Concentrations Of Crude Extract Research Articles

Anti-inflammatory, Anxiolytic and Antioxidant Property of Lactuca sativa L and Formulation of Microspheres Loaded Sustained Release Anti-inflammatory Gel

Anti-inflammatory and anxiolytic properties of Lactuca sativa L extract was evaluated by formalin induced mice paw edema test, and elevated plus maze animal model respectively. Solid microspheres containing dispersed extract were obtained by water-in-oil-in-water multiple emulsion system followed by solvent evaporation method. Optimization was carried out using MINITAB 16 and optimized microspheres were loaded into a gel base. Anti-oxidant activity of optimized microspheres loaded gel was evaluated using DPPH (2,2-diphenyl-1-picrylhydrazyl) assay. The gel was also evaluated for its physical properties, drug release kinetics and anti-inflammatory activity using formalin induced mice-paw edema test where the anti-inflammatory potential was compared to marketed diclofenac gel (1.16% w/w). All doses of extract as well as microsphere loaded sustained release anti-inflammatory gel showed a dose and time dependent inhibition of edema (P<0.05), the extract also showed a dose dependent inhibition of level of anxiety (P<0.001). Potential anti-oxidant activity was seen with different concentration of crude extract and microsphere loaded gel. The anti-oxidant potential was compared using IC50 value which was 5.62 µg/mL, 6.34 µg/ml, 8.25 µg/mL for ascorbic acid, methanolic extract of L. sativa and microspheres loaded gel respectively.

Antibacterial Activity of Leaf Extracts of Anredera cordifolia (Ten.) Steenis and Muntingia calabura L. Against Streptococcus pneumoniae

Antibacterial resistance in Streptococcus pneumoniae has been increasing and is one of ongoing global concern. The need to find new antibacterial agents against Streptococcus pneumoniae is of paramount importance. Medicinal plants are prospective sources of antibacterial agents. The aims of the present study were to determine the activity of leaf extraxt of Anredera cordifolia (Ten.) Steenis and Muntingia calabura L. against Streptococcus pneumoniae. Leaves of Anredera cordifolia (Ten.) Steenis were extracted using 96% ethanol, while the leaves of Muntingia calabura L were extracted using 100% methanol. The leaf extracts of the two plants obtained were bioassayed for antibacterial activity against Streptococcus pneumoniae ATCC 49619 and a clinical isolate Streptococcus pneumoniae PU 067. Results showed that leaf extracts of both Anredera cordifolia (Ten.) Steenis and Muntingia calabura L. have antibacterial activity in vitro against Streptococcus pneumoniae ATCC 49619 at crude extract concentrations of 25%, 50%, 75% and 100% (w/v). Both plants extracts showed strongest activity against S. pneumoniae ATCC 49619 at extract concentration of 75%. In addition, the extracts of both plants have inhibitory activity against growth of the clinical isolate Streptococcus pneumoniae PU 067. Both plant extracts showed strongest activity against S. pneumoniae PU 067 at extract concentration of 100%. Therefore, leaf extracts of Anredera cordifolia (Ten.) Steenis and Muntingia calabura L. can potentially be used as a source of antibacterial agent for Streptococcus pneumoniae. 
 Keywords: Antibacterial agent, Anredera cordifolia (Ten.) Steenis, Muntingia calabura L., Streptococcus pneumoniae.

Antibacterial Activity of Leaf Extracts of Anredera cordifolia (Ten.) Steenis and Muntingia calabura L. Against Streptococcus pneumoniae

