Phytochemical screening and comparative antimicrobial potential of different extracts of Stevia rebaudiana Bertoni leaves

ObjectiveTo evaluate in vitro antimicrobial potential and phytochemical screening of the crude extracts of leaves of Stevia rebaudiana Bertoni.MethodsThe essential oil and crude extracts were prepared by using different usual method. Antimicrobial and antifungal activities were measured by the well established methods.ResultsHighest antifungal index [(12.13±0.08) mm)] and lowest antifungal index [(9.13±0.04) mm] as well as highest antibacterial index [(11.89±0.07) mm] and lowest antibacterial index [(7.24±0.03) mm] were obtained for extracts B, H, A and F, respectively. Invariably extract C, E, I, J and H did not show antimicrobial activity. The extract F showed all antifungal and antibacterial activity except Bacillus cereus and Bacillus megaterium.ConclusionsThe above findings support the idea that plant extracts of Stevia rebaudiana Bertoni leaves may have a role to be used as pharmaceuticals or preservatives.     

Phytochemical,antioxidant and antibacterial potential of Elaeagnus kologa (Schlecht.) leaf

ObjectiveTo screen different solvent extracts of Elaeagnus kologa (E. kologa) leaf to determine the phytochemicals, potent antioxidant and antibacterial activity to find out the possible source of applied pharmaceutical formulations.MethodsSolvent extracts of leaf material were prepared using the Soxhlet apparatus. A study was performed on antioxidant activity of methanolic extract of leaf by 1-1-diphenyl-2-picrylhydrazyl method. The phenolic and flavonoid content of all the fractions were determined using high performance liquid chromatography. Leaves were also subjected to protein and carbohydrate test.ResultsThe total phenols, flavonoids were found to be high in petroleum ether as compare to other solvent fraction. The IC₅₀ value of methanolic extract of the sample was 62.20 μg/mL which showed significant antibacterial activity against Bacillus subtilis (Gram-positive).ConclusionsThe present study suggests that the methanolic extract of E. kologa leaf possesses antioxidant and antibacterial properties. Such properties may be of great use in mitigating the detrimental effects of oxidative stress and reducing susceptibility to bacterial infection. Notably, extracts of E. kologa leaf also contain proteins and carbohydrates which add to its nutritional value.     

A comparative in vitro antioxidant potential profile of extracts from different parts of Fagonia cretica

ObjectiveTo evaluate antioxidant and radical scavenging activities of organic extracts from fruit, roots and aerial parts of Fagonia cretica.MethodsShed dried and powdered plant parts were initially extracted in methanol and subsequently partitioned in n-hexane, chloroform, ethyl acetate and 1-butanol successively. Antioxidant and radical scavenging potential of the methanol extracts and the fractions of each part were evaluated using total phenolic contents (TPC) and total flavonoid contents (TFC), 2,2-diphenyl-1-picrylhydrazyl and 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) radical cation radicals scavenging, reducing power (potassium ferricyanide-trichloroacetic acid system), ferric ion reducing antioxidant potential, lipid peroxidation inhibition activity (linoleic acid system) and total antioxidant activity (phosphomolybdate) assays.ResultsTPC and TFC values for methanol extracts and various fractions ranged from 0.23-4.30 mg/L gallic acid equivalents and from 30-545 mg/L rutin equivalents, respectively. Overall, methanol extracts and all the fractions of root and aerial parts showed higher TPC and TFC values. Methanol extracts and aqueous fractions of root and aerial parts and the n-butanol fraction of root showed lower EC₅₀ values for 2,2-diphenyl-1-picrylhydrazyl scavenging than the other plant extracts. The 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging, total antioxidant potential and ferric ion reducing antioxidant potential values confirmed the presence of potent antioxidant principles in the methanol extract of roots. In general, all the extracts/fractions and especially those of root showed high antioxidant and radical scavenging activities.ConclusionsThe crude methanol extract of root can be explored further for in vivo studies. This study revealed the potent antioxidant potential of Fagonia cretica and its prospective efficacy against various reactive oxygen species-mediated diseases.     

