Biological activity of tree marigold, Tithonia diversifolia, on cowpea seed bruchid, Callosobruchus maculatus (Coleoptera: Bruchidae)

The powder and ethanol extract of Tithonia diversifolia leaves were tested for their efficacy at five different concentrations (0.0%, 0.5%, 1.0%, 1.5% and 2.0%) on bruchid mortality, oviposition and adult emergence of cowpea seed beetle Callosobruchus maculatus at ambient tropical storage conditions of temperature and relative humidity. Results showed that the leaf extract had a higher bioactivity on oviposition, adult emergence and mortality of C. maculatus. The mean number of eggs laid on seeds treated with extract was reduced from 20.7 in the solvent-treated to 4.7 at 2%Tithonia extract concentration while adult emergence reduced from a mean of 92.2 in the solvent-treated seeds to 72.2 at 2.0% extract treatment. Mortality was 100% at higher concentrations of 3%, 4% and 5% within 24 h of extract application but at lower concentrations mortality was 73.3% and 93.3% at 1% and 2%, respectively after 24 h. Fourty-eight hours after application, 100% mortality of adult C. maculatus was obtained at all concentrations. The mean number of eggs laid was reduced from 41.3 in the untreated to 17.3 at 2.0% powder concentration while adult emergence dropped from 98.5% in the control to 74.2% at the highest powder concentration. The powder was effective at higher concentrations and longer exposure time. At 3%, 4% and 5%, 63–75% mortalities occurred within 24 h of application while at 48 h, mortality was 76–98% at 3–5% powder application rates. The results of this study revealed T. diversifolia as a potential candidate for bioinsecticide preparations because of antiovipositional, ovicidal and knockdown properties of its products, which have some volatile components.     

蛇床子素粉剂对玉米象成虫的杀虫活性及酶活性的影响

研究1.0%蛇床子素(osthole)粉剂对玉米象Sitophilus zeamais Motschusky成虫的杀虫活性及其对玉米象成虫羧酸酯酶、乙酰胆碱酯酶、谷胱甘肽S-转移酶及蛋白质活性的影响。结果表明,1.0%蛇床子素粉剂对玉米象成虫有很好的杀虫活性,处理玉米象成虫3d后,0.8mg/kg以上剂量的蛇床子素粉剂对玉米象成虫的校正死亡率达100%;用0.19mg/kg蛇床子素粉剂处理玉米象成虫2d后,试虫体内乙酰胆碱酯酶、羧酸酯酶和蛋白质活性均表现出受抑制,而谷胱甘肽S-转移酶活性随处理时间的延长整体趋势表现出被诱导。     

Effect of spice essential oils on growth and aflatoxin B1 production by Aspergillus flavus

Aflatoxin B¹ production by Aspergillus flavus was studied in yeast extract sucrose broth in the presence of cinnamon, clove, almond and cardamom oils. Growth and aflatoxin B₁ production was inhibited by 0.5 μl cinnamon oil ml^-1 medium and by 1 μl clove oil ml_-1. Almond and cardamom oils only affected growth when their concentration exceeded 1.25 μl ml^-1 medium. Aflatoxin B₁ production was stimulated by 0.75 and 1 μl almond oil ml^-1 medium or by 0.25 and 0.5 μl cardamom oil ml^-1.     

Protectability of nine Nigerian medicinal plants against cowpea beetle,Callosobruchus maculatus (Fab.) (Coleoptera: Bruchiidae) in storage

A study was conducted to examine the protectability of nine Nigerian medicinal plants against Callosobruchus maculatus at an ambient temperature of 28?±?2?°C and relative humidity of 70?±?5%. The nine plants used were dried and milled into fine powder before application. Among the nine plant powders used, Zanthoxylum zanthoxyloides effected highest mortality rate of 73.40 and 100% at 5% (wt/wt) concentration within two and three days of application, respectively. The effect of this plant at this level of concentration was significantly (p?<?0.05) different from other plants. However, all the plant powders effected high mortality rate as they all achieved more than 50% beetle mortality within four days of application at 20% (wt/wt) concentration. Only the powder of Z. zanthoxyloides at 10% (wt/wt) concentration was able to achieve 0% adult emergence, 0% seed damage and 100% damage reduction. Moreover, powder of Z. zanthoxyloides, Aristolochia ringens and Colocasia esculenta at 20% (wt/wt) was also able to prevent the emergence of adult C. maculatus, prevent seed damage and achieve 100% damage reduction. All the powders had low weevil perforation index when compared to the control which had above 50% weevil perforation index. At all levels of concentration, the effect of the powders was significantly (p?<?0.05) different from the control. However, Z. xanthoxyloides appeared to be the most effective; therefore, the effective utilisation of Z. xanthoxyloides as a botanical pesticide could minimise the use of hazardous chemicals in stored product pest control since it is of a botanical source.     

