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Fulltext Analysis of chemical compositions and larvicidal activity of nut extracts from Areca catechu Linn against Aedes (Diptera: Culicidae)

Bharathithasan M, Ravindran DR, Rajendran D, Chun SK, Abbas SA, Sugathan S, et al.

PLoS One, 2021;16(11):e0260281.
PMID: 34843539 DOI: 10.1371/journal.pone.0260281

BACKGROUND: There is a growing need to use green alternative larvicidal control for Aedes larvae compared to chemical insecticides. Substantial reliance on chemical insecticides caused insecticide resistance in mosquito populations. Thus, research for alternate chemical compounds from natural products is necessary to control Aedes larvae. This study explores the analysis of chemical compositions from Areca catechu nut as a potential larvicide for Aedes (Diptera: Culicidae).
METHODS: The Areca catechu nut collected from Ipoh, Perak, Malaysia was grounded into powder and used for Soxhlet extraction. The chemical analysis of the extracts and their structures were identified using the GCMS-QP2010 Ultra (Shimadzu) system. National Institute of Standards and Technology (NIST) Chemistry WebBook, Standard Reference Database 69 (https://webbook.nist.gov/chemistry/) and PubChem (https://pubchem.ncbi.nlm.nih.gov/), the two databases used to retrieve the synonyms, molecular formula, molecular weight, and 2-dimensional (2D) structure of chemical compounds. Next, following WHO procedures for larval bioassays, the extracts were used to asses larvicidal activity against early 4th instar larvae of Aedes aegypti and Aedes albopictus.
RESULTS: The larvicidal activities were observed against early 4th stage larvae with different concentrations in the range from 200 mg/L to 1600 mg/L. The LC50 and LC95 of Aedes aegypti were 621 mg/L and 2264 mg/L respectively; whereas the LC50 and LC95 of Aedes albopictus were 636 mg/L and 2268 mg/L respectively. Mortality was not observed in the non-target organism test. The analysis using gas chromatography and mass spectrometer recovered several chemical compounds such as Arecaidine, Dodecanoic acid, Methyl tetradecanoate, Tetradecanoic acid , and n-Hexadecanoic acid bioactive components. These chemical constituents were used as additive formulations in pesticides, pest control, insect repellent, and insecticidal agents.
CONCLUSIONS: Our study showed significant outcomes from the extract of Areca catechu nut and it deserves further investigation in relation to chemical components and larvicidal actions between different species of Aedes mosquitoes. Even though all these findings are fundamental, it may have some interesting potentials to be developed as natural bio-larvicidal products.

Matched MeSH terms: Insecticides/chemistry
Fulltext Indoor and outdoor residual spraying of a novel formulation of deltamethrin K-Othrine® (Polyzone) for the control of simian malaria in Sabah, Malaysia

Rohani A, Fakhriy HA, Suzilah I, Zurainee MN, Najdah WMAW, Ariffin MM, et al.

PLoS One, 2020;15(5):e0230860.
PMID: 32413033 DOI: 10.1371/journal.pone.0230860

Since 2000, human malaria cases in Malaysia were rapidly reduced with the use of insecticides in Indoor Residual Spray (IRS) and Long-Lasting Insecticide Net (LLIN). Unfortunately, monkey malaria in humans has shown an increase especially in Sabah and Sarawak. The insecticide currently used in IRS is deltamethrin K-Othrine® WG 250 wettable granule, targeting mosquitoes that rest and feed indoor. In Sabah, the primary vector for knowlesi malaria is An. balabacensis a species known to bite outdoor. This study evaluates an alternative method, the Outdoor Residual Spray (ORS) using a novel formulation of deltamethrin K-Othrine® (PolyZone) to examine it suitability to control knowlesi malaria vector in Sabah, compared to the current method. The study was performed at seven villages in Sabah having similar type of houses (wood, bamboo and concrete). Houses were sprayed with deltamethrin K-Othrine® (PolyZone) at two different dosages, 25 mg/m2 and 30 mg/m2 and deltamethrin K-Othrine® WG 250 wettable granule at 25 mg/m2, sprayed indoor and outdoor. Residual activity on different walls was assessed using standard cone bioassay techniques. For larval surveillances, potential breeding sites were surveyed. Larvae were collected and identified, pre and post spraying. Adult survey was done using Human Landing Catch (HLC) performed outdoor and indoor. Detection of malaria parasite in adults was conducted via microscopy and molecular methods. Deltamethrin K-Othrine® (PolyZone) showed higher efficacy when sprayed outdoor. The efficacy was found varied when sprayed on different types of wall surfaces. Deltamethrin K-Othrine® (PolyZone) at 25 mg/m2 was the most effective with regards to ability to high mortality and effective knock down (KD). The vector population was reduced significantly post-spraying and reduction in breeding sites as well. The number of simian malaria infected vector, human and simian malaria transmission were also greatly reduced.