Antibacterial resistance in Streptococcus pneumoniae has been increasing and is one of ongoing global concern. The need to find new antibacterial agents against Streptococcus pneumoniae is of paramount importance. Medicinal plants are prospective sources of antibacterial agents. The aims of the present study were to determine the activity of leaf extraxt of Anredera cordifolia (Ten.) Steenis and Muntingia calabura L. against Streptococcus pneumoniae. Leaves of Anredera cordifolia (Ten.) Steenis were extracted using 96% ethanol, while the leaves of Muntingia calabura L were extracted using 100% methanol. The leaf extracts of the two plants obtained were bioassayed for antibacterial activity against Streptococcus pneumoniae ATCC 49619 and a clinical isolate Streptococcus pneumoniae PU 067. Results showed that leaf extracts of both Anredera cordifolia (Ten.) Steenis and Muntingia calabura L. have antibacterial activity in vitro against Streptococcus pneumoniae ATCC 49619 at crude extract concentrations of 25%, 50%, 75% and 100% (w/v). Both plants extracts showed strongest activity against S. pneumoniae ATCC 49619 at extract concentration of 75%. In addition, the extracts of both plants have inhibitory activity against growth of the clinical isolate Streptococcus pneumoniae PU 067. Both plant extracts showed strongest activity against S. pneumoniae PU 067 at extract concentration of 100%. Therefore, leaf extracts of Anredera cordifolia (Ten.) Steenis and Muntingia calabura L. can potentially be used as a source of antibacterial agent for Streptococcus pneumoniae. 
 Keywords: Antibacterial agent, Anredera cordifolia (Ten.) Steenis, Muntingia calabura L., Streptococcus pneumoniae.

Optimization of aqueous two-phase micellar system for partial purification of L-asparaginase from Penicillium sp. grown in wheat bran as agro-industrial residue.

L-asparaginase has been used in the remission of malignant neoplasms such as acute lymphoblastic leukemia. The search for new sources of this enzyme has become attractive for therapeutics. Traditional methods for biomolecule purification involve several steps. A two-phase system may be a good strategy to anticipate one of these stages. This study aimed to produce and purify a fungal L-asparaginase through an aqueous two-phase micellar system (ATPMS) using Triton X-114. The fungus Penicillium sp.-encoded 2DSST1 was isolated from Cerrado soil. Plackett-Burman design followed by a 24 full factorial design was used to determine the best conditions to produce L-asparaginase. The evaluated variables were L-asparagine, L-proline, wheat bran, potato dextrose broth, ammonium sulfate, yeast extract, sucrose and glucose concentrations, incubation temperature, incubation period, and initial pH of the culture medium. L-asparaginase quantification was valued by the formation of β-aspartyl hydroxamate. The significant positive variables, L-asparagine, L-proline, potato dextrose broth, and sucrose concentrations, were evaluated at 2 levels (+ 1 and - 1) with triplicate of the central point. After 34 runs, maximum activity (2.33IU/mL) was achieved at the factorial design central point. A central composite design was performed in ATPMS at two levels (+ 1 and - 1) varying Triton X-114 concentration (w/v), separation phase temperature, and crude extract concentration (w/v). The L-asparaginase partition coefficient (K) was considered the experimental design response. Out of the 16 systems that were examined, the most promising presented a purification factor of 1.4 and a yield of 100%.

Green synthesized ZnO nanosheets from banana peel extract possess anti-bacterial activity and anti-cancer activity

Recently, green synthesis of metal oxide nanoparticles has gained extensive attention because it is an environment-friendly and cost-effective approach. This study therefore focused on green synthesis of zinc oxide nanoparticles (ZnO NPs) by using waste material, banana peel crude extract, as reducing as well as capping agents in the reaction with zinc acetate. The synthesized ZnO NPs with the average electronic band gap ∼3 eV were obtained and found to have rod-like or sheet-like structures depended on concentration of crude extract used in the reaction. By performing antibacterial activity assay, these green synthesized ZnO nanosheets inhibited growth of gram-positive bacteria, Bacillus subtilis, Staphylococcus epidermidis and gram-negative bacterium, Escherichia coli. Moreover, the synthesized ZnO nanosheets demonstrated potent anti-cancer activity against cell viability of skin cancer cell (A431), colorectal cancer cell (SW620) and liver cancer cell (HepG2) without affecting normal cell line (Vero). Therefore, these studies firstly reported potential usage of the green-synthesized ZnO nanosheets for development of anti-bacterial substances or anticancer drugs. Moreover, this study showed the opportunity to increase values of agricultural waste.

Antibacterial Potential and Apoptosis Induction by Pigments from the Endophyte Burkholderia sp. WYAT7.

