Acaricidal activity of Aloe vera L. leaf extracts against Tetranychus cinnabarinus (Boisduval) (Acarina: Tetranychidae)

Four different extracts of Aloe vera L. leaves were evaluated for acaricidal activity against female adults of carmine spider mite, Tetranychus cinnabarinus (Boisduval), by slide-dip bioassay. At 72 h after treatment, the acetone extract showed the strongest acaricidal activity with LC₅₀ value of 90 ppm. The LC₅₀ values for ethyl acetate, water, and ethanol extracts were 113, 340, and 391 ppm, respectively. The acetone extract was fractionated using a silica gel column. Among the twenty-two fractions obtained the fifth, tenth, eleventh, twelfth, fifteenth, and seventeenth fractions showed strong acaricidal activity, causing 80.39 to 92.16% mortality at 72 h after treatment. The tenth and eleventh fractions had the strong activity, with LC₅₀ values of 44 ppm and 33 ppm, respectively. The results suggested that A. vera has a great potential for development as a botanical acaricide for T. cinnabarinus control.     

Mosquito larvicidal activity of Aloe vera (Family: Liliaceae) leaf extract and Bacillus sphaericus,against Chikungunya vector,Aedes aegypti

The bio-efficacy of Aloe vera leaf extract and bacterial insecticide, Bacillus sphaericus larvicidal activity was assessed against the first to fourth instars larvae of Aedes aegypti, under the laboratory conditions. The plant material was shade dried at room temperature and powdered coarsely. A. vera and B. sphaericus show varied degrees of larvicidal activity against various instars larvae of A. aegypti. The LC₅₀ of A. vera against the first to fourth instars larvae were 162.74, 201.43, 253.30 and 300.05 ppm and the LC₉₀ 442.98, 518.86, 563.18 and 612.96 ppm, respectively. B. sphaericus against the first to fourth instars larvae the LC₅₀ values were 68.21, 79.13, 93.48, and 107.05 ppm and the LC₉₀ values 149.15, 164.67, 183.84, and 201.09 ppm, respectively. However, the combined treatment of A. vera + B. sphaericus (1:2) material shows highest larvicidal activity of the LC₅₀ values 54.80, 63.11, 74.66 and 95.10 ppm; The LC₉₀ values of 145.29, 160.14, 179.74 and 209.98 ppm, against A. aegypti in all the tested concentrations than the individuals and clearly established that there is a substantial amount of synergist act. The present investigation clearly exhibits that both A. vera and B. sphaericus materials could serve as a potential larvicidal agent. Since, A. aegypti is a container breeder vector mosquito this user and eco-friendly and low-cost vector control strategy could be a viable solution to the existing dengue disease burden. Therefore, this study provides first report on the mosquito larvicidal activity the combined effect of A. vera leaf extract and B. sphaericus against as target species of A. aegypti.     

Comparative study of three herbal formulations against dengue vectors Aedes aegypti

The efficacy of three formulations (i.e., natural lavender crude, essential oil, and gel) extracted from Lavender angustifolia was tested against vectors of the epidemic dengue virus, Aedesaegypti, to evaluate their larvicidal activity effect. The ethanolic extract of the lavender crude was prepared using a rotary evaporator, while the other extracts, such as essential oil and gel, were obtained from iHerb, a supplier of medicinal herbs in the US. The mortality rate of larvae was evaluated 24 h after exposure. Larvicidal activity of the lavender crude was 91% mortality at 150 ppm, 94% for essential oil at a concentration of 3000 ppm, and 97% for lavender gel at a 1000 ppm. Natural lavender crude was one of the most promising extracts tested against Ae.aegypti larvae, with lethal concentrations at LC₅₀ and LC₉₀ of 76.4 and 174.5 ppm post-treatment. The essential oil had the least effect on mosquito larvae, with LC₅₀ and LC₉₀ reaching 1814.8 and 3381.9 ppm, respectively. The lavender gel was moderately effective against Ae. aegypti larvae, with LC₅₀ and LC₉₀ values reaching 416.3 and 987.7 ppm after exposure. The occurrence of morphological abnormalities in the larvae treated with the three compounds, in turn, resulted in an incomplete life cycle. Therefore, our results indicated that natural lavender crude displayed the highest larvicidal activity against larvae, followed by gel and essential oil. Thus, this study concluded that lavender crude is an effective, eco-friendly compound that can be used as an alternative to chemical products to control vector-borne epidemic diseases.     

