In vitro total phenolics, flavonoids contents and antioxidant activity of essential oil, various organic extracts from the leaves of tropical medicinal plant Tetrastigma from Sabah

ObjectiveTo detect the in vitro total phenolics, flavonoids contents and antioxidant activity of essential oil, various organic extracts from the leaves of tropical medicinal plant Tetrastigma from Sabah.MethodsThe dry powder leaves of Tetrastigma were extracted with different organic solvent such as hexane, ethyl acetate, chloroform, butanol and aqueous methanol. The total phenolic and total flavonoids contents of the essential oil and various organic extracts such as hexane, ethyl acetate, chloroform, butanol and aqueous ethanol were determined by Folin - Ciocalteu method and the assayed antioxidant activity was determined in vitro models such as antioxidant capacity by radical scavenging activity using α, α-diphenyl- β-picrylhydrazyl (DPPH) method.ResultsThe total phenolic contents of the essential oil and different extracts as gallic acid equivalents were found to be highest in methanol extract (386.22 mg/g) followed by ethyl acetate (190.89 mg/g), chloroform (175.89 mg/g), hexane (173.44 mg/g), and butanol extract (131.72 mg/g) and the phenolic contents not detected in essential oil. The antioxidant capacity of the essential oil and different extracts as ascorbic acid standard was in the order of methanol extract > ethyl acetate extract >chloroform> butanol > hexane extract also the antioxidant activity was not detected in essential oil.ConclusionsThe findings show that the extent of antioxidant activity of the essential oil and all extracts are in accordance with the amount of phenolics present in that extract. Leaves of Tetrastigma being rich in phenolics may provide a good source of antioxidant.     

Phytochemical analysis and in vitro antimicrobial activity of Illicium griffithii Hook. f. & Thoms extracts

ObjectiveTo evaluate the antimicrobial activity of hexane, ethyl acetate and methanol extracts of seeds and fruits of Illicium griffithii (I. griffithii)(Family: Schisandraceae).MethodsThe antimicrobial activity of the organic extracts were determined using disc diffusion assay against Gram-positive bacterial strains (three reference cultures and three clinical isolates), Gram-negative bacterial strains (nine reference cultures and six clinical isolates), and six fungi. The primary phytochemical and chemical compositions were analyzed using qualitative chemical analysis and gas chromatography-mass spectrometry respectively.ResultsEthyl acetate extract of fruits was effective against most of the tested reference cultures such as Staphylococcus aureus, Yersinia enterocolitica, Vibrio parahaemolyticus, Bacillus subtilis, Salmonella paratyphi, Enterococcus feacalis, Xanthomonas oryzae and Pseudomonas aerugenosa, whereas methanol extract showed activity only against Staphylococcus aureus, Bacillus subtilis and Xanthomonas oryzae. The hexane and ethyl acetate extracts of fruits were more effective against most of the clinical isolates, whereas methanol extract was effective only against Klebsiella pneumoniae ESBL. The extracts of fruits and seeds did not show any significant antifungal activity against tested fungi. The presence of phenols, tannins, flavonoids, triterpenoids, steroids, alkaloids, saponis and carbohydrates in the different extracts was established. Gas chromatography-mass spectrometry studies on hexane and ethyl acetate extract of fruits resulted in the identification of 31 and 39 compounds respectively.ConclusionsPotent antibacterial phytochemicals are present in ethyl acetate extract of I. griffithii fruits. Further studies are needed to investigate activities of I. griffithii against multidrug resistant bacteria.     

Antimicrobial study of plant extracts of Datura metel L. against some important disease causing pathogens

ObjectiveIn this present study antimicrobial activity of aerial parts of Datura metel L were evaluated against the resistant pathogens belong to aquatic, human and plant origin.MethodsSoxhlet extraction method was used to get the corresponding extracts of hexane, chloroform and methanol. The antimicrobial activities of the organic solvent extracts on the various test microorganisms, including bacteria and fungi investigated using agar well diffusion technique. The length of inhibition zone was measured in millimeters from the edge of the well to the edge of the inhibition zone. Methanol and chloroform extracts exhibited promising antimicrobial activity than hexane extracts.ResultsThe zone of inhibition of chloroform varies from (9 to 18 mm) where as with methanol (11 to 30 mm) at 100 mg/ml and chloroform (11 to 19 mm) and methanol (12 to 35 mm) with 250 mg/ml DMSO concentrations consequently. Among all microorganisms studied Erwinia caratovara and Pseudomonas syringae showed the considerable growth inhibition with chloroform and methanolic extracts.ConclusionsD. metel can be used in the treatment of infectious diseases caused by resistant pathogenic microorganisms. Further studies are being carried out in order to separate the individual components that are present in plant extracts of D. metel using column chromatography.     