Pigment from the endophyte Burkholderia sp. WYAT7 isolated from the medicinal plant Artemisia nilagirica (Clarke) Pamp. was extracted. The antibacterial efficacy of the crude pigment Y was assessed as a source of antibiotic against both Gram-positive and Gram-negative bacterial pathogens. The pigment Y exhibited a significant level of antibacterial activity against the tested pathogens Salmonella typhi (MTCC 733), Staphylococcus aureus (MTCC 1430), Pseudomonas aeruginosa (MTCC 2453), Klebsiella pneumoniae (MTCC 432), Escherichia coli (MTCC 1610), Salmonella paratyphi (3220), Bacillus subtilis (441) and Acinetobacter baumannii (12,889). The minimum inhibitory concentration of crude pigment extract Y for most of the bacterial pathogens tested was below or equal to 0.25 µg/mL and the minimum bactericidal concentration was below or equal to 0.5 µg/mL. In the cytotoxicity evaluation, crude pigment Y exhibited less toxicity toward normal cells lines (L929). Crude pigment extract Y also showed powerful anticancer activity toward melanoma cancer cells (A375). The IC50 value obtained was 68.08 µg/mL. Acridine orange (AO) and ethidium bromide (EB) double staining of cells treated with the pigment helped in the morphological assessment of nuclear condensation, apoptotic bodies and live cells. The DNA fragmentation analysis and caspase-9 quantification in the pigment-treated A375 cells determined the apoptosis activity mediated by the crude pigment extract Y. The compounds in the crude pigment extract Y was identified by HR-LCMS analysis. Further studies on the active compounds can lead to a rise in new drugs for cancer treatment and also against rising antibacterial resistant pathogens.

Efficacy of Aqueous Crude Fruit Extract of Desert Date (Balanites aegyptiaca) in Anaesthetization of African Catfish (Clarias gariepinus) Fingerlings

Chemicals have been used to anaesthetize fish but due to their hazardous effects on the environment, fish and humans environmentally friendly plant anaesthetics are being sought. Fruit of Desert date (Balanites aegyptiaca) is nontoxic to humans but has been reported to have anaesthetic potentials on fish. This study investigates anaesthetic effect of aqueous crude fruit extract of B. aegyptiaca on African catfish (Clarias gariepinus) fingerlings. Phytochemical and proximate compositions of the fruit were screened. Exactly 120 C. gariepinus fingerlings (mean weight 32.13±2.43g and mean total length 23.88±2.11cm) were used for the experiment. A total of 10 fingerlings were exposed to each of 2.00, 2.50, 3.00, 3.50 and 4.00g/L concentrations of aqueous crude fruit extract of B. aegyptiaca and a control in 6 plastic tanks (45x28x25cm) filled with 10L of tap water. Setup was arranged in randomized block design and replicated. Temperature, dissolved oxygen, pH, free carbon dioxide and total alkalinity were monitored. Results revealed long mean induction (25.05±3.35 min) and recovery (108.35±2.45 min) times with resultant mortalities (40%) of C. gariepinus fingerlings. significant correlation (P<0.01) exists between concentration of the fruit extract and induction time as well as between fruit extract concentrations and survival of fingerlings. Aqueous crude fruit extract of B. aegyptiaca is, therefore, not effective for anaesthetization of C. gariepinus fingerlings hence should be avoided.
 Keywords: Anaesthetic, Balanites aegyptiaca, Clarias gariepinus

Low-sugar content betaxanthins extracts from yellow pitaya (Stenocereus pruinosus)

