Citratus Extract Research Articles

The Difference of Surface Roughness of Heat Cured Acrylic Resin After Brushing with 30% and 60% Lemongrass Extract in Pasta

Background: Tooth loss can be replaced by the use of dentures. Cleaning of dentures by brushing using toothpaste can cause surface roughness because of abrasive materials. The use of toothpaste can be replaced with paste of extract Cymbopogon citratus because it has antibacterial and antifungal effects. Purpose: to determine the effect of brushing using paste of extract Cymbopogon citratus on the surface roughness of heat cured acrylic resin. Methods: Sample were heat cured acrylic resin (62.5 x 10 x 2.5) mm, divided into 4 groups consist of negative control group was brushed with basic paste, positive control group was brushed with herb paste, and two groups were brushed with paste of Cymbopogon citratus extract with 30% and 60% concentrations. Brushing was done for 3 minutes with 60 brushing times and then measured with surface roughness tester. The data was processed by ANOVA test. Result: The average surface roughness in K-, K+, P1, and P2 were 0,1217, 0,3433, 0,1633, and 0,27 μm. There was significant difference between negative control group and positive control group; negative control group with P1 and P2 group; positive control group with P1 and P2 group; P1 group with P2 group (P <0.05). Conclusion: The paste of Cymbopogon citratus extract concentration of 30% was effectively used because the level of surface roughness below the maximum limit of recommended surface roughness of dentistry material which is 0,2 μm. The 60% concentration paste of Cymbopogon citratus extract was less effective because the level of surface roughness above the maximum limit of surface roughness is recommended.

Formulation Effects in the Antioxidant Activity of Extract from the Leaves of Cymbopogon citratus (DC) Stapf.

Cymbopogon citratus DC (Stapf.) is a perennial grass and it is distributed around the world. It is used as a condiment for food and beverage flavouring in the form of infusions and decoctions of its dried leaves. Our previous studies have shown antioxidant, anti-inflammatory and gastroprotective activities for the infusion and its phenolic fractions. The aim of the present work was to develop oral dosage forms from a Cymbopogon citratus extract to be used as a functional food with antioxidant properties. Initially, an essential oil-free infusion was prepared, lyophilized and characterized by HPLC-PDA. Total phenols were quantified with the Folin–Ciocalteu method and the antioxidant activity was assessed by DPPH assay. Gelatine capsules containing the extract with different excipients, selected after DSC and IR trials, were prepared. A formulation exhibiting better antioxidant behaviour in a gastric environment was attained. These results suggest that the proposed formulation for this extract could be a valuable antioxidant product and, consequently, make an important contribution to “preventing” and minimizing diseases related to oxidative stress conditions.

Kajian in Silico Aktivitas Antioksidan Senyawa Bioaktif dalam Minyak Serai (Cymbopogon citratus)

stress oxidative is a factor promoting metabolic syndrome and other diseases. oxidative stress could be minimalized by exogen and endogen antioxidants. Essential oil from Cymbopogon citratus extract have potential activities as anti-inflammatory and relaxing. This study determined the potential activity as antioxidant through kelch ECH associating protein 1 (KEAP1) inhibition. Four phytosterol compounds from Cymbopogon citratus essential oil, including 3,7-dimethyl-1,3,6-octatriene, decanal, elemol, dan selina- 6-en-4-ol, were downloaded from PubChem database. four compounds were docked with KEAP1 protein and analyzed using Discovery studio ver. 19.0.0. 3,7-dimethyl-1,3,6-octatriene, decanal, elemol, and selina-6-en-4-ol bound to KEAP1 in certain amino acid residues with hydrophobic interaction and hydrogen bond. Interestingly, 3,7-dimethyl-1,3,6-octatriene proved five hydrophobic interaction, higher than decanal and selina-6-en-4-ol. The elemol, and selina-6-en-4-ol interacted with KEAP1 showing lower binding affinity and tight interaction. This study suggested that 3,7-dimethyl-1,3,6-octatriene, decanal, elemol, and selina-6-en-4-ol promoted antioxidant activity.

Environmental Sustainability Evaluation of Iron Oxide Nanoparticles Synthesized via Green Synthesis and the Coprecipitation Method: A Comparative Life Cycle Assessment Study.

