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.     

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.     

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.     

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.     

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.     

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.     

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.     

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

ObjectiveTo 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).MethodsThe larvicidal activity was assayed against three mosquito species at various concentrations ranging from (50-450 ppm) under the laboratory conditions. The LC₅₀ and LC₉₀ value of the O. thymiflorus leaf extract was determined by Probit analysis.ResultsThe LC₅₀ values of hexane, chloroform, ethyl acetate, acetone and methanol extract of O. thymiflorus third instar larvae of An. stephensi were LC₅₀= 201.39, 178.76, 158.06, 139.22 and 118.74 ppm; Cx. quinquefasciatus were LC₅₀=228.13, 209.72, 183.35, 163.55 and 149.96 ppm and Ae. aegypti were LC₅₀=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.ConclusionsThe 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.     

Larvicidal and adulticidal potential of medicinal plant extracts from south India against vectors

ObjectiveTo determine the larvicidal and adulticidal activities of hexane, ethyl acetate and methanol extracts of Momordica charantia (M.charantia), Moringa oleifera(M. oleifera), Ocimum gratissimum (O. gratissimum), Ocimum tenuiflorum (O. tenuiflorum), Punica granatum(P. granatum) and Tribulus terrestris (T. terrestris) against Culex gelidus (Cx. gelidus) and Culex quinquefasciatus (Cx. quinquefasciatus).MethodsBioassay test was carried out by WHO method for determination of larvicidal and adulticidal activity against mosquitoes.ResultsAll plant extracts showed moderate larvicidal and adulticidal activities, however the effective larval mortality was found in the leaf ethyl acetate and methanol extract of O. gratissimum and bark methanol extract of M. oleifera against Cx.gelidus with LC₅₀ values of 39.31, 66.28, and 21.83 μg/mL respectively, and methanol extract of O. gratissimum, O. tenuiflorum and P. granatum against Cx. quinquefasciatus with LC₅₀ values of 38.47, 24.90 and 67.20 μg/mL, respectively. The adult exposed for 1 h and mortality was recorded at 24 h recovery period. Above 90% mortality was found in the ethyl acetate and methanol extract of all experimental plants at the concentrations of 500 μg/mL.ConclusionsThe present results suggest that the medicinal plant extracts provided an excellent potential for controlling Cx. gelidus and Cx. quinquefasciatus.     

Antibacterial activity and characterization of secondary metabolites isolated from mangrove plant Avicennia officinalis

ObjectiveTo explore antibacterial activity and characterization of secondary metabolites isolated from mangrove plant Avicennia officinalis (A. officinalis).MethodsIn the present study the leaf extracts of A. officinalis were examined for its antibacterial potential using five different solvents against some reference strains of human pathogenic bacteria for the crude extract. Maximum activity was observed for ethyl acetate and hence different concentrations like 15 μL, 25 μL, and 50 μL of ethyl extracts was checked for its antibacterial activity. Partial purification of crude extract was carried by column chromatography and fractions were analyzed using gas chromatography-mass spectrometry (GC-MS) to identify compounds.ResultsThe crude ethyl acetate extracts of A. officinalis showed remarkable antibacterial activity with zones of inhibition of 13 mm against Eschericia coli (E. coli) and 11 mm against Staphylococcus aureus (S. aureus). Fraction 13 (ethyl acetate÷methanol= 8÷2) as the most potent one against with the minimal inhibitory concentration of 30 mm against E. coli and 25 mm against S. aureus. The GCMS resultsof active column fraction (F13) revealed that the active principals were a mixture of hydroxy-4 methoxybenzoic acid, diethyl phthalate, oleic acid.ConclusionsThe leaf extracts with proven antibacterial effects can clearly be directed towards cancer treatment as to inhibiting cancer cell growth. The limited number of test organisms owes to a constraint of resource. So, the effect of strong bursts of leaf extracts on human pathogenic bacteria should further be tested on a wide range of test organisms.     

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.     

Efficacy of larvicidal and pupicidal activity of Catharanthus roseus aqueous and solvent extracts against Anopheles stephensi Liston and Culex quinquefasciatus Say (Diptera: Culicidae)