White shrimp Litopenaeus vannamei immersed in seawater containing Sargassum hemiphyllum var. chinense powder and its extract showed increased immunity and resistance against Vibrio alginolyticus and white spot syndrome virus

This study was to examine the immune response of white shrimp Litopenaeus vannamei and its resistance against Vibrio alginolyticus and WSSV when shrimp received the Sargassum hemiphyllum var. chinense powder and its hot-water extract. Both powder and extract showed activation of prophenoloxidase and generation of superoxide anion in the shrimp in vitro. The haemocyte count, phenoloxidase (PO) activity, respiratory burst, and lysozyme activity were examined after the shrimp were immersed in seawater containing S. hemiphyllum var. chinense powder or its extract at 0, 100, 300, and 500 mg L?1 for 1, 3, and 5 h. These immune parameters of shrimp immersed in 300 and 500 mg L?1 powder, and 100 and 300 mg L?1 extract were significantly higher than those of control shrimp after 3 h, but slightly decreased after 5 h. In another experiment, shrimp immersed in seawater containing the powder or the extract at 0, 100, 300, and 500 mg L?1 after 3 h were challenged with V. alginolyticus at 8 × 10? colony-forming unit (cfu) shrimp?1, or challenged with WSSV at 1 × 10? copies shrimp?1, and then placed in seawater. Survival rate of shrimp immersed in 500 mg L?1 powder was significantly higher than that of control shrimp after 24-120 h in the V. alginolyticus-challenge test, and after 72 h in the WSSV-challenge test, respectively. Survival rate of shrimp immersed in 300 mg L?1 extract was significantly higher than that of control shrimp after 72-120 h in both V. alginolyticus-challenge and WSSV-challenge tests. It was concluded that the shrimp immersed in seawater containing the powder at 500 mg L?1, and the extract at 300 mg L?1 had increased immunity and resistance against V. alginolyticus infection, and the shrimp that received extract at 300 mg L?1 showed resistance against WSSV infection.     

An ATP-synthesizing system in seeds

Using onion seed powder, a semi-in vitro system for ATP synthesis in seeds has been developed. The system requires AMP, phosphoenolpyruvate (PEP) and orthophosphate with apparent Km values of 0.8, 1.5 and 3.0 mM, respectively. ATP synthesis is pH-dependent with a sharp optimum at pH 6.4, it exhibits linearity with time up to 40 min, and with a seed powder concentration between 25 and 150 mg ml^-1. The system is stimulated by low concentrations (<25 mM) of K⁺ and Mg²⁺ but is inhibited by higher concentrations of K⁺ and Mg²⁺ as well as by low concentrations of Li⁺, Na⁺ and especially Ca²⁺. The maximal rate is about 5 pmol min^-1 mg seed powder^-1 in dry onion seeds. During seed imbibition the rate of activity increases by about 120% after 3 h, reaching a plateau which is steady up to 18 h, when the radicle emerges. A comparison of the ATP content in seeds during the early period of imbibition with the capacity of ATP synthesis at this stage reveals that the described system could provide, during germination, 100 times more ATP than that found in imbibed seeds. The system is shown to be present in ten different types of seeds.     

The effects of clove oil on coral: An experimental evaluation using Pocillopora damicornis (Linnaeus)

Clove oil solution (10% clove oil, 90% ethanol) is an anaesthetic that is widely used to catch demersal fish on coral reefs. This study assessed the effects of clove oil solution on colonies of Pocillopora damicornis, a cosmopolitan reef coral. In the laboratory, low concentrations (0.5 ppt) of clove oil solution had no effect on coral colour or photosynthetic efficiency, irrespective of exposure time (1-60 min). Corals treated with high concentrations (50 ppt) of clove oil solution died immediately, including those that were exposed briefly (1 min). Intermediate concentrations (5 ppt) of clove oil solution produced variable results: a 1 min exposure had no effect, a 10 min exposure caused bleaching and reduced photosynthetic efficiency, and a 60 min exposure caused total mortality. To validate these observations, clove oil solution was applied to corals in situ. Sixty-three days after application, corals treated with 10 ml of clove oil solution appeared to be unaffected. It was concluded that (1) limited amounts of clove oil solution are unlikely to harm this coral, and (2) clove oil solution may represent an ‘eco-friendly’ alternative to cyanide for use in the live reef-fish trade.     