Analgesic and anti-inflammatory activities of Piper nigrum L.

ObjectiveTo evaluate and compare the analgesic and anti-inflammatory activity of pure compound, piperine along with hexane and ethanol extracts of Piper nigrum L. fruit in mice and rats.MethodsThe analgesic activity was determined by tail immersion method, analgesy-meter, hot plate and acetic acid induced writhing test. While the anti-inflammatory activity was evaluated by carrageenan-induced paw inflammation in rats.ResultsPiperine at a dose of 5 mg/kg and ethanol extract at a dose of 15 mg/kg after 120 min and hexane extract at a dose of 10 mg/kg after 60 min exhibited significant (P<0.05) analgesic activity by tail immersion method, in comparison to ethanol extract at a dose of 10 mg/kg using analgesy-meter in rats. However, with hotplate method, piperine produced significant (P<0.05) analgesic activity at lower doses (5 and 10 mg/kg) after 120 min. A similar analgesic activity was noted with hexane extract at 15 mg/kg. However, in writhing test, ethanol extract significantly (P<0.05) stopped the number of writhes at a dose of 15 mg/kg, while piperine at a dose of 10 mg/kg completely terminated the writhes in mice. In the evaluation of anti-inflammatory effect using plethysmometer, piperine at doses of 10 and 15 mg/kg started producing anti-inflammatory effect after 30 min, which lasted till 60 min, whereas hexane and ethanol extracts also produced a similar activity at a slightly low dose (10 mg/kg) but lasted for 120 min.ConclusionsIt is concluded from the present study that Piper nigrum L possesses potent analgesic and anti-inflammatory activities.     

In vitro antimicrobial activity of plant extracts of Avicennia alba against some important pathogens

ObjectiveIn this present study antimicrobial activity of aerial parts of Avicennia alba were evaluated against the resistant pathogens belong to aquatic, human and plant origin.MethodsSoxhlet extraction method was used to get the corresponding extracts of hexane, chloroform and methanol. The antimicrobial activities of the organic solvent extracts on the various test microorganisms, including bacteria and fungi investigated using agar well diffusion technique. The length of inhibition zone was measured in millimeters from the edge of the well to the edge of the inhibition zone. Methanol and chloroform extracts exhibited promising antimicrobial activity than hexane extracts.ResultsThe zone of inhibition of chloroform varies from (9 to 17 mm) where as with methanol (11 to 28 mm) at 100 mg/ml concentration. Among all microorganisms studied Erwinia caratovara and Pseudomonas syringae showed the considerable growth inhibition with chloroform and methanolic extracts.ConclusionsA. alba can be used in the treatment of infectious diseases caused by resistant pathogenic microorganisms. Further studies are being carried out in order to separate the individual components that are present in plant extracts of A. alba using column chromatography.     

Adulticidal activity of Ageratum houstonianum Mill. (Asteraceae) leaf extracts against three vector mosquito species (Diptera: Culicidae)

ObjectiveTo determine the intrinsic toxicity of hexane, ethyl acetate and methanol crude extracts of Ageratum houstonianum leaves against adult Anopheles stephensi, Aedes aegypti and Culex quinquefasciatus mosquitoes.MethodsBioassay was performed in 2-day-old laboratory reared unfed adult female mosquitoes by topical application at concentrations of 0.01, 0.05, 0.10, 0.25 and 0.50 μg/mg female adult mosquito.ResultsAedes aegypti was found to be more susceptible to ethyl acetate and hexane extracts with LD₅₀ value of 0.10 μg/mg, and both Anopheles stephensi and Culex quinquefasciatus were susceptible to methanol extract with LD₅₀ values of 0.12 μg/mg female adult mosquito.ConclusionsThe results show promising adulticidal activity on topical application and further studies followed by in-depth laboratory and field bioassays are needed to screen, isolate and purify bioactive phytochemical constituents or compounds.     

