Article

Larvicidal and mosquitocidal extracts, a coumarin, isoflavonoids and pterocarpans from Neorautanenia mitis

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  • University of Dar es Salaam, Mbeya College of Health and Allied Sciences
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Abstract

The present study aimed to evaluate extracts and compounds from tubers of Neorautanenia mitis against the malaria- and filariasis-transmitting mosquitoes, Anopheles gambiae and Culex quinquefaciatus, respectively. The extracts exhibited activity against larvae of A. gambiae and C. quinquefaciatus mosquitoes, and were also active against adult A. gambiae mosquitoes. The active extracts yielded the coumarin derivative pachyrrhizine, the isoflavonoids neotenone and neorautanone, and the pterocarpans neoduline, nepseudin and 4-methoxyneoduline as the active constituents. The activity of the crude extracts was at about the same magnitude as that of the constituent natural products, the latter's efficacy being almost at the same level for all the isolated compounds. The mosquitocidal activities of the pure compounds were comparable to those of the standard mosquitocides deltamethrin and alphacypermethrin. These findings corroborate traditional insecticidal application of N. mitis and the results can be extended for the control of mosquitoes especially at breeding sites.

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... They are also used as an anticonvulsant, anti-malarial, fish poison, insecticide, and for killing bilharziascarrying fresh water snails in many African countries [6][7][8][9][10]. The crude extracts and phytochemical constituents isolated from N. mitis have shown antidiarrheal [3,11], acaricidal, insecticidal [12], antinocicetive, antiinflammatory [9,13], larvicidal, mosquitocidal [14], cytotoxicity [11,15], and antimicrobial, activities [16]. H. abyssinica, is referred to as one of the strangest plants in the world, with its vegetative body consisting of only flowers, fruits and roots and has no leaves. ...
... Our studies led to the isolation of salidroside for the first time from this plant. Several other phytochemical studies on the roots of N. mitis have resulted in the isolation of neorautanone, 4methoxyneoduline [14] 12a-hydroxyerosone, iseoliptol [15], neoraudiol [16], together with neodulin (6), pachyrrhizine (10), neotenone (11), 12a-hydroxydolineon (13), dolineon (14), rotenone (20), 12a-hydroxyrotenone (21), dehydroneotenone (22) [11,[14][15][16], nepseudin (16) [62], rautandiol A (23) and rautandiol B (24) [15]. Our earlier studies led to the isolation of one new compound (12) and nine known compounds including compounds 5, 7, 8, 9, 12, 15, 17, 18 and 19, which were isolated for the first time from N. mitis [11]. ...
... Our studies led to the isolation of salidroside for the first time from this plant. Several other phytochemical studies on the roots of N. mitis have resulted in the isolation of neorautanone, 4methoxyneoduline [14] 12a-hydroxyerosone, iseoliptol [15], neoraudiol [16], together with neodulin (6), pachyrrhizine (10), neotenone (11), 12a-hydroxydolineon (13), dolineon (14), rotenone (20), 12a-hydroxyrotenone (21), dehydroneotenone (22) [11,[14][15][16], nepseudin (16) [62], rautandiol A (23) and rautandiol B (24) [15]. Our earlier studies led to the isolation of one new compound (12) and nine known compounds including compounds 5, 7, 8, 9, 12, 15, 17, 18 and 19, which were isolated for the first time from N. mitis [11]. ...
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Background Neorautanenia mitis, Hydnora abyssinica, and Senna surattensis are medicinal plants with a variety of traditional uses. In this study, we sought to isolate the bioactive compounds responsible for some of these activities, and to uncover their other potential medicinal properties. Methods The DCM and ethanol extracts of the roots of N. mitis and H. abyssinica, and the leaves of S. surattensis were prepared and their phytochemical components were isolated and purified using chromatographic methods. These extracts and their pure phytochemical components were evaluated in in-vitro models for their inhibitory activities against Plasmodium falciparum, Trypanosoma brucei rhodesiense, Mycobacterium tuberculosis, α-amylase (AA), and α-glucosidase (AG). Results Rautandiol B had significant inhibitory activities against two strains of Plasmodium falciparum showing a high safety ratio (SR) and IC50 values of 0.40 ± 0.07 μM (SR - 108) and 0.74 ± 0.29 μM (SR - 133) against TM4/8.2 and K1CB1, respectively. While (−)-2-isopentenyl-3-hydroxy-8-9-methylenedioxypterocarpan showed the highest inhibitory activity against T. brucei rhodesiense with an IC50 value of 4.87 ± 0.49 μM (SR > 5.83). All crude extracts showed inhibitory activities against AA and AG, with three of the most active phytochemical components; rautandiol A, catechin, and dolineon, having only modest activities against AG with IC50 values of 0.28 mM, 0.36 mM and 0.66 mM, respectively. Conclusion These studies have led to the identification of lead compounds with potential for future drug development, including Rautandiol B, as a potential lead compound against Plasmodium falciparum. The relatively higher inhibitory activities of the crude extracts against AG and AA over their isolated components could be due to the synergistic effects between their phytochemical components. These crude extracts could potentially serve as alternative inhibitors of AG and AA and as therapeutics for diabetes.
... It was a well-grounded knowledge that plants may have anti-insect activities including larvicidal activities due to their chemical substances. Earlier studies reported that several plant extracts possess larvicidal qualities, i.e: Aristolochia saccata and Annona squamosal [1]; Nelumbo nucifera [2]; Quercus Lusitania [3]; Saraca indica/asoca, Nyctanthes arbor-tristis, and Clitoria ternatea [4] Solanum villosum [5]; Argemone mexicana, Jatropha curcus, Pergularia extensa and Withania somnifera [6]; Neorautanenia mitis [7]; Solanum nigrum [8]; Solanum xanthocharpum [9]; Abuta grandifolia and Minthostachys setosa [10]; Piper longum [11]; oil of Cryptomeria japonica [12]; Apium graveolens [13]; Murayya koeginii, Coriandrum sativum, Ferula asafoetida, and Trigonella foenum gracium [14]; Azadirachta indica [15] and many others. From all of these plants, one of the plants with ubiquitous presence in coastal and riverbank area of Indonesia and low utilization of its biomass is Bintaro (Cerbera odollam). ...
... An earlier study reported that crude extract of C. odollam exhibited high larvicidal effect against Aedes aegypti [27]. Other earlier studies reported that plants crude extracts had larvicidal activities against mosquitoes, i.e: Aristolochia saccata and Annona squamosa [1]; Nelumbo nucifera [2]; Quercus Lusitania [3]; Saraca indica/asoca, Nyctanthes arbortristis, and Clitoria ternatea [4]; Solanum villosum [5]; Argemone mexicana, Jatropha curcus, Pergularia extensa and Withania somnifera [6]; Neorautanenia mitis [7]; Annona crassiflora, and Pterodon polygalaeflorus [28]; Jatropha curcas and Euphorbia tirucalli [29]; Annona glabra, and Anacardium occidentalis [30]. Those earlier studies suggested that plants extract, including C. odollam extract, had larvicidal effect in larval mortality of C. quinquefasciatus. ...
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Mosquitoes are known for their bites which caused discomfort and its role as vector for various dangerous diseases that has been the bane of humanity since antiquity. One of them is Culex quinquefasciatus which facilitates the spread of arbovirus and nematodes that caused debilitating impact for human life. To eliminate mosquito, the study for evaluating plant-based mosquito larvicidal extract of Cerbera odollam extract against C. quinquefasciatus was conducted. Twenty-five second instar of C. quinquefasciatus were subjected to the crude and fractionated extracts of C. odollam, and the larval mortality was observed at 24, and 48 h of exposure. The results showed that the crude extracts of leaves, rinds, and stem bark exhibited low larvicidal activities. Interestingly, crude extract of the seed kernel exhibited high larvicidal activity. We found that the fractionated extract derived from the seed kernel extract using ethyl acetate and n-hexane exhibited high larvicidal activities, suggesting that C. odollam extract could be promoted as a material for larval control.
... This plant is used for insecticidal preparations, the treatment of syphilis (Olayemi et al. 2016), the control of bilharzia-carrying freshwater snails (Reithinger et al. 2006), intestinal parasites caused by tapeworms (Lasisi et al. 2018), and fish poison. In addition, antispasmodic, analgesic, antiinflammatory, antitumor (Sakurai et al. 2006), acaricidal (Puyvelde et al. 1987), molluscicidal (Puyvelde et al. 1987;Puyvelde et al. 1990), and larvicidal and mosquitocidal (Joseph et al. 2004) activities have been observed. Cytotoxic activities of the EtOAc extract of N. mitis were also described for human MCF-7 breast and A-549 lung cancer cells (Lasisi and Adesomoju 2015). ...
... During the chemical studies of N. mitis tubers, various compounds were isolated (Fig. S1, Supplemetary Material), including rotenone (1), neotenone (2), dehydroneotenone (3), pachyrrhizine (4), dolineone (5), neoduline (6), n e p s e u d i n e , 1 2 -α -h y d r o x y d o l i n e o n e , a n d 1 2 -αhydroxyrotenone, were identified (Puyvelde et al. 1987). Later, two new pterocarpans, rautandiol A and rautandiol B, along with isoelliptol, p-bromobenzoate of rautandiol A, pbromobenzoate of rautandiol B, and 12-α-hydroxyerosone, were also isolated (Sakurai et al. 2006), as well as 4methoxyneoduline (Joseph et al. 2004). Two of the isolated compounds have been reported to possess anti-scabies activity, including rotenone (1) and its derivative 12-αhydroxyrotenone (Puyvelde et al. 1987), and various pharmaceutical formulations, including emulsions (Woodrow 1919) and ointment (Puyvelde et al. 1990), were manufactured containing this natural products. ...
Article
An HPLC-UV method for standardization of the methanol-soluble extracts from tubers of Neorautanenia mitis (A.Rich.) Verdc., Fabaceae, harvested during different periods and from different sites, is described. The chemical fingerprint was established with six identified markers using LC-ESI (+)-MS/MS, including rotenone; the total error was used as validation criterion, the accuracy and risk profiles demonstrated the reliability of the method. The study verified that the major degradation product of rotenone in methanol is dehydrorotenone. The detection range of rotenone was between 40 and 400 μg/ml. The collected samples contained 868–5732 μg/g of rotenone. The concentrations of rotenone in the wild samples from the Ngoma site (5167 ± 565 μg/g) were higher than those registered in the samples from the other sites. No significant differences were observed among the remaining sampling sites, and most of the rotenone was located in the inner part of the tubers (2165 ± 1051 μg/g) when compared with that in their peels (961 ± 320 μg/g). Graphical abstract
... Due to the presence of various bioactive elements and its significant role in generating oxidative stress in mosquito vectors, the traditionally used medicinal plants have taken a significant place in the regions where human population is threatened by severe infectious diseases (Joseph et al. 2004;Kunwar and Priyadarsini 2011). An inevitable form of specific metabolism in insects has led to the development of oxidative stress by the action of too much amount of free radicals or reactive oxygen species (ROS) (Sies 1997). ...