Acetylenic 2-phenylethylamides and new isobutylamides from Acmella oleracea (L.) R. K. Jansen,a Brazilian spice with larvicidal activity on Aedes aegypti

Ethanol extract obtained from dried leaves of Acmella oleracea afforded after a liquid/liquid partition procedure a larvicidal hexane fraction (LC₅₀ = 145.6 ppm) and a non larvicidal dichloromethane one. From the inactive fraction, three amides were identified, two new structures, named deca-6,9-dihydroxy-(2E,7E)-dienoic acid isobutylamide (1), deca-8,9-dihydroxy-(2E,6Z)-dienoic acid isobutylamide (2) and the known nona-2,3-dihydroxy-6,8-diynoic acid 2-phenylethylamide (3). Bioassay-guided chromatographic fractionation of the hexane partition led to the identification of an amide mixture, nona-(2Z)-en-6,8-diynoic acid 2-phenylethylamide (4) and deca-(2Z)-en-6,8-diynoic acid 2-phenylethlylamide (5). This mixture was active against Aedes aegypti larvae at LC₅₀ = 7.6 ppm. Low toxicity of crude extracts and derived fractions on Artemia salina nauplies showed the possibility of using them to control the A. aegypti mosquito larvae. This is the first report on larvicidal activity of acetylenic 2-phenylethylamides and their identification in A. oleracea leaves.     

Biological activity of Xanthium strumarium seed extracts on different cancer cell lines and Aedes caspius,Culex pipiens (Diptera: Culicidae)

Effects of methanol extracts of Xanthium strumarium on different cancer cell lines and on the mortality rates of Aedes caspius, Culex pipiens (Diptera: Culicidae) were investigated. Among the cell lines tested, the Jurkat cell line was the most sensitive to the methanol extract and ethyl acetate fraction, with reported LC₅₀ values of 50.18 and 48.73 μg/ml respectively. Conversely, methanol extracts were not that toxic to the A549 cell line though the toxicity increased on further purification. The percentage of growth inhibition was dose dependent for the methanol extract and ethyl acetate fraction. The ethyl acetate fraction showed higher toxicity to all cell lines tested when compared to the methanol extract. The results showed that methanol extracts of plant seeds caused 100% mortality of mosquito larvae at a concentration of 1000 μg/ml after 24 h of treatment. The LC₅₀ and LC₉₀ values of X. strumarium were found to be 531.07 and 905.95 μg/ml against Ae. caspius and 502.32 and 867.63 μg/ml against Cx. Pipiens, respectively. From the investigations, it was concluded that the crude extract of X. strumarium showed a weak potential for controlling the larval instars of Ae. caspius and Cx. pipiens. However, on further purification the extract lost the larvicidal activity. The ethyl acetate fraction showed higher toxicity to all cell lines tested when compared to the methanol extract. The ethyl acetate fraction investigated in this study appears to have a weak larvicidal activity but a promising cytotoxic activity. Future studies will include purification and investigation in further detail of the action of X. strumarium on Cancer Cell Lines and mosquitoes.     