Green synthesis, based on green chemistry, is replacing the traditional methods, aiming to contribute with an enhanced environmental sustainability, which can be achieved using nontoxic compounds from biological resources, such as natural extracts from plants. In this study, the life cycle assessment (LCA) of iron oxide nanoparticles prepared through the green synthesis and the coprecipitation method is reported by following a cradle-to-gate approach. The LCA allowed quantifying and normalized the environmental impacts produced by the green synthesis (1.0 × 10–9), which used a Cymbopogon citratus (C. citratus) extract and sodium carbonate (Na2CO3). The impacts were also determined for the coprecipitation method (1.4 × 10–8) using the iron(II) salt precursor and sodium hydroxide (NaOH). The contribution of C. citratus extract and Na2CO3 as the precursor and pH-stabilizing agents, respectively, was compared regarding the iron(II) and NaOH compounds. Environmental sustainability was evaluated in human toxicity, ecosystem quality, and resource depletion. The major environmental contribution was found in the marine aquatic ecotoxicity (7.6 × 10–10 and 1.22 × 10–8 for green synthesis and the coprecipitation method) due to the highest values for ethanol (3.5 × 10–10) and electricity (1.4 × 10–8) usage since fossil fuels and wastewater are involved in their production. The C. citratus extract (2.5 × 10–12) presented a better environmental performance, whereas Na2CO3 (4.3 × 10–11) showed a slight increase contribution compared to NaOH (4.1 × 10–11). This is related to their fabrication, involving toxic compounds, land occupation, and excessive water usage. In general, the total environmental impacts are lower for the green synthesis, suggesting the implementation of environmentally friendlier compounds based on natural sources for the production of nanomaterials.

Optimization of extraction conditions of phenolic compounds from Cymbopogon citratus and evaluation of phenolics and aroma profiles of extract

Decoction extraction procedure was implemented to regain phenolic compounds from C. citratus leaves. The extraction variables, solid/liquid ratio (2–5 g/100 mL), temperature (85–95 °C), and time (5–10 min) were assessed by central composite design for process optimization. Antioxidant activity (DPPH) and total polyphenol content (TPC) were monitored as responses. The TPC and DPPH were 71.98 ± 0.33 mg GAE/100 mL extract and 80.63 ± 0.49 mg TE/100mL extract respectively under optimal conditions (solid/liquid ratio = 5, temperature = 93.8 °C and time 11.3 min). The evaluation of phenolic compounds and volatile compounds of C. citratus extract at conditions for optimum extraction revealed that caffeic (20.81 ± 0.003 mg/100mL) and syringic acids (18.63 ± 7.390 mg/100mL) were the main phenolic compounds while citral and geraniol were the primary volatile compounds. The results achieved herein suits the potential use of C. citratus extract as natural source of antioxidant and aroma compounds that can be employed in different industrial sectors. Practical applicationLemongrass obtained at the optimal extraction conditions is a good source of antioxidants and the extract has organic acids and a lemon scent due to the presence of citral. This extract can thereby be incorporated in the production of beverages which can help aromatize the beverage and also contribute in the addition of the antioxidant property of the beverage. It is also rich in organic acids, the main being propionic acid, which is known to have antimicrobial activity primarily against bacteria and mold. The lemongrass extract can therefore, extend the shelf life of the beverage they are incorporated in and also the citral present in lemongrass has antimicrobial properties.

Antioxidant and Antimicrobial activities of MEOH Extract of Lemongrass (Cymbopogon citratus)

Cymbopogon citratus, universally known as Lemongrass is a small herbaceous plant of Poaceae family. It is used as traditional medicine for treatment of numerous diseases such as fever, sore throats, cough, laryngitis, bronchitis, oral candiasis, body ache, head ache, digestive problems etc. This study deals with the antioxidant activities such as DPPH and FRAP of mehanol extract of lemon grass leaves followed by quantitative analysis of total phenolics (TPCs) and flavonoids (TFCs) content. Antimicrobial activity of the extract was also been tested to highlight the medicinal values. The methanol extract showed significant antioxidant activity using DPPH and FRAP (26.03±1.60 μM; 922.43 μM trolox/100 g dry weight, respectively) compare to the standard Trolox.C. citratus extract has phenolic and flavonoid content as 130.33±1.23; 193.63±4.63, respectively. The results showed that extract of C. citratus exhibited maximum zone of inhibition (35mm) against Bacillus subtilis. at the highest concentration 150mg/ml methanol extract.