Hepatoprotective activity of Spillanthes acmella Extracts against CCl4-induced liver toxicity in rats

ObjectiveHepato protective activity of Spillanthes acmella Extracts (70% ethanol, methanol, ethyl acetate and hexane) were investigated.MethodsHepatoprotective activity was assessed against CCl4 induced liver intoxication.ResultsThe extracts were produced concentration dependent percentage protection in the reduction of enzymes (Serum Glutamate Oxaloacetate Transaminase, Serum Glutamate Pyruvate Transaminase, Alkaline phasphatase and Total bilirubin) levels against CCl4 induced liver intoxication in rats. Among all extracts methanol extract showed better activity compare to other extracts with percentage protection of SGOT (84.39%), SGPT (79.04%), ALP (78.15%) and Total bilirubin (80.00%) levels at a dose of 500mg/kg.ConclusionsFrom the results obtained during the present study it could be concluded that Spillanthes acmella extracts has components that have hepato protective effects.     

Effects of Lactuca sativa extract on exploratory behavior pattern,locomotor activity and anxiety in mice

ObjectiveTo evaluate antianxiety property of Lactuca sativa, an important and commonly used leafy vegetable known for its medicinal properties belongs to Asteraceae family.MethodsElevated plus maze (EPM), open field test (OFT), rat exposure test, hyponeophagia and marble burying test were performed in mice models to assess the exploratory behaviour and to assess anxiolytic property of hydro-alcohol extract of Lactuca sativa. Diazepam (1 mg/kg body wt.) served as the standard anxiolytic agent for all the tests. The dried extract of the plant leaf in doses of 100, 200 and 400 mg/kg body weight was administered orally to mice for duration of 15 or 30 days and evaluated exploratory behaviour, locomotor and anxiolytic activities.ResultsTime spent and number of entries into the open arm was measured in EPM followed by total locomotor activity in OFT and latency to enter the food zone in hyponeophagia.ConclusionsThe study suggested that hydro-alcohol extract of Lactuca sativa leaves possess potent anxiolytic property.     

Evaluation of larvicidal activity of medicinal plant extracts against three mosquito vectors

ObjectiveTo evaluate the mosquito larvicidal activity of plant extracts.MethodsThe hexane, chloroform, ethyl acetate, acetone, and methanol leaf, flower and seed extracts of Abrus precatorius (A. precatorius), Croton bonplandianum (C. bonplandianum), Cynodon dactylon (C. dactylon), Musa paradisiaca (M. paradisiaca) and Syzygium aromaticum (S. aromaticum) were tested against fourth instar larvae of Anopheles vagus (An. vagus), Armigeres subalbatus (Ar. subalbatus) and Culex vishnui (Cx. vishnui).ResultsThe highest larval mortality was found in seed ethyl acetate extracts of A. precatorius and leaf extracts of C. bonplandianum, flower chloroform and methanol extracts of M. paradisiaca, and flower bud hexane extract of S. aromaticum against An. vagus with LC₅₀ values of 19.31, 39.96, 35.18, 79.90 and 85.90 μg/mL; leaf ethyl acetate and methanol extracts of C. dactylon, flower methanol extract of M. paradisiaca, flower bud methanol extract of S. aromaticum against Ar. subalbatus with LC₅₀ values of 21.67, 32.62, 48.90 and 78.28 μg/mL, and seed methanol of A. precatorius, flower methanol extract of M. paradisiaca, flower bud hexane extract of S. aromaticum against Cx. vishnui with LC₅₀ values of 136.84, 103.36 and 149.56 μg/mL, respectively.ConclusionsThese results suggest that the effective plant crude extracts have the potential to be used as an ideal ecofriendly approach for the control of disease vectors. This study provides the first report on the larvicidal activity of crude solvent extracts of different mosquitoes.     