Phytochemical and biological activities of Bituminaria bituminosa L. (Fabaceae)

ObjectiveTo investigate the phytochemical composition, the antioxidant and antibacterial activities of Bituminaria bituminosa L. (Fabaceae) (B. bituminosa).MethodsThe aerial parts of B. bituminosa yielded two compounds. The structures of these compounds were determinated using UV, ¹H-NMR and ¹³C-NMR experiments and comparison of their spectroscopic properties with literature data. The antibacterial activity of the extracts (CH₂Cl₂, ethyl acetate and n-BuOH) was determinated using disk diffusion method against standard and clinical strains. Antioxidant potential of n-BuOH extract was evaluated through two methods: DPPH and cupric ion reducing antioxidant capacity assay.ResultsThe n-BuOH extract from B. bituminosa yielded the isolation of isoflavone and flavone. The extracts CH₂Cl₂, ethyl acetate and n-BuOH demonstrated significant antibacterial activities. CH₂Cl₂ extract showed the maximum antibacterial activity with high concentration of 2 mg/mL against Staphylococcus aureus ATCC 29213, Klebsiella pneumonia and Escherichia coli ATCC 25922 (20.45 mm, 16.41 mm and 15.74 mm inhibition zone, respectively). The value IC₅₀ was 0.26 μg/mL for n-BuOH extract using DPPH method. Whereas the E% value was 0.10 L/mg every centimeter for cupric ion reducing antioxidant capacity assay.ConclusionsThe phytochemical study of B. bituminosa revealed the presence of isoflavone (daidzin) and flavone (isoorientin) and identified for the first time in this specie. The antibacterial activity of the plant B. bituminosa is certainly related to its chemical content. The n-BuOH extract showed a significant antioxidant activity.     

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

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

Development of in vitro screening system for assessment of antifilarial activity of compounds

Evaluation of antifilarial activity of new potential agents in vivo is extremely time consuming and uneconomic. In the present study effort has been made to develop an in vitro screening method using Acanthocheilonema viteae, a subcutaneously dwelling rodent filariid with anaerobic metabolic characteristics like human filariids, W. Bancrofti/Brugia malayi as test parasite. Motility test and tetrazolium (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide, MTT) based colorimetric assay were used as parameters in in vitro assay. Results showed that 92.3% of compounds (in vivo active) could be picked up in the in vitro assay when both adults and microfilarae (mf) were used simultaneously. Mf and adult stages separately detected, respectively, 84.6 and 69.2% of in vivo active compounds. The adults and mf separately and both the life stages together exhibited, respectively, 80.0, 50.0 and 80.0% false positive results in the in vitro test with in vivo inactive compounds. It is felt that mf stage when used in in vitro test using motility and MTT assays as parameters would be useful in primary screening of new potential filaricides.     

Preliminary screening for in vitro anti-enteritic properties of a traditional herb Dillenia pentagyna Roxb. fruit extracts

ObjectiveTo explore anti-enteric properties of Dillenia pentagyna Roxb. (D. pentagyna) fruit extract fractions of different polarities by comparative antimicrobial activity against municipal sewage microflora and to assess its urease inhibition potential.MethodsDifferent polar fractions of D. pentagyna fruit extracts were studied by antimicrobial susceptibility test with several adjustments in this resource limited setup. Tests were done against municipal sewage microbes at various bacterial load (initially with 1.0 McFarland followed by 1.5 McFarland) using basal (nutrient agar) and selective medium (MacConkey's agar with and without supplementation of 5% NaCl). All assays statistically scaled with a gradient for uniformity and comparison with ciprofloxacin standard. Fraction with highest activity was studied for urease inhibition potential by kinetic method.ResultsDP-47 separated by 30% ethyl acetate (EtOAc) in CHCl₃ from CHCl₃ extract had slightly higher antimicrobial potency (y=0.758x+7.571) as dissolved in methanol than in dimethylsulfoxide (y=0.300x+6.000). EtOAc extract fractioned by 10% methanol in EtOAc (DP-43) was more potent antimicrobial (y=1.428x+8.392) and soluble in water. Butanol extract fractioned by water (DP-50) showed highest antimicrobial potency (y=3.384x+2.000) than both DP-47 and DP-43 in disk diffusion assays. In higher microbial load DP-50 was potent antimicrobial (y=1.538x+3.000) and completely inhibited any vegetative growth at lower load of 0.5 McFarland. In selective environment DP-50 was effective (y=1.076x+7.500 in MacConkey's, y=1.307x+6.000 in 5% NaCl supplemented). It was evident that enteric pathogens may not easily develop resistance against DP-50 and at high concentration it inhibited urease activity by 94.87%. The standard inhibition by thiourea (1%) is 33.914%.ConclusionsHighly polar fraction of D. pentagyna Roxb. fruit extract DP-50 have potential antimicrobial activity against sewage microflora in basal and selective culture indicating its potential against non-fastidious, coliforms and Vibrio pathogens. Urease inhibition indicates efficacy against Helicobactor pylory.     