... It is very familiar in the mosquito control research to reports on the arthropod-borne viruses and its impacts in the global human population together with various infectious diseases including dengue, yellow fever, Zika, and chikungunya (Joseph et al. 2004;Anoopkumar et al. 2017b). Zika infection in the fetal stage can cause high risk by microcephaly and birth defects. ...
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The excessive accumulation of Reactive oxygen species (ROS) has been linked to myriad of toxic effects in several signaling pathways including growth regulatory pathways and apoptosis in insects. The current upsurge in mosquito research into the underlying mechanism of phytochemicals induced reactive oxygen species accumulation and larvicidal potential prompts the attention to exploring the role of oxidative stress and microbial consortia inhabited in the mosquitoes. In addition, understanding the impacts of mosquito microbiomes annihilation is vital for disentangling their underlying effects on arboviral diseases transmission. No investigation has been conducted in this aspect using isolated bioactive compounds from Jasminum brevilobum, Aglaia edulis and Pogostemon auricularius against Aedes aegypti. This study aimed to investigate the mode of action of bioactive compounds with special inference on ROS production and microbial inhabitants. Isolation and characterization of bioactive compounds were performed using the Thin-layer chromatography, Column chromatography, Gas chromatography-mass spectrometry and Fourier-transform infrared spectroscopy. R software and SPSS were used for statistical analyses. The isolated bioactive compounds induced excessive production of reactive oxygen species thereby leading to oxidative stress and death. All the isolated compounds exhibited a sturdy inhibitory effect against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Klebsiella pneumonia, and Proteus mirabilis, with strong MIC values ranging from 0.08–1.65 mg/ml. Also, they showed promising larvicidal efficacy against Aedes aegypti larvae.
... The flavonoids in Millettia pinnata seeds showed a positive larvicide effect on three different mosquito species [22] . Coumarin was also reported to be responsible for mosquito larvicide activity in plant extract [23] . The presence of such secondary metabolites in the methanol extract of the root of Coriandrum sativum suggested that they might be responsible for the larvicidal effect either singly or combinedly. ...
... [12,13] Insecticides are used to kill or repel adult mosquitoes in order to disrupt the disease transmission cycle or to target mosquito breeding places by spraying stagnant water on them. [14,15] Plant preparations have been utilized traditionally all across the world to repel mosquitoes among various populations. [16] Natural or synthetic repellents are harmless, but their flavor and odor can influence insect behavior. ...
... Many pesticides, like pyrethroids, are particularly harmful to aquatic life, including fish, and should be avoided in ecosystems that support fish or crustaceans. Additionally, the repeated use of synthetic insecticides can disrupt ecosystems and contribute to the development of resistance in pest populations [3] . In recent times, there has been growing interest in using environmentally friendly and biodegradable natural insecticides derived from plants as an alternative, eco-friendly approach to controlling arthropods that pose public health risks [4] . ...
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The study aimed to assess the larvicidal potential of essential oils from Eucalyptus teriticornis (Eucalyptus), Melaleuca alternifolia (Tea tree), Mentha piperita L. (Peppermint), Lavandula angustifolia (Lavender) Citrus sinensis (Orange) and Cymbopogan flexuosus (Lemongrass) against Aedes aegypti mosquito larvae. Various dilations (12.5ppm, 25ppm, 50ppm, 75ppm, 100ppm, 200ppm, 250ppm, 500ppm) of commercially available steam distilled essential oil used to carry out laboratory bioassays. The percentage of mortality of Aedes aegypti (L.) was calculated after 24, 48, 72 and 96 hours of exposure. Among the essential oils tested Eucalyptus showed the highest larvicidal activity against larvae of C. pipiens (LC50 86.84ppm and LC90 275.42ppm) on 24 hours of exposure. Lemongrass, Peppermint and Lavender showed significant amount of larvicidal activity (LC50 150.52ppm, 165.57ppm, 198.51ppm and LC90 615.85ppm, 295.32ppm, 404.42ppm respectively). Orange and Lavender showed moderate mortality rates (LC50 722.08ppm, 788.04ppm and LC90 19109.53ppm, 19455.6 ppm respectively). As all the essential oils show significant larvicidal effect, it can be concluded that essential oils can combat Aedes aegypti larvae. Thus, these compounds may provide an alternative to synthetic insecticides as they are environmentally safe insecticides
... In addition to insecticides, a variety of extracts and chemicals from several plant groups have been studied as potential new larvicides 9 . Plant extracts or essential oils contain a variety of phytochemicals such as tannins 10 , essential oils 11 , isoflavonoids 12 , and stimulants 13 , which can kill mosquito larvae. The effects range from oviposition inhibition, developmental toxins, hatching inhibition, adulticides, ovicides, and emergence inhibitors 4,14 . ...
Article
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Mosquitoes, one of the deadliest animals on the planet, cause millions of fatalities each year by transmitting several human illnesses. Synthetic pesticides were previously used to prevent the spread of diseases by mosquitoes, which was effective in protecting humans but caused serious human health problems, environmental damage, and developed mosquito pesticide resistance. This research focuses on exploring new, more effective, safer, and environmentally friendly compounds to improve mosquito vector management. Phytochemicals are possible biological agents for controlling pests and many are target-specific, rapidly biodegradable, and eco-friendly. The potential of extracts of Lantana camara, Melia azedarach, Nerium oleander, Ricinus communis, and Withania somnifera against 3rd instar Culex pipiens (Common house mosquito) larvae was evaluated. Methanol extracts had more toxic effects against Cx. pipiens larvae (95–100%, 24 h post-treatment) than aqueous extracts (63–91%, 24 h post-treatment). The methanol extracts of Nerium oleander (LC50 = 158.92 ppm) and Ricinus communis (LC50 = 175.04 ppm) were very effective at killing mosquito larvae, 24 h after treatment. N. oleander (LC50 = 373.29 ppm) showed high efficacy in aqueous plant extracts. Among the different extracts of the five plants screened, the methanol extract of R. communis recorded the highest ovicidal activity of 5% at 800 ppm concentration. Total developmental duration and growth index were highly affected by R. communis and M. azedarach methanol extracts. In field tests it was clear that plant extracts decreased mosquito larval density, especially when mixed with mosquito Bti briquette, with stability up to seven days for N. oleander. GC–MS results showed that the methanol extract had a higher number of chemical compounds, particularly with more terpene compounds. A high-performance liquid chromatography (HPLC) technique was used to detect the existence of non-volatile polyphenols and flavonoids. All five methanol extracts showed high concentrations of active ingredients such as gallic acid, chlorogenic acid (more than 100 μg/ml) and the rosmarinic acid was also found in all the five extracts in addition to 17 active polyphenols and flavonoids presented at moderate to low concentrations. Molecular modeling of 18 active ingredients detected by the HPLC were performed to the vicinity of one of the fatty acid binding proteins of lm-FABP (PDB code: 2FLJ). Rutin, Caffeic acid, coumaric acid and rosmarinic acid which presented densely in R. communis and N. oleander showed multiple and stable intermolecular hydrogen bonding and π–π stacking interactions. The inhibition ability of the fatty acid binding protein, FABP4, was evaluated with remarkable receptor inhibition evident, especially with R. communis and N. oleander having inhibitory concentrations of IC50 = 0.425 and 0.599 µg/mL, respectively. The active phytochemical compounds in the plants suggest promising larvicidal and ovicidal activity, and have potential as a safe and effective alternative to synthetic insecticides.
... Every year, large number of peoplefound to get infectedwith this disease worldwide and most of them shows common chronic manifestation [7]. Theeradication of the disease can be managed by either targeting mosquito larvae through spraying stagnant water breeding sites or by eliminating adult mosquitoes, using insecticides [6]. Larvicide is an effective method for reducing mosquito populations in their breeding places before they emerge as adult. ...
Article
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A study was conducted to assess the larvicidal potential of spice essential oils from Piper nigrum (Black pepper), Murraya koenigii (Curry leaf), Allium sativum (Garlic) and Allium cepa (Onion) against Culex quinquefasciatus mosquito larvae under laboratory condition. Various dilutions (12.5ppm, 25ppm, 50ppm, 75ppm, 100ppm, 150 ppm, 200ppm, 250ppm, 500ppm) of commercially available steam distilled essential oil used to carry out laboratory bioassays. The percentage of mortality of Culex quinquefasciatus was calculated after 24, 48, 72 and 96 hours of exposure. Among the essential oils tested Garlic, showed the highest larvicidal activity against larvae of Culex quinquefasciatus (LC 50 0.258 ppm and LC 90 0.335 ppm) on 24 hours of exposure. Black pepper, Curry leaf and Onion also showed significant amount of larvicidal activity (LC 50 0.288 ppm, 0.385 ppm, 0.361 ppm and LC 90 0.471, 0.443, 0.416 respectively). As all the essential oils show significant larvicidal effect, it can be concluded that essential oils can combat Culex quinquefasciatus larvae. And thus, these compounds may provide an alternative to synthetic insecticides as they are environmentally safe insecticides.
... The eradication of these diseases primarily relies on interrupting the disease transmission cycle. This can be achieved by targeting the mosquito larvae in their breeding sites or eliminating adult mosquitoes with the use of pesticides (Joseph et al., 2004). ...
Article
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Despite their diminutive size, mosquitoes serve as significant vectors for numerous pathogenic organisms. In this research, five commercial essential oils (EOs) were screened (lemon, camphor, sandalwood, orange, and black pepper oil)against larvae of the filarial vector Culex pipiens to evaluate their larvicidal activity, their effects on different biological aspects and midgut histological architecture. Moreover, the chemical profile of the tested EOs was conducted employing gas chromatography-mass spectrometry (GC-MS) analysis. Results revealed that the most toxic oil was orange oil, with LC50 of 117.69 ppm and LC90 of 442.64 ppm. With LC50 and LC90 values of 1439.63 and 22489.03 ppm, respectively, lemon oil exhibited the least larvicidal activity. Larval treatments with the five EOs decreased pupation, pupal duration, adult female longevity, fecundity, and egg hatchability, with complete inhibition of egg deposition due to orange and black pepper oil treatments. The effects of EOs revealed destructive changes in midgut epithelial cells and peritrophic membranes. GC-MS analysis revealed that monoterpenes and fatty acids were the major constituents of the studied EOs. In conclusion, EOs can be used as effective alternatives to conventional insecticides for disease vector Cx. pipiens control
... Several phytochemical and pharmacological studies have been reported on Dolichos species such as Dolichos mitis [19][20][21][22], Dolichos biflorus [23], Dolichos erosus [24][25], and Dolichos lablab [26] among others with potentially therapeutic and prophylactic importance. On the other hand, based on the literature, there is no any phytochemical and or pharmacological activity reported on the D. pachyrhizus specie. ...