Chemical composition,oviposition deterrent and larvicidal activities against Aedes aegypti of essential oils from Piper marginatum Jacq. (Piperaceae)

The essential oils of leaves, stems and inflorescences of Piper marginatum, harvested in the Atlantic forest in the State of Pernambuco, Brazil, were obtained by hydrodistillation. GC and GC–MS analyses revealed the presence of 40 components accounting, respectively, for 99.6%, 99.7% and 99.1% of the leaf, stem and inflorescence oil, the most abundant being (Z)- or (E)-asarone and patchouli alcohol. The essential oil of the inflorescences exhibited potent activity against the 4th instar of Aedes aegypti with LC₁₀ and LC₅₀ values of 13.8 and 20.0 ppm, respectively. Furthermore, the inflorescence oil did not interfere in the oviposition of A. aegypti females when assayed at 50 ppm. These properties suggest that P. marginatum oil is a potential source of valuable larvicidal compounds for direct use or in conjunction with baits in traps constructed to capture eggs and larvae.     

Larvicidal effects of some essential oils against Aedes aegypti (L.), the vector of dengue fever in Saudi Arabia

Essential oils are very popular among organic growers because they are ecologically safe, do not have mammalian toxicity, and cannot be resistant to a variety of contaminants. Four essential oils, Lemon, Lavender, Peppermint, and Neem, were tested for larvicide efficacy against the dengue fever vector Aedes aegypti larvae under laboratory conditions using dipping bioassay techniques. Among the essential oils tested, lemon, peppermint, and lavender oils showed high larvicidal activity against larvae of Ae. aegypti. Lemon oil showed the highest effects (LC₅₀ 10.676 ppm), while Peppermint, Lavender and Neem oil showed the lowest effects (LC₅₀ 21.380, 29.818 and 38.058 ppm, respectively). As a result, the mixture of lemon oil (LC₅₀) with Peppermint oil (LC₂₅) showed the highest co-toxicity factor, whereas the mixture of Lemon oil (LC₅₀) with Diesel oil (LC₂₅) showed the lowest co-toxicity factor. Based on the results of this study, it appears that essential oils may be useful as larvicides against Ae. aegypti larvae. In search of new natural larvicides, these compounds may provide an alternative to Synthetic insecticides as these are environmentally safe insecticides.     

Evaluation of larvicidal efficacy of Ricinus communis (Castor) and synthesized green silver nanoparticles against Aedes aegypti L.

Aedes mosquitoes are the most important group of vectors that transmit pathogens, including arboviruses, and cause human diseases such as dengue fever, yellow fever, Zika virus, and Chikungunya. Biosynthesis and the use of green silver nanoparticles (AgNPs) is a vital step to identify reliable and eco-friendly controls for these vectors. In this study, Aedes (Ae.) aegypti larvae (2nd and 3rd instar) were exposed to leaf extracts of Ricinus communis (Castor) and AgNPs synthesized from the extract to evaluate their larvicidal potential. Synthesized AgNPs were characterized by UV–Vis spectroscopy, Fourier transform infrared spectroscopy (FTIR), and energy-dispersive X-ray spectroscopy (XRD). Ae. aegypti larvae were treated with different concentrations (50–250 ppm) of the leaf extract and synthesized AgNPs. There were five replicates per treatment, in addition to a positive (temephos) and negative control (dechlorinated water). Mortality was recorded after 12, 24, 36, and 48 h and the data were subjected to Probit analysis. The nanoparticles were more toxic (LC₅₀ = 46.22 ppm and LC₉₀ = 85.30 ppm) than the plant extract (106.24 and 175.73 ppm, respectively). The leaf extracts of Ricinus communis were subjected to HPLC analysis to identify their chemical constituents. This study suggests that plant extracts and synthesized nanoparticles are excellent alternatives to hazardous chemical pesticides used to control vector mosquitoes. This is a potentially useful technique that can reduce aquatic toxicity from insecticide use.     