Matched MeSH terms: Insecticides/chemistry
Fern-synthesized nanoparticles in the fight against malaria: LC/MS analysis of Pteridium aquilinum leaf extract and biosynthesis of silver nanoparticles with high mosquitocidal and antiplasmodial activity

Panneerselvam C, Murugan K, Roni M, Aziz AT, Suresh U, Rajaganesh R, et al.

Parasitol Res, 2016 Mar;115(3):997-1013.
PMID: 26612497 DOI: 10.1007/s00436-015-4828-x

Malaria remains a major public health problem due to the emergence and spread of Plasmodium falciparum strains resistant to chloroquine. There is an urgent need to investigate new and effective sources of antimalarial drugs. This research proposed a novel method of fern-mediated synthesis of silver nanoparticles (AgNP) using a cheap plant extract of Pteridium aquilinum, acting as a reducing and capping agent. AgNP were characterized by UV-vis spectrophotometry, Fourier transform infrared (FTIR) spectroscopy, energy-dispersive X-ray spectroscopy (EDX), and X-ray diffraction (XRD). Phytochemical analysis of P. aquilinum leaf extract revealed the presence of phenols, alkaloids, tannins, flavonoids, proteins, carbohydrates, saponins, glycosides, steroids, and triterpenoids. LC/MS analysis identified at least 19 compounds, namely pterosin, hydroquinone, hydroxy-acetophenone, hydroxy-cinnamic acid, 5, 7-dihydroxy-4-methyl coumarin, trans-cinnamic acid, apiole, quercetin 3-glucoside, hydroxy-L-proline, hypaphorine, khellol glucoside, umbelliferose, violaxanthin, ergotamine tartrate, palmatine chloride, deacylgymnemic acid, methyl laurate, and palmitoyl acetate. In DPPH scavenging assays, the IC50 value of the P. aquilinum leaf extract was 10.04 μg/ml, while IC50 of BHT and rutin were 7.93 and 6.35 μg/ml. In mosquitocidal assays, LC50 of P. aquilinum leaf extract against Anopheles stephensi larvae and pupae were 220.44 ppm (larva I), 254.12 ppm (II), 302.32 ppm (III), 395.12 ppm (IV), and 502.20 ppm (pupa). LC50 of P. aquilinum-synthesized AgNP were 7.48 ppm (I), 10.68 ppm (II), 13.77 ppm (III), 18.45 ppm (IV), and 31.51 ppm (pupa). In the field, the application of P. aquilinum extract and AgNP (10 × LC50) led to 100 % larval reduction after 72 h. Both the P. aquilinum extract and AgNP reduced longevity and fecundity of An. stephensi adults. Smoke toxicity experiments conducted against An. stephensi adults showed that P. aquilinum leaf-, stem-, and root-based coils evoked mortality rates comparable to the permethrin-based positive control (57, 50, 41, and 49 %, respectively). Furthermore, the antiplasmodial activity of P. aquilinum leaf extract and green-synthesized AgNP was evaluated against CQ-resistant (CQ-r) and CQ-sensitive (CQ-s) strains of P. falciparum. IC50 of P. aquilinum were 62.04 μg/ml (CQ-s) and 71.16 μg/ml (CQ-r); P. aquilinum-synthesized AgNP achieved IC50 of 78.12 μg/ml (CQ-s) and 88.34 μg/ml (CQ-r). Overall, our results highlighted that fern-synthesized AgNP could be candidated as a new tool against chloroquine-resistant P. falciparum and different developmental instars of its primary vector An. stephensi. Further research on nanosynthesis routed by the LC/MS-identified constituents is ongoing.

Matched MeSH terms: Insecticides/chemistry*
Seaweed-synthesized silver nanoparticles: an eco-friendly tool in the fight against Plasmodium falciparum and its vector Anopheles stephensi?

Murugan K, Samidoss CM, Panneerselvam C, Higuchi A, Roni M, Suresh U, et al.

Parasitol Res, 2015 Nov;114(11):4087-97.
PMID: 26227141 DOI: 10.1007/s00436-015-4638-1