Consumer preferences, and potential health risks associated with the consumption of synthetic food colors, explain the commercial interest in alternatives from natural sources. Betaxanthins from cactus fruit have been used to color food products, but sugars are not usually removed from these extracts leading to processing and formulation challenges. In this study, low-sugar betaxanthin preparations were obtained from a crude yellow pitaya Stenocereus pruinosus extract using aqueous two-phase systems (ATPS). This study focuses on the effect of the salts and polymer choice (polyethylene glycol (MW 1000; PEG1000) or polyalkylene glycol copolymer (MW 3930, UCON), tie line length (TLL), phase volume ratio (Vr), and crude extract percentage on the partitioning of betaxanthins and sugars in the crude extract. PEG1000-phosphates were more suitable than UCON-salts for the extraction of betaxanthin. Multivariate analysis of variance (MANOVA, α = 0.05) showed that TLL, Vr and crude extract concentration effects were statistically significant (P < 0.05). The correlation with Vr, crude extract concentration, and TLL was determined by multiple linear regression. The desirability function was used to identify an ATPS (TLL = 37.7 %, Vr = 0.3, and 7 % crude extract) yielding a top phase with minimum total sugar (2.8 %) and maximum betaxanthin content (52.3 %).

Impact of Spray-Drying on Biological Properties of Chitosan Matrices Supplemented with Antioxidant Fungal Extracts for Wine Applications.

Black aspergilli produce many bioactive compounds: enzymes, organic acids, and secondary metabolites. One such fungus, Aspergillus tubingensis G131, isolated from French Mediterranean vineyards, produces secondary metabolites with antioxidant properties that can be extracted with ethanol. In this study, crude antioxidant extracts obtained from A. tubingensis G131 cultures were encapsulated with two types of chitosan matrix. Spray-drying was used to obtain dried particles from a dispersion of fungal crude extracts in a solution of the coating agent chitosan. This process appeared to be an efficient method for obtaining a dry extract with antioxidant activity. Three types of fungal extracts, with different antioxidant capacities, were produced: two different concentrations of crude extract and a semi-purified extract. In this study, the chitosan matrices for encapsulation were chosen on the basis of their antimicrobial activities for wine applications. Classical low molecular weight chitosan was compared with NoBrett Inside® which is already used to prevent the development of Brettanomyces spp. in wine. The objective of this study was to confirm that both antioxidant (fungal extract) and antimicrobial (chitosan) properties were preserved after spray-drying. The combination of these two properties and the powder formulation of this entirely natural product would make it a good alternative to chemicals, such as sulfites, in the food and wine industries.

Effects of crude ethanolic extract of &lt;i&gt;Gloriosa superba&lt;/i&gt; L. tuber, on root growth and root tip mitosis, of &lt;i&gt;Allium sativum&lt;/i&gt; L.

Colchicine is an alkaloid produced by some members of the Liliaceae family which include Gloriosa superba L. Apart from its other medicinal uses, it is used for both cytological and plant breeding studies. Absence of pure colchicine in Nigeria has retarded research progress in the above-mentioned areas of research. In this study, the genotoxic and cytotoxic effect of ethanolic crude extract of G. superba tubers, obtained by freeze-drying method, on Allium sativum meristematic roots were examined; to explore the possibility of using it, in research, in the absence of pure colchicine. The mitotic index of the roots treated with aqueous crude extract concentrations of 500mg/L, 1000mg/L and 2000mg/L for 3, 6, 12 and 24 hours, showed that there was significant reduction in the number of dividing cells with time. There were evidences of disturbed mitotic phases, C-metaphase, precocious chromosome movement and anaphase bridges, which increased as concentration and duration of treatment increased. Distilled water and 8-hydroxyquinoline were used as negative and positive controls. A. sativum roots exposed to the crude extract concentrations for 3, 6, 12, 24, 48 and 72 hours showed significant inhibition of root growth which increased with concentration and duration of treatment. The results obtained from this study indicate that the crude colchicine contained in G. superba , is an effective tubulin binder, which can arrest cells at the metaphase stage and is therefore recommended for cytological studies in Nigeria and other underdeveloped economies, in the absence of pure colchicine. Keywords: Root growth, root tip, mitosis, Gloriosa superba , Allium sativum , colchicine

Acaricidal and Chemical Composition of Allium sativum L. Crude Extracts Against Stored Product Mites Suidasia pontifica Oudemans