The Hypoglycemic Effects of Ethanol Leaves Extract of Cymbopogon citratus and Its Fractions in Alloxan-Induced Diabetic Mice

Varieties of plants including Cymbopogon citratus are traditionally used in controlling hyperglycemia by either stimulating insulin secretion, inhibition α- Glucosidase or α-amylase activity. Cymbopogon citratus leaves were shade dried, grinded into fine powder and then extracted by cold maceration using ethanol. Fractionation was done by VLC using dichloromethane, ethyl acetate and ethanol. OGTT was performed for both crude extract and fractions. Diabetes was induced in mice by intraperitoneal injection of freshly prepared alloxan monohydrate (170 mg/kilogram body weight). The mice were treated with ethyl acetate fraction once daily at 400 mg/kilogram body weight dose for the period of 20 days.FBG and weight were then recorded in days 1, 5, 10, 15 and 20 after six hours of fasting. Safety of crude water extract and ethyl acetate fractions were evaluated in mice by using Lorke’s method, followed by 5 days observation for their mortality and behavioral changes. Comparisons of results among groups were analyzed using One-way ANOVA. The difference between the means of the two population groups (each against negative control) was considered significant at p< 0.05. Results were expressed as mean ± SD. Both crude and ethyl acetate fractions from C. citratus showed significant hypoglycemic activity. Moreover, higher hypoglycemic activity was shown by ethyl acetate fraction (p = 0.004). No mortality was observed at 5000 mg/kilogram body weight dose but sleeping and tremor were observed at a 1000 -5000 mg/kilogram body weight dose. Good hypoglycemic and safety results from ethyl acetate fraction highly suggest that Cymbopogon citratus extracts are effective against insulin-dependent hyperglycemia, which may be contributed by the action of the present of alkaloids, saponins, antraquinone, phenol and tannins. Isolation and testing of the active ingredients from the C. citratus extract are thus warranted for use in developing pharmaceutical anti-hyperglycemic drugs from this herbal plant.

Thermogravimetric Analysis of Modified Montmorillonite Clay for Mycotoxin Decontamination in Cereal Grains.

Thermogravimetric analysis (TGA) was carried out to study the stability of nanoformulations used for the decontamination of mycotoxins. The TGA patterns of the nanoformulations from montmorillonite clay and Cymbopogon citratus (lemongrass) extracts were assessed with temperature ranging from ambient (20°C) to 1000°C. The various nanoformulations studied included unmodified montmorillonite clay (Mont), montmorillonite washed with sodium chloride (Mont-Na), montmorillonite mixed with lemongrass essential oil (Mont-LGEO), and montmorillonite mixed with an equal quantity of lemongrass powder (Mont-LGP). There was no significant difference in the median of the various nanoformulations within 4 weeks at p < 0.05 using the Kruskal–Wallis nonparametric test. For the TGA, the first degradation for montmorillonite clay and the nanoformulations occurred at a temperature between 80 and 101°C and was attributed to the loss of lattice water outside the coordination sphere with a range of 3.5–6.5% weight loss. The second degradation occurred within the temperature of 338 to 344°C, and the third, at a temperature between 640 and 668°C for Mont and the formulations of Mont-Na, Mont-LGEO, and Mont-LGP. There were strong similarities in the degradation patterns of Mont and Mont-Na with the minimum difference being the relatively higher weight loss of the sodium-exchanged cation for Mont-Na at the third degradation step. Hence, the order of stability from the most resistant to the least resistant to degradation is as follows: Mont-LGEO ≥ Mont-Na ≥ Mont ≥ Mont-LGP.