Repellent activity of Ageratum houstonianum Mill. (Asteraceae) leaf extracts against Anopheles stephensi,Aedes aegypti and Culex quinquefasciatus (Diptera: Culicidae)

ObjectiveTo determine the repellent activity of hexane, ethyl acetate and methanol crude extracts of Ageratum houstonianum(A. houstonianum) leaves against adult Anopheles stephensi (An. stephensi), Aedes aegypti (Ae. aegypti) and Culex quinquefasciatus (Cx. quinquefasciatus) mosquitoes.MethodsBioassay on laboratory reared Swiss albino mice by topical application at a fixed concentration of 0.01 per cent with coconut oil as a base.ResultsCrude leaf extracts of A. houstonianum in combination with coconut oil repelled vector mosquitoes. Maximum protection for a period of 11.30 h was obtained against Cx. quinquefasciatus and An. stephensi when treated with methanol and hexane extracts followed by 8.30 h against Ae. aegypti in methanol extract. Amongst the three extracts, methanol extract gave the maximum protection of 95.0% against Cx. quinquefasciatus. Hexane and ethyl acetate extracts gave a maximum of 93.4% protection against An. stephensi.ConclusionsThe crude extracts of A. houstonianum leaves in combination with coconut oil showed repellent activity with repellent quotient ranging from 0.6 to 0.9.     

Effect of Ichnocarpus frutescens (L.) R. Br. hexane extract on preadipocytes viability and lipid accumulation in 3T3-L1 cells

ObjectiveTo investigate the crude extracts of Ichnocarpus frutescens (I. frutescens) for antiobesity effect.MethodsLeaves of I. frutescens were sequentially extracted with hexane, ethyl acetate, and methanol and their effect on viability of 3T3-L1 preadipocytes were evaluated. Based on this the apoptosis on preadipocytes was confirmed by DNA fragmentation and LDH (Lactate dehydrogenase) leakage assays. Anti-adipogenesis was performed by oil red O (ORO) staining and free glycerol release in the medium of differentiated adipocytes.ResultsThe hexane extract of I. frutescens (IFHE) inhibited cell viability in a time- and dose-related manner. An increased release of LDH, as a marker of membrane integrity, was observed at a dose of 200 μ g/mL. The discontinuous DNA fragments on agarose gel electrophoresis showed the apoptotic effect of the IFHE. Morphological observations of cells stained with ORO showed a decrease in cellular lipid content at the concentrations tested compared to the induced control cells. In the experiment of lipolytic activity, treatment with IFHE enhanced glycerol secretion with the rates of approximately 28%, 55%, and 46% at the concentrations of 100, 200 and 300 μ g/mL, respectively.ConclusionsThe observed properties clearly revealed the medicinal property of I. frutescens in the treatment of obesity.     

Clerodendron inerme Gaertn. plant as an effective natural product against dengue and filarial vector mosquitoes

ObjectiveTo investigate insecticidal properties of organic solvent extracts of Clerodendron inerme (C. inerme) leaves against larval stages of Aedes aegypti (Ae. aegypti) and Culex quinquefasciatus (Cx. quinquefasciatus) mosquito species.MethodsThe sundried leaf powder of C. inerme was subjected for extraction using organic solvents viz. methanol, chloroform, petroleum ether and hexane extract, and were tested against third/fourth instar larvae of Ae. aegypti and Cx. quinquefasciatus species in accordance with WHO standard methods. Experiments were conducted in four replicates with control group containing water alone and positive control group containing respective solvent (dimethylsulfoxide/acetone) used for dissolving the extracts.ResultsAmong the four solvent extracts, hexane extract has effective growth disruptive activity against Ae. aegypti, and showed positive tests for presence of four groups of phytochemical constituents viz. tanin, phytosteriod, terpenoid and cardiac glycoside. The hexane extract was tested against field collected filarial vector Cx. quinquefasciatus larvae for growth disruptive activity. Adult emergence inhibition values for 50 percent suppression (EI₅₀) of the tested population for methanol, chloroform, petroleum ether and hexane extracts treated against third instar larvae of Ae. aegypti were found to be 37.45, 14.79, 2.56 and 1.96 mg/L respectively, while hexane extract treated against Cx. quinquefasciatus was found to be equally effective with EI₅₀ value of 3.74 mg/L. Hexane extract treated against fourth instar larvae of Ae. aegypti and Cx. quinquefasciatus showed EI₅₀ values of 8.07 and 19.55 mg/L respectively in comparison with that of standard insect growth regulator methoprene demonstrating EI₅₀ value of 0.05 mg/L. Besides, the hexane extract was also found to possess toxic effect against non-target organism Gambusia affinis (a bio-control agent), however, the lethal concentration (LC₅₀=172.7 mg/L for 24 h) against Gambusia affinis was much higher in comparison with that of tested concentrations against Ae. aegypti and Cx. quinquefasciatus.ConclusionsWe conclude from the present investigation that the hexane extract of C. inerme has positive implications for its consideration in integrated control of dengue/filarial vectors due to their ecological distinctness in comparison with non-target organism and further due to ecofriendly nature of the extract in terms of easy biodegradability.     