Natural product calls the attention of the public nowadays, because of its promising control measures which are eco-friendly, safe and yet effective against a wide range of stored product mite pest. Current investigation aims to evaluate the efficacy garlic crude extract (GCE) against Suidasia pontifica, that causes allergenic and possess a great challenge in postharvest agricultural products especially in areas of human activities. Based on the response of S. pontifica the estimated minimum effective concentration (MEC) of garlic crude extracts to give complete kill at different developmental stages was 0.75 - 1.0 g/L concentration. GC/MS analysis revealed various biologically active components of garlic, including oleyl alcohol (41.41 %), γ-sitosterol (16.49 %), 3-vinyl-1 2-dithiacyclohex-4-ene (5.78 %), 2-vinyl-4h-1 3-dithiine (5.52 %), 24-nourse-3,12-diene (4.39 %) and 1-octadecanol methyl ether (4.37 %) and its derivatives. Four out of six major components of the identified compound from GCE were used for industrial application. The other two were still unknown for its uses. The results support the possible use of A. sativum extracts as an alternative to synthetic acaricide.

Antibacterial Effects of Green Betel (Piper betle Linn.) Leaf Against Streptococcus agalactiae and Escherichia coli

This study investigated the effect of betel (Piper betle L.) leaf at two physiological ages (young, 3rd leaf, and old, 8th leaf) at three concentrations of crude boiled-water extracts (10%, 20%, and 30%) against Streptococcus agalactiae and Escherichia coli. A completely randomized design with nesting was adopted for the six treatments and six replicates. The inhibition zone on nutrient agar media was measured. Overall there were no significantly differences. However, the inhibition zone diameters with 10%, 20%, and 30% crude water extracts of young leaves with S. agalactiae were 5.18 ± 0.99, 5.96 ± 0.34, and 6.38 ± 1.52 mm, respectively, and for old leaves, they were 5.76 ± 0.62, 5.67 ± 0.43, and 4.68 ± 0.33 mm, respectively. For E. coli, the corresponding values for young leaves were 3.96 ± 1.45, 4.54 ± 0.72, and 3.51 ± 0.48 mm, respectively, and for old leaves, the values were 3.85 ± 1.20, 4.14 ±0.68, and 2.35 ± 0.83 mm, respectively. The strongest inhibition was shown by the 30% crude water extract of young leaves against S. agalactiae.

Effects of Lysobacter antibioticus HS124, an effective biocontrol agent against Fusarium graminearum, on crown rot disease and growth promotion of wheat.

Lysobacter antibioticus HS124 inhibited mycelial growth of Fusarium graminearum (74.66%) under the dual culture method. Microscopic investigation clearly showed that amendment with different concentrations (10%, 30%, and 50%) of HS124 bacterial culture filtrate on potato dextrose agar plates caused abnormal hyphal structures, including swelling and distortion. Its inhibition toward mycelial growth of F. graminearum was increased with increasing concentration of n-butanol crude extract of HS124. The highest inhibition (43.14%) was detected at a crude concentration of 10 mg/disc, whereas the lowest inhibition (21.57%) was observed at 2 mg/disc. Although mycelial growth of F. graminearum was promoted by volatile organic compounds (VOCs) produced by HS124 as compared with the control, these VOCs clearly decreased fungal pigmentation resulting in a reduction of fungal sporulation. Microscopic investigation revealed hyphal deformation of F. graminearum due to VOCs. These compounds also had a negative effect on spore germination of F. graminearum. In vivo evaluations demonstrated that HS124 inoculation of wheat plants reduced crown rot disease incidence by 73.70% as compared with the control. HS124 inoculation of wheat plants also promoted most of the growth characteristics compared with the control or fungicide-treated plants. Our results provide strong evidence that HS124 could control F. graminearum infections and promote growth of wheat plants as part of management strategies for crown rot disease.

In vitro anticoagulant effect of Crassocephalum crepidioides leaf methanol extract and fractions on human blood.

