The use of Eucalyptus tereticornis Sm. (Myrtaceae) oil (leaf extract) as a natural larvicidal agent against the malaria vector Anopheles stephensi Liston (Diptera: Culicidae)

Secondary metabolites obtained from the indigenous plants with proven mosquito control potential can be used as an alternative to synthetic insecticides under the integrated vector control. The essential oil extract from the forest redgum, Eucalyptus tereticornis Sm. (Myrtaceae) was tested against mature and immature mosquito vector Anopheles stephensi Liston (Diptera) under laboratory condition. The extract showed strong larvicidal, pupicidal and adulticidal activity. The leaf oil extracts showed high bioactivity at high doses. Results obtained from the laboratory experiment showed that the leaf extracts suppressed the pupal and adult activity of Anopheles stephensi at higher doses. In general, first and second instar larvae were more susceptible to all treatments. Clear dose -response relationships were established with the highest dose of 160ppm plant extract evoking almost 100% mortality. The results obtained suggest that, in addition to their medicinal activities, E. tereticornis can also serve as a natural mosquitocide.     

Studies on effects of Pelargonium citrosa leaf extracts on malarial vector,Anopheles stephensi Liston

Methanol extracts of Pelargonium citrosa leaf were tested for their biological, larvicidal, pupicidal, adulticidal, antiovipositional activity, repellency and biting deterrency against Anopheles stephensi. Larval mortality was dose dependent with the highest dose of 4% plant extract evoking 98% mortality. The extracts affected pupicidal and adulticidal activity and significantly decreased fecundity and longevity of A. stephensi. The larval, pupal and adult development were completely inhibited by the treatment. At 4% the extracts evoked strong repellent action. They also interfered with oviposition, egg hatchability, and exhibited a growth inhibiting effect against larvae and good repellency against adults of A. stephensi. The leaf extract treatment significantly enhanced biting deterrency. As naturally occurring insecticides, these plant derived materials could be useful as an alternative for synthetic insecticides controlling field populations of mosquitoes.     

Efficacy of two tropical plant extracts for the control of mosquitoes

The larvicidal activity of seed and leaf extracts of Calophyllum inophyllum and leaf extract of Rhinacanthus nasutus on the juveniles of Culex quinquefasciatus , Anopheles stephensi and Aedes aegypti was determined. Ethyl acetate (EA) soluble fractions of C. inophyllum and petroleum ether (PE) fraction of R. nasutus extracts showed very high larvicidal activity. Irrespective of the species of the mosquitoes tested, at concentrations ranging from 3.91 to 9.39 ppm, 9.04 to 35.49 ppm and 13.21 to 28.92 ppm of the active fractions of seed and leaf extracts of C. inophyllum and the leaf extract of R. nasutus , respectively, killed 50% of the treated larvae. The fractions also interfered with adult emergence. Exposure of the mosquitoes at any stage of their larval development to less than 0.86, 5.49 and 6.81 ppm of the active fractions of seed and leaf extracts of C. inophyllum and the leaf extract of R. nasutus , respectively, inhibited 50% of the treated larvae from emerging as adults. Experiments under laboratory and semi-field conditions showed that the activity of the extracts persisted for up to 10 days.     

Effects of Dysoxylum malabaricum Bedd. (Meliaceae) extract on the malarial vector Anopheles stephensi Liston (Diptera: Culicidae)

In recent years, use of environmentally friendly and biodegradable natural insecticides of plant origin have received renewed attention as agents for disease vector control. Methanol extracts of leaves from the Indian white cedar Dysoxylum malabaricum Bedd. (Meliaceae) were tested against mature and immature Anopheles stephensi Liston (Diptera) mosquitoes under laboratory conditions. The extract showed strong larvicidal, pupicidal, adulticidal, and antiovipositional activity. The maximum leaf extract concentration tested in this study was 4%, which produced pronounced effects. In general, first and second instars were more susceptible to leaf extract than older insects. Clear dose-response relationships were established, with the highest dose of 4% plant extract causing 97% mortality of first instars.     