Mosquito repellent properties of Delonix elata (L.) gamble (Family: Fabaceae) against filariasis vector,Culex quinquefasciatus Say. (Diptera: Culicidae)

ObjectiveTo determine the repellent activity of hexane, ethyl acetate, benzene, chloroform and methanol extract of Delonix elata (D. elata) leaf and seed against Culex quinquefasciatus (Cx. quinquefasciatus).MethodsEvaluation was carried out in a net cage (45 cm×30 cm×25 cm) containing 100 blood starved female mosquitoes of Cx. quinquefasciatus. Repellent activity was carried out in the laboratory conditions according to the WHO 2009 protocol. Plant crude extracts of D. elata were applied at 1.0, 2.5, and 5.0 mg/cm² separately in the exposed fore arm of study subjects. Ethanol was used as the sole control.ResultsIn this study, the applied plant crude extracts were observed to protect against mosquito bites. There were no allergic reactions experienced by the study subjects. The repellent activity of the extract was dependent on the strength of the extract. Among the tested solvents, the leaf and seed methanol extract showed the maximum efficacy. The highest concentration of 5.0 mg/cm² provided over 150 min and 120 min protection, respectively.ConclusionsCrude extracts of D. elata exhibit the potential for controlling Cx. quinquefasciatus, the mosquito vector of filariasis.     

Comparative study of total phenolics,flavonoids contents and evaluation of antioxidant and antimicrobial activities of different polarities fruits crude extracts of Datura metel L.

ObjectiveTo determine the total phenolics and flavonoids and to evaluate antioxidant and antimicrobial activities of different extracts from fruits of Datura metel (D. metel).MethodsDifferent crude extracts from the fruits of D. metel were subjected to determination of total phenolics, flavonoids, antioxidant and antimicrobial activities by established methods.ResutlsThe total phenolics results showed that ethyl acetate extract was the most efficient (60.26%) compared to hexane, chloroform, butanol and methanol extracts which had phenolic contents of 50.08, 35.50, 52.54 and 26.49%, respectively. Almost similar results were obtained from the fruits crude extracts for total flavonoids and results found that methanol crude extract was the highest (1.71%) compared to other crude extracts. The antioxidant activity results showed that methanol extract acted the highest activity compared to other extracts and in the order of methanol>ethyl acetate>hexane>chloroform>butanol extract. All extracts were displayed moderate antibacterial potential against the tested bacteria such as Staphylococcus aureus, Escherichia coli and Pseudomonus aeruginosa in the range of 0%–10%.ConclusionsThe results of this present study clearly showed that the crude extracts of D. metel demenstrated antimicrobial and antioxidant activities and it may act as potential antioxidant sources for human biological system.     

Mosquito larvicidal and ovicidal properties of Eclipta alba (L.) Hassk (Asteraceae) against chikungunya vector, Aedes aegypti (Linn.) (Diptera: Culicidae)

ObjectiveThe present study deals with the investigation of larvicidal and ovicidal activities of benzene, hexane, ethyl acetate, methanol and chloroform leaf extract of Eclipta alba (E. alba) against dengue vector, Aedes aegypti (Ae. Aegypti).MethodsTwenty five early III instar larvae of Ae. aegypti was exposed to various concentrations (50–300 ppm) and was assayed in the laboratory by using the protocol of WHO 2005; the 24 h LC₅₀ values of the E. alba leaf extract was determined by Probit analysis. For ovicidal activity, slightly modified method of Su and Mulla was performed. The ovicidal activity was determined against Ae. aegypti to various concentrations ranging from 100–350 ppm under the laboratory conditions. The egg hatch rates were assessed 48 h post treatment.ResultsThe LC₅₀ values of benzene, hexane, ethyl acetate, methanol and chloroform extract of E. alba against early third instar larvae of Ae. aegypti were 151.38, 165.10, 154.88, 127.64 and 146.28 ppm, respectively. Maximum larvicidal activity was observed in the methanol extract followed by chloroform, benzene, ethyl acetate and hexane extract. No mortality was observed in control. Among five solvent tested the methanol extract was found to be most effective for ovicidal activity against Ae. aegypti. The methanol extracts exerted 100% mortality (zero hatchability) at 300 ppm.ConclusionsFrom the results it can be concluded the crude extract of E. alba was an excellent potential for controlling Ae. aegypti mosquito.     