BackgroundBlood coagulation is a rapid and efficient process that produces clot formation which requires regulation. A derangement of blood coagulation is a feature of many disease conditions. This study investigated the in vitro effects of Crassocephalum crepidioides Benth S. Moore leaf methanol (crude) extract and its partitioned solvent fractions on blood coagulation of Healthy human volunteers.MethodsThe secondary metabolites from dried and ground C. crepidioides leaves were extracted with 70% methanol, and the concentrated crude extract was subsequently subjected to solvent partitioning with Hexane, Ethyl acetate, and Butanol. Varying concentrations (5–20 mg/mL) of the extract and fractions were tested in vitro on blood coagulation profile; clotting time (CT), prothrombin time (PT), and activated partial thromboplastin time (aPTT) of apparently healthy human volunteers, while phytochemical characterization of the Hexane fraction was done by gas chromatography-mass spectrometry (GC-MS).ResultsC. crepidioides leaf methanol extract and fractions significantly (P<0.05) prolonged the clotting time, prothrombin and activated partial thromboplastin times in the blood obtained from the volunteers. The highest prolongation effect was recorded with the Hexane fraction at concentration of 10mg/mL. GC-MS analysis of the Hexane fraction indicated the presence of phytochemicals such as unsaturated fatty acids and esters, phenolic compounds, flavonoids, and coumarin-related compounds known to exhibit antiaggregant, antiplatelet and antimicrobial activities.ConclusionThese results showed that C. crepidioides possesses bioactive components with anticoagulant properties which may be exploited in the treatment of blood coagulation disorders.

Comparison of in vitro antioxidative activities of crude methanolic extracts of three species of Passiflora from greenhouse using DPPH, ABTS and FRAP methods

Summary Introduction:. It is well documented that many species from Passifloraceae family can provide edible and nutritious fruits while the leaves of cultivated plants are renewable and waste material. This biomass may be further used in various sectors, especially as a bioactive food additive and as source of innovative pharmaceuticals, cosmetics or feed additives. The biomaterials and green chemistry are new sectors bioeconomy according to the high-level horizontal strategies and bio-based industries in Europe. In recent years, attention has been paid to the biological activity and phytochemical profiles of extracts from different species of Passiflora. However, there is little comparative studies using the same procedures and techniques in the same laboratory conditions for study of plant material obtained from the similar greenhouse conditions. Objective: This study was focused on the examination of antioxidative activities of low concentrations of crude extracts from leaves of Passiflora incarnata L., Passiflora caerulea L., and Passiflora alata Curtis. Methods: The activity was evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2’-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical scavenging and ferric reducing antioxidant power (FRAP) methods. Results of study were supported by estimation of chemical composition with secondary metabolites profiling in extracts which were carried out previously for the same extracts from three Passiflora species. One-way ANOVA analysis revealed significant differences in the antioxidant activity of various concentrations of the extracts using the DPPH and ABTS radical models, and FRAP method. Results: Measurement of antioxidant capacity (expressed as trolox equivalent, TE) showed that the most active was extract of P. caerulea &gt; P. alata &gt; P. incarnata. Phytochemical analysis for extracts of P. caerulea and P. incarnata showed greater similarities in metabolites content than P. alata. However, comparative statistical analysis of antioxidant activity showed that despite this phytochemical similarities, extract from P. alata leaves had higher activities than extract from leaves P. incarnata. Antioxidant effect of extract from P. alata can be explain by terpenoids presented in this extract. In this work, there have been discussed activities against Acanthamoeba castellanii strain, antibacterial and antifungal activities against selected clinical microorganisms (Enterococcus faecalis, Escherichia coli, Staphylococcus aureus, and Candida albicans, Micro-sporum gypseum), and anti-leukemic activities tested in human acute lymphoblastic leukemia cell lines for this extracts, which have been described in previous authors’ publications. Conclusion: Our current and previous studies showed that the same crude extracts from leaves of P. alata, P. caerulea, P. incarnata exerted not only antioxidant potential in vitro but also few interesting properties such as antibacterial, antifungal, amoebostatic, amoebicidal activities, which indicate the possibility of using these extracts in both a healthy diet and natural cosmetics. Leaves of this species may become an interesting source of biomaterials which can exert health-promoting effects.

