Kalimuthu Kovendan

Larvicidal activity of Morinda citrifolia L. (Noni) (Family: Rubiaceae) leaf extract against Anopheles stephensi, Culex quinquefasciatus, and Aedes aegypti

Morinda citrifolia leaf extract was tested for larvicidal activity against three medically important mosquito vectors such as malarial vector Anopheles stephensi, dengue vector Aedes aegypti, and filarial vector Culex quinquefasciatus. The plant material was shade dried at room temperature and powdered coarsely. From the leaf, 1-kg powder was macerated with 3.0 L of hexane, chloroform, acetone, methanol, and water sequentially for a period of 72 h each and filtered. The yield of extracts was hexane (13.56 g), chloroform (15.21 g), acetone (12.85 g), methanol (14.76 g), and water (12.92 g), respectively. The extracts were concentrated at reduced temperature on a rotary vacuum evaporator and stored at a temperature of 4°C. The M. citrifolia leaf extract at 200, 300, 400, 500, and 600 ppm caused a significant mortality of three mosquito species. Hexane, chloroform, acetone, and water caused moderate considerable mortality; however, the highest larval mortality was methanolic extract, observed in three mosquito vectors. The larval mortality was observed after 24-h exposure. No mortality was observed in the control. The third larvae of Anopheles stephensi had values of LC50 = 345.10, 324.26, 299.97, 261.96, and 284.59 ppm and LC90 = 653.00, 626.58, 571.89, 505.06, and 549.51 ppm, respectively. The Aedes aegypti had values of LC50 = 361.75, 343.22, 315.40, 277.92, and 306.98 ppm and LC90 = 687.39, 659.02, 611.35, 568.18, and 613.25 ppm, respectively. The Culex quinquefasciatus had values of LC50 = 382.96, 369.85, 344.34, 330.42, and 324.64 ppm and LC90 = 726.18, 706.57, 669.28, 619.63, and 644.47 ppm, respectively. The results of the leaf extract of M. citrifolia are promising as good larvicidal activity against the mosquito vector Anopheles stephensi, Aedes aegypti, and Culex quinquefasciatus. This is a new eco-friendly approach for the control of vector control programs. Therefore, this study provides first report on the larvicidal activities against three species of mosquito vectors of this plant extracts from India.

Mosquito larvicidal and pupicidal activity of Euphorbia hirta Linn. (Family: Euphorbiaceae) and Bacillus sphaericus against Anopheles stephensi Liston. (Diptera: Culicidae).

OBJECTIVE To explore the larvicidal and pupicidal activity of Euphorbia hirta (E. hirta) leaf extract and Bacillus sphaericus (B. sphaericus) against the malarial vector, Anopheles stephensi (An. stephensi). METHODS The larvicidal and pupicidal activity was assayed against An. stephensi at various concentrations ranging from (75-375 ppm) under the laboratory as well as field conditions. The LC(50) and LC(90) value of the E. hirta leaf extract was determined by probit analysis. RESULTS The plant extract showed larvicidal effects after 24 h of exposure; however, the highest larval mortality was found in the methanol extract of E. hirta against the first to fourth instars larvae and pupae of values LC(50)= 137.40, 172.65, 217.81, 269.37 and 332.39 ppm; B. sphaericus against the first to fourth instars larvae and pupae of values LC(50)= 44.29, 55.83, 68.51, 82.19 and 95.55 ppm, respectively. Moreover, combined treatment of values of LC(50)= 79.13, 80.42, 86.01, 93.00 and 98.12 ppm, respectively. No mortality was observed in the control. CONCLUSIONS These results suggest methanol leaf extracts of E. hirta and B. sphaericus have potential to be used as an ideal eco-friendly approach for the control of the malarial vector, An. stephensi as target species of vector control programs. This study provides the first report on the combined mosquito larvicidal and pupicidal activity of this plant crude extract and bacterial toxin against An. stephensi mosquitoes.