Efficacy of extracts of Melia azedarach L. callus, leaves and fruits against adults of the sweetpotato whitefly Bemisia tabaci (Hom., Aleyrodidae)

Bioassays with extracts of callus, fruit and leaves of the Chinaberry tree, Melia azedarach L., were performed against adults of Bemisia tabaci (Gennadius). Tissue culture of M. azedarach was carried out in Murashige and Skoog (MS) medium supplemented with indole butyric acid and benzyl adenine. Fresh and frozen leaves or fruits and the callus product were extracted in water or methanol at a ratio of 1 : 5 (w/v) for 48 h. The aqueous and methanol extracts were applied on tomato plants to determine their effect on B. tabaci adults and their corresponding oviposition and consequent adult emergence in comparison with the control, distilled water. Results have shown that extracts of callus and different age classes of M. azedarach leaves and fruits have shown significant repellent activity of 58.9–67.7% and have significantly decreased the oviposition rate of the insect without affecting the adult whitefly emergence in comparison with the control. Aqueous and methanol extracts have shown comparable effects against adult whiteflies indicating a similar efficacy of the two solvents in extracting the bioactive components of Melia . Extracts of frozen samples were found to be as effective against the pest as fresh samples, thus allowing storage of Melia parts to be used in case of shortage. This is the first report of the use of M. azedarach callus against B. tabaci; the M. azedarach callus, leaf and fruit extracts seem to present a potential source for management of B. tabaci .     

三种植物提取物对菟丝子及大豆生长发育和宿主保护酶活性的影响

利用不同浓度的苦楝树皮和叶、隆缘桉叶和乌桕叶的乙醇提取物对菟丝子及其宿主大豆幼苗进行处理,15d后评价三种提取物对菟丝子和大豆幼苗的影响。结果表明:三种提取物在低浓度时对菟丝子及其宿主大豆幼苗生长发育均无显著影响,在高浓度(0.25g/mL)下,桉树叶提取物对大豆和菟丝子的损伤程度分别达到了64%和70%,苦楝树皮提取物对菟丝子损伤程度为78%,但对大豆幼苗仅为7%。桉树叶和苦楝树皮提取物处理均导致大豆叶片超氧化物歧化酶(SOD)活性升高,最高值分别为相应对照组的2.37倍和2.0倍;但对过氧化物酶(POD)和过氧化氢酶(CAT)活性的影响不同,桉树叶提取物使大豆幼苗POD活性最大值为对照组的2.28倍,而苦楝树皮提取物处理则是CAT活性升高,最大值为对照组的1.58倍,提示桉树叶提取物对大豆较强的伤害作用与其较低的CAT活性有关。     

In vitro efficacy of extracts of Melia azedarach against the tick Boophilus microplus

The efficacy of ripe fruit extracts of Melia azedarach L. (Rutales: Meliaceae) was evaluated against the tick, Boophilus microplus (Canestrini) (Acari: Ixodidae). Ripe fruits of M. azedarach dried and powdered were extracted by Soxhlet apparatus successively using hexane, CHCl3 and 96% aqueous ethanol. Larvae and engorged females were immersed in decreasing concentrations from 0.25% to 0.015% of each extract. The mortality of larvae was evaluated 24, 72 and 168 h after treatment. The effectiveness of treatment against engorged females was assessed by measuring egg production. All tested extracts caused mortality of B. microplus larvae, with higher mortality rates observed in CHCl3 (100%) and hexanic extract (98%) than in ethanolic extract (50%) 168 h after treatment. The mortality was dependent on concentration and on time after treatment. Similarly hexanic and CHCl3 extracts showed higher effectiveness (varying from 14% to 100%) against B. microplus engorged females than ethanolic extract (varying from 0% to 46%). Melia azedarach extracts did not kill the adult females, but inhibited partially or totally egg production and embryogenesis. These results show that the less polar the extract of M. azedarach ripe fruits the more its effectiveness against larvae and engorged females of B. microplus. This plant may therefore be useful in the control of resistant B. microplus populations.     