... quinquefaciatus and A. gambiae. Mann et al. [29] discovered that the root of M. senegalensis include alkaloids, flavonoids, saponins, tannins, and steroidal substances that were efficient against mosquitoes. ...
... Plants possess a variety of bioactive mosquito larvicidal phytoconstituents such as steroids, tannins, terpenes, saponins, etc. These phytochemicals are specific in action, ecofriendly in nature, less toxic to human health and rapidly biodegradable (Ghosh et al., 2012;Isman, 2006;Joseph et al., 2004). Consequently, consideration has been progressively diverted toward insecticides of plant origin for mosquito control. ...
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The present research was conducted to assess the mosquito larvicidal potential of selected medicinal plants using an effective but simple method. Aqueous extracts of roots of three selected medicinal plants viz. Derris scandens, Rubia cordifolia and Saussurea lappa were evaluated for their mosquito larvicidal potential against the 3rd instar larvae of C. quinquefasciatus Say (1823) under laboratory settings. Aqueous extracts of these plants at seven different concentrations (1, 25, 50, 100, 150, 200 and 300 ppm) exhibited considerable mortality of the 3rd instar larvae after 24 and 48 h exposure. Among the plants, D. scandens root extract exhibited the highest toxicity inducing 100% larval mortality after 24 h exposure at 250 ppm concentration, followed by the root extracts of R. cordifolia and S. lappa inducing 98.4% and 87.8% larval mortality, respectively. Overall, extracts of all the plants exhibited a strong positive correlation between the concentration of extracts and larval mortality (p˂0.001) with a correlation coefficient of more than 0.90. The LC50 and LC90 values after 24 h contact demonstrated D. scandens as the most toxic with the lowest LC50 and LC90 values (LC50=78.20 ppm, LC90=147.33 ppm) followed by R. cordifolia (LC50= 89.32 ppm, LC90=204.09 ppm) and S. lappa (LC50=112.29 ppm, LC90=248.72 ppm), respectively. Our results clearly indicated that all the plants' aqueous extracts showed considerable larvicidal potential against the 3rd instar larvae of C. quinquefasciatus. To conclude, the application of aqueous extracts from these plants to larval habitats may efficiently control C. quinquefasciatus mosquitoes, hence, can be recommended as a potential alternative to chemical insecticides against these vectors. Asian J. Med. Biol. Res. 2022, 8 (4), 187-193
... Similarly, marmesin isolated from A. marmelos exhibits toxicity against An. gambiae adults with LC 50 and LC 90 values of 0.082 and 0.152 mg/L, respectively [55]. Other report, imperatorin isolated from Cnidium monnieri fruit, show insecticidal activity against susceptible Cx. pipiens pallens and Ae. ...
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The Aegle marmelos (AM) is a deciduous tree recognized in traditional medicine for the treatment of various illnesses due to the presence of phytoconstituents such as coumarin component of imperatorin. The current investigation, obtained three end products, such as (1b) 9-hydroxy-7H-furo[3,2 g]chromen-7-one, (2b) N-(8-hydroxy-2,6-dimethyloctan-2-yl)acetamide, and (Z) N-(2-(4-methylcyclohex-3-en-1-yl)propan-2-yl)acetamide due to modification in isoprenyl group. Interestingly, in the case of four mono terpenes, Geraniol, Linalool, α-Pinene, and Limonene, are single reaction products (Z) yielded from the Ritter reaction. The obtained compounds are to test in vitro anti-microbial, were subjected to molecular docking, mosquito larvicidal, pupicidal, and brine shrimp activities were accompanied against Staphylococcus aureus, Klebsiella pneumonia, dengue vector Aedes aegypti and Brine shrimp lethality assay (BSLA) on Artemia nauplii. The imperatorin (1a), isoprene contains compounds (2a-6a) and semi-synthetic modified compounds (1b), (2b), and (Z) exhibited potential pharmacological activities. The highest-level zone of inhibition was present in imperatorin (1a), modified compounds (1b), (2b), and (Z) against Staphylococcus aureus, Klebsiella pneumonia (17.8, 18.9, 17, and 18.2 mm) (17.2, 21.2, 20, and 22.1 mm), and antibiotics chloramphenicol (CP) inhibit (24.2 and 27.4 mm). In comparison to the reference drug Ciprofloxacin, compound (1b) showed the best potency against both bacterial strains. To ascertain the potential binding orientation of PDB ID: 3OZU, docking research was used. In accordance with the docking data, compound (1b) had a greater binding affinity and an energy of 7.62 kcal/mol. These findings shed light on the process of binding development and offer a prestigious route for designing and structurally modifying Ritter reactions as a cutting-edge class of antibacterial agents, respectively. 100% potential larvicidal and pupicidal was observed in imperatorin (1a), derivatives (1b), (2b), and (Z) against larvae of A. aegypti (LC50 = 42.37, 57.07, 42.89, and 45.08 ppm) and pupicidal with LC50= 37.20, 49.82, 46.76, and 41.65 ppm, respectively at 24 h observation. Isolated and all the modified compounds revealed a low toxic effect on Artemia nauplii with the viability of 96, 96.2, 97, 85, 98, 85, 87, 86, 85.4, and 98% at 500 ppm, respectively at 24 h treatments. The findings clearly support the prospective usage of these compounds in the pharmaceutical industry. Graphical Abstract
... It is suggested that as this happened there may be deficiency of dissolved oxygen owing to the presence of the antioxidant (saponin molecules). Phenolic molecules have been reported to be excellent facilitators of larvicidal activity against mosquito larvae generally through complex fomation (David et al., 2000;Joseph et al., 2004). The phenolic compounds in citrus are known to exhibit antiseptic, antifungal and antipathogenic properties (Okwu and Morah, 2007b. ...
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This collaborative study to evaluate the minimum lethal concentrations (MLCs) of phytochemical larvicide extracts from peels, pulp and seeds of Citrus sinensis, Citrus limonum, Citrus aurantifolia, Citrus reticulata and Citrus vitis, was undertaken in support of the ongoing global search for phytochemical alternatives to synthetic chemical insecticides which have lost their effectiveness in malaria vector control. Peels, pulp and seeds were obtained from these fruits, processed and air-dried in the laboratory for 21 days avoiding contamination. The materials were ground into powder form, and then subjected to phytochemical extraction using Soxchlet extraction method with Diethyl ether as solvent at temperature range of 60 0 C-80 0 Cfor 6 hours. The extracts were left overnight for the remaining ether in them to evaporate. The active compounds were qualitatively and quantitatively determined using appropriate standard methods. Five different concentrations were prepared (volume for volume), 5%, 10%, 15%, 20% and 25% from each extract stock and tested on live and active mosquito larvae and pupae, respectively, to determine their minimum lethal concentrations (MLSc). The results were matched with each other, and with those of the control, Altosid Liquid Larvicide, (a commercial water-soluble larvicide) using Chi-square test. The observed variations in minimum lethal concentrations (MLCs) exhibited by the different extracts were statistically significant (P < 0.05). These differential MLCs of the extracts may be due to the corresponding variations in their active ingredients contents. There was also a significant variation (P < 0.05) between the 5% MLCs of the extracts from peels and the control larvicide (Altosid Liquid Larvicide). This implies that the phytochemical extracts have proved more efficacious in killing mosquito larvae and pupae than the control larvicide used in this study. INTRODUCTION The discovery of resistance to chemical insectidices (like DDT) between 1946-1947 (Herringway and Ranson, 2000), and the recent report that over 500 species of arthropods are resisting various insecticides (Shelton, et al., 2007) had been the motivating factor behind the global ongoing search for phytochemicals as the best possible alternative to synthetic insecticides in the nearest future. Phytochemicals are relatively safe, inexpensive, environmentally friendly, and are readily available through out the world (ICMR, 2003).
... The finding of the present investigation is comparable with earlier reports the larvicidal activities of the four MPCs D-terpinene, linalool, borneol and germacrene D tested against larvae of HVMs [25 -28]. Similarly, Isoflavonoids from tubers of N. mitis had a larvicidal effect on malaria and filariasis vectors [29]. Saponin isolated from A. aspera against Ae. ...
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Mosquitocidal activities of Lavandula angustifolia (L. angustifolia) different concentration of essential oil (EO) and its major phytocompounds (MPCs) tested against three important human vector mosquitoes (HVMs). The quantitative analyses of EO phyto-chemical compositions (PCCs) were analyzed by using Gas Chromatography-Mass Spectrometry (GCMS). The HVMswere exposed to various concentrations of EO and its MPCs tested under laboratory condition by using standard protocols. Vector mortalities were subjected to log-probit analysis. Chemical compositions (CCs) of 47 compounds were identified and the MPCs of EO were Terpinen (38.0339%) followed by Linalool (34.4992%), Caryophyllene (6.1480%), Octanone (2.3906%) and Camphene (2.0989%). The maximum larval mortality was found in Linalool against the larvae of Aedes aegypti (Ae. aegypti) followed by Anopheles stephensi (An. stephensi) and Culexquinquefasciatus (Cx. quinquefasciatus) with the LC50 values were 36.26, 36.81 and 37.49 ppm respectively. Ovicidal activity of the Linalool found most effective than other compounds. These results are clearly suggests that EO and its MPCs have the potential to be used as an ideal ecofriendly approach, traditional method for control of HVMs and this is the first report on the mosquitocidal activities of L. angustifolia EO of MPCs.
... EL-Kamali [6] reported that crude aqueous extracts of dried fruit pericarp, flowers, root and stem of Solenostemma argel, Sudanese herb rich with saponins, were showed larvicidal activity agaist Culex quinquefasciatus. Isoflavonoids from tubers of Neoeautanenia mitis had a larvicidal effect against the malarial transmitting mosquitoes, Anopheles gambiae and Culex quinquefasciatus, respectively [13]. Studies with caraway, celery, fennel, mullilam and zedoary essential oils suggested that they are a biocontrol agent against mosquito vectors [14]. ...
... Phytochemical and biological studies on this plant have been reported by many groups. Individual phytochemicals and crude extracts have been shown to have cytotoxicity (Sakurai et al., 2006), acaricidal, insecticidal (Puyvelde et al., 1987), larvicidal, mosquitocidal (Joseph et al., 2004), antinocicetive, anti-inflammatory (Vongtau et al., 2000(Vongtau et al., , 2004, antimicrobial (Lasisi and Adesomoju, 2015) and antidiarrheal activities (Dawurung et al., 2019). In our current study, we continue to explore Nigerian medicinal plants that are useful in alleviating the symptoms of diarrhrea and sought to identify the compound(s) responsible for this activity. ...