Mosquito larvicidal properties of Orthosiphon thymiflorus (Roth) Sleesen. (Family: Labiatae) against mosquito vectors, Anopheles stephensi, Culex quinquefasciatus and Aedes aegypti (Diptera: Culicidae)

OBJECTIVE To determine the mosquito larvicidal activities of hexane, chloroform, ethyl acetate, acetone and methanol leaf extract of Orthosiphon thymiflorus (O. thymiflorus) against Anopheles stephensi (An. stephensi), Culex quinquefasciatus (Cx. quinquefasciatus) and Aedes aegypti (Ae. aegypti). METHODS The larvicidal activity was assayed against three mosquito species at various concentrations ranging from (50-450 ppm) under the laboratory conditions. The LC(50) and LC(90) value of the O. thymiflorus leaf extract was determined by Probit analysis. RESULTS The LC(50) values of hexane, chloroform, ethyl acetate, acetone and methanol extract of O. thymiflorus third instar larvae of An. stephensi were LC(50)= 201.39, 178.76, 158.06, 139.22 and 118.74 ppm; Cx. quinquefasciatus were LC(50)=228.13, 209.72, 183.35, 163.55 and 149.96 ppm and Ae. aegypti were LC(50)=215.65, 197.91, 175.05, 154.80 and 137.26 ppm, respectively. Maximum larvicidal activity was observed in the methanolic extract followed by acetone, ethyl acetate chloroform and hexane extract. The larval mortality was observed after 24 h exposure. No mortality was observed in control. CONCLUSIONS The present results suggest that the effective plant crude extracts have potential to be used as an ideal eco-friendly approach for the control of mosquito vectors. This study provides the first report on the larvicidal activity of this plant crude solvent extract of against An. stephensi, Cx. quinquefasciatus and Ae. aegypti mosquitoes.

Antimalarial activity of Carica papaya (Family: Caricaceae) leaf extract against Plasmodium falciparum

Abstract Objective To determine the antimalarial activity of the ethanol leaf extract of Carica papaya (C. papaya), blood stages of CQ-sensitive and CQ resistant strains against Plasmodium falciparum (P. falciparum) as target species. Methods C. papaya leaf was collected in and around Kalveerampalyam village, Coimbatore, Tamil Nadu, India. C. papaya leaf was washed with tap water and shade dried at room temperature. An electrical blender powdered the dried plant materials (leaves). The powder 500g of the leaf was extracted with 1.5 L of organic solvents of ethanol for 8 h using a Soxhlet apparatus. The crude plant extracts were evaporated to dryness in rotary vacuum evaporator. One gram of the plant residue was dissolved in 100 mL of acetone (stock solution) and considered as 1% stock solution. From this stock solution, different concentrations were prepared ranging from 2%, 4%, 6%, 8% and 10%, respectively. Results The highest larval mortality in the ethanol leaf extract of C. papaya against the 1st to 4th instars larvae and pupae values of LC50= 3.65%, 4.28%, 5.41%, 6.70%, and 7.50%, respectively. The LC90values of 9.61%, 11.75%, 13.53%, 16.36%, and 16.92%, respectively. Plant extracts showed moderate to good antiparasitic effects. These four concentrations (25, 50,100 and 150 μg/mL) of ethanol leaf extracts exhibited promising inhibitory activity against the CQ sensitive strain with (IC50) values 40.75%, 36.54%, 25.30%, and 18.0% and in CQ resistant 50.23%, 32.50%, 21.45%, and 23.12% against P. falciparum. Conclusions In conclusion, the results indicate the effective plant extracts have the potential to be used as an ideal eco-friendly approaches for the control of vector mosquitoes.

Larvicidal efficacy of Catharanthus roseus Linn. (Family: Apocynaceae) leaf extract and bacterial insecticide Bacillus thuringiensis against Anopheles stephensi Liston.

OBJECTIVE To explore the larvicidal activity of Catharanthus roseus (C. roseus) leaf extract and Bacillus thuringiensis (B. thuringiensis) against the malarial vector Anopheles stephensi (An. stephensi), when being used alone or together. METHODS The larvicidal activity was assayed at various concentrations under the laboratory and field conditions. The LC50 and LC90 values of the C. roseus leaf extract were determined by probit analysis. RESULTS The plant extract showed larvicidal effects after 24 h of exposure; however, the highest larval mortality was found in the petroleum ether extract of C. roseus against the first to fourth instars larvae with LC50=3.34, 4.48, 5.90 and 8.17 g/L, respectively; B. thuringiensis against the first to fourth instars larvae with LC50=1.72, 1.93, 2.17 and 2.42 g/L, respectively; and the combined treatment with LC50=2.18, 2.41, 2.76 and 3.22 g/L, respectively. No mortality was observed in the control. CONCLUSIONS The petroleum ether extract of C. roseus extract and B. thuringiensis have potential to be used as ideal eco-friendly agents for the control of An. stephensi in vector control programs. The combined treatment with this plant crude extract and bacterial toxin has better larvicidal efficacy against An. stephensi.