Observations on the suppression of root-knot nematode (Meloidogyne arenaria) on tomato by incorporation of cyanobacterial powder (Oscillatoria chlorina) into potting field soil

Experiments were carried out to investigate the nematicidal potential of a cyanobacterium, Oscillatoria chlorina, against the root-knot nematode, Meloidogyne arenaria on tomato plants grown in pots filled with 500 cm3 of field soil infested with 12-s stage juveniles (J2)/cm3 soil. Incorporation of freeze-dried cyanobacterial powder into potted field soil at the rate of 0.2%, 0.4%, 0.6%, 0.8% and 1.0% (w/w) 5 days prior to tomato planting, reduced root galling, final population of M. arenaria and increased vegetative growth of tomato plants and root-mass production, compared with untreated control (P > or = 0.05). The beneficial effect of adding cyanobacterial powder into infested potted field soil increased exponentially with concentration up to 0.8%. Root galling and nematode population decreased by 68.9% and 97.6%, respectively at the highest dose (1%) of cyanobacterial powder compared with the untreated control. Addition of cyanobacterial powder into infested potted field soil at 5 days before planting was the most effective followed by 2 days before and at the time of tomato planting. We conclude that application rate and timing are important factors in the control of root-knot nematodes with O. chlorina.     

制首乌醇提物及其主要成分大黄素对斑马鱼非酒精性脂肪肝的治疗作用

研究制首乌醇提物及其主要成分大黄素对斑马鱼非酒精性脂肪肝疾病(non-alcoholic fatty liver disease, NAFLD)的治疗作用。选取野生型斑马鱼若干,随机均分为对照组、模型组、制首乌醇提物(RPMP)组和大黄素(emodin)组,于胚胎受精后5天,对照组给于普通饲料AP100,模型组给予2 mg/mL蛋黄粉(EY powder),制首乌醇提物组分别给予2 mg/mL蛋黄粉与低剂量组(1 mg/mL)、中剂量组(1.5 mg/mL)、高剂量组(2 mg/mL),大黄素组分别给予2 mg/mL蛋黄粉与低剂量组(0.25μg/mL)、中剂量组(0.5μg/mL)、高剂量组(1μg/mL)。72 h后观察斑马鱼存活率和体重、体长、BMI的变化■,用整体油红染色评判脂肪肝发生率,石蜡切片观察肝组织病理形态,甘油三酯(TG)、总胆固醇(TC)试剂盒判断斑马鱼体脂含量。制首乌醇提物组与大黄素组能显著降低非酒精性脂肪肝斑马鱼的死亡率、BMI、TG含量,并显著改善斑马鱼幼鱼肝脏脂质沉积情况(P<0.05)。由此可见制首乌醇提物与大黄素可有效治疗斑马鱼NAFLD,且大黄素可能为制首乌治疗NAFLD的主要有效成分。     

印楝种子提取物对荔枝蝽的毒性及与其等位酶基因型之间的关系

用5.2 mg/mL（LC₅₀）的印楝种子提取物对荔枝蝽1龄若虫进行急性毒性处理,24 h死亡率为51.8%。通过等位酶分析检测了死亡与存活试虫两种酶（PGI和MDH）,两个基因座（Pgi和Mdh）上各基因型及等位基因与印楝种子提取物毒性之间的关系,进行致死性差异比较研究。结果表明,印楝种子提取物对具有不同基因型及等位基因个体的致死性存在差异。在Pgi基因座上,Pgi-bb基因型死亡率最高,为84%,Pgi-aa 和Pgi-cc基因型死亡率较低,分别为0和7%,且与死亡率最高的Pgi-bb基因型存在显著差异（P<0.05）。在基因座Mdh上,Mdh-aa基因型个体死亡率最高（93%）,而具有Mdh-cc基因型的个体全部存活了下来, 另外3个基因型Mdh-ab、Mdh-bb与Mdh-bc死亡率居中,都与Mdh-aa、Mdh-cc基因型死亡率之间存在显著差异。在等位基因上,Pgi-a和Mdh-c个体的死亡率都最低,与各自其他两个等位基因的死亡率之间存在显著差异。结果说明不同基因型个体对印楝提取物具有不同的反应,印楝种子提取物对荔枝蝽等位酶基因型及等位基因存在选择性致死作用。这种荔枝蝽对印楝种子提取物的敏感性与其等位酶基因型及等位基因之间显明的相关关系提示我们,可将荔枝蝽种群中对印楝种子提取物敏感性低的基因型及等位基因作为遗传标记去监测荔枝蝽对印楝种子提取物的抗性状况。     