English

The study evaluates the sub-acute toxicity and antioxidant potential of ethanolic leaf extract of Cymbopogon citratus against CCl4-induced toxicity in Sprague Dawley rats. The ethanolic leaf extract of C. citratus was prepared by solvent maceration method. The phytochemicals present in the extract were determined using standard methods. The potential sub-acute toxicities were evaluated using OECD procedure. The sub-acute toxicity of the extract at the doses of 125, 250 and 500 mg/kg, b.wt. was administered orally for 28 days. Another sets of rats were made hepatotoxic by orally administered with CCl4 (20% CCl4 in olive oil) twice per week for a period of five weeks. They were treated with C. citratus extract (300 and 600 mg/kg body weight) once a day for 35 days. Biochemical parameters were used to assess the hepatoprotective effects of the extract on liver tissues. Phytochemical screening of C citratus shows the presence of anthraquinones, alkaloids, flavonoids, etc. The administration of C. citratus is not hematotoxic and significantly reduced (P<0.05) elevated liver biomarker enzymes, urea, creatinine and the level of malondialdehyde. Treatment with the extract was found to significantly increase (P<0.05) TP level, the activities of superoxide dismutase and catalase. Liver histopathology shows that the extract reduced the incidence of liver lesions induced by CCl4. The administration of C. citratus did not produce any toxic effects in the sub-acute study. The plant exhibits potent protective effects in CCl4-induced liver damage due to decrease in liver biomarker enzymes activities, increase of antioxidant-defense system and inhibition of lipid peroxidation. Key words: Sub-acute toxicity, protective effects, Cymbopogon citratus, carbon tetrachloride, hematological, oxidative stress parameters.

Green synthesis of iron oxide nanoparticles using Cymbopogon citratus extract and sodium carbonate salt: Nanotoxicological considerations for potential environmental applications

Synthesis of functional and biocompatible nanomaterials, based on the green chemistry paradigm, aims to innovate by using environmentally friendly techniques. Green synthesis using natural extracts instead of chemicals is proving to be an efficient route to prepare metal and metal oxide nanoparticles. In this study, the green synthesis of iron oxide nanoparticles (FeO-NPs) is reported, using a Cymbopogon citratus (C. citratus) extract and sodium carbonate as the reducing and pH stabilizer agents, respectively. FeO-NPs are extensively studied and applied due to the exceptional physicochemical properties, outstanding the superparamagnetism, and the large surface area. These properties are corroborated using different characterization techniques, in which a regular crystal structure and the magnetic response are similar compared with FeO-NPs synthesized via the traditional methods. The presence of magnetite and maghemite (Fe3O4 and γ-Fe2O3) phases are evidenced. A major composition of Fe3O4 allows predominant superparamagnetism. However, surface functionalization reduces the spin coordination avoiding a high saturation magnetization. The presence of phytochemical content in the C. citratus allows the reduction of iron(III) to iron(II) using H+ radicals produced from hydroxyl and carbonyl groups, and the in-situ functionalization using these groups. Additionally, the biocompatibility of the FeO-NPs is evaluated performing a nanotoxicological assessment, in which Caenorhabditis elegans nematodes are used as the biological model. The presence of organic molecules on FeO-NPs promotes no toxicity and low effects on the locomotion, growth, and reproduction, suggesting a low risk using these functional nanoparticles for environmental applications, and outstanding the synthesis route with a green approach.

Antiplasmodial activities and abortifacient properties of three commonly used African indigenous anti-malarial plants in Plasmodium berghei infected pregnant mice: implication for maternal and fetal health

BackgroundThe use of herbs for malaria treatment is common among pregnant women in Nigeria. This study through a survey documented three most commonly used herbs in the management of pregnancy-associated malaria in Abeokuta, Nigeria. This study also evaluated the efficacy and abortifacient properties of the selected herbs against established Plasmodium berghei NK65 infection in 110 experimental pregnant mice randomly distributed into 22 groups and treated with extracts of Morinda lucida (L.) Benth. (Rubiaceae), Enantia chlorantha (oliv.) (Annonaceae), and Cymbopogon citatrus (Stapf) (Poaceae) at a graded dose of 100, 200, and 300 mg/kg and Sulphadoxine-pyrimethamine (Fansidar) at 10 mg/kg.ResultsFrom the survey, Cymbopogon citratus (Leaf), Morinda lucida (Leaf), and Enanthia chlorantha (Bark) were the most frequently mentioned to be useful in management of malaria during pregnancy. Both M. lucida and E. chlorantha produced up to 70% P. gerghei chemosuppression in a dose dependent manner. Chemosupression was less than 50% in mice treated with C. citratus extracts. E. chlorantha induced abortion, while extracts of C. citratus and M. lucida caused miscarriage in pregnant mice. Progesterone titters were reduced in mice treated with plant extracts compared with those administered with Fansidar and untreated groups (p < 0.05).ConclusionThis study showed that M. lucida and E. chlorantha had anti-malarial properties, which are promising in reducing problems with pregnancy associated malaria in the face of growing resistance to currently available drugs. However, they are capable of inducing abortion by impairing the production of progesterone. In order to reduce the risk of danger posed by use of herbs in pregnancy on mothers and the developing fetus, there is need for proper awareness on the possible abortifacient and teratogenic properties of herbs used in management of malaria during pregnancy.