Evaluation of larvicidal and pupicidal activity of Morinda citrifolia L. (Noni) (Family: Rubiaceae) against three mosquito vectors

Abstract Objective To evaluate the mosquito larvicidal and pupicidal activity against three important medically mosquito vector such as malarial vector, Anopheles stephensi (An. stephensi), dengue vector, Aedes aegypti (Ae. aegypti) and filarial vector Culex quinquefasciatus (Cx. quinquefasciatus). Methods Morinda citrifolia (M. citrifolia) leaf was collected in and around Alleppy districts, Kerala, India. M. citrifolia leaf was washed with tap water and shade dried at room temperature. An electrical blender powdered the dried plant materials (leaves). From the leaf, 1 kg powdered was macerated with 3.0 L of methanol sequentially for a period 72 h and filtered. The crude plant extracts were evaporated to dryness in rotary vacuum evaporator. The larvicidal and pupicidal activity was assayed at various concentrations ranging from (100–500 ppm) under the laboratory as well as field conditions. The LC50and LC90value of the M. citrifolia leaf extract was determined by Probit analysis. Results The plant extract showed larvicidal and pupicidal effects after 24 and 48 hrs of exposure; All larval instars and pupae have considerably moderate mortality; however, the highest larval and pupal mortality was methanolic extract of M. citrifolia observed in three mosquito vectors at 48 h. The LC50and LC90of M. citrifolia against the first to fourth instar larvae and pupae against mosquito vectors. An. stephensi had values of LC50=146.08, 159.07, 172.16, 185.08 and 202.68 ppm and LC90=322.12, 363.48, 388.56, 436.51 and 513.56 ppm, respectively. The Ae. aegypti had values of LC50=181.27, 210.40, 229.80, 256.73 and 292.01 ppm and LC90=407.99, 485.65, 534.14, 624.16 and 756.79 ppm, respectively. The Cx. quinquefasciatus had values of LC50=226.70, 256.97, 290.05, 316.33 and 358.11 ppm and LC90=560.35, 652.07, 733.03, 797.09 and 875.25 ppm, respectively at 24 h. Conclusions The results of the leaf extract of M. citrifolia are promising as good larvicidal and pupicidal activity against the mosquito vector, An. stephensi, Ae. aegypti, Cx. quinquefasciatus. This is a new eco-friendly approach for the control of vector control programs. Therefore, this study provides first report on the larvicidal and pupicidal activities against three species of mosquito vectors of this plant extract from India.

Do Nanomosquitocides Impact Predation of Mesocyclops edax Copepods Against Anopheles stephensi Larvae

Mosquitoes transmit serious human diseases, causing millions of deaths every year. The use of synthetic insecticides to control vector mosquitoes cause physiological resistance and adverse environmental effects, in addition to enormous operational costs. In this study, silver nanoparticles (AgNP) were biosynthesized using a cheap extract of the Acorus calamus rhizome, as reducing and stabilizing agent. The biosynthesized AgNP were characterized by using UV–Vis spectrophotometry, X-ray diffraction, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). R. calamus extract and green-synthesized AgNP showed ovicidal, larvicidal, pupicidal and adulticidal toxicity against the malaria vector Anopheles stephensi. In ovicidal experiments, egg hatchability was reduced by 100 % after treatment with 25 and 50 ppm of AgNP. In larvicidal and pupicidal assays, LC50 values of A. calamus extract were 219.06 ppm (I instar), 246.01 ppm (II), 285.79 ppm (III), 345.19 ppm (IV) and 470.93 ppm (pupa); green-synthesized AgNP were highly effective, with LC50 of 8.94 ppm (I), 11.64 ppm (II), 14.94 ppm (III), 19.15 ppm (IV) and 28.66 ppm (pupa). In adulticidal trials, A. calamus extract and AgNP showed LC50 of 251.71 ppm and 12.74 ppm, respectively. The predatory efficiency of the cyclopoid crustacean Mesocyclops edax in standard laboratory conditions was 71 % and 58 % against I and II instar larvae of A. stephensi, respectively. In an aquatic environment treated with ultra-low doses of AgNP, M. edax predation efficiency was 84 % and 69 %, respectively. Predation was higher against I instar larvae over other instars. Overall, these results suggest that A. calamus-synthesized AgNPs represents a concrete possibility for eco-friendly control of A. stephensi.