Larvicidal activity of acetone extract and green synthesized silver nanoparticles from Allium sativum L. (Amaryllidaceae) against the dengue vector Aedes aegypti L. (Diptera: Culicidae)

Mosquito vectors of major human diseases are currently controlled using chemical and biological products. Extensive insecticide use has led to resistance development and human/environmental health risks, and alternative sustainable control options are needed; in this study, activity of an extract of garlic (Allium sativum; Amaryllidaceae), and silver nanoparticles (AgNPs) synthesized from the extract, were evaluated against 2nd and 3rd instar larvae of the yellow fever mosquito, Ae. aegypti (Diptera: Culicidae). Synthesis of AgNPs was confirmed using UV–Vis spectroscopy, and characterised using powdered X-ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopy. Larvae were exposed to five concentrations (50, 100, 150, 200, 250 ppm) of garlic extract or synthesized AgNPs, with distilled water and silver nitrate solution (1 mM) as controls. The mortality of larvae was recorded after 6, 12, 24, 36, and 48 h following addition of the respective extracts.Dose- and time-dependent toxicity were recorded in both treatment groups with no mortality in control groups. Exposure to AgNPs at 250 ppm for 48 h yielded 100% mortality for both larval instars, with corresponding LC₅₀ values of 44.77 (2nd) and 62.82 ppm (3rd). Exposure to garlic extract resulted in similar 48-hour mortality (99 ± 0.77% (2nd) and 98 ± 1.10% (3rd), but consistently higher LC₅₀ values after all exposure times compared to AgNPs (e.g. 48-hour exposure: 108.42 ppm (2nd), 129.11 ppm (3rd), suggesting that AgNPs may potentially be used at lower concentrations for Ae. aegypti control.     

Prevalence and resting behaviour of dengue vectors,Aedes aegypti and Aedes albopictus in dengue high risk urban settings in Colombo,Sri Lanka

Understanding local geographical variation in vector density and bionomics related to virus transmission are critical for planning effective vector control programs to control dengue virus transmission. This study investigated the prevalence and resting behaviour of Aedes aegypti and Ae. albopictus in three dengue high-risk areas in the Colombo District, Sri Lanka. Monthly sampling of resting adult mosquitoes was conducted from August 2019 to February 2020. Thirty-seven percent of the households (289/776) harboured Aedes mosquitoes, and 603 Aedes mosquitoes were collected. The proportion of Ae. aegypti was higher in the overall collection during the collection period (94% [569/603]), and 62% (352/569) were females. Significant monthly variations in Ae. aegypti were observed with respect to the indices: number of females per surveyed house (F/SH; p = 0.001), number of females per Aedes positive house (F/PH; p = 0.029), adult house index (AHI; p = 0.001), adult density (AD; p = 0.005) and resting ratio (RR; p = 0.001). AHI, AD, and RR had statistically significant positive correlations with monthly rainfall (p = 0.001, p = 0.011, and p = 0.002 respectively) and one-month lagged dengue cases (p = 0.002, p = 0.005, and p < 0.001 respectively). A statistically significantly higher proportion of Ae. aegypti females were caught resting indoors (N = 309, 88%) than outdoors (N = 43, 12%; p < 0.001). The most common resting areas were bedrooms (51%) & living/dining rooms (37%), and places were under or on furniture (47%) & hangings (34%) for Ae. aegypti. Conversely, 74% of female Ae. albopictus were collected outdoors. Results of this study could have strong implications to improve vector surveillance and control by early detection of dengue to detect outbreaks and minimization of disease transmission.     

Permethrin resistance in Aedes aegypti (Linnaeus) collected from Kuala Lumpur,Malaysia

Permethrin resistance status of a laboratory strain, a permethrin-selected strain and three field strains of Aedes aegypti collected in Kuala Lumpur, Malaysia were evaluated using three standard laboratory bioassays: WHO larval bioassay, WHO adult mosquito bioassay, and mixed function oxidase (MFO) enzyme microassay. The LC₅₀ values of field strains from the WHO larval bioassay did not differ significantly. The highest LC₅₀ value was from the Taman Melati field strain (0.39 mg/L). The resistance ratio for the permethrin-selected strain and the field strains ranged from 1.86 fold to 5.57 fold. Pre-exposure to piperonyl butoxide (PBO) in the WHO adult bioassay and MFOs enzyme microassay reduced the LT₅₀ values and reduced the mean optical density of elevated oxidase activity (0.28–0.42) at 630 nm. The LC₅₀ or LT₅₀ values and the level of oxidases were significantly correlated (r = 0.825; p< 0.05). This study confirmed the presence of permethrin resistance in these mosquito populations.     