ObjectiveTo investigate the larvicidal and pupicidal activities of aqueous, ethyl acetate and methanol extracts of Catharanthus roseus (C. roseus) against malaria and filariasis vectors.MethodsThe larvicidal and pupicidal activities of C. roseus leaf extracts were tested against the fourth instar larvae and pupae of Anopheles stephensi (An. stephensi) and Culex quinquefasciatus (Cx. quinquefasciatus). The mortality was observed after 24 and 48 h post the treatment. The data were subjected to probit analysis to determine the lethal concentrations (LC₅₀ and LC₉₀) at which 50% and 90% of the treated larvae or pupae of the tested species were killed.ResultsThe larval and pupal mortality were observed after 24 and 48 h of exposure of aqueous, ethyl acetate and methanol extracts of C. roseus; no mortality was observed in the control group. The LC₅₀ values against the fourth-instar larvae of An. stephensi were 68.62 and 72.04 mg/mL for the aqueous extract, 82.47 mg/mL for the ethyl acetate extract, and 78.80 and 86.64 mg/mL for the methanol extract, while the aqueous, ethyl acetate and methanol extracts had LC₅₀ values of 85.21, 76.84 and 94.20 mg/mL against the fourth-instar larvae of Cx. quinquefasciatus. The aqueous, ethyl acetate and methanol extracts had LC₅₀ values of 118.08, 182.47 and 143.80 mg/mL against the pupae of An. stephensi and 146.20, 226.84 and 156.62 mg/mL against the pupae of Cx. quinquefasciatus, respectively.ConclusionsThe aqueous and methanol extracts of C. roseus leaves had an excellent potential to control the malarial vector An. stephensi and filariasis vector Cx. quinquefasciatus.     

Insecticidal and Repellant Activities of Four indigenous medicinal Plants Against Stored Grain Pest,Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae)

ObjectiveThe present investigation was aimed to assess the impact of four indigenous plants for their insecticidal and repellent activity against Tribolium castaneum (Herbst), a stored grain pest and they were tested in the laboratory.MethodsFour widely distributed plants (Artemisia vulgaris, Sphaeranthus indicus, Tephrosia purpurea, and Prosopis juliflora) were sequentially extracted with increasing polarity of organic solvents such as, hexane, chloroform and ethyl acetate were evaluated for their insecticidal and repellent activities against Tribolium castaneum by adapting the standard protocol in in vitro.ResultsData pertaining to the present investigation clearly revealed that the percentage of mortality was maximum in(72 hr 58%) hexane extract of A. vulgaris, chloroform extract (72 hr 34%) of S. indicus, and ethyl acetate extract (72 hr 52%) of T. purpurea. Repellant activities of plant extracts were tested against T. castaneum, repellent activity was maximum in hexane extract of P. fuliflora, (EPI value for P. fuliflora in 2.5% was ?0.11 and ?0.33 at 1hr and 6 hr respectively) chloroform extract of T. purpurea (2.5% was ?0.17 at 6 hr) and ethyl acetate extract of S. indicus (2.5% was ?0.65 at 6 hr) against T. castaneum.ConclusionsThe present work for botanical products to control the insect pest of stored grain Tribolium castaneum (Herbst). These results suggest the presence of actives toxic substances acting after consumption or topical application.     

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.     

Antibacterial activity of medicinal plant Cyclea peltata (Lam) Hooks & Thoms

ObjectiveTo investigate the antibacterial activity of Padathaali (Cyclea peltata) against three gram positive and eight gram negative bacterial strains.MethodsThe fresh whole plants were collected from Kerala, India. The dry crude nonpolar and polar extract of whole plant of C. peltata i. e. Petroleum ether, hexane, chloroform, ethyl acetate, acetone, methanol and aqueous extracts of five concentrations (1, 2, 5, 10 mg/ml) were used to investigate the antibacterial activity. NCCL standards were strictly followed to perform antibacterial disc susceptibility test using disc diffusion method.ResultsAll the extracts showed varying degree of inhibitory potential against all the tested bacteria. Methanol extract of plant had higher inhibitory action against Staphylococcus aureus, Streptococcus haemolyticus, Klebsiella pneumonia and Proteus vulgaris. Acetone extract of plant showed maximum inhibitory action against Klebsiella pneumonia and Streptococcus haemolyticus.ConclusionsThe present investigation showed the effectiveness of crude extract of this plant against tested bacterial strains. This study further suggests the use of whole plant extract in treating disease caused by tested microbial organisms.     

Larvicidal and repellent activity of medicinal plant extracts from Eastern Ghats of South India against malaria and filariasis vectors

ObjectiveTo evaluate the larvicidal and repellent activities of ethyl acetate and methanol extracts of Acacia concinna (A. concinna), Cassia siamea (C. siamea), Coriandrum sativum (C. sativum),Cuminum cyminum (C. cyminum), Lantana camara (L. camara), Nelumbo nucifera (N. nucifera) Phyllanthus amarus (P. amarus), Piper nigrum (P. nigrum) and Trachyspermum ammi (T. ammi) against Anopheles stephensi (An. stephensi) and Culex quinquefasciatus (Cx. quinquefasciatus).MethodsThe larvicidal activity of medicinal plant extracts were tested against early fourth-instar larvae of malaria and filariasis vectors. The mortality was observed 24 h and 48 h after treatment, data were subjected to probit analysis to determine the lethal concentrations (LC₅₀ and LC₉₀) to kill 50 and 90 per cent of the treated larvae of the tested species. The repellent efficacy was determined against two mosquito species at five concentrations (31.25, 62.50, 125.00, 250.00, and 500.00 ppm) under the laboratory conditions.ResultsAll plant extracts showed moderate effects after 24 h and 48 h of exposure; however, the highest activity was observed after 24 h in the leaf methanol extract of N. nucifera, seed ethyl acetate and methanol extract of P. nigrum against the larvae of An. stephensi (LC₅₀ = 34.76, 24.54 and 30.20 ppm) and against Cx. quinquefasciatus (LC₅₀ = 37.49, 43.94 and 57.39 ppm), respectively. The toxic effect of leaf methanol extract of C. siamea, seed methanol extract of C. cyminum, leaf ethyl acetate extract of N. nucifera, leaf ethyl acetate and methanol extract of P. amarus and seed methanol extract of T. ammi were showed 100% mortality against An. stephensi and Cx. quinquefasciatus after 48 h exposer. The maximum repellent activity was observed at 500 ppm in methanol extracts of N. nucifera, ethyl acetate and methanol extract of P. nigrum and methanol extract of T. ammi and the mean complete protection time ranged from 30 to 150 min with the different extracts tested.ConclusionsThese results suggest that the leaf and seed extracts of C. siamea, N. nucifera, P. amarus, P. nigrum and T. ammi have the potential to be used as an ideal ecofriendly approach for the control of the An. stephensi and Cx. quinquefasciatus.     