Insecticidal, antimicrobial and antioxidant activities of bulb extracts of Allium sativum

ObjectiveTo evaluate the insecticidal, antimicrobial and antioxidant activities of bulb extracts of Allium sativum (A. sativum).MethodsDried bulbs of A. sativum were extracted with different solvents and evaluated for insecticidal, antimicrobial and antioxidant activities.MethodsAqueous and methanol extracts showed highest insecticidal activity (mortality rate of 81% and 64% respectively) against the larvae of Spodoptera litura (S. litura) at a concentration of 1 000 ppm. With regard to antimicrobial activity, aqueous extract exhibited antibacterial activity against gram positive (Bacillus subtilis, Staphylococcus aureu,) and gram negative (Escherichia coli and Klebsiella pneumonia) strains and antifungal activity against Candida albicans. While methanol extract showed antimicrobial activity against all the tested micro organisms except two (Staphylococcus aureus and Candida albicans), the extracts of hexane, chloroform and ethyl acetate did not show any anti microbial activity. Minimum inhibitory concentration of aqueous and methanol extracts against tested bacterial and fungal strains was 100–150 μg/mL. Antioxidant activity of the bulb extracts was evaluated in terms of inhibition of free radicals by 2, 2′-diphenly-1-picrylhydrazyl. Aqueous and methanol extracts exhibited strong antioxidant activity (80%–90% of the standard).ConclusionsAntioxidant and antimicrobial activity of A. sativum against the tested organisms therefore, provides scientific basis for its utilization in traditional and folk medicine. Also, our results demonstrated the insecticidal efficacy of A. sativum against S. litura, a polyphagous insect.     

Antimotility effects of extracts and fractions of Eastern Nigeria mistletoe (Loranthus micranthus Linn)

ObjectiveTo evaluate the antimotility activity of Eastern Nigerian mistletoe[Loranthus micranthus (L. micranthus) Linn] parasitic on six different host trees viz. Baphia nitida, Persia americana, Kola accuminata, Irvingia gabonensis, Citrus simensis and Pentacletra macrophylla (P. mycrophylla).MethodsThe antimotility of the methanol extracts and solvent fractions were evaluated in castor oil induced diarrheoa in rats.ResultsThe methanol extracts (200 mg/kg, i.p.) inhibited defeacation significantly (P < 0.05) 4 h after administration (75.73% to 93.33%) more than that of atropine sulphate (2 mg/kg, i.p.) which inhibited defeacation by 80.0%. The methanol extract (200 mg/kg, i.p.) of L. micranthus parasitic on P. mycrophylla exhibited significant (P<0.05) inhibition in gastrointestinal transit (67.6%) more than that of atropine sulphate (2 mg/kg, i.p.) which inhibited gastrointestinal transit by 26.4%. The solvent fractions of L. micranthus parasitic on P. mycrophylla at dose levels of 150 mg/kg inhibited significantly the gastrointestinal transit of mice. Fraction F₅ exhibited inhibitory activity which was comparable to loperamide (73.3%).ConclusionThe methanol extract of L. micranthus parasitic on P. macrophylla exhibits higher antimotility activity that other extracts. The solvent fractions could serve as source of novel antimotility agents.     