Importance of seed Zn content for wheat growth on Zn-deficient soil

Seed nutrient reserves may be important for an early establishment of crops on low-fertility soils. This glasshouse pot study evaluated effects of seed Zn content on vegetative growth of two wheat (Triticum aestivum L.) genotypes differing in Zn efficiency. Low-Zn (around 250 ng Zn per seed) and high-Zn seed (around 700 ng Zn per seed on average) of Excalibur (Zn efficient) and Gatcher (Zn inefficient) wheats were sown in a Zn-deficient siliceous sand fertilised with 0, 0.05, 0.2, 0.8 or 3.2 mg Zn kg^-1 soil. After 3 weeks, plants derived from the high-Zn seed had better root and shoot growth; the cv. Excalibur accumulated more shoot dry matter than the cv. Gatcher. After 6 weeks, greater root and shoot growth of plants grown from the high-Zn seed compared to those from the low-Zn seed was obvious only at nil Zn fertilisation. A fertilisation rate of 0.2 mg Zn kg^-1 soil was required for achieving 90% of the maximum yield for plants grown from the high-Zn seed compared to 0.8 mg Zn kg^-1 soil for plants derived from the low Zn seed. The critical Zn level in youngest expanded leaves for 90% maximum yield was 16 mg Zn kg^-1 dry matter for both genotypes. Zn-efficient Excalibur had greater net Zn uptake rates compared to Zn-inefficient Gatcher after 3 weeks but they were not different at the 6-week harvest. Zinc-deficient plants had greater net uptake rates of Cu, Mn, B, P, and K but a reduced uptake rate of Fe. It is concluded that higher seed Zn content acted similar to a starter-fertiliser effect by improving vegetative growth and dissipating differences in Zn efficiency of wheat genotypes.     

四种植物精油对黑翅土白蚁触杀和驱避作用

为筛选出高效防治黑翅土白蚁的天然植物精油,减少有机合成农药的使用,该文研究了大蒜精油、肉桂油、丁香油和印楝素油四种植物精油对黑翅土白蚁的触杀效果和驱避作用。结果表明:大蒜精油、肉桂油和丁香油的浓度为5和10 mg·m L~(-1)时,处理2 h后,黑翅土白蚁的校正死亡率达100%,而相同浓度的印楝素油和对照处理的黑翅土白蚁校正死亡率低于5%。随着处理时间延长,浓度为1.25和2.5 mg·m L~(-1)的大蒜精油、肉桂油和丁香油处理6 h时,黑翅土白蚁的校正死亡率仍达100%,而此时对应的印楝素油和对照处理的黑翅土白蚁校正死亡率仅为10%,说明大蒜精油、肉桂油和丁香油对黑翅土白蚁具有较强的触杀效果。大蒜精油、丁香油和肉桂油在处理黑翅土白蚁2 h后LC_(50)值(半致死量)分别为1.572、1.05和1.03mg·m L~(-1),说明肉桂油对黑翅土白蚁的毒性相对最大,触杀效果最好。此外,10 mg·m L~(-1)的大蒜精油、肉桂油、丁香油和印楝素油的驱避试验表明,处理4、6、8和12 h后,大蒜精油、肉桂油和丁香油三精油处理区的黑翅土白蚁数均显著低于对照区的,驱避率总体93%,而对应的印楝素油的驱避率总体28.5%,表明大蒜精油、丁香油和肉桂油三种植物精油对黑翅土白蚁均有显著的驱避活性。综上可知,四种植物精油中大蒜精油、肉桂油和丁香油在防治黑翅土白蚁方面应用潜力很好,是开发绿色环保白蚁防治药剂的可选材料。     