Evaluation of antibacterial activity of selected medicinal plant extracts from south India against human pathogens

ObjectiveThe present study was to evaluate the antibacterial properties of 21 crude extracts from leaf and flower of Aristolochia indica (A. indica), Cassia angustifolia (C. angustifolia), leaf of Catharanthus roseus (C. roseus), Diospyros melanoxylon (D. melanoxylon), Dolichos biflorus (D. biflorus), Gymnema sylvestre (G. sylvestre) and Justicia procumbens (J. procumbens).MethodsThe ethyl acetate, acetone and methanol extract of medicinal plants were evaluated against Gram-positive Bacillus cereus (B. cereus) and Gram-negative bacteria Aeromonas hydrophila (A. hydrophila), Enterobacter aerogenes (E. aerogenes), Escherichia coli (E. coli) and Klebsiella pneumoniae (K. pneumoniae) by using well diffusion assay and minimum inhibitory concentration (MIC).ResultsThe crude plant extracts demonstrated broad spectrum activity against all bacteria. The highest inhibitory zone was observed in leaf methanol extract of A. indica against E. aerogenes (25 mm), and E. coli (20 mm), flower methanol extract of C. angustifolia against B. cereus (22 mm) and leaf acetone extract of G. sylvestre against B. cereus (22mm). The MIC values of leaf methanol extract of A. indica against K. pneumonia (22.6μg/ml), and flower extract showed against E. coli (MIC: 24.2μg/ml), leaf ethyl acetate extract of C. angustifolia against K. pneumoniae (MIC: 28.4μg/ml). Acetone ethyl acetate and methanol extracts of D. melanoxylon and D. biflorus showed the lowest MIC activity value of >30 μg/ml against all tested pathogens.ConclusionThe antibacterial activity could be confirmed in most species used in traditional medicine in South India. Nevertheless, traditional knowledge might provide some leads to elucidate potential candidates for future development of new antibiotic agents.     

Pharmacological properties and related constituents of stem bark of Pterocarpus erinaceus Poir. (Fabaceae)

ObjectiveTo screen methanol and dichloromethane extracts of stem bark of Pterocarpus erinaceus for anti-inflammatory, analgesic, in vitro antioxidant activities and phytochemical analysis.MethodsAnti-inflammatory activity was determined by using carrageenan induced-edema of mice paw and croton oil-induced edema of mice ear; analgesic effect was evaluated using acetic acid-induced writhing. Phytochemical screening of extracts was performed by thin layer chromatography. The chromatographic fractionation led to the isolation of main active components as friedelin, lupeol and epicathechin. The structures were established by TLC and nuclear magnetic resonance studies.ResultsBoth methanol and dichloromethane extracts, friedelin, lupeol and epicatechin showed a significant anti-inflammatory effect using croton oil induced-ear edema. Furthermore, the action of dichloromethane extract was more important. At the doses of 100 and 200 mg/kg, the methanol extract was able to reduce the carrageenan induced-hind paw edema, while at the doses of 100, 200 and 400 mg/kg, it showed an important analgesic effect against writhing induced by acetic acid injection of 38.8%, 68.0% and 74.3%, respectively. Antioxidative properties of methanol extract and its dichloromethane and ethyl acetate fractions were assessed by using the 1,1-diphenyl-2-picrylhydrazyl method. The methanol extract showed the stronger radical scavenging activity than dichloromethane and ethyl acetate fractions, with an antiradical power of 5, 3.5 and 2 respectively. The main components isolated from these extracts as friedelin, lupeol and epicathechin were responsible of these activities.ConclusionsThe results suggest that the stem bark extracts of Pterocarpus erinaceus possessed important anti-inflammatory, analgesic activities and strong antioxidant properties, therefore, they could be used as natural potential ingredients for pharma ceutical industry.     

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.