Evaluation of Andrographis paniculata Burm.f. (Family:Acanthaceae) extracts against Culex quinquefasciatus (Say.) and Aedes aegypti (Linn.) (Diptera:Culicidae)

ObjectiveTo investigate the larvicidal and ovicidal efficacy of different extracts of Andrographis paniculata (A. paniculata) against Culex quinquefasciatus (Cx. quinquefasciatus) Say and Aedes aegypti (Ae. aegypti) L. (Diptera: Culicidae).MethodsLarvicidal efficacy of the crude leaf extracts of A. paniculata with five different solvents like benzene, hexane, ethyl acetate, methanol and chloroform was tested against the early third instar larvae of Cx. quinquefasciatus and Ae. aegypti. The ovicidal activity was determined against two mosquito species to various concentrations ranging from 50-300 ppm under the laboratory conditions.ResultsThe benzene, hexane, ethyl acetate, methanol and chloroform leaf extract of A. paniculata was found to be more effective against Cx. quinquefasciatus than Ae. aegypti. The LC₅₀ values were 112.19, 137.48, 118.67, 102.05, 91.20 ppm and 119.58, 146.34, 124.24, 110.12, 99.54 ppm respectively. Among five tested solvent, methanol and ethyl acetate crude extract was found to be most effective for ovicidal activity against two mosquito species. The extract of methanol and ethyl acetate exerted 100% mortality at 200 ppm against Cx. quinquefasciatus and at 250 ppm against Ae. aegypti.ConclusionsFrom the results it can be concluded the crude extract of A. paniculata was a potential for controlling Cx. quinquefasciatus and Ae. aegypti mosquitoes.     

Adulticidal properties of Pithecellobium dulce (Roxb.) Benth. (Family: Fabaceae) against dengue vector,Aedes aegypti (Linn.) (Diptera: Culicidae)

To examine the toxicity of mosquito adulticidal activity of different solvent leaf and seed extracts of Pithecellobium dulce (P. dulce) against dengue vector, Aedes aegypti (Ae. aegypti).MethodsAdulticidal efficacy of the crude leaf and seed extracts of P. dulce with five different solvents like benzene, hexane, ethyl acetate, methanol and chloroform was tested against the five to six day old adult female mosquitoes of Ae. aegypti. The adult mortality was observed after 24 h under the laboratory conditions.ResultsAmong the tested solvents the maximum efficacy was observed in the leaf and seed methanol extract. The LC₅₀ and LC₉₀ values of P. dulce leaf and seed extract against adults of Ae. aegypti were 218.64, 257.99 mg/L and 426.05, 507.73 mg/L, respectively. No mortality was observed in controls. The Chi-square values were significant at P<0.05 level.ConclusionsFrom the results it can be concluded the crude extract of P. dulce leaf and seed was an excellent potential for controlling dengue vector mosquito, Ae. aegypti.     

In vitro screening for acetylcholinesterase inhibition and antioxidant activity of medicinal plants from southern Africa

ObjectiveTo determine the acetylcholinesterase inhibitory (AChEI) and antioxidant activity of the ethyl acetate and methanol extracts of 12 traditional medicinal plants used in the treatment of neurological disorders.MethodsAChEI activity was determined spectrophotometrically using the Ellman's colorimetric method. Antioxidant activity was carried out by determining the ability of the extracts to scavenge 2,2-diphenyl-1-picryl hydrazyl (DPPH) and 2,2′-azinobis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radicals. The levels of total phenols, flavonoids and flavonols were determined quantitatively using spectrophotometric methods.ResultsAChEI was observed to be dose-dependent. Lannea schweinfurthii (L. schweinfurthii) (Engl.) Engl. and Scadoxus puniceus (S. puniceus) (L.) Friis &; I. Nordal. root extracts showed the lowest IC₅₀ value of 0.000 3 mg/mL for the ethyl acetate extracts while Zanthoxylum davyi (Z. davyi) (I. Verd.) P.G. Watermann had the lowest IC₅₀ value of 0.01 mg/mL for the methanol extracts in the AChEI assay. The roots of Piper capense (P. capense) L.f., L. schweinfurthii, Ziziphus mucronata (Z. mucronata) Willd., Z. davyi and Crinum bulbispermum (C. bulbispermum) (Burm.f.) Milne-Redh. &; Schweick. showed noteworthy radical scavenging activity and good AChEI activity.ConclusionsFive plants show good antioxidant and AChEI activity. These findings support the traditional use of the plants for treating neurological disorders especially where a cholinesterase mechanism and reactive oxygen species (ROS) are involved.