Chemical composition and larvicidal activity of leaf essential oil from Clausena dentata (Willd) M. Roam. (Rutaceae) against the chikungunya vector,Aedes aegypti Linn. (Diptera: Culicidae)

Larvicidal activity of essential oil and isolated compounds from Clausena dentata leaves were tested against early fourth instar Aedes aegypti larvae. GC–MS analysis of essential oil revealed the presence of fourteen compounds of which the major compounds were sabinene (21.27%), biofloratriene (19.61%), borneol (18.34%) and β-bisabolol (17.68%). The essential oil of C. dentata exhibited significant larvicidal activity, with 24 h LC₅₀ and LC₉₀ values of 140.2 and 341.6 mg/l, respectively. Larvicidal activities of the four major compounds of essential oil were also tested. The LC₅₀ values of sabinene, biofloratriene, borneol and β-bisabolol were 27.3, 47.4, 43.5 and 33.2 mg/l, respectively. Results of this study show that the leaf essential oil of C. dentata and its four major compounds may be a potent source of natural larvicides.     

Chrysanthemum extract and extract prepared silver nanoparticles as biocides to control Aedes aegypti (L.), the vector of dengue fever

Mosquitoes play a key role in the transmission of some important diseases. The need for controlling these insects is critical to reduce their risks to human and domesticated animals. Recently the trend to explore effective chemical compounds from local plants has begun as a safe means of control. The present study aimed to evaluate the anti-larval activity of Chrysanthemum extract and the prepared silver nanoparticle (AgNPs) against the Aedes aegypti mosquito, the dengue vector in Saudi Arabia. A series of different concentrations of ethanol extract and extract prepared AgNPs against the fourth-life larvae was tested. The effective concentrations of crude extract and AgNPs ranged from 50 to 250 and 10 to 30 ppm respectively, and the death percentages corresponding to these concentrations ranged from 18 to 92 and 36 to 96% respectively. According to the LC₅₀ values of treated larvae, AgNPs (12.754 ppm) is more effective against A. aegypti mosquito larvae than the crude extract (228.345 ppm) at about 17.9 times. The mixing of the plant extract with the silver nitrate has led to potentiation. This is due to the synergy that occurs between the extract and the silver particles during the reduction process. The compounds in the extract are related to the surface of the particles, increasing the strength of their effects. It is recommend to separate the active elements in the Chrysanthemum plant and its preparation in the form of nanoparticles as a promising compound in mosquito control programs with least damage to human kind and the environment.     

Use of plant products and copepods for control of the dengue vector, <Emphasis Type="Italic">Aedes aegypti</Emphasis>

The efficacy of plant extracts (neem tree, Azadirachta indica A. Juss.; Meliaceae) and copepods [Mesocyclops aspericornis (Daday)] for the control of the dengue vector Aedes aegypti L. was tested in the laboratory. Neem Seed Kernel Extract (NSKE) at 25, 50, 100, 200 and 400 ppm caused significant mortality of Ae. aegypti larvae. Lethal concentrations (LC₅₀ and LC₉₀) were worked out. The LC₅₀ and LC₉₀ values for I to IV larval instars were 111.98, 138.34, 158.93, 185.22 ppm and for pupae was 146.13 ppm, respectively. The LC₉₀ value of I instar was 372.95 ppm, II instar was 422.77 ppm, III instar was 440.63 ppm, IV instar was 456.96 ppm, and pupae was 476.92 ppm, respectively. A study was conducted to test the whether the predatory efficiency of copepods on first instars changed in the presence of NSKE. The percentage of predatory efficiency of copepod was 6.80% in treatments without NSKE and the percentage of predatory efficiency increased up to 8.40% when copepods were combined with NSKE. This increase in predation efficiency may caused by detrimental effects of the neem active principle compound (Azadirachtin) on the mosquito larvae. Our results suggest that the combined application of copepods and neem extract to control Aedes populations is feasible. Repeated application of neem does not cause changes in copepod populations, because neem is highly degradable in the environment.     