Article
A phytochemical study on the root extracts of Neorautanenia mitis, a Nigerian medicinal plant used in the management of diarrhea, led to the isolation of one new and 19 known natural products. These compounds and crude extracts were evaluated for Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) Cl⁻ channel and calcium-activated Cl⁻ channel (TMEM16A) inhibitory activities in T84 and Calu-3 cells, respectively. Four compounds namely dolineon, neodulin, pachyrrhizine, and neotenone inhibited cAMP-induced Cl− secretion across T84 cell monolayers with IC50 values of ~0.81 μM, ~2.42 μM, ~2.87 μM, and ~4.66 μM, respectively. Dolineon having the highest inhibitory activity also inhibited a Ca + activated Cl⁻ channel (TMEM16A) with an IC50 value of ~4.38 μM. The in vitro antidiarrheal activity of dolineon was evaluated on cholera toxin (CT) induced chloride secretion in T84 cells, where it inhibited CT-induced chloride secretion by >70% at 100 μM. Dolineon also inhibited CT-induced fluid secretion by ~70% in an in vivo mouse closed loop model at a dose of 16.9 μg/loop. The cytotoxicity of the extracts and compounds was evaluated on KB, Vero and BHK21 cells, dolineon showed low cytotoxicity of >29.6 μM and 57.30 + 6.77 μM against Vero and BHK21 cells, respectively. Our study revealed that several compounds isolated from N. mitis showed antidiarrheal activity. The most active compound dolineon can potentially serve as a lead compound towards the development of CFTR and TMEM16A inhibitors as future therapeutics for secretory diarrhea.
... In recent years, the top priority in finding a new insecticide is that, they must be of plant origin and should not have any ill effects on the ecosystem. Researchers have proved the effectiveness of plant derived secondary compounds, such as saponin [4] , steroids [5] , isoflavonoids [6] , essential oil [7] , alkaloids and tannins [8] , as mosquito larvicides. Plant compounds and their essential oils provide alternative source of mosquito repellents agents [9] . ...
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The frequent use of systemic insecticides to manage insect pests leads to a destabilisation of ecosystem and enhanced resistance to insecticides and pests suggesting a clear need for alternatives. In addition, increasing documentation of negative environmental and health impact of synthetic insecticides and increasingly stringent environmental regulation of pesticides have resulted in renewed interest in the development and use of bio insect management products for controlling mosquitoes and pest. The present study focuses on larvicidal activity of methanol, ethanol, hexane, chloroform and aqueous extracts of whole plant (Argyreia nervosa) against Culex larva of Aedes, Anopheles and Culex. Argyreia nervosa was found to effective against the tested larvae. The extracts of Argyreia nervosa were found to exhibit potent mosquito to larvicidal activity. Since there is no previous report on the mosquito larvicidal activity of Argyreia nervosa whole plant extract, this plant can be further exploited to identify the active principle.
... Recent research has proved that effectiveness of plant derived compounds, such as saponine (Chowdhury et al. 2008), steroids, isoflavonoids, essential oils, alkaloids and tannins (Ghosh et al. 2011) have potential mosquito larvicides. Plant secondary metabolites and their synthetic derivatives provide alternative source in the control of mosquitos (Joseph et al. 2009). The present investigation was carried out to validate the larvicidal potential of different solvent extracts of five medicinal plants (Blepharis maderaspatensis (L.) B. Heyne ex Roth., Elaeagnus indica Servett., Maesa indica (Roxb.) ...
Article
The larvicidal potential of different solvent (hexane, chloroform, ethyl acetate, acetone and methanol) crude leaf extracts of five plants (Blepharis maderaspatensis, Elaeagnus indica, Maesa indica, Phyllanthus wightianus and Memecylon edule) were tested against the fourth-instar larvae of Aedes aegypti. All the tested extracts showed moderate to good larvicidal activities. However, the maximum larval mortality was detected in acetone extract of E. indica (LC50 90.89, LC90 217.21 and LC99 441.88 ppm) followed by M. indica acetone extract (LC50 173.21, LC90 289.86 and LC99 441.04 ppm). The results revealed that larvicidal properties of the four selected plants and encourages further investigation for the bioactive compounds that might possess good larvicidal properties in pure form. Asiat. Soc. Bangladesh, Sci. 44(1): 61-67, June 2018
... The mosquito has approximately 3500 species and present in tropical and subtropical regions of the world [77][78][79][80][81][82][83][84][85]. The larvicidal effect of the plant and plant-based products have well documented by several researchers, this attributed due to the presence of a wide array of phyto groups and novel compounds present in the plants [86][87][88][89][90][91][92][93][94][95][96]. ...
Article
The present investigation is designed and carried out with an objective of pesticidal and larvicidal activity of Citrus aurantium plant volatile oil against the adzuki bean weevil, Callosobruchus maculatus and Aedes aegypti larvae in the laboratory condition. In the present study, the insecticidal activity of C. aurantium was tested against the adults of C. maculatus with different concentrations such as 50, 100, 150 and 200 mg/mL. A perusal of the experimental data revealed that the 200 mg/mL concentration of the C. aurantium oil-induced significant mortalities at 24 hrs (82.2%), 48 hrs (84.6%) and 72 Hrs (94.2%). The lethal concentration (LC 50 value of 124.09 mg/mL with the LC 90 value of 227.88 mg/mL were calculated for 24 hrs. Similarly, the LC 50 value of 95.88 mg/mL and the LC 90 value of 223.44 mg/mL was calculated for 48 hrs. In the same way, the LC 50 value of 81.01 mg/mL with the LC 90 value of 184.64 mg/mL were also recorded for 72 hrs. C. aurantium induced significant larval mortality of 82.6, 86.8 and 90.2% at 24, 48 and 72 hrs exposure period respectively against the experimental larvae of Ae. aegypti at 200 mg/mL concentration. Whereas, the LC 50 values of 116.97 mg/mL was recorded; LC 90 was found to be 234.34 mg/mL for 24 hrs. The LC 50 values of 93.142 mg/mL with the LC 90 value of 217.93 mg/mL was calculated for 48 hrs. in the same way, the LC 50 values of 81.313 mg/mL and LC 90 was found to be 211.52 mg/mL calculated for 72 hrs. A detailed report is given in the manuscript and inferred that the application of plant volatile oil in general C. aurantium, in particular, will be of much use to keep the populations of selected pest and vector in check condition. This present investigation paves the way for the search for green pesticides in the future.
... Spreng and Blumea densiflora (Bagavan et al., 2008;Conti et al., 2010;Pitarokili et al., 2011;Rahuman et al., 2008a,b,c;Senthilkumar and Venkatesalu, 2010;Sharma et al., 2009;Xiao et al., 2012;Zhu and Tian, 2011). Several phytochemical compounds such as lansiumamide B, hrymarolin-I, haedoxane A, and haedoxane E, furocoumarins, 5-methoxypsoralen, 8methoxypsoralen, imperatorin, osthole, methyl-p-hydroxybenzoate, C15 acetogenin, evodiamine, rutaecarpine, wuchuyuamide I, evodol, limonin, 1α,3α,4β-trihydroxy-9-cadinen-8-one, Pectolinaringenin, meliternatin (3,5-dimethoxy-3′,4′,6,7-bismethylendioxyflavone) (6), flavones, prenylated flavonoids, isoflavonoids neotenone, neorautanone, pterocarpans eoduline, nepseudin, 4-methoxyneoduline, 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one, poncirin, rhoifolin, naringin marmesin, ecbolin A, niloticin, ecbolin B, m-pentadecadienyl-phenol, pyriproxyfen, diflubenzuron, (−)-3-epicaryoptin, etc, have mosquitocidal activity (Abou-Elnaga et al., 2011;Cecilia et al., 2014;Chung et al., 2011;Ho et al., 2003;Joseph et al., 2004;Kannathasan et al., 2011;Liu et al., 2012;Moon et al., 2011;Muthu et al., 2012;Niu et al., 2010;Pereira and Gurudutt, 1990;Rajkumar and Jebanesan, 2008;Reegan et al., 2014;Sathish Kumar and Maneemegalai, 2008;Souza et al., 2012;Suman et al., 2013;Wang et al., 2012;Xiao et al., 2012). ...
Article
The present study was aimed to check the mosquitocidal activity of tiliamosine isolated from Tiliacora acuminata (Lam.) Hook. f. & Thom against immature stages of Culex quinquefasciatus. Eggs and larvae of Cx. quinquefasciatus were exposed to different concentrations of tiliamosine - 0.5, 1.0, 1.5 and 2.0 ppm - prepared using DMSO. The compound tiliamosine showed good larvicidal activity with LC50 and LC90 values of 1.13 and 2.85 ppm respectively, against third-instar larvae of Cx. quinquefasciatus at 24 h. In control, the larvae exhibited normal movement. Tiliamosine exhibited 91% ovicidal activity at 2.0 ppm concentration after 120 h post-treatment. Lowest concentration of tiliamosine (0.5 ppm) showed 19% egg mortality. Histopathology study of the compound-treated larvae showed serious damage on the larval midgut cells. The treated larvae showed restless movement which was different from that of the control larvae. The larvae exhibited malformation in development. The compound tiliamosine was harmless to non-target organisms P. reticulata and Dragon fly nymph at tested concentrations. The compound was highly active and inhibited AChE in a concentration-dependent manner. Computational analysis of the tiliamosine had strong interaction with AChE1 of Cx. quinquefasciatus. This report clearly suggests that the isolated compound can be used as an insecticide to control mosquito population and thus prevent the spread of vector-borne diseases.
... There are several reports of the insecticidal and repellent effects of coumarins (De Oliveira et al. 2005;Tunon et al. 2006;Oranday et al. 2008). In addition, previous studies have shown that some coumarins with a structure of linear furanocoumarin or halogenated (3-mono/dibromo acetyl, 6-halogenated) coumarin have potent anti-mosquito properties (Khan et al. 2002;Joseph et al. 2004;Wang et al. 2012). In the present research, only oxypeucedanin with a structure of linear furanocoumarin showed moderate toxicity against A. stephensi with LC 50 and LC 90 values of 116.54 and 346.41 ppm, respectively. ...