Malaria, the most widespread mosquito-borne disease, affects 350-500 million people each year. Eco-friendly control tools against malaria vectors are urgently needed. This research proposed a novel method of plant-mediated synthesis of silver nanoparticles (AgNP) using a cheap seaweed extract of Ulva lactuca, acting as a reducing and capping agent. AgNP were characterized by UV-vis spectrophotometry, Fourier transform infrared (FTIR) spectroscopy, energy-dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM), and X-ray diffraction (XRD). The U. lactuca extract and the green-synthesized AgNP were tested against larvae and pupae of the malaria vector Anopheles stephensi. In mosquitocidal assays, LC50 values of U. lactuca extract against A. stephensi larvae and pupae were 18.365 ppm (I instar), 23.948 ppm (II), 29.701 ppm (III), 37.517 ppm (IV), and 43.012 ppm (pupae). LC50 values of AgNP against A. stephensi were 2.111 ppm (I), 3.090 ppm (II), 4.629 ppm (III), 5.261 ppm (IV), and 6.860 ppm (pupae). Smoke toxicity experiments conducted against mosquito adults showed that U. lactuca coils evoked mortality rates comparable to the permethrin-based positive control (66, 51, and 41%, respectively). Furthermore, the antiplasmodial activity of U. lactuca extract and U. lactuca-synthesized AgNP was evaluated against CQ-resistant (CQ-r) and CQ-sensitive (CQ-s) strains of Plasmodium falciparum. Fifty percent inhibitory concentration (IC50) values of U. lactuca were 57.26 μg/ml (CQ-s) and 66.36 μg/ml (CQ-r); U. lactuca-synthesized AgNP IC50 values were 76.33 μg/ml (CQ-s) and 79.13 μg/ml (CQ-r). Overall, our results highlighted out that U. lactuca-synthesized AgNP may be employed to develop newer and safer agents for malaria control.

Matched MeSH terms: Insecticides/chemistry
Fulltext Insecticidal activity and the mechanism of action of three phenylpropanoids isolated from the roots of Piper sarmentosum Roxb

Hematpoor A, Liew SY, Azirun MS, Awang K

Sci Rep, 2017 10 03;7(1):12576.
PMID: 28974710 DOI: 10.1038/s41598-017-12898-z

Hexane, dichloromethane and methanol extracts of the roots of Piper sarmentosum Roxb. were screened for toxicity towards Sitophilus oryzae (L.), Rhyzopertha dominica (F.), and Plodia interpunctella (Hübner) and the hexane extract exhibited the highest mortality percentage. Bioassay-guided fractionation of the hexane extract resulted in the isolation of asaricin 1, isoasarone 2, and trans-asarone 3. Asaricin 1 and isoasarone 2 were the most toxic compounds to Sitophilus oryzae, Rhyzopertha dominica, and Plodia interpunctella. Sitophilus oryzae and Rhyzopertha dominica exposed to asaricin 1 and isoasarone 2 required the lowest median lethal time. Insecticidal activity of trans-asarone 3 showed consistent toxicity throughout the 60 days towards all three insects as compared to asaricin 1 and isoasarone 2. Asaricin 1 and isoasarone 2 at different doses significantly reduced oviposition and adult emergence of the three insects in treated rice. Trans-asarone 3 had lowest toxicity with highest LC and LT values in all tested insects relative to its mild oviposition inhibition and progeny activity. Moreover, asaricin 1 and isoasarone 2 significantly inhibited acetylcholinesterase in comparison with trans-asarone 3 and the control. Acetylcholinesterase inhibition of Rhyzopertha dominica and Plodia interpunctella by asaricin 1 and isoasarone 2 were lower than that of Sitophilus oryzae, which correlated with their higher resistance.

Matched MeSH terms: Insecticides/chemistry
Fulltext The Cytochrome P450 gene CYP6P12 confers pyrethroid resistance in kdr-free Malaysian populations of the dengue vector Aedes albopictus

Ishak IH, Riveron JM, Ibrahim SS, Stott R, Longbottom J, Irving H, et al.

Sci Rep, 2016 Apr 20;6:24707.
PMID: 27094778 DOI: 10.1038/srep24707

Control of Aedes albopictus, major dengue and chikungunya vector, is threatened by growing cases of insecticide resistance. The mechanisms driving this resistance remain poorly characterised. This study investigated the molecular basis of insecticide resistance in Malaysian populations of Ae. albopictus. Microarray-based transcription profiling revealed that metabolic resistance (cytochrome P450 up-regulation) and possibly a reduced penetration mechanism (consistent over-expression of cuticular protein genes) were associated with pyrethroid resistance. CYP6P12 over-expression was strongly associated with pyrethroid resistance whereas CYP6N3 was rather consistently over-expressed across carbamate and DDT resistant populations. Other detoxification genes also up-regulated in permethrin resistant mosquitoes included a glucuronosyltransferase (AAEL014279-RA) and the glutathione-S transferases GSTS1 and GSTT3. Functional analyses further supported that CYP6P12 contributes to pyrethroid resistance in Ae. albopictus as transgenic expression of CYP6P12 in Drosophila was sufficient to confer pyrethroid resistance in these flies. Furthermore, molecular docking simulations predicted CYP6P12 possessing enzymatic activity towards pyrethroids. Patterns of polymorphism suggested early sign of selection acting on CYP6P12 but not on CYP6N3. The major role played by P450 in the absence of kdr mutations suggests that addition of the synergist PBO to pyrethroids could improve the efficacy of this insecticide class and overcome resistance in field populations of Ae. albopictus.

Matched MeSH terms: Insecticides/chemistry