Influence of Griffonia simplicifolia on male sexual behavior in rats: Behavioral and neurochemical study

The seeds of Griffonia simplicifolia Baill. are rich in 5-HTP (5-hydroxytryptophan), a direct precursor of the neurotransmitter serotonin. In the present study we investigated the influence of the plant extract on male sexual behavior. The seed extract was orally administered to Sprague-Dawley male rats at three dose levels (25, 50 and 100 mg/kg) both acutely and subchronically (daily for 9 days). Mating test with receptive female rats was performed 60 min after the acute treatment or the last dose when repetitively administered. Mount, intromission and ejaculation latencies and post-ejaculatory interval were recorded. Food intake and body weight were measured over the 9-day period of treatment. Microdialysis technique was used to detect the extracellular levels of serotonin (5-HT) and its metabolite 5-hydroxyindoleacetic acid (5-HIAA) in rat brain following the acute administration of the extract dosed at 100 mg/kg. The acute treatment significantly increased mount latency (at any dosage), intromission and ejaculation latencies (at 100 mg/kg) and post-ejaculatory interval (at 50 and 100 mg/kg). On the contrary the subchronic treatment failed to exert a significant influence on copulatory behavior. The daily administration of the extract dosed at 50 and 100 mg/kg for 9 days significantly reduced food intake and body weight. Finally in the microdialysis experiments we found a dramatic increase in 5-HT and its metabolite 5-HIAA.     

Cardioprotective mechanisms of Prunus cerasus (sour cherry) seed extract against ischemia-reperfusion-induced damage in isolated rat hearts

The effects of kernel extract obtained from sour cherry (Prunus cerasus) seed on the postischemic cardiac recovery were studied in isolated working rat hearts. Rats were treated with various daily doses of the extract for 14 days, and hearts were then isolated and subjected to 30 min of global ischemia followed by 120 min of reperfusion. The incidence of ventricular fibrillation (VF) and tachycardia (VT) fell from their control values of 92% and 100% to 50% (not significant) and 58% (not significant), 17% (P<0.05), and 25% (P<0.05) with the doses of 10 mg/kg and 30 mg/kg of the extract, respectively. Lower concentrations of the extract (1 and 5 mg/kg) failed to significantly reduce the incidence of VF and VT during reperfusion. Sour cherry seed kernel extract (10 and 30 mg/kg) significantly improved the postischemic recovery of cardiac function (coronary flow, aortic flow, and left ventricular developed pressure) during reperfusion. We have also demonstrated that the extract-induced protection in cardiac function significantly reflected in a reduction of infarct size. Immunohistochemistry indicates that a reduction in caspase-3 activity and apoptotic cells by the extract, beside other potential action mechanisms of proanthocyanidin, trans-resveratrol, and flavonoid components of the extract, could be responsible for the cardioprotection in ischemic-reperfused myocardium.     

Insecticidal efficacy of some plant powders and extracts against the Angoumois grain moth,Sitotroga cerealella (Olivier) (Lepidoptera: Gelechiidae)

Powder and extract from four plants were evaluated for their insecticidal efficacy against the Angoumois grain moth, Sitotroga cerealella (Olivier) in the laboratory at a temperature of 28 ± 2°C and a relative humidity of 75 ± 5%. The plants included Aristolochia ringens L., Khaya ivorensis (K.), Strophanthus hispidus (D.C.) and Zanthoxylum zanthoxyloides Lam. The powder was applied at the rate of 0.2, 0.4 and 0.6 g/20 g of paddy rice, while the extract was applied at the rate of 1%, 2% and 3%/20 g of paddy rice. Parameters evaluated were adult moth mortality, adult emergence and weight loss in treated paddy after infestation. Results shows that adult moth mortality increased as concentration of powder increased. Significant differences (p < 0.05) existed among the plant powders andthe concentration. A 100% mortality rate was obtained within 7 days when A. ringens was applied at 0.4 and 0.6 g/20 g of paddy. S. hispidus was able to effect 100% mortality only at 0.6 g. This shows that A. ringens had the greatest insecticidal activity while the least effective was K. ivorensis. Adult emergence shows that more adult S. cerealella emerged from the control (40.3) which was significantly higher (p < 0.05) than others. Fewer adults emerged from paddy treated with plant powder with the least in A. ringens. Generally, adult emergence reduced with an increase in the concentration of powder. The extract from all the four plants tested against S. cerealella was able to effect 100% mortality of the adult moths within 24 h of application at all concentrations. Significant differences (p < 0.05) existed among all the different plant powders in terms of weight loss. The weight loss in paddy was significantly higher (p < 0.05) in the control (57.7%) than others. Weight loss was least in paddy treated with A. ringens at 0.4g/20 g of paddy with 2.2%. Generally, weight loss decreased with increase in powder concentration. The treatment with the highest adult emergence (control) also had the highest weight loss, while the treatment with the lowest adult emergence (A. ringens) had the lowest weight loss.     