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Many researchers have focused on controlling pest insects and vectors by natural products because of their low environmental pollution. The present study was conducted to evaluate the antioxidant and larvicidal activities of chloroform and methanol extracts of the leaves, fruits, roots, and isolated coumarin compounds (prantschimgin, oxypeucedanin, and 6-hydroxymethylherniarin) of Ferulago trifida from the Apiaceae family against Anopheles stephensi as one of the main malaria vectors. For insecticidal evaluation, A. stephensi larvae were exposed to different concentrations of the extracts and pure compounds (0.625–1280 ppm) according to the WHO protocol. The mortality percentages were measured 24 h after treatment and lethal concentration values were calculated. In addition, radical scavenging activities of the mentioned extracts and compounds were measured by the DPPH method. The methanol extract of fruits showed potent insecticidal properties with LC50 and LC90 values of 2.94 and 18.12 ppm, respectively. The chloroform extracts of the fruits and leaves were the second and third extracts with larvicidal effects. Among pure compounds, only oxypeucedanin showed moderate toxicity against A. stephensi with LC50 and LC90 values of 116.54 and 346.41 ppm, respectively. The antioxidant activities of the methanol extracts of leaves and fruits were stronger than other extracts with IC50 values of 155.83 and 159.32 ppm, respectively. In conclusion, the methanol extract of F. trifida fruits can be used as a potent bio-insecticide in green control programs of mosquitoes, especially A. stephensi.
... In recent years, the top priority in finding a new insecticide is that, they must be of plant origin and should not have any ill effects on the ecosystem. Researches have proved the effectiveness of plant derived secondary compounds, such as saponin [10] , steroids [11] , isoflavonoids [12] , essential oil [13] , alkaloids and tannins [14] , as mosquito larvicides. Plant compounds and their essential oils provide alternative source of mosquito repellents agents [15] . ...
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The resistance to chemical insecticides among mosquito species has been considered as a setback in vector control. The present study is focused on natural products of plant origin with insecticidal properties for control of insect vectors. Aqueous, ethanol, methanol, acetone and chloroform extracts of Lantana camara aculeata were evaluated against the fourth instar larvae of three important medically significant mosquito species namely Aedes aegypti, Anopheles stephensi and Culex quinquefasciatus. Phytochemical screening of the leaves showed the presence of phytocompounds such as tannins, alkaloids, flavonoids, anthocyanin, quinines, triterpenoids, flavonoids, saponin and steroids. The leaf extract was also subjected to GC-MS analysis. The percentage mortality of the different mosquito species was tested after 24 hrs of exposure to different concentration of the leaf extract. The extracts of this plant showed potent larvicidal efficacy and can be considered for further investigation.
... Dovepress Dovepress 24 Badawy et al insecticide for generations increases the risk of mosquitoes developing resistance accompanied by dangerous effects on human, nontarget organism, and the environment. 1,[11][12][13][14] Organophosphates are insecticides which accumulate at low levels in the environment and are hydrolyzed at high or low pH. 15,16 These were first developed as nerve gases, and their insecticidal effectiveness was discovered shortly thereafter. ...
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Efficacy of spinosad and malathion loaded in eco-friendly biodegradable formulations was evaluated for controlling Culex pipiens larvae. Malathion (organophosphorus larvicide) and spinosad (naturally derived insecticide) were loaded on chitosan/alginate/gelatin capsules. Capsules were characterized by size measurement, scanning electron microscopy, Fourier transform infrared spectroscopy, and water uptake. In vitro release kinetics of the larvicides was studied in the running and stagnant water. Biochemical studies on the larvae treated with technical and formulated insecticides were also demonstrated. The results indicated that the released spinosad was active for a long time up to 48 and 211 days in the running and stagnant water, respectively. However, the capsules loaded with malathion showed larvicidal activity for 20 and 27 days in the running and stagnant water, respectively. Technical and formulated malathion and spinosad had an inhibition effect on acetylcholinesterase, carboxylesterase, and glutathione S-transferase. The results proved that the prepared capsules consisting of biodegradable polymers containing larvicides could be effective as controlled-release formulation against C. pipiens larvae for a long period.
... Many natural compounds have been reported for larvicidal activity. For example, flavonoids namely poncirin, rhoifolin, naringin and marmesin from Poncirus trifoliate (13), lupinfolin and rotenone and deguelin from Derris trifoliate (14), new iridoid glycosides like 6'-O-rhamnosylharpagide and 6-O-xylosylharpagoside-B form Ajuga remota (15) and coumarins such as umbelliferone, herniarin, psoralen and xanthotoxin from Cnidium monnieri (16) and coumarin derivative pachyrrhizine from Neorautanenia mitis (17). ...
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Background Scrophularia striata is a perennial plant which is native in all parts of Iran, Turkey, and Azerbaijan. In this study, the total phenol content, antioxidant and larvicidal activities of total extract and different fractions of this plant were evaluated. Methods The aerial parts of S. striata were collected from Boli village, Illam Province, western Iran in Apr 2013. The total phenol content of total extract and different fractions were evaluated by Folin-Ciocalteu method. Moreover, antioxidant activity was tested by DPPH and FRAPS assays. Larvicidal activity was investigated according to standard method described by WHO. Results Ethyl acetate fraction (EF) had the highest content of total phenol (75.9±0.06mg Gallic acid equivalent/g dry extract). Furthermore, among the tested extract, methanol-water fraction (MWF), total methanol extract (TME) and water fraction (WF) showed the highest antioxidant activity in the DPPH assay (IC50= 226.8, 283.66 and 299.4 μg.ml⁻¹, respectively). In FRAP assay MWF and WF and TME had the highest antioxidant activities (664.4±0.002, 565.3±0.003, 519.5±0.003mmol FeII/g dry extract, respectively). Ethyl acetate fraction had maximum larvicidal activity (LC50 49.1ppm) followed by TME (LC50 64.26ppm) and hexane fraction (HF) (LC50 89.69). Conclusion Scrophularia striata collected from west of Iran illustrated considerable antioxidant and larvicidal effects and further in vitro and in vivo experimental models for investigation would be required.
... The effectiveness of secondary metabolites such as alkaloids, isoflavonoids, saponine and steroids has potential mosquito larvicides. [22][23][24] According to Pedro et al 25 phytocompounds such as flavonoids, alkaloids and saponins are responsible for insecticidal activity. Kotkar et al 26 reported that flavonoids isolated from Annona squamosa are effective as insecticides against Callosobruchus chinensis. ...
Article
Objective: The bio-efficacy of Tephrosia purpurea leaf extract and bacterial insecticide, Bacillus sphaericus larvicidal activity was assessed against the first to fourth instars larvae of Aedes aegypti, under the laboratory conditions. Methods: The plant material was shade dried at room temperature and powdered coarsely. T. purpurea and B. sphaericus show the various concentrations of larvicidal and pupicidal activity against various instars larvae of A. aegypti. Results: The LC50 of T. purpurea against the first to fourth instars larvae were 139.24, 176.24, 219.28, 256.27, and 326.29 ppm and the 480.72, 541.21, 580.34, 672.20, and 762.80 ppm, respectively. B. sphaericus against the first to fourth instars larvae the LC50 values were 46.16, 56.23, 69.82, 80.81 and 96.12 ppm and the LC90 values 141.68, 172.46, 184.21, 193.31 and 218.16 ppm, respectively. However, the combined treatment of T. purpurea + B. sphaericus (1:2) material shows highest larvicidal activity of the LC50 values 80.08, 82.21, 88.00, 92.21 and 98.16 ppm; The LC90 values of 108.39, 118.71, 136.75, 149.02 and 153.24 ppm, against A. aegypti in all the tested concentrations than the individuals and clearly established that there is a substantial amount of synergist act. Conclusion: The present study reported that both T. purpurea and B. sphaericus materials could serve as a potential larvicidal agent. Since, A. aegypti is a container breeder vector mosquito this user and eco-friendly and low-cost vector control strategy could be a viable solution to the existing dengue disease burden. Therefore, this study provides first report on the mosquito larvicidal activity the combined effect of T. purpurea leaf extract and B. sphaericus against as target species of A. aegypti.
... All of these vector-borne diseases occur mainly in tropical countries where more than two billion people live in endemic regions [10]. The approaches to combating vector-borne diseases relies on the interruption of the disease transmission cycle by either targeting the adult or larvae through spraying breeding sites or targeting adults using insecticides [11]. Synthetic pesticides have been extensively used for mosquito control by either killing the vectors, preventing adult mosquitoes from biting humans or by killing mosquito larvae at breeding sites [12,13]. ...
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Background Mosquitoes are well-known vectors of many diseases including malaria and lymphatic filariasis. Uses of synthetic insecticides are associated with high toxicity, resistance, environmental pollution and limited alternative, effective synthetic insecticides. This study was undertaken to evaluate the larvicidal efficacy of clove and cinnamon essential oils against laboratory Anopheles gambiae (sensu stricto) and wild An. arabiensis larvae. Methods The standard WHO guideline for larvicides evaluation was used, and the GC-MS machine was used for active compounds percentage composition analysis and structures identification. Probit regression analysis was used for LC50 and LC95 calculations while a t-test was used to test for significant differences between laboratory-reared and wild larvae populations in each concentration of plant extract. Results Mortality effect of clove and cinnamon essential oils against wild and laboratory-reared larvae had variations indicated by their LC50 and LC95 values. The mortality at different concentrations of cinnamon and clove post-exposure for wild and laboratory-reared larvae were dosage-dependent and were higher for cinnamon than for clove essential oils. The mortality effect following exposure to a blend of the two essential oils was higher for blends containing a greater proportion of cinnamon oil. In the chemical analysis of the active ingredients of cinnamon essential oil, the main chemical content was Eugenol, and the rarest was β-Linalool while for clove essential oil, the main chemical content was Eugenol and the rarest was Bicyclo. Conclusion The essential oils showed a larvicidal effect which was concentration-dependent for both laboratory and wild collected larvae. The active ingredient compositions triggered different responses in mortality. Further research in small-scale should be conducted with concentrated extracted compounds.
... The ethyl acetate and butanol fractions enriched in polyphenols and flavonoids proved to be active against malaria with a promising to moderate activity (specificity index of 3.1 and 2.4, respectively). Numerous studies have been reported wide varieties of pharmacological activities of polyphenols and flavonoids, including antiplasmodial activity [24,25]. Antiplasmodial activity has been reported for some biflavonoids primarily (I-30, II-8)-biflavones, in which a high number of methoxy substituents were associated with high activity [26]. ...