Field efficacy of triflumuron against Aedes and Culex mosquitoes in temperate Argentina

Aedes aegypti and Culex pipiens s.l. (Linnaeus, 1762 and 1758, respectively) (Diptera: Culicidae) are important vectors of diseases to humans and a growing public health concern. In order to contribute to the control of mosquito vectors by low environmental impact approaches we assessed the susceptibility of natural populations of container-breeding mosquitoes to triflumuron, an insect growth regulator, in temperate Argentina. A field trial was conducted to evaluate the efficacy of two doses (0.5 ppm and 1 ppm) of triflumuron (SC 48%) against natural populations of Ae. aegypti and Culex spp. immatures in flower vases of four cemeteries. The results demonstrated the susceptibility of both target mosquitoes to triflumuron in field conditions. For Ae. aegypti, dose-dependent reductions were achieved in the presence of pupae and the percentage of water-holding containers harbouring L3–4 and/or pupae, whereas the larvae abundance was equally reduced for both doses. For Culex spp., similar levels of reduction of larvae abundance and pupae presence were achieved with both doses. Significant effects on the response variables measured were recorded up to six to eight weeks post-intervention. Bimonthly applying 1 ppm triflumuron in the context of an integrated mosquito management should achieve a lasting control of Ae. aegypti and Culex spp. in small artificial containers with minimal environmental impacts.     

Synergistic effects of essential oil-based cream formulations against Culex quinquefasciatus Say and Aedes aegypti L. (Diptera: Culicidae)

Mosquitoes are major arthropod vectors responsible for several pathogenic diseases. In recent years, repellents of botanical origin, particularly essential oils, have been used against mosquitoes and have been found effective and safe. In this study, five different repellent cream formulations (CF1–5) were prepared using combinations of essential oils, including camphor, cinnamon, citronella, lemongrass, lime, orange, neem, basil, Vitex, Lantana, eucalyptus, and clove, and their repellency was tested using Culex quinquefasciatus Say and Aedes aegypti L. under laboratory conditions and compared to the standard synthetic repellent N,N-diethyl-meta-toluamide (DEET-12%, w/w). Among the five cream formulations, CF2 at a dose of 5 mg/cm² showed the longest protection time of 4.18 h and 3.31 h against C. quinquefasciatus and A. aegypti, respectively, under laboratory conditions. CF3 at a dose of 5 mg/cm² was moderately effective, with protection times of 3.42 h and 2.58 h against C. quinquefasciatus and A. aegypti, respectively, under laboratory conditions. CF2 at a dose of 5 mg/cm² was also tested in the field against wild mosquitoes for 3 h, and 100% protection was observed for the entire study period. Thus, CF2 could be used in developing an effective natural repellent as an alternative to the existing synthetic repellents to C. quinquefasciatus and A. aegypti.     

In vitro cytotoxicity and genotoxicity of five Ochna species (Ochnaceae) with excellent antibacterial activity