Effects of plant extracts on fecundity and fertility of mosquitoes

Rearing of Culex quinquefasciatus , Anopheles stephensi and Aedes aegypti larvae in water at concentrations less than the critical concentration for inhibition of adult emergence in 50% of treated larvae (EC₅₀) of the ethyl acetate fractions of Calophyllum inophyllum seed and leaf, Solanum suratense and Samadera indica leaf extracts and the petrol ether fraction of Rhinocanthus nasutus leaf extract, from hatching to emergence significantly decreased the fecundity of the mosquitoes and the hatchability of their eggs. At the highest concentration of 50% EC₅₀ of the extracts, the decrease in the fecundity over the control ranged between 62.4 and 87.4%. Sterility index of the mosquitoes reared in the media with the different extracts at this concentration ranged between 82.8 and 93.3%.     

Larvicide and oviposition deterrent effects of fruit and leaf extracts from Melia azedarach L. on Aedes aegypti (L.) (Diptera: Culicidae)

Aedes aegypti (L.) (Diptera: Culicidae), the main urban vector of dengue, has developed resistance to various insecticides, making its control increasingly difficult. We explored the effects of Argentine Melia azedarach L. (Meliaceae) fruit and senescent leaf extracts on Ae. aegypti larval development and survival, by rearing cohorts of first instar mosquitoes in water with different extract concentrations. We also analysed oviposition deterrent activity in choice tests with extract-treated ovitraps. The leaf extract showed a strong larvicide activity, with all larvae dying before pupation, and significantly delayed development time. It strongly inhibited oviposition by Ae. aegypti females. The fruit extract showed much weaker effects. This first report of highly effective larvicidal, growth regulating and oviposition deterrent activity of a senescent leaf extract of M. azedarach against Ae. aegypti, suggests that such extract could represent a promising tool in the management of this mosquito pest.     

Laboratory evaluation of Melia azedarach L. and Eucalyptus globulus Labill. Extracts in order to control Ocneridia volxemi Bolivar (Orthoptera, Pamphaginae) hoppers

This study was carried out to evaluate the effect of Melia azedarach L. (Meliaceae) dry fruit extracts (oil and water) and Eucalyptus globulus Labill. (Myrtaceae) dry leaves extracts (water) on Oneridia volxemi hoppers (fifth-instar) feeding on cereals leaves (Triticum durum) under laboratory conditions. Larva feeding reduced and mortality was significatly (p < 0.05) on cereals leaves sprayed with three concentrations 0, 5, 1 and 2% of oil extracted from Melia azederach. In addition, O. volxemi feeding and mortality was significantly (p < 0.05) on cereals leaves sprayed with two concentrations 50 g/l and 80 g/l of water extracts from Melia azedarach dry fruits soaked for 24 hours. the water extract solution of 80 g/l significantly reduced feeding than the other concentrations 50 and 25 g/l. This study showed also the water extract solution from Eucalyptus globulus dry leaves reduced also feeding and induced the mortality of O. volxemi but not better than Melia azedarach dry fruit extracts water at the same concentration (80 g/l). The aim of this study is in an integrated management program for control of O.     

The Role of Bivalent Cations on the Isolation of Allantoinase from the Soybean Seed Extracts

Allantoinases (ALNase) in the water extracts distilled from seeds and leaves of soybean (Glycine max L. cv. Keyu 10) were. remarkably heat stable. However the enzyme and non-enzyme protein in the seed extract, but not leaf extract, lost their activity and were denaturated at 75℃ for 5 min in the presence of Ca2+, Mg2+. or Mn2+ions respecitively. At room temperature over 40%～50% of the non-enzyme proteins in the seed extract could be removed by the bivalent cations without affecting the enzyme activity. This effect was weakend by the increase of concentration. Both extracts had different responses to all sorts of insoluble Ca2. salts. For the seed extract about 50 % of the non-enzyme proteins were removed by 5 % CaSO4 (W/V), without effecting the enzyme activity, while the leaf extract was sensible to Ca3 (PO4) 2. After treatment with 5 % Ca3 (PO4) 2 about 50 % of the enzyme activities and about 70% of proteins were lost. Mn2+ ions could enhance the enzyme activity in crude seed extract, but had no effect on partially purified enzyme from seeds and enzyme in crude extract from leaves. Further, EDTA had no effect on enzyme activity in both extracts.     