Article
Introduction Drugs resistant Plasmodium falciparum is a recurring issue that threatens public health. New antiplasmodial drugs are needed to overcome this problem. The aim of this study was to characterize in vitro antiplasmodial activity of Withania frutescens (Solanaceae) against chloroquine-resistant Plasmodium falciparum strain. Methods The in vitro antiplasmodial activity of leaves and roots extracts from Withania frutescens was performed in 96 well plates and preliminary phytochemical analysis was performed for the active fractions. The toxicity of the plant extract against CHO (Chinese Hamster Ovary) cells was assessed using the tetrazolium salt MTT colorimetric assay. The selectivity index (SI) was calculated as the ratio between the cytotoxic and antiparasitic activities. Results The methanol extract of W. frutescens leaves showed a good antiplasmodial activity (CC50 18.1 μg/ml). Furthermore, ethyl acetate and butanol fractions showed promising in vitro antiplasmodial activity with a selectivity index of 3.1 and 2.4, respectively. The roots of W. frutescens were found to be inactive with a CC50 value >80 μg/ml. Conclusion The antiplasmodial activity of W. frutescens may in part be attributed to the presence of polyphenolic and flavonoid compounds. Based on our results, ethyl acetate and butanol leaves fractions could be considered as a promising source for the development of putative antiplasmodial drugs.
... The highest larvicidal activity was observed at 20 ppm dose against third instar larvae at 97.33%, and no mortality was observed in the control group. Dosedependent mortality was highly corroborated with previously reported studies (Joseph et al. 2004;Muthu et al. 2012). ...
Article
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Upon screening for novel and potential biocompounds with larvicidal activities, we successfully isolated hamisonine (HMSN) a limonoid compound from endophytic fungi Penicillium oxalicum LA-1 of Limonia acidissima. The extracted compound structure was elucidated by spectral studies such as UV-vis spectroscopy, thin-layer chromatography, FTIR, LC-ESI-MS, ¹H NMR, and ¹³C NMR upon comparing with the spectral data available in the literature. Further, the isolated HMSN was tested against III and IV instar Culex quinquefasciatus larvae. The outcome of this study clearly emphasize that the extracted compound HMSN possesses a stupendous larvicidal activity in a dose-dependent manner with the LC50 and LC90 values of 1.779 and 7.685 ppm against III instar larvae and 3.031 and 28.498 ppm against IV instar larvae of C. quinquefasciatus, respectively. Interestingly, the histological studies evidently showing the damage of peritrophic membrane and epithelial cells of testing mosquito larvae.
... ULV applications involve small quantities of pesticide active ingredient in relation to the size of the area treated, which minimizes exposure and risks to people and the environment [9,10]. However, continued use of adulticides for generations develops the phenomenon of resistance accompanied by harmful effects 2 Journal of Tropical Medicine on human health and the environment [1,[11][12][13]. The search for ecofriendly alternative mosquitocides that have minimal risk to human health and the environment is considered the goal of many researchers. ...
Article
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Different mixtures of monoterpenes (ketone, alcohol, and alkene) were loaded on paper discs and wax and their knockdown activities were evaluated against Culex pipiens adults. Some individual monoterpenes were also evaluated by residual toxicity technique. Citronella oil as a reference was also loaded separately or in combination with monoterpenes on paper discs and wax. The ketone monoterpenes mixture (camphor, menthone, carvone, and fenchone) on paper discs was the most active (KT 50 = 17.20 min) followed by ketone monoterpenes with citronella oil (KT 50 = 20.79 min) and citronella oil alone (KT 50 = 28.72 min). Wax formulations proved that the ketone and alcohol (geraniol, thymol, and menthol) monoterpenes gave the most activity as knockdown (KT 50 = 31.79 and 43.39 min, resp.). Alcohol monoterpenes formulation recorded KT 50 = 43.39 min. Residual activity of tested individual monoterpenes reported that the menthol was more toxic than camphor and camphene. Generally, this study suggests that the monoterpenes have the properties, which make them used as eco-friendly compounds in the control programs of Cx. pipiens adult. The use of paper discs is more applicable than wax in the adulticidal formulations.
... This indicates that constituents active against adult mosquitoes were eluted in the dichloromethane fraction. The finding in the present study that dichloromethane partitioned of O. africana had superior toxicity against adults An. arabiensis is supported by the report of Joseph et al. [41] who show DCM extracts of the plant Neorautanenia mitis, to have the highest (LC 50 3.05 ppm) anti-adult An. gambiae activity. The high potency of the DCM fraction of O. africana and EtOAc fraction of P. capense against An. ...
Article
The efficacy of synthetic inorganic insecticides to control malaria vector mosquitoes is compromised by increased mosquito resistance to insecticides. Furthermore, use of inorganic insecticides raises serious environmental toxicity concerns. The test plants, Oreosyce africana and Piper capense were identified in Ethiopia through ethnobotanical leads obtained on the basis formal and informal field interviews and discussions coupled with literature search for sister species tested elsewhere. The plant powder from these species was extracted using 80% methanol and the methanol crude extracts of Oreosyce africana and Piper capense were sequentially fractionated with solvents (dichloromethane, ethyl acetate and deionized water). Each fraction was dissolved in dimethyl sulfoxide and deionized water; test concentration prepared and tested for their bioactivity against Anopheles arabiensis adults. The dichloromethane fraction of Oreosyce africana and ethyl acetate fraction of Piper capense had higher adulticidal activities with LC50 and LC90 values of 4.27 and 14.12 ppm and 10.72 and 30.59 ppm, respectively. Comparison of dichloromethane fraction of Oreosyce africana with ethyl acetate and water fractions showed significant differences at p<0.05. And comparison of ethyl acetate fraction of Piper capense with dichloromethane and water fractions showed significant differences at p<0.05. Thus, the bioassays with dichloromethane fraction of Oreosyce africana and ethyl acetate fraction of Piper capense exhibited higher adulticidal effect against Anopheles arabiensis than other solvent fractions. Dichloromethane fraction of Oreosyce africana and ethyl acetate fraction of Piper capense were examined under HPLC and UV-Vis for the proximate analysis. These plant products would be ideal alternatives for the control of malaria vector mosquitoes upon fractionation and preparation of suitable delivery packages.
... Sua estrutura química se baseia na presença de quatro anéis; os diferentes Essas substâncias atuam como fitoalexinas, sendo produzidas pelas plantas como forma de defesa em resposta a agressões extrernas, como por exemplo infecções por fungos (Brooks e Watson, 1991). De fato vários pterocarpanos isolados de plantas mostraram atividade anti-microbiana (Joseph et al., 2004). Uma série de outras propriedades biológicas tem sido relatada para substâncias deste grupo, tais como ação antiofídica, inibindo as atividades miotóxica e hemorrágica de doses letais do veneno de Bothrops jararaca; estrogênica, ativando os receptores estrogênicos α e β (Kostelac et al., 2003); ação inibitória em diversas enzimas como fosfolipase D, ciclooxigenases 1 e 2 e da bomba Na + /K + -ATPase (Hegde et al., 1995;Selvam et al., 2004;Poças, 2003); e ainda, efeito antitumoral. ...
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Multidrug Resistance (MDR) is one of the main causes for cancer therapy failure, where once sensitive cells are selected, then show cross-resistance to different substances with no functional or structural relation. The MDR phenomenon is multi-factorial, and different molecular mechanisms are linked to this resistance. The aim of this work was to describe the anti-tumor effect of new synthetic compounds in human leukemias and lung cancer, searching for a correlation between cytotoxicity and MDR-associated mechanisms. Results from the first part of this work showed that pterocarpans had promising anti-tumor effects, being able to induce cell death, disrupt the cell cycle and reduce the viability of diverse leukemic cells. When comparing the cytotoxic effect to the structure of the compound evaluated, it was possible to spot specific chemical groups that were involved on the cytotoxicity. However, two most promising compounds showed toxicity toward normal cells as well as stability-related problems. Thus, it was important to search for new chemical groups that could contribute to overcome these drawbacks. Quinones are well-known substances on pharmacology, being present on widely used chemotherapy agents such as vincristine, daunorubicin and mitomycin C. Despite not presenting cytotoxic effect on their own, it was proposed that the chemical structure of quinones studied on this work could be used to produce a new class of synthetic compounds, hybrid between pterocarpans and quinones. These new compounds, named pterocarpanquinones, showed effects comparable to the pterocarpans, however overcoming the stability problems. Cytotoxicity could also be observed to human lung cancer cells, where the effect was modest when compared to the leukemias. However, since there are few options for the therapy of this malignancy, the result is still of interest. Keywords: 1. Leukemia. 2. Lung Cancer. 3. Pterocarpans. 4. Quinones. 5. Multidrug Resistance. 6. Chemotherapy.
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Mosquito-borne diseases represent a growing health challenge over time. Nanostructured lipid carriers (NLCs) are the second generation of solid lipid nanoparticles (SLNs), and they continue to attract significant interest as potential diagnostic and therapeutic tools in disease inhibition and insect control. Activated ingredients presented in the Poinciana leaves were extracted and GC–MS data indicated an increased abundance of terpenes, flavonoids, and phenolic substances. Poinciana extract was encapsulated to the vicinity of nanostructure lipid carrier, Po-NLC, and surface modified with magnetic nanoparticles, Po-NLC-MNPs. The synthesized nanoparticles depicted average particle size of 73.2 and 75.55 nm while zeta potential of (− 29.4) and (‒ 4.44 mV) for Po-NLC and Po-NLC-MNPs, respectively. Transmission electron microscope and morphology determination showed regular, irregular spherical and oval shapes with diverse single particle size. X-rays diffraction pattern of the freely synthesized MNPs was compared to the decorated NLC and the results manifested that the NLC was successfully decorated with MNPs. The larvicidal activity of plant extract, Poinciana extract (Po), and their nanoparticle conjugates against 3rd instar larvae of Culex pipiens was evaluated at 50, 100, 200, 500, 1000, and 1500 ppm concentrations. Both high and low concentrations of Po-NLC-MNPs, indicated potential larval mortality than plant extracts (Po extract) itself. The mortality rate reached 100% for 3rd instar larvae. Based on their relative toxicity, (Po-NLC-MNPs) was the best at killing larvae, followed by Po-NLC. The synthesized nps were checked for their cytotoxic effect against wi38 cell line. The in-vitro cytotoxicity results indicated that there was no significant cytotoxicity and the nanocomposite barely caused weak changes in the tested cells. The synthesized nanoparticles have potential to create a new generation of eco-friendly, effective alternatives for controlling mosquito-borne diseases.
