials, the total sample size, and the average methodological quality of the primary studies, were too limited to draw firm conclusions. Furthermore, the safety has not been proved yet. Therefore, the efficacy and safety should be tested in larger studies.     

A double-blind, randomized, pilot dose-finding study of maca root (L. meyenii) for the management of SSRI-induced sexual dysfunction

We sought to determine whether maca, a Peruvian plant, is effective for selective-serotonin reuptake inhibitor (SSRI)-induced sexual dysfunction. We conducted a double-blind, randomized, parallel group dose-finding pilot study comparing a low-dose (1.5 g/day) to a high-dose (3.0 g/day) maca regimen in 20 remitted depressed outpatients (mean age 36 ± 13 years; 17 women) with SSRI-induced sexual dysfunction. The Arizona Sexual Experience Scale (ASEX) and the Massachusetts General Hospital Sexual Function Questionnaire (MGH-SFQ) were used to measure sexual dysfunction. Ten subjects completed the study, and 16 subjects (9 on 3.0 g/day; 7 on 1.5 g/day) were eligible for intent-to-treat (ITT) analyses on the basis of having had at least one postbaseline visit. ITT subjects on 3.0 g/day maca had a significant improvement in ASEX (from 22.8 ± 3.8 to 16.9 ± 6.2; z =−2.20, P = 0.028) and in MGH-SFQ scores (from 24.1 ± 1.9 to 17.0 ± 5.7; z =−2.39, P = 0.017), but subjects on 1.5 g/day maca did not. Libido improved significantly ( P < 0.05) for the ITT and completer groups based on ASEX item #1, but not by dosing groups. Maca was well tolerated. Maca root may alleviate SSRI-induced sexual dysfunction, and there may be a dose-related effect. Maca may also have a beneficial effect on libido.     

玛咔根脂溶性部位化学成分研究

目的:研究玛咔根脂溶性部位的化学成分。方法:通过研究不同的提取方法,包括超临界CO2萃取法、回流提取法、水蒸气蒸馏法,提取得到玛咔根脂溶性部位并对其进行化学成分研究。结果:通过GC-MS分析,超临界CO2萃取法、回流提取法(石油醚、80%乙醇)、水蒸气蒸馏法(包括比重大于1与小于1部位)分离鉴定的化合物数目分别为38、31、14、21(比重小于1部位)、25(比重大于1部位),分别占其脂溶性样品总量的85.79%、81.18%、62.08%、98.36%(比重小于1部位)、81.54%(比重大于1部位)。结论:该结果为玛咔的进一步深入研究与开发奠定了一定基础。     

Maca extracts and estrogen replacement therapy in ovariectomized rats exposed at high altitude

PurposeHormone Replacement Therapy (HRT) and herbal remedies are often used to alleviate menopausal symptoms, but their effects and efficacy at high altitudes presents with several uncertainties. The purpose of this study was to evaluate whether pre‐treatment with maca (Lepidium meyenii Walp) improved the tolerance to high altitude on an ovariectomized (OVX) rat model at sea level.MethodThe animals were treated with 17β‐estradiol (200 µg/kg; E2), red and black maca (1.5 g/kg) for 28 days and exposed at high altitude or sea level.ResultOur findings showed that red and black maca extracts significantly (P < .001) reduced the MDA level in OVX rat serum under hypoxia in a similar way to E2. Red and black maca extracts had similar effects with E2, by significantly (P < .001) reversing and increasing the ovariectomized induced decrease in cornified endometrial cell number. Under hypoxic conditions, the black maca (P < .05) and E2 (P < .01) increased the uterine weight in OVX rats. Finally, E2 alone significantly recovered the frequency of the uterine contractile response.ConclusionAqueous extract of L. meyenii partially protects the reproductive function in hypobaric hypoxic environment, through the recovery of the cornified endometrial cells and uterine weight in a menopausal model of OVX rats.     

Effect of Black maca (Lepidium meyenii) on one spermatogenic cycle in rats

Lepidium meyenii (Maca) grows exclusively between 4000 and 4500 m above sea level in the Peruvian central Andes. The hypocotyls of this plant are traditionally used in the Andean region for their supposed fertility-enhancing properties. The hypocotyls have different colours. Of these, Black maca has better effects on spermatogenesis. The present study aimed to test the hypothesis that Black maca has early effects during a spermatogenic cycle (12 days) of male rats. For this, testicular spermatid, epididymal sperm and vas deferens sperm counts were measured after 1, 3, 5, 7 and 12 days of treatment with Black maca. Aqueous extract of Black maca was given orally by daily gavage at a dose of 2 g kg(-1). In a spermatogenic cycle, compared with day 1, daily sperm production (DSP) was lower at day 7 (control), whereas with Black maca, the difference was observed at day 12. Epididymal sperm count was higher in rats treated with Black maca at days 1, 3 and 7, but similar to controls at days 5 and 12; similarly sperm counts in vas deferens was higher in rats treated with Black maca in days 3, 5 and 7, but similar to controls at days 1 and 12. From this, it is suggested that first action of Black maca was at epididymal level increasing sperm count after 1 day of treatment, whereas an increase in sperm count was observed in vas deferens at day 3 of treatment. Finally, an increase in DSP was observed after 7 days of treatment with Black maca. Testicular testosterone was not affected after 7 days treatment with Black maca. In conclusion, Black maca affects sperm count as early as 1 day after beginning of treatment.