Application of neem seed kernel extracts result in mouthpart deformities and subsequent mortality in Nezara viridula (L.) (Hem: Pentatomidae)

Abstract:  The effect of topical application of neem seed kernel aqueous suspension (NSKAS) and neem seed kernel hexane extract (NSKHE) on 2-day-old fourth instar nymphs of Nezara viridula (L.) was studied under laboratory conditions. The applications resulted in loosening of the proboscis, along with separation and deformation of mouthparts, predominantly in the stylets in fifth instar nymphs, adults and in inter-stadial moults. This rendered the insects incapable of feeding and led them to death. Application of NSKAS at 2.5% concentration led to 100% mortality, of which 40% was due to mouthpart deformities. Application of NSKHE at 2.5% concentration led to only 70% mortality, of which 3.33% was due to mouthpart deformities. At 5% concentration, mortality was again 100% for NSKAS and reached close to 100% for the NSKHE application. Dose-dependent mortality was observed for both the applications. However, dose-dependent mouthpart deformities were observed only for NSKAS, the highest being 60% at the 5% concentration. Moreover, for both the applications, more than 50% of the total mortality was observed up to the fifth instar at almost all the concentrations. The LC₅₀ values for NSKAS and NSKHE applications, for mortality up to the fifth instar were 0.36% and 5.22%, and for mortality to the adult stage (10 days old) they were 0.23% and 1.32% respectively. The percentage of bugs showing mouthpart deformities and toxicity was higher for NSKAS than NSKHE, and indicated that NSKAS was more potent than NSKHE.     

Rubratoxin production by penicillium rubrum when grown in a synthetic medium containing different sources of carbon and nitrogen

A sterile mineral salts broth was fortified with different additives, inoculated with conidia ofPenicillium rubrum P-13, and incubated quiescently for 14 days or with shaking for 3 to 5 days. Maximal fungal growth and rubratoxin production occurred when the broth contained 20% sucrose. Broth with 10% glucose, 10% fructose, 5% maltose, or 1% asparagine supported formation of substantial amounts of rubratoxin (52.9–78.5 mg/100 ml). When the broth was fortified with glucose plus lysine, arginine aspartic acid, cystine, ammonium citrate, or ammonium phosphate, moderate amounts (27.5–39.5 mg/100 ml) of rubratoxin and mycelium (0.1–1.5 g/100 ml) were produced. Presence in the broth of 5% galactose or starch resulted in accumulation of small amounts (22.2 and 24.6 mg/100 ml, respectively) of rubratoxin and mold tissue (0.70 and 0.5 g/ 100 ml, respectively). Whereas some toxin was recovered from mineral salts broth fortified with lactose or ribose, toxin was not recovered when the mold grew in broth containing mannitol or fumarate. With the exception of gluconate which supported some growth and toxin formation and ethanol which permitted formation of small amounts of toxin, other carbon sources resulted in little or no fungal growth and no toxin formation. Yields of rubratoxin decreased with an increase in amount of agitation or length of incubation ofP. rubrum cultures. Mold growth increased and toxin formation decreased with an increase in volume of culture.     