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Mosquitoes are one of the deadliest and most hazardous animals on Earth, where they transmit several diseases that kill millions of people annually. There is an ongoing search almost everywhere in the world for more effective and contemporary ways to control mosquitoes other than pesticides. Phytochemicals are affordable, biodegradable biological agents that specialize in eliminating pests that represent a risk to public health. The effectiveness of Acacia nilotica methanol and aqueous leaf extracts against 4th instar larvae was evaluated. The results revealed that the methanol extract of A. nilotica had a noticeable influence on the mortality rate of mosquito larvae, especially at high concentrations. Not only did the mortality rate rise significantly, but the hatching of the mosquito eggs was potentially suppressed.Terpenes, fatty acids, esters, glycosides, pyrrolidine alkane, piperazine, and phenols were the most prevalent components in the methanol extract, while the aqueous extract of A. nilotica exclusively showed the presence of fatty acids. The insecticidal susceptibility tests of both aqueous and alcoholic extract of A. nilotica confirmed that the Acacia plant could serves as a secure and efficient substitute for chemical pesticides because of its promising effect on killing larvae and egg hatching delaying addition to their safety as one of the natural pesticides. Molecular docking study was performed using one of the crucial and life-controlling protein targets, fatty acid binding protein (FABP) and the most active ingredients as testing ligands to describe their binding ability. Most of the structurally related compounds to the co-crystallized ligand, OLA, like hexadecanoic acid furnished high binding affinity to the target protein with very strong and stable intermolecular hydrogen bonding and this is quite similar to OLA itself. Some other structural non-related compounds revealed extraordinarily strong binding abilities like Methoxy phenyl piperazine. Most of the binding reactivities of the majortested structures are due to high structure similarity between the positive control, OLA, and tested compounds. Such structure similarity reinforced with the binding abilities of some detected compounds in the A. nilotica extract could present a reasonable interpretation for its insecticidal activity via deactivating the FABP protein. The FABP4 enzyme inhibition activity was assessed for of both methanolic and aqueous of acacia plant extract and the inhibition results of methanol extract depicted noticeable potency if compared to orlistat, with half-maximal inhibitory concentration (IC50) of 0.681, and 0.535 µg/ml, respectively.
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This work was conceived in the context of valorisation of the endemic forest species Cedrus atlantica (Pinaceae family), widespread in the mountainous massif of eastern Algeria. This study aimed to investigate the antioxidant and insecticidal activity of the methanolic extract of the aerial part (leaves) of C. atlantica (CAMeOH). The extraction made it possible to obtain a yield of approximately 7.49% from 350 g of dry powdered plant material. The results of the phytochemical screening revealed the presence of tannins, alkaloids, terpenoids and flavonoids as major components. In vitro antioxidant evaluation was carried out using two different methods. The reducing power assay test result revealed an optical density (DO) value of 1.7±0.02 at a dose of 600 µg/mL of CAMeOH. Concerning the iron chelation activity, the recorded IC50 value was 62.12 μg/mL and R²=0.87. The insecticidal activity against the stored-food insect Tribolium confusum was evaluated using the contact treatment mode and showed a significant dose-dependent effect (P≤0.05) with a mortality rate of 98.32 ± 0.50 % at a dose of 50 mg/mL (after 96 hours of contact). The results of this study confirmed the potential antioxidant and insecticidal activity of the methanolic extract from the leaves of C. atlantica.
Article
Mosquitoes are a vector of dangerous diseases that kill millions of people annually. The traditional methods of control depend on the use of pesticides, which leads to the emergence of resistance against them over time, in addition to the pollution they leave in the environment and the targeting of beneficial organisms. Therefore, this study aimed to use extracts of natural products from Juniperus procera and Dodonaea viscosa plants in the control of mosquito larvae of Culex pipiens, as well as their applications in nanoparticle synthesis and effectiveness on mosquito larvae. These nanoparticles were determined and confirmed using multiple techniques, including UV–visible spectrometry, Fourier transform infrared spectroscopy and scanning electron microscopy. The IC50 values of the extracts plus silver nanoparticles were 20.871 and 105.166 ppm, a 5.03- and 2.17-fold increase over the individual extracts, with IC50 values of 105.166 and 228.271 ppm, respectively. In addition, some morphological deformations were observed on the treated larvae through the stage of larval development into a pupa and the stage of emergence from a pupa into a complete insect.
Article
Vector borne diseases can be controlled by managing the mosquito population. So the present study was done to evaluate larvicidal activities of Cajanus cajan mature leaf extracts against the Japanese encephalitis vector Culex vishnui. Crude and three different solvent extracts of C. cajan leaves were applied for larvicidal bioassay against the all instars larvae of Cx. vishnui. For statistical justifications log probit, regression and ANOVA analyses were performed. Non-target organisms were also evaluated against crude and ethyl acetate solvent extract of mature leaves. The IR analysis and GC-MS analyses were carried out to find out the active ingredient. 0.5% concentration of crude extract showed highest larval mortality after 72 h of exposure. Amongst the three tested solvent extracts namely n-Hexane, ethyl acetate and chloroform: methanol (1:1 v/v), ethyl acetate extract exhibited the most potent larvicidal activity. In ethyl acetate extract 100% mortality was found in 100 ppm concentration against 1st instar larvae after 72 h of exposure. Chemical characterization revealed that the active ingredient belongs to the flavonoids group of compound which might be responsible for larval toxicity. However, the bioassay against the non-target organisms revealed that, they were mostly safe to the extracts. The results support that C. cajan mature leaves can be used as an ecofriendly larvicidal agent against the Cx. vishnui in near future.
Article
Japanese encephalitis is a vector borne disease and the best procedure for control of this disease is control of vector population. Now a day use of phyto-chemicals more preferred over use of chemical insecticides. Isolation, purification and determination of chemical structures of bioactive compounds were done successfully from n-hexane extract of leaf of M. ferrea. The compounds shows better potentiality to control Cx. vishnui 3rd instars larvae. n-hexane extract of leaf of M. ferrea was prepared by Sohxlet apparatus and further used for bioassay against 3rd instars larvae of Cx. vishnui. n-hexane extract was further fractioned by Thin layer chromatography to isolate bioactive compounds. From different band of TLC, bioactive compounds bearing band was isolated by bioassay test. Structures of active principles were determined by FTIR, gas chromatography, mass spectrometry and with the help of library data list. Cent percent mortality of Cx. vishnui larvae was recorded at 45 ppm concentration of n-hexane extract of M. ferrea after 72 h of exposure. In isolated bioactive compounds 3-(2-Hydroxyphenoxy)-1, 2-propanediol is one of predominant compound, may be responsible for mortality of Cx. vishnui larvae. LC50 value for Cx. vishnui 3rd instars larvae of active compound are 26.76, 25.64 and 20.32 ppm for 24 h, 48 h and 72 h respectively. No mortality were recorded when sub lethal concentration (LC50) of 24 h of bioactive compound applied on non-target organisms i.e. Chironomus circumdatus, Daphnia, Diplonychus etc. The compound i.e. 3-(2-Hydroxyphenoxy)-1, 2-propanediol is predominant compound of active principles and its chemical structure is determine which is major component of n-hexane extract of leaf of M. ferrea. These bioactive principles are safe for other organisms (non-target) those share the same natural habitat.
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Biopesticides from botanicals are nowadays actively encouraged in the mosquito control program because of their low mammalian toxicity, biodegradability, and target specificity. However, leaf methanolic extracts and essential oils of Callistemon rigidus and Eucalyptus camaldulensis were evaluated individually and in combination on third- and fourth-instar larvae of Anopheles gambiae. The extracts were tested individually and in combination at doses of 125, 250, 500, and 1000 ppm while essential oils were applied at 25, 50, 100, and 200 according to the standard protocol of WHO. The commercial insecticide Bi-one tested at the recommended dose of 1000 ppm was used as positive control while the solution of tap water containing 0.5 ml of methanol was used as negative control. The mortality of the larvae was recorded after 24 h postexposure. In the results, 100% mortality of the larvae was recorded with the extracts of C. rigidus and the combinations E50% : C50% and E25% : C75% of the plants as well as positive control (1000 ppm). Similarly, essential oils of the two plants and their combinations caused 100% mortality of the larvae. Among the various combinations of the extracts and essential oils, only the combination E75% : C25% of essential oils presented a synergistic effect. Therefore, the essential oil combination (E75% : C25%) of the plants E. camaldulensis and C. rigidus is recommended in order to promote the its use in the form of natural biocide in the implementation of effective insect controls against the mosquito larvae, vector of malaria.
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Mosquitoes are a serious threat to the society, acting as vector to several dreadful diseases. Mosquito management programes profoundly depend on the routine of chemical insecticides that subsequently lead to the expansion of resistance midst the vectors, along with other problems such as environmental pollution, bio magnification, and adversely affecting the quality of public and animal health, worldwide. The worldwide risk of insect vector transmitted diseases, with their associated illness and mortality, emphasizes the need for effective mosquitocides. Hence there is an immediate necessity to develop new eco-friendly pesticides. As a result, numerous investigators have worked on the development of eco-friendly effective mosquitocidal compounds of plant origin. These products have a cumulative advantage of being cost-effective, environmentally benign, biodegradable, and safe to non-target organisms. This review aims at describing the current state of research on behavioral, physiological, and biochemical effects of plant derived compounds with larvicidal effects on mosquitoes. The mode of physiological and biochemical action of known compounds derived from various plant families as well as the potential of plant secondary metabolites, plant extracts, and also the essential oils (EO), as mosquitocidal agents are discussed. This review clearly indicates that the application of vegetal-based compounds as mosquito control proxies can serve as alternative biocontrol methods in mosquito management programes.
Article
To evaluate the bioefficacy of crude extract and fractions from the leaves of Couroupita guianensis Aubl. against second and fourth instar larvae of Culex quinquefasciatus Say and Aedes aegypti L. The phytochemical parameters of hexane extract derived fraction were analyzed. Chromatographically enriched fractions from hexane extract were eluted by hexane: ethyl acetate solvent system through silica gel. Larval toxicity assay was conducted with water containing the crude extract from 125 to 1000 ppm and fractions of effective crude extract was tested from 25 to 200 ppm concentrations against C. quinquefasciatus and A. aegypti. Among the three solvent crude extracts hexane extract of C. guianensis showed promising larvicidal activity against the two vector mosquitoes followed by chloroform and ethyl acetate. Chromatographically eluted fraction 3 showed promising larvicidal activity followed by fractions 2 & 8 compared with the crude extract. It is concluded that C. guianensis extract has the potential to control Cx. quinquefasciatus and Ae. aegypti without harming nontarget fish.
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A series of sixteen 8-azacoumarin derivatives bearing aryl moieties at C-5 and C-7 was designed and synthesized by a concise and facile procedure utilizing grinding and ultrasound approaches. The efficient multi-component protocols proceeded smoothly and in the absence of solvent to furnish the target products in moderate to good yields. All the synthesized molecules were characterized via ¹HNMR, ¹³CNMR, IR, mass spectra, and elemental analyses. The density functional theory (DFT) was then used to discover the structural and electronic characteristics of such compounds. Finally, an insecticidal study against Plutella xylostella and Helicoverpa armigera on the synthesized compounds is reported. The bioassay results indicated that some of the tested compounds showed potency ranging from good to moderate. In particular, analogs 6i and 6l, among the tested compounds, showed even more potency than commercial chlorpyrifos. On the other hand, the rest of the tested compounds showed moderate to weak activities.