Larvicidal efficacy of Aloe barbadensis and Cannabis sativa against the malaria vector Anopheles stephensi (Diptera: Culicidae)

Anopheles stephensi is the primary vector of malaria, an endemic disease in India. An effort to control An. stephensi larvae by leaf extracts of Aloe barbadensis (Liliaceae) and Cannabis sativa (Moraceae) was made under laboratory conditions. A carbon tetrachloride extract of A. barbadensis was the most effective of all the extracts tested for larvicidal activity against the anopheline larvae, with LC₅₀ 15.58 and 8.04 p.p.m. after 24 and 48 h of exposure, respectively. Thus, the leaf extract of A. barbadensis has active components that could be useful as a larvicide of ecocongenial nature against malaria vectors.     

Effects of tomato genotypes and aqueous extracts of Melia azedarach leaves and Azadirachta indica seeds on Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae)

Insecticide plants are an important tool among the new alternatives for pest control in IPM systems because they reduce the use of synthetic insecticides, preserving human health and the environment. We investigated the effects of aqueous extracts of Melia azedarach leaves and Azadirachta indica seeds and three tomato genotypes, 'Santa Clara', 'IPA-5'--Solanum lycopersicum (=Lycopersicon esculentum Mill), and LA444-1--S. peruvianum (=L. peruvianum), on the development, reproduction and longevity of the tomato pinworm Tuta absoluta (Meyrick), under laboratory conditions. The trials were set up in a completely randomized design, with nine treatments [three genotypes x two extracts (M. azedarach and A. indica) and control]. The replication consisted on five tubes, each with three newly hatched larvae, totalizing 90 individuals per treatment. The larvae were fed with tomato leaves treated with aqueous extracts at 0.1% concentration or distilled water (control) and daily observed until adults' emergence. Larval and pupal development and mortality, pupal weight, longevity and fecundity were evaluated. The accession LA444-1 negatively affected the development and reproduction of T. absoluta; the tomato pinworm had similar development and reproduction on 'IPA-5' and 'Santa Clara' (the susceptible control). The association of resistant tomato genotypes and extracts of M. azedarach leaves and neem seeds did not result in synergistic or antagonistic effects on T. absoluta.     

In vitro anthelmintic effect of Melia azedarach L. and Trichilia claussenii C. against sheep gastrointestinal nematodes

The control of parasitic diseases in small ruminants is mainly done with the use of synthetic anthelmintics. However, incorrect and indiscriminate use of these products has caused the emergence of parasite resistance. Plants with anthelmintic activity are used in folk veterinary medicine, but it is necessary to investigate and scientifically validate low-cost phytotherapeutic alternatives for future use to control gastrointestinal nematodes in small ruminants by family farmers. Thus, the aim of this study was to evaluate the in vitro anthelmintic effect of plant extracts from Melia azedarach and Trichilia claussenii by the egg hatch test (EHT) and larval development test (LDT) against sheep gastrointestinal nematodes. The hexane extract of M. azedarach fruits was extracted through cold percolation and the methanol extract of T. claussenii leaves was obtained by extraction at room temperature in solvents in order of increasing polarity. The efficacy results were analyzed using the Probit program of SAS. The M. azedarach extract showed a LC(50) of 572.2 μg/mL and LC(99) of 1137.8 μg/mL in the EHT, and LC(50) of 0.7 μg/mL and LC(99) of 60.8 μg/mL in the LDT. In turn, the T. claussenii extract presented a LC(50) of 263.8 μg/mL and LC(99) of 522.5 μg/mL in the EHT and LC(50) of 1.1 μg/mL and LC(99) of 26.4 μg/mL in the LDT. Comparing the extracts of the species from the Meliaceae family, T. claussenii showed greater anti-parasite potential in vitro than M. azedarach. However, studies on the isolated compounds, toxicity and administration forms to animals are also needed to validate low-cost alternative herbal remedies for use to control gastrointestinal nematodes by family farmers.     