Evaluation of Mosquito Larvicidal Activity of Ethanolic Extract of Grewia flavescens Juss. Whole Plant (Family: Tiliaceae) Against Culex quinquefasciatus

To evaluate the mosquito larvicidal activity on the ethanolic extract of Grewia flavescens juss (EEGF). Whole plant against Culex quinquefasciatus larvae. The larval mortality of 4th instar larvae of Culex quinquefasciatus after 24h and 48h of treatment which were tested separately in control and five test concentrations of 125 ppm, 250 ppm, 500 ppm,750 ppm, 1000 ppm concentration. The plant extract was screened to identify phytochemical bioactive compounds like alkaloids, flavonoids, saponins, tannins and glycosides. Different concentration of crude ethanolic extract of Grewia flavescensjuss. whole plant effectively showed larvicidal activity on Culex quinquefasciatus larvae. Based on the probit analysis values for 24h and 48h ethanolic extract of Grewia flavescens shows pronounced larvicidal activity. The LC50 and LC90 values of EEGF against mosquito 4th instar larvae of Culex quinquefasciatus was found 223.87 ppm and 724.43 ppm at 24hrs and for 48hrs the LC50 and LC90 values was found to be 181.97ppm and 374.76 ppm respectively. The preliminary phytochemical was performed in search of plants secondary metabolites which might be responsible for the larvicidal activity. The bioactive phytochemical classes which were identified and confirmed as alkaloids, flavonoids, saponins, tannins and glycosides. The ethanolic extract of this plant showed potent larvicidal activity and can be considered for further investigation. This experimental study was a pioneer attempt to establish Grewia flavescens juss. as a valuable resource of effective target specific natural mosquito larvicide. Keywords: Culex quinquefasciatus, larvicidal activity, ethanolic ext., phytochemical.

In vitro antibacterial activity of mangosteen (Garcinia mangostana Linn.) crude extract against Staphylococcus pseudintermedius isolates from canine pyoderma.

Staphylococcus pseudintermedius, commonly involved in canine pyoderma, can be classified as meticillin-susceptible S.pseudintermedius (MSSP) or meticillin-resistant S.pseudintermedius (MRSP). MRSP infections may be difficult to treat due to broad β-lactam resistance of MRSP and typically additional multidrug-resistance. Topical antibacterial treatment is the preferred treatment modality for surface and superficial skin infections. HYPOTHESIS⁄OBJECTIVES: Mangosteen crude extract containing the antibacterial compound α-mangostin will have in vitro activity against MSSP and MRSP isolated from canine pyoderma. Twenty-three samples, MSSP (n=12) and MRSP (n=11), isolated from canine pyoderma. Minimum inhibitory concentrations (MICs) were determined for mangosteen crude extract by broth microdilution. High-performance liquid chromatography (HPLC) analysis was used to determine the amount of α-mangostin in mangosteen crude extract. A time-kill assay was performed at 30min and 2h after exposure to a high concentration of crude extract (100× MIC). Antibacterial activity for α-mangostin was calculated according to HPLC results. The concentration of α-mangostin was 17.72±1.42% w/w. The mean MIC of α-mangostin towards MSSP was 0.53±0.35μg/mL, whereas the mean value for MRSP was 0.47±0.27μg/mL. There was no difference between the mean MIC of MRSP and MSSP (P=0.84). After a 30min exposure to 100× MIC of the crude extract, a 95% reduction in colony forming units was found. The results showed that α-mangostin in mangosteen crude extract was effective in inhibiting S.pseudintermedius (both MRSP and MSSP). Clinical studies are needed to investigate this effectiveness further in vivo.

Bio-herbicide potential of naturalised Desmodium uncinatum crude leaf extract against the invasive plant species Parthenium hysterophorus