Pathogenicity of the Hyphomycete Fungi Verticillium lecanii and Metarhizium anisopliae to the Western Flower Thrips,Frankliniella occidentalis

The pathogenicity of several isolates of the hyphomycete fungi Verticillium lecanii and Metarhizium anisopliae to Frankliniella occidentalis was investigated. Treatment of adult thrips with M. anisopliae resulted in at least 94% mortality at 7 days post-inoculation. In contrast, V. lecanii isolates only gave mortalities of between 20 and 70%. Detailed studies were made on the most virulent isolate of M. anisopliae (275) to determine its efficacy at different doses and temperatures. At 23 C the LC was ca. 3 105 conidia ml-1 after 5 days and the LTs were 50 50 3 and 4.5 days at 10 7 and 106 conidia ml-1 respectively. Temperature influenced fungal virulence to adult thrips; the LT at 18 and 20 C was ca. 4 days and at 23 or 26 C it was ca. 3 days. 50 Larvae were less susceptible to infection than adult thrips (27% versus 100% mortality), presumably due to the inoculum being shed with the exuvium during ecdysis. Conidia of M. anisopliae isolate 275 germinated rapidly on the surfaces of larvae, pupae and adults, with most germlings producing appressoria within 24 h post-inoculation. Fungal elements were present in significant amounts in the body 3 days after treatment.     

Grape Seed Extract Dose-Responsively Decreases Disease Severity in a Rat Model of Mucositis; Concomitantly Enhancing Chemotherapeutic Effectiveness in Colon Cancer Cells

Objective

Mucositis is a serious disorder of the gastrointestinal tract that results from cancer chemotherapy. We investigated the effects of increasing grape seed extract doses on the severity of chemotherapy in a rat model and its coincident impact on chemotherapeutic effectiveness in colon cancer cells.

Design

Female Dark Agouti rats were gavaged with grape seed extract (400–1000 mg/kg) or water (day 3–11) and were injected intraperitoneally with 5-Fluorouracil (150 mg/kg) or saline (control) on day 9 to induce mucositis. Daily metabolic data were collected and rats were sacrificed on day 12. Intestinal tissues were collected for histological and myeloperoxidase analyses. Caco-2 cell viability was examined in response to grape seed extract in combination with 5-Fluorouracil by 3-(4,5-Dimethylthiazol-2yl)-2,5-diphenyl-tetrazolium bromide) assay.

Results

Compared with 5-Fluorouracil controls, grape seed extract (400–1000 mg/kg) significantly decreased the histological damage score (P<0.05) in the jejunum. Grape seed extract (1000 mg/kg) increased jejunal crypt depth by 25% (P<0.05) in 5-Fluorouracil treated rats compared to 5-Fluorouracil controls, and attenuated the 5-Fluorouracil -induced reduction of mucosal thickness (25%, P<0.05). Grape seed extract (600 mg/kg) decreased myeloperoxidase activity by 55% (P<0.01) compared to 5-Fluorouracil controls. Grape seed extract was more effective at ameliorating 5-Fluorouracil induced intestinal injury, with effects most pronounced in the proximal jejunum. Grape seed extract (10–25 ug/mL) significantly enhanced the growth-inhibitory effects of 5-Fluorouracil by 26% (P<0.05) in Caco-2 cells and was more potent than 5-Fluorouracil at 50–100 µg/mL.

Conclusion

Grape seed extract may represent a new therapeutic option to decrease the symptoms of intestinal mucositis while concurrently impacting on the viability of colon cancer cells.     

In vitro germination and origin of thallus in Griffithella hookeriana (Podostemaceae)

Griffithella hookeriana (Tul.) Warm. (Podostemaceae) is a thalloid plant with no true leaves, stem or root. The seeds are extremely small (1000 seeds weigh 0.809 mg) and can be germinated on moist filter paper, but the resulting seedlings fail to survive beyond 5–6 days. A technique of germinating seeds in vitro on thermocole cubes floated in Murashige and Skoog's liquid medium (MS 1/5 strength with 0.5% sucrose) in continuous light (500–1000 lux) at 27±2°C has been developed. During germination, the radicular pole emerges from the seed coat and elongation of the two cotyledons follows. Rhizoids arise from the radicular pole and secrete a sticky substance that helps the seedling to adhere firmly to the substratum. The plumular apex ceases to funciton after producing 2 or 3 pairs of leaf-like outgrowths. A lateral protuberance is formed from the primary axis below the level of cotyledons and develops into a flat, green and oval, round or tubular (branched or unbranched) thallus (up to 0.5–0.8 cm in diameter) within 65–70 days. There is a high mortality of seedlings and plants at various stages of development: about 20% senesce before the initiation of the plumule, 15–20% after the formation of the leaf-like structures and 2–4% during the thallus stage. Seeds retain 83% viability for more than a year when stored dry at 10–15°C.