Chemical characterization and in vitro biological activity of Cymbopogon citratus extracts against Haemonchus spp. and Trichostrongylus spp. nematodes from sheep.

Medicinal plants have been the focus of several studies due to their nematicide properties which can be used to control nematodes in sheep. No study has examined the morphological effects of Cymbopogon citratus on nematodes. Thus, this study evaluated the chemical composition, nematicidal activity and effects of C. citratus extracts on the morphology of eggs and infective larvae (L3) of sheep. Aqueous and methanolic extracts and fractions of C. citratus were obtained and analysed in vitro. The C. citratus extracts were effective against Haemonchus spp. and Trichostrongylus spp. larvae and eggs. Ten fractions were obtained from C. citratus, six of which had high ovicidal activity at 1000 μg mL-1, and two fractions had high activity at all tested concentrations. The phytochemical analysis identified the presence of compounds such as terpenoids, various ketones, esters, and fatty acids. The ultrastructural analysis showed deformations of the cuticle and wilting along the body of the nematodes at all concentrations. The muscular layer, intestinal cells and the mitochondria profile showed damage compared to the typical pattern. Ultra-thin sections of eggs treated with methanolic fractions of C. citratus presented modifications. This study showed the biological activity and effects of C. citratus on the gastrointestinal nematodes in sheep.

Antibacterial activity of Cymbopogon citratus against clinically important bacteria

Antibiotic resistance has become a major problem worldwide, and has impacted patients emotionally and financially. In order to overcome this problem, alternative therapeutic agents should be investigated. Cymbopogon citratus possesses various pharmacological activities including antibacterial activity, which is useful in treating multidrug resistant bacterial infections. The antibacterial property is due to the presence of resistance modifying agents that are present in the plant. In this study, multidrug resistant bacterial isolates that have been collected from healthy individuals in Nilai were identified and confirmed. Aqueous and methanolic extracts of C. citratus were used in agar diffusion assays to determine the efficacy of C. citratus in treating multidrug resistant bacterial infections. Moreover, different parts of C. citratus were used to examine the difference in antibacterial activity. The inhibition zones were measured and compared among the different extracts and C. citratus essential oil, which was used as the positive control. The extracts were also compared with the antibiotics commonly used to treat multidrug resistant bacterial infections. In this experiment, C. citratus essential oil showed the greater antibacterial activity than methanolic extract due to the fact that the methanolic extract was not concentrated enough while boiled extract did not exhibit any antibacterial activity. The C. citratus extract also exhibited better antibacterial activity in gram positive bacteria than in gram negative bacteria, with the exception of P. aeruginosa which showed a high susceptibility towards the methanolic extracts. Thus, C. citratus could have the potential use in the treatment of biofilm development related infections.

UPLC-Orbitrap HRMS metabolic profiling of Cymbopogon citratus cultivated in Egypt; neuroprotective effect against AlCl3-induced neurotoxicity in rats