The exotic plant Parthenium hysterophorus is rapidly invading ecosystems in sub-Saharan Africa, with negative effects on the environment, economy and human and animal health. With the exception of some synthetic herbicides, none of the available management methods have been effective against P. hysterophorus, and carry risks to the environment. Therefore, additional management methods must be explored for an effective integrated approach. Despite the fact that bio-herbicides are considered cost-effective and eco-friendly in mitigating biological invasions, little work has been done to utilize them for controlling P. hysterophorus. We investigated allelopathic effects and, thus, bio-herbicide potential of naturalised Desmodium uncinatum leaf (DuL) crude extract in various concentrations to control P. hysterophorus. Our results revealed that DuL crude extract can suppress P. hysterophorus, particularly at higher concentrations. The 75% and 100% DuL crude extract concentrations reduced the total leaf chlorophyll content by 26% and 22% in pots and plots, respectively. Further, these higher concentrations inhibited P. hysterophorus seed germination by 73% in petri dishes, 60% in pots, and 57% in plots, and negatively interfered with seedling growth vigour. Seedling stem heights under 75% and 100% DuL concentrations in pot and plot experiments was about 30% and 36% shorter than those sprayed with lower concentrations (< 70%) and the control, respectively. We show that naturalised plants with allelochemicals can be used as a management tool for controlling P. hysterophorus infestations in sub-Saharan Africa, particularly in Tanzania, and this method should become part of an integrated control toolkit being deployed in a community-based approach.

Monitoring of active constituents of turmeric (Curcuma longa L.) rhizome stored under supplemented white LED-light with different light intensities

Previous research showed possible applications of supplemented light to increase active compounds in harvested underground part of medicinal plants. Accordingly, the effect of supplementing white LED (light emitting diode) at different light intensities on the main constituents (curcumin, demethoxycurcumin, bisdemethoxycurcumin) of turmeric (Curcuma longa L.) rhizomes was investigated every week during storage. Rhizomes were stored for six weeks at room temperature of 24.7-34.5°C and 56-76% RH. During storage, rhizomes were illuminated with varied number (0 (control), 1, 2 or 3 tube (s)) of white LEDs at light intensities of 0 µmol m‑2 s‑1, 14-15 µmol m‑2 s‑1, 41-42 µmol m‑2 s‑1 and 61-62 µmol m‑2 s‑1, respectively. The LEDs were operated for 6 h (3:00 to 6:00 am and 6:00 to 9:00 pm) daily. Concentrations of curcuminoid, crude extracts and volatile oil fluctuated during storage. There was an increase in these attributes during the first week of storage and then a decline thereafter till week 4. The highest increase in all parameters occurred in week 5 and decreased at week 6 where there were significant differences among treatments (p<.05). Under the treatment using 61-62 µmol m‑2 s‑1 of white light LEDs, curcuminoid content (4.42% w/w) and crude extract (5.72% w/v) were 10.78 and 16.02% greater than the control. There was no significant difference in volatile oil content (1.10-2.10%).

Novel approach to combat antibiotic resistance: evaluation of some Armenian herb crude extracts for their antibiotic modulatory and antiviral properties.

One of the strategies to combat antibiotic resistance can be the use of plant materials in combination with antibiotics, taking into account that phytochemicals can act as antibiotic resistance-modifying agents. This can give a second life to the traditional antibiotics. The aim was to evaluate antibiotic modulatory effect of crude extracts from Agrimonia eupatoria, Hypericum alpestre, Rumex obtusifolius and Sanguisorba officinalis herbs towards several commercial antibiotics using some Gram-positive and Gram-negative bacteria. The antibiotic modulatory activity was tested by determining MICs of antibiotics in the absence and presence of plant crude extracts at subinhibitory concentrations. Antiviral potential of different extracts of tested plant materials was also explored by double overlay plaque assay. The tested plant crude extracts exhibited high modulatory activity towards used antibiotics. Particularly, high modulatory activity was observed with extracts of H. alpestre and R. obtusifolius. Many plant-antibiotic combinations induced the decrease in MICs of antibiotics up to ~fourfold indicating synergy. Moreover, the similar change was observed at both subinhibitory concentrations (MIC/2 and MIC/4) of the same plant crude extract. High anti-phage activity of plants with the exception of Lilium armenum against T4 phage of Escherichia coli C-T4 was also shown. Plant crude extract or commercial antibiotic combinations significantly increased the efficiency of antibiotics. Tested plant materials with exception of L. armenum have antiviral property. For the first time, antibiotic modulatory activity of tested herb extracts was shown, which could have potential in practical applications. Tested plant materials with exception of L. armenum could have prospective, as a source of new antiviral compounds.