Neem cake as a promising larvicide and adulticide against the rural malaria vector Anopheles culicifacies (Diptera: Culicidae): a HPTLC fingerprinting approach

Abstract Mosquitoes are insects of huge public health importance, since they act as vectors for important pathogens and parasites. Here, we focused on the possibility of using the neem cake in the fight against mosquito vectors. The neem cake chemical composition significantly changes among producers, as evidenced by our HPTLC (High performance thin layer chromatography) analyses of different marketed products. Neem cake extracts were tested to evaluate the ovicidal, larvicidal and adulticidal activity against the rural malaria vector Anopheles culicifacies. Ovicidal activity of both types of extracts was statistically significant, and 150 ppm completely inhibited egg hatching. LC50 values were extremely low against fourth instar larvae, ranging from 1.321 (NM1) to 1.818 ppm (NA2). Adulticidal activity was also high, with LC50 ranging from 3.015 (NM1) to 3.637 ppm (NM2). This study pointed out the utility of neem cake as a source of eco-friendly mosquitocides in Anopheline vector control programmes.

Bio Fabrication of Silver Nanoparticle from Argemone mexicana for the Control of Aedes albopictus and their Antimicrobial Activity

BACKGROUND Plant synthesized silver nanoparticles give rapid control on mosquito larvae of dengue vector, Aedes albopictus. AgNPs synthesized from the plant, Argemone mexicana for the control of larvae and these nanoparticles inhibit the growth of microbes are broad spectrum of nanoparticle activities. METHODS Nanoparticles were subjected to analysis by UV-vis spectrophotometry, Fourier transform infrared spectroscopy, scanning electron microscopy and transmission electron microscopy. Furthermore, laboratory evaluation of plant mediated nano-particle carried out lethal toxicity on Aedes albopictus. The characterization studies confirmed the spherical shape and size (5-50 nm) of silver nano-particles. RESULTS The efficacy of AgNPs was tested at concentration of 2 to 10 ppm against L1 to L4 larval instar of A. albopictus. The LC50 followed by LC90 values were (L1) 5.24, 8.66; (L2) 5.56, 8.85; (L3) 6.20, 10.01 and (L4) 7.04, 10.92 at 10 ppm of silver nanoparticle, whereas LC50 (LC90) values of (L1) 7.63, 11.58; (L2) 8.17, 11.88; 8.80, 12.82 and 8.94, 12.26 at 10 ppm of plant extract alone treated larvae, respectively. The mortality rates were positively correlated with the concentration of AgNPs. Significant (P<0.05) high square value changes in the larval mortality were also recorded between the period of exposure against all larval instar of A. albopictus. Silver nanoparticles were also tested for antimicrobial activity and significant toxicity inhibition was observed against the gram positive microbes and it exhibited mild toxicity against P. aeroginosa. CONCLUSION Plant, A. mexicana synthesized silver nano-particles are rapid and potential mosquito larvicidal as well as antimicrobial agents. Finding of our results support that silver nanoparticles can be prepared in a simple and cost-effective manner and are suitable for bio-formulation against mosquitoes and microbes.

Isolation and characterization of dipropyl-, S-propyl ester from Exiguobacterium mexicanum (MSSRF-S9) against larvae of malaria and dengue vectors

Objective To evaluate the insecticidal property of the compound dipropyl-, S-propyl ester extracted from the Gram-positive rhizosphere bacterium against the fourth instars larvae of malaria vector, Anopheles culicifacies (An. culicifacies) and dengue vector, Aedes albopictus (Ae. albopictus).