Feeding deterrence,larvicidal and haemolymph protein profiles of an Indian traditional medicinal plant Alangium salviifolium (L.F.) Wangerin on cluster caterpillar,Spodoptera litura (Fabricius) (Lepidoptera: Noctuidae)

Different organic solvent crude extracts from the leaves of Alangium salviifolium (L.F.) Wangerin, were tested for their feeding deterrence, larvicidal activity and protein concentrations on the fourth instar larvae of Spodoptera litura L. under laboratory conditions. Treatments were given through two different host plant leaves such as brinjal and castor. The bioassay was carried out at different concentrations viz., 0.625, 1.25, 2.5 and 5%. The maximum antifeedant activity in brinjal (52.0%) and castor (29.97%) leaf discs was recorded in ethyl acetate extract as compared with hexane and chloroform extracts at 5% concentration. The result of larvicidal activity revealed that the maximum larval mortality was registered in brinjal leaves (65.81%) and castor with (57.48%) in ethyl acetate extract as compared to hexane and chloroform extracts at 5% concentration. The ethyl acetate extract of A. salviifolium contained alkaloids, diterpenoids, and saponins. The treatment also reduced haemolymph protein concentration after 48 h.     

Laboratory evaluation of methanolic extract of Atlantia monophylla (Family: Rutaceae) against immature stages of mosquitoes and non-target organisms

Methanolic extracts of the leaves of Atlantia monophylla (Rutaceae) were evaluated for mosquitocidal activity against immature stages of three mosquito species, Culex quinquefasciatus, Anopheles stephensi, and Aedes aegypti in the laboratory.Larvae of Cx. quinquefasciatus and pupae of An. stephensi were found more susceptible, with LC50 values of 0.14 mg/l and 0.05 mg/l, respectively. Insect growth regulating activity of this extract was more pronounced against Ae. aegypti, with EI50 value 0.002 mg/l. The extract was found safe to aquatic mosquito predators Gambusia affinis, Poecilia reticulata, and Diplonychus indicus, with the respective LC50 values of 23.4, 21.3, and 5.7 mg/l. The results indicate that the mosquitocidal effects of the extract of this plant were comparable to neem extract and certain synthetic chemical larvicides like fenthion, methoprene, etc.     

Neuropharmacological potential of various morphological parts of Camellia sinensis L.

Camellia sinensis L. has long been used as a therapeutic agent for the Central nervous system (CNS) due to the presence of flavonoids. The present study aimed to evaluate the dose-dependent Neuropharmacological behavioral potential of Camellia sinensis seed and leaf extracts on mice. To evaluate the differential potential of leaf and seed extract various doses were prepared and examined in open field, head dip, rearing, cage cross, swimming and traction tests. One-way ANOVA set at P* < 0.05 followed by POST HOC LSD (P* < 0.01) was applied to evaluate the significant difference among the treatments. Herein both seed and leaf extract showed significant results at high doses. Interestingly leaf extract at high dose showed significant effect on mice CNS in open field and head dip test, while seed at high dose revealed significant stimulus on mice CNS in rearing, cage cross, swimming and traction tests. Overall results showed that seed produced more stimulant effect and less calmness as compared to leaf extract was. Tea leaves had already known as potential CNS stimulant drugs; current investigation suggests that tea seed can be used as an alternative CNS stimulant agent with more effective stimulant action.     