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The present study focused on the insecticidal potential of easily available local botanicals using a simple but effective method. Seven indigenous plants (Cinnamomum tamala (taiz pat), Aloe vera (aloe vera), Datura alba (datura), Allium sativum (garlic), Allium cepa (onion), Zingiber officinale (ginger), and Ocimum basilicum (niazbo/basil) were tested for their larvicidal efficacy against Culex quinquefasciatus (Say) under laboratory conditions. The evaluation of a series of five concentrations (1%, 2%, 3%, 4%, and 5%) of aqueous plant extracts against the 4th instar larvae revealed convincing larval mortality effects at 24 and 48 h after exposure. Larval mortality showed a significant concentration-dependent correlation. No mortality was observed in the control. The LC50 values demonstrated garlic as the most effective (1.37%), followed by taiz pat (1.48%) and aloe vera (1.96%), at 24 h. Moreover, the LC50 at 48 h showed high efficiency by aloe vera (0.37%), followed by garlic (0.55%) and taiz pat (0.98%). The sequence of LC50 values for the other plants were onion (2.20%) < datura (2.49%) < niazbo (5.32%) < ginger (7.48%) after 24 h and datura (1.13%) < niazbo (1.17%) < onion (1.24%) < ginger (2.43%) after 48 h. Taken together, the aqueous extracts of all plants exhibited potential efficacy against C. quinquefasciatus larvae and could be considered as potent natural larvicidal agents. These plants may be recommended for use in mosquito management programs as potential alternatives to synthetic insecticides. The simple aqueous extraction method is easy and inexpensive and can be used at the home level for mosquito management
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Based on a rationally conceived pharmacophore model to build a dual-target mosquito larvicide, a family of coumarin-dibenzothiophene or -carbazole hybrids with various substituents on phenyl were synthesized in moderate yields. Larvicidal activity of hybrid molecules were evaluated against fourth instar larvae of Aedes aegypti. Most of the synthesized hybrids displayed moderate to high activity and the activities of coumarin-linked carbazole hybrids were better than those of dibenzothiophene hybrids. The structure–activity relationships revealed that coumarin, dibenzothiophene and carbazole were the key pharmacophore and carbazole derivatives consisting of an electron-withdrawing group in the coumarin–carbazole hybrid molecular structure possess better activity than their corresponding parent compound. Graphical Abstract Open image in new window
Article
Botanical insecticides provide a multitude of chemistries for the development of new pest management products. Despite relatively low rates of expansion of botanically based pesticides, regulatory changes in many parts of the world are driving a renaissance for the development of new natural pest control products that are safer for human health and the environment. Africa is arguably the continent with the most to gain from developing natural plant-based pesticides. Hundreds of indigenous and exotic species with pesticidal properties have been reported from Africa through various farmer surveys and subsequent research, many of which have been confirmed to be active against a range of arthropod pests. On-farm use of pesticidal plants, particularly among resource-poor smallholder farmers, is widespread and familiar to many African farmers. Until recently, the pyrethrum industry was dominated by East African production through small holder farmers, showing that non-food cash crop production of pesticidal plants is a realistic prospect in Africa when appropriate entrepreneurial investment and regulatory frameworks are established. This paper reviews the current status of research and commercialisation of pesticidal plant materials or botanically active substances that are used to control pests in Africa and establishes where major gaps lie and formulates a strategy for taking research forward.
Chapter
Mosquitoes act as vectors for many life-threatening diseases like malaria, yellow fever, dengue fever, chikungunya, filariasis, encephalitis, West Nile virus infection, etc. Vector control is by far the most successful method for reducing the incidence of mosquito-borne diseases, but the emergence of widespread insecticide resistance and the potential environmental issues associated with some synthetic insecticides has indicated that additional approaches to control the proliferation of mosquito population would be an urgent priority research. Mosquitoes develop genetic resistance to synthetic insecticides and even to biopesticide such as Bacillus sphaericus. Also synthetic insecticides adversely affect the environment by contaminating air, water, and soil. There is an urgent need to find alternatives to the synthetic insecticides which are more potent and low cost. Plants are a rich source of alternative agents for control of mosquitoes, because they possess bioactive chemicals, which act against a limited number of species including specific target insects and are eco-friendly. Traditionally, plant-based products have been used in human communities for many centuries for managing insects. Several secondary metabolites present in plants serve as a defense mechanism against insect attacks. These bioactive chemicals may act as insecticides, antifeedants, molting hormones, oviposition deterrents, repellents, juvenile hormone mimics, growth inhibitors, antimolting hormones, as well as attractants. Plant-based pesticides are less toxic, and there is a delay in the development of resistance because of their new structure and easy biodegradability. In present article, the local and traditional uses of plants in mosquito control, current state of knowledge on phytochemical sources, and the mosquitocidal properties of secondary metabolites have been reviewed.
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The Ocimum plant was traditionally used for mosquitoes repellent and control in India especially in Tamil Nadu. In this research, deals with the larvicidal, pupicidal and adulticidal potential of three different solvent extracts of O. canum against Aedes aegypti. The overall result highlights that the chloroform extracts of O. canum were shown significant larvicidal (15.027 mg/L) activity at 24 h of exposure. The pupicidal and adulticidal activity of this plant exhibits highest mortality against A. aegypti within 24 h at the dose ranges of 89.773 mg/mL, 41.912 mg/mL respectively. The chloroform extracts contain major phyto-constituents like phenol, alkaloids, protein and tannins. Thin layer chromatography profiles also provide a database for the presence of active components. GC-MS analysis of bioactive chloroform extract revealed that a total of seventeen compounds, six were considered as major and the remaining as minor compounds. The spectral studies of FT-IR denoted the functional groups of bioactive components like alkenes, ketone, hydroxyl and others. Based on the outcome of results show that Ocimum canum have found to potent ability for controlling the mosquitoes, it can be used as an ideal eco-friendly agent for arresting dengue fever in future.
Article
The Hoesch reaction of 6-hydroxy-2,3-dihydrobenzo[b]furan with 2,3,4-trimethoxyphenylacetonitrile yielded 6-hydroxy-5-(2,3,4-trimethoxyphenylacetyl)-2,3-dihydrobenzo[b]furan. The cyclization of the dihydrobenzofuran with ethyl orthoformate-pyridine-piperidine gave dihydrodehydronepseudin, an isoflavone. The dehydrogenation of the above isoflavone with N.B.S. or Pd-G yielded dehydronepseudin. Nepseudin was derived by the reduction of dehydronepseudin with sodium borohydride and by subsequent oxidation with the chromium trioxidepyridine complex.
Article
The isolation and structural elucidation of six pterocarpans : neorautenane, neorautanol, edulenane, edulenanol ambonane, and neorautenanol, as well as two new isoflavanones : ambonone and neoraunone, are reported. The structures of neorautenane and neorautanol have also been confirmed by syntheses where the key step involves the reaction between 2H-chromen and o-chloromercuriphenol in the presence of lithium chloropalladite.
Article
Investigation of the roots of Neorautanenia mitis, collected in Rwanda (Central Africa), revealed the presence of three compounds, neotenone [1], dolineone [3], and pachyrrhizine [2], which were previously isolated from Neorautanenia pseudopachyrrhiza, the former name of the title plant. However, neotenone [1], which was previously reported as an optically inactive substance, was isolated now in optically active form for the first time. In addition, four isoflavanone-type compounds were isolated for the first time from N. mitis, including dehydroneotenone [5], neoduline [4], 12a-hydroxydolineone [6], and 12a-hydroxyrotenone [7]. Detailed 360 MHz nmr spectra of all compounds are reported for the first time, providing correction to previously incorrectly reported low resolution data. Also, the 13C-nmr and mass spectral data of all these compounds are reported for the first time. The petroleum ether total extract of N. mitis roots showed significant acaricidal properties that were attributed to the presence of 12a-hydroxyrotenone [7].
Article
In a Bancroftian filariasis survey on the coast of Tanzania microfilaria rates rose with age reaching 53% in the 60-69 year group followed by a slight fall above this age. The most important clinical manifestations were hydrocoele, funiculitis and elephantiasis, with hydrocoele presenting the most serious public health problem. Hydrocoele rates increased with age reaching 90% above the age of 70. The highest proportion of large hydrocoeles were also in the older age groups. A satisfactory methodology was established for the planning of future surveys leading to control.
Article
A series of 108 samples from 42 medicinal plants of Rwanda have been screened for acaricidal activity against the female tick Rhipicephalus appendiculatus. Two plants, Solanum dasyphyllum (fruits) and Neorautanenia mitis (roots) showed apparent acaricidal activity in the petroleum ether fraction.
Article
The pharmacological effects of the aqueous extract of Neorautanenia mitis (family Papilonaceae) were studied in rodents. Investigations were carried out on acetic acid-induced writhing (pain) in mice and hind paw oedema in rats. The effects of the extract were also studied on the isolated non-pregnant rat uterus and rabbit jejunum. Results showed the extract to possess significant (P<0.05) dose-dependent anti-nociceptive activity between 12.5 and 50.0 mg/kg p.o. in mice and slight anti-inflammatory activity at 25 and 50 mg/kg p.o. in rats. The extract also produced a concentration-dependent inhibition of the normal rhythmic contraction of the isolated non-pregnant rat uterus. It was found to inhibit oxytocin-induced as well as acetylcholine-induced contractions in the rat uterus. The extract also exhibited concentration-dependent inhibition of spontaneous contractions of the rabbit jejunum. Preliminary phytochemical analysis of the extract revealed the presence of saponin glycosides, flavonoids, tannins and alkaloids. The extract had an intraperitoneal (i.p.) LD(50) of 282.84+/-3.2 mg/kg in mice. These data corroborate the traditional use of this plant in the treatment of dysmenorrhea.
Neorautanenia isoflavenoids II. Neofolin and ficinin, two new furoiso flavanoids from Neorautanenia ficifolia Molluscicidal activity of three plants of Malawi
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Report of the 5th Malaria Network Meeting Screening of medic-inal plants of Rwanda for acaricidal activity Iso-lation and structural elucidation of potentially insecticidal and acaricidal isoflavone-type compounds from Neorautane-nia mitis
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Larvicidal and Mosquitocidal Flavonoids from a Neorautanenia species occurring in Tanzania
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Toxic effects of Azadirachta indica seed extracts on mosquitoes
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Tanzania filariasis project. Survey methodology and clinical manifestation of bancroftian filariasis Vector control for malaria and other mosquito-borne diseases Report of the WHO informal consultation on the evaluation and testing of insecticides
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Neorautanenia isoflavenoids II. Neofolin and ficinin, two new furoiso flavanoids from Neorautanenia ficifolia
  • Brink