Ethnopharmacological relevanceCymbopogon citratus (lemongrass) is commonly used in teas, soups and treat inflammatory-based ailments, vascular and nervous disorders. Aim of the studyThe study aimed to evaluate the neuroprotective effect of Cymbopogon citratus leaves through scientific protocol. The effect of aqueous (AE) and ethanolic (EE) extracts was evaluated against AlCl3-induced Alzheimer's disease (AD) in rats. Metabolic profiling of the plant, isolation of bioactive compounds and standardization of the active fraction were investigated. Materials and methodsAE of Cymbopogon citratus leaves was prepared as per traditional method (infusion), EE was prepared by repeated maceration in 90% ethanol, bioactive fraction (BAEE) was obtained from EE and the active compounds thereof were obtained by column chromatography. Metabolic profiling of Cymbopogon citratus was performed by UPLC-Orbitrap HRMS and HPLC was used for standardization. AlCl3-induced Alzheimer's rats were used to assess neuroprotective effect of the extracts. Neuroprotective mechanism(s) of Cymbopogon citratus extracts was clarified through histopathological examination of brain tissues, estimation of AD biochemical markers, oxidative stress and neuroinflammation in brain homogenates. In addition, antioxidant (using DPPH assay) and anticholinesterase (using modified Ellman's method) activities were investigated. ResultsAlCl3-treated rats (17 mg/kg/day) showed histopathological alteration in brain tissues together with elevated levels of Aβ, tau proteins, MDA, NF-kB and IL-6. However, treatment with AE and EE of Cymbopogon citratus leaves prevented the pathological changes and maintained the levels of oxidative stress and inflammatory markers. In addition, BAEE significantly inhibited acetylcholinesterase enzyme (2.11 ± 0.11 mg/ml) and exhibited a strong antioxidant activity (24.99 ± 0.00 μg/ml). UPLC-MS of Cymbopogon citratus leaves showed peaks for twenty-eight compounds, twenty-one of them were identified. Three flavonoids; isoorientin, isoschaftoside and luteolin-7-O-neohesperidoside were isolated from BAEE as major constituents. The powdered leaves of Cymbopogon citratus was found to contain remarkable amounts of caffeic acid (3.49 mg/g dry wt.) and isoorientin (7.37 mg/g dry wt.) as determined by HPLC. ConclusionCymbopogon citratus ethanolic extract attenuates AlCl3-induced neurotoxicity in rats through inhibition of oxidative stress and inflammatory markers. This effect could possibly attributed, in part to its high content of phenolic acids and flavonoids. Accordingly, we recommend Cymbopogon citratus leaves for protection against AD.

Phytochemical characterization and antimicrobial activity of Cymbopogon citratus extract for application as natural antioxidant in fresh sausage

The development of natural additives is considered an important research topic. In this work, the use of Cymbopogon citratus (CC) extract as a natural additive for chicken sausage refrigerated was investigated. The CC extract was characterized by electrospray ionization with high-resolution time-of-flight mass spectrometry (ESI-ToF-MS) and the identified compounds were directly related to the antioxidant activity demonstrated by CC in the fresh sausage. In total, 31 phytochemical compounds were identified, and 27 of these still were not described in the literature for CC. The antimicrobial activity showed that CC extract is a potential antibacterial agent. Besides, the results showed that CC extract reduced lipid oxidation compared to synthetic additive. The sensorial characteristics were maintained, demonstrating good acceptability by the consumer. The results confirmed that CC can keep the quality of chicken sausage refrigerated for up to 42 days of storage.

Multi-Drug Resistant Salmonella typhi among Out-Patients in Hospitals within Ilorin, Nigeria and their Susceptibility to Cymbopogon Citratus

The indiscriminate use of drugs, medication and non-adherence are one of the factors that has led to the emergence of multi-drug resistant Salmonella typhi. This study was conducted to assess the incidence of typhoid fever among out-patients in some selected Specialist Hospitals in Ilorin Metropolis and to determine the susceptibility of the causative agent to antibiotics and plant extract of Cymbopogon citratus. A cross-sectional survey was completed over a five-month surveillance period in these four locations namely: The Children Specialist Hospital Centre Igboro; Cottage Hospital; Adewole Specialist Hospital Alagbado; and Civil Service Hospital with a total of about 400 blood samples from out-patients across ages. Antibiogram profiling of the isolates to standard gram-negative antibiotics and antibacterial activity of Cymbopogon citratus extracts were determined using disc diffusion method. A total of Eight (8) Salmonella typhi isolates were recovered collectively from the patients. All the isolates were multi-drug resistant with a notable resistance to chloramphenicol, ampicillin and co-trimoxazole. Molecular confirmation of the isolates showed DNA size of 500 base pairs. The ethanolic extract of Cymbopogon citratus was more potent with MIC of 12.5mg/ml and MBC 25mg/ml while the phytochemical screening of the plants revealed the presence of alkaloids, flavonoids, phenols, tannins, saponins, steroids and glycosides. The promising outcome of the plant extract against Salmonella typhi posits its possible application in treatment against the infectious agent.