Phytogenic compounds from avocado (Persea americana L.) extracts; antioxidant activity,amylase inhibitory activity,therapeutic potential of type 2 diabetes

Diabetes is a worldwide public health disease. Currently, the most effective way to treat diabetes is to mitigate postprandial hyperglycemia by inhibiting carbohydrate hydrolysis enzymes in the digestive system. Plant extracts are rich in bioactive compounds, which can be used in diabetes treatment. This study aims to evaluate the polyphenols content in ethanolic extracts of avocado fruit and leaves (Persea americana Mill.). Additionally, their antioxidant activity using DPPH, while the inhibition ability of α-amylase was examined by reacting different amounts of the extracts with α-amylase compared to acarbose as standard inhibitor. The active compounds were detected in the extracts by LC/MS. The obtained results showed that the leaf extract recorded a significant content of total phenolic compounds compared to the fruit extract (178.95 and 145.7 mg GAE /g dry weight, respectively). The total flavonoid values ??ranged from 32.5 to 70.08 mg QE/g dry weight of fruit and leaves extracts, respectively. Twenty-six phytogenic compounds were detected in leaf and fruit extract by LC/MS. These compounds belong to fatty acids, sterols, triterpenes, phenolic acids, and flavonoids. The antioxidant activity of the extracts is due to the exist of phytogenic compounds, i.e., polyphenols and flavonoids. The antioxidant activity increased in a concentration dependant manner. Avocado fruit extract (1000 µg/mL) scavenged 95% of DPP? while leaf extract rummaged 91.03% of free radicals compared with Vit C and BHT. Additionally, higher α-amylase inhibitory activity was observed in fruit extract than the leaf extract, where the fruit and leaf extract (1000 μg/ml) inhibited the enzyme by 92.13% and 88.95%, respectively. The obtained results showed that the ethanolic extracts of avocado could have a significant impact on human health due to their high content of polyphenols.     

The toxicity and biological effect of Pedalium murex L. extracts on the tobacco cutworm,Spodoptera litura (Fabr.) larvae

Petroleum ether, acetone, water and aqueous extract of Pedalium murex L. (Pedalaceae) leaves, root and fruit were tested against fourth instar larvae of the tobacco cutworm, Spodoptera litura (Fabr.) under laboratory conditions using leaf dip method. Larval mortality; larval, pupal and adult periods; pupal weight, pupation and adult emergence; larval and pupal deformities of S. litura were recorded. All the tested solvent extracts of P. murex were effective against S. litura life stages by causing mortality in a dose dependent manner. However, the efficacy was more significant with respect to acetone (leaf and root) and petroleum ether (root) at higher concentrations (0.8%) which leads to 100% larval mortality. The water and aqueous extracts of root caused 86.6 and 88.0% larval mortality respectively at 4% concentration. Among the plant parts tested, root had more importance followed by leaf and fruit. Plant extracts extended the larval, pupal and adult periods; reduced the pupal weight, pupal and adult emergence and caused larval–pupal deformities. Total life time was highly prolonged in acetone extracts of P. murex root. Though all the extracts were found to have insecticide activity, acetone and petroleum ether extracts of P. murex root can be used as an effective alternative to modern synthetic insecticides. Bioactive principles from these extracts can be isolated, identified and integrated in S. litura management.     

Differential belowground allelopathic effects of leaf and root of Mikania micrantha

This study evaluates the relative contributions of leaves and roots to the belowground allelopathic effects of Mikania micrantha. The hypothesis that leaves contribute more to the allelopathic effect than roots was experimentally tested. We assessed the allelopathic effects of aqueous extracts from Mikania leaves and roots on the seed germination and seedling growth of two co-occurring woody plants in southern China, Lagerstroemia indica L. and Robinia pseudoacacia L. The results showed that the aqueous extracts from Mikania leaves and roots had inhibitory effects on the woody species. Allelopathic activity depended on the concentration of the extracts, target species, and the extract sources (i.e., leaves vs. roots of Mikania). Leaf extract showed stronger allelopathic effects than root extract on germination percentage, initial germination time, speed of germination, and shoot height; while root extract had greater allelopathic effects on roots than leaf extract. The latter phenomenon might greatly promote the invasion success of Mikania due to more direct and effective allelopathy of root. Our results suggest that allelopathy of root extract on belowground biomass might be greater than that of leaf extract for some species in contrast allelopathy of leaf extract on belowground biomass might also be greater than that of root extract for other species, at least for their effects on root growth of the target species.