Extracts and fractions of some Ochna species had excellent antibacterial activity. Before considering the potential therapeutic use of these extracts it is important to determine the safety of extracts. The cytotoxicity of Ochna natalitia, Ochna pretoriensis, Ochna pulchra, Ochna gamostigmata, and Ochna serrulata (Ochnaceae) was determined in monkey kidney (Vero) cells, human hepatocellular carcinoma (C3A) cells and bovine dermis cells using the mitochondrial viability MTT assay. Their potential mutagenic effects were also determined using the Ames test with strains Salmonella typhimurium TA98 and TA100 with and without metabolic activation. The LC₅₀ values (the lethal concentration at which 50% of the cells are killed) of the extracts on the various cell lines ranged from 26 to 99 μg/ml. None of the plant species was mutagenic (mutagenic index values ≤ 1.59 for TA98 and ≤ 0.92 for TA100). In a previous study, we determined the antibacterial activity of the five extracts against Staphylococcus aureus, Escherichia coli, Enterococcus faecalis and Pseudomonas aeruginosa. From this we calculated the selectivity index (SI) values by dividing the LC₅₀ value by the minimum inhibitory concentration (MIC) to obtain the ratio of toxicity to bioactivity of each extract. The plant extracts had low SI values ≤ 1.307. This is a clear indication of non-selective toxicity, i.e. extracts are almost equally toxic to the bacteria and mammalian cell lines used in the assays. As a result, the extracts may have limited application as ingestible or intravenous therapeutic agents based on the in vitro findings. However, it may be necessary to also evaluate in vivo toxicity of the extracts in animal models as in vitro toxicity does not always equate to in vivo toxicity because of the difference in physiological microenvironment in live animals and tissue culture. Additionally, if it is the case that the toxic compounds are not the same as the active compounds, it may be possible to potentiate the extracts by the removal of toxic compounds and concentration of active compounds. The extracts may then be useful for development into treatments for topical bacterial infections.     

Larvicidal activities of the stem bark extract and rotenoids of Millettia usaramensis subspecies usaramensis on Aedes aegypti L. (Diptera: Culicidae)

The dichloromethane/methanol (1:1) extract of the stem bark of Millettia usaramensis subspecies usaramensis was tested for its larvicidal activity against the 4th instar Aedes aegypti larvae and demonstrated activity with LC₅₀ value of 50.8 ± 0.06 μg/mL at 48 h. Compounds isolated from the extract were also tested for their larvicidal activities, and the rotenoid usararotenoid-A (LC₅₀ 4.3 ± 0.8 μg/mL at 48 h) was identified as the most active principle. This compound appears to be the first rotenoid having a trans-B/C ring junction and methylenedioxy group at C-2/C-3 with high larvicidal activity. Related rotenoids with the same configuration at the B/C-ring junction did not show significant activity at 100 μg/mL.     

Chemistry,antioxidant and antimicrobial potential of nutmeg (Myristica fragrans Houtt)

Antioxidant and antimicrobial activities of nutmeg (Myristica fragrans Houtt) seed extracts were evaluated. Seeds were extracted with acetone, ethanol, methanol, butanol and water. All the extracts have shown significant antioxidant and antimicrobial activities against the tested microorganisms. Among all extracts, acetone extract has shown the highest antioxidant activity. The acetone extract showed 93.12 ± 1.48 mg gallic acid equivalents (GAE)/100 g dry weight total phenolic content, DPPH scavenging activity of 63.04 ± 1.56%, chelating activity of 64.11 ± 2.21% and 74.36 ± 1.94% inhibition of β-carotene bleaching, at 1 mg/mL extract concentration. Out of all extracts, acetone extract was able to exert antimicrobial activity against all tested bacteria and fungi. Acetone extract has shown the strongest antibacterial and antifungal activity with Staphylococcus aureus (13.8 ± 0.42 mm) and Aspergillus niger (14.4 ± 0.37 mm), respectively. GC–MS analysis of acetone extract has revealed the presence of 32 compounds of extract representing 99.49%. Sabinene (28.61%) has shown the highest occurrence in the extract. β-Pinene (10.26), α-pinene (9.72), myristicin (4.30%), isoeugenol (2.72%), p-cymene (1.81%), carvacrol (1.54%), eugenol (0.89%) and β-caryophellene (0.82%) were reported as possible contributor for antioxidant and antimicrobial activity of nutmeg.