Defect related photoluminescence study of V2O5: Dy3+ nanostructures

Nanostructures of V2O5, doped with Dy3+ ions of different concentrations were prepared though solution combustion technique using Cymbopogon citratus extract as a fuel for its application towards white light LEDs (WLEDs). The characterization tools such as PXRD, FTIR, Raman spectroscopy, DRS, SEM, TEM, EDS and SAED was employed to study the structural and morphological features of the V2O5: Dy3+ nanostructures. Positron annihilation lifetime spectroscopy (PALS) is a non-destructive technique carried out to find out the type of defects evolved during Dy3+ ion doping into the host matrix, which has greater influence on the photoluminescence properties of the V2O5 nanostructures. The positron lifetime annihilation spectrum was analyzed with τ1, τ2 the lifetime components, τ1 is the shortest and attributes to the free positrons. τ2 was found to be longer and arises due to trapped positrons at the grains, grain boundaries and their interface. As the Dy3+ ion concentration increases positron annihilation lifetime increases due to development of strain gradient in host matrix.

Larvicidal Activity of Two Cymbopogon Species Leaf Extracts and Essential Oils against Anopheles gambiae Gilles (Diptera: Culicidae)

Aims: The present investigation aimed to assess the toxic effect of hexane, acetone and methanol extracts of Cymbopogon citratus and Cymbopogon giganteus against 3rd and 4th instar of Anopheles gambiae larvae under laboratory conditions.&#x0D; Place and Duration of Study: Plant products were extracted from November 2017 to February 2018 in the Chemistry laboratory, while the larvicidal tests were conducted from April to June 2018 in the laboratory of Applied Zoology of the Faculty of Science, University of Ngaoundere, Cameroon.&#x0D; Methodology: Twenty five (25) 3rd and 4th instars of An. gambiae were subjected to methanol, acetone and methanol plant extracts of the two plants at doses of 1000, 500, 250 and 125 mg/L each while their essential oils were tested at concentrations of 200, 100, 50 and 25 mg/L. Dichlovos tested at the recommended dose of 1000 mg/L was performed as positive control while 1mL of tween-80 in 99 mL of natural breeding site water was used as negative control. Larval mortality was recorded after 24 h post treatment for plant extracts and after 1, 6, 12, 18 and 24 h post-exposure for plant essential oils.&#x0D; Results: At the highest concentration of 1000 mg/L, C. citratus extract caused 100% mortality of mosquito larvae while 84, 81 and 88% mortality of larvae were recorded with hexane, acetone and methanol leaf extract of C. giganteus, respectively. C. citratus (LC50=58.32 mg/L) and C. giganteus (LC50=372.36 mg/L) hexane extracts were more potent than acetone and methanol extracts of the plants. C. citratus extracts were the most effective against larvae compared to C. giganteus extracts. Essential oil of C. citratus (LC50=27.98 mg/L after 1h) was also the most toxic on mosquito larvae compared to C. giganteus (LC50=180.07 mg/L after 1h) essential oil.&#x0D; Conclusion: C. citratus plant and specially its hexane extract and essential oil could be taken into consideration as a new source of botanical insecticide and may be used in the mosquito control programs for An. gambiae larvae elimination in their breeding sites.

Phytochemical constituents and larvicidal efficacy of methanolic extracts of &lt;i&gt;Cymbopogon citratus&lt;/i&gt;, &lt;i&gt;Ocimum gratissimum&lt;/i&gt; and &lt;i&gt;Vernonia amygdalina&lt;/i&gt; against &lt;i&gt;Culex quinquefasciatus&lt;/i&gt; larvae

This study assessed the larvicidal efficacy of the methanolic extract of Cymbopogon citratus, Ocimum gratissimum and Vernonia amygdalina against the third instar larvae of Culex quinquefasciatus. Qualitative analysis of the plants revealed that alkaloids, flavonoids, saponins, steroids, tannins, terpenoids and glycosides were present in all three plant extracts. Phlobatannins was present in trace amounts in O. gratissimum and absent in C. citratus and V. amygdalina. Larvicidal activities of the leaf extracts were studied on laboratory reared larvae of Cx. quinquefasciatus at a concentration range of 250 ppm to 1000 ppm. The percentage mortality was calculated and LC50, LC90 values were obtained from probit analysis using SPSS version 16.0 at 95% confidence limit (CL). Result of this study indicated that the percentage mortality of O. gratissimum extract was dose dependent with 250 and 1000 ppm having the percentage mortality of 18.33 and 43.3% respectively after 72 hrs. The percentage mortality in C. citratus extract after 72 hrs was 66.67% at 1000ppm concentration whereas at 750 ppm mortality was 8.33%. The percentage mortality for V. amygdalina increased from 250 to 750 ppm but decreased at 1000ppm with 750 ppm having a mortality of 63.33% and 1000ppm having a percentage mortality of 56.6% after 72 hrs. The LC50 and LC90 values of the methanolic leaf extract obtained after 72 hrs was 1008.19 and 1930.992 ppm for C. citratus, 1148.47 and 2210.727 ppm for O. gratissimum and 754.712 and 1548.499 ppm for V. amygdalina respectively. The methanolic extract of V. amygdalina exhibited a higher degree of potency when compared with the methanolic extract of C. citratus and O. gratissimum with a low LC50 value of 758.403ppm, 758.03 ppm and 754. 712 ppm at 24, 48 and 72 hrs respectively. In summary, this study reports the larvicidal effects of C. citratus, O. gratissimum and V. amygdalina against Cx. quinquefasciatus larvae which can serve as an lternative to synthetic pesticides in Nigeria.Keywords: Leaf extracts, Culex quinquefasciatus, larvae, toxicity, mortality

Analytical Investigation of Cymbopogon citratus and Exploiting the Potential of Developed Silver Nanoparticle Against the Dominating Species of Pathogenic Bacteria.

Indian biodiversity is a hub for medicinal plants. Extensive research has been carried out to select plants with numerous properties which can be used for human welfare. Present research is about Cymbopogon citratus, an economically valuable medicinal plant. In this study Cymbopogon citratus was elected as a subject plant over the five selected plants (Azadirachta indica, Plumeria obtuse, Sapindus mukorossi, Capsicum annuum and Phyllanthus emblica) on the basis of antibacterial effect against dominating pathogenic species of gram positive (Bacillus cereus, Bacillus licheniformis) and gram negative (Pseudomonas aeruginosa, Escherichia coli) bacteria. Further, bioactive agents behind antibacterial potential of Cymbopogon citratus was analyzed using analytical method (Phyto-chemical, FTIR, NMR and GC-MS). Due to the broad antimicrobial spectrum, silver nanoparticles have turned into a noteworthy decision for the improvement of new medication. Therefore, this investigation further elaborated in the development of Cymbopogon citratus silver nano-particles (CNPs). Antibacterial potential of CNPs examine in a range of C25–C150 (μg/ml) through minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) where, C25 (μg/ml) concentration of CNPs were recorded as the MIC for all bacterial species and C25 (μg/ml) and C50 (μg/ml) noted as the MBC for Pseudomonas aeruginosa, Escherichia coli and Bacillus cereus, Bacillus licheniformis, respectively. In agar disk diffusion assay of CNPs, maximum diameter of zone of inhibition was observed for C150 (μg/ml) concentration Bacillus cereus (20.12 ± 0.42), Bacillus licheniformis (22.34 ± 0.4), Pseudomonas aeruginosa (35.23 ± 0.46) and Escherichia coli (31.87 ± 0.24). Involvement of bioactive component as a reducing and capping agent can be confirmed through FTIR spectrum of CNPs. Moreover XRD, EDXRF and SEM showed crystalline and cuboidal nature of CNPs with ∼35 nm sizes. Prominently, cytotoxic analysis was conducted to understand the toxic effect of CNPs. This research highlights the potential of CNPs due to the bioactive components present in Cymbopogon citratus extract: Polyphenols (phenol; 1584.56 ± 16.32 mg/L, Flavanoids) and mixture of terpenoids (Citral, Myrcene, Farnesol, β-myrcene and β –Pinene)