A comparison of polyphenolic content,antioxidant activity and insecticidal properties of Jatropha species and wild Ricinus communis L. found in Mauritius

ObjectiveTo evaluate the phytochemical, antimicrobial and insecticidal properties of different Jatropha species and Ricinus communis (castor) (R. communis) growing in Mauritius.MethodsQualitative and quantitative methods were used for the determination of the presence of phytochemicals in the crude plants solvent extracts. The antimicrobial sensitivity (disc diffusion method) and Antibacterial activity (MIC-microdilution method) of 13 microorganisms were studied. The insecticidal properties of the crude solvent extracts against larvae of two insects, Bactrocera zonata and Bactrocera cucurbitae (Diptera, Tephritidae), which cause important economic losses to local fruits were also demonstrated.ResultsEthyl acetate was proved to be a good solvent for extraction. Jatropha multifida showed very interesting activity against Bacillus algicola and Staphylococcus epidermis. Both R. communis and Jatropha multifida were proved to be very effective as biopesticide against different types of insect larvae.ConclusionsThis study was able to demonstrate that Jatropha species as well as R. communis growing in Mauritius possess antimicrobial, phytochemical and insecticidal properties.     

Evaluation of extracts and essential oil from Callistemon viminalis leaves: Antibacterial and antioxidant activities,total phenolic and flavonoid contents

ObjectiveTo investigate antioxidant and antibacterial activities of Callistemon viminalis (C. viminalis) leaves.MethodsThe essential oil of C. viminalis leaves obtained by hydro-distillation was analyzed by GC/MS. Different extracts were tested for total phenolic and flavonoid contents and in vitro antioxidant (DPPH assay) and antibacterial (agar disc diffusion and 96-well micro-plates methods) actives.ResultsFourteen components were identified in the essential oil, representing 98.94% of the total oil. The major components were 1,8-cineole (64.53%) and α-pinene (9.69%). Leaf essential oil exhibited the highest antioxidant activity of (88.60±1.51)% comparable to gallic acid, a standard compound [(80.00±2.12)%]. Additionally, the biggest zone of inhibitions against the studied bacterial strains was observed by the essential oil when compared to the standard antibiotic (tetracycline). The crude methanol extract and ethyl acetate fraction had a significant antibacterial activity against the tested bacterial strains.ConclusionsIt can be suggested that C. viminalis is a great potential source of antibacterial and antioxidant compounds useful for new antimicrobial drugs from the natural basis. The present study revealed that the essential oil as well as the methanol extracts and ethyl acetate fraction of C. viminalis leaves exhibited highly significant antibacterial activity against the tested bacterial strains.     

In vitro bioactivity and phytochemical screening of selected spices used in Mauritian foods

Objective

To investigate the in vitro antioxidant and antimicrobial activities along with phytochemical screening of organic and aqueous extracts of spices used in Mauritian foods.

Methods

Antioxidant activity of the crude extracts was evaluated in terms of total antioxidant capacity, total phenol content and total flavonoid content. The antimicrobial activity of the spices was determined by the agar well diffusion method against a gram positive and a gram negative bacteria. The qualitative and quantitative phytochemical screening were carried out by standard biochemical assays.

Results

All six spices were found to possess alkaloids, coumarins, flavonoids, saponins, steroids, tannins and phenols. Total phenolic content of the extracts varied between 177 and 1 890 mg GAE/g DW while the total flavonoid content varied between 2.8 and 37.6 mg QE/g DW. All six spices were found to possess strong antioxidant properties as well. Highest value was obtained for cinnamon [(24.930±0.198) µmol Fe²⁺/g DW] whilst turmeric showed the lowest antioxidant activity [(5.980±0.313) µmol Fe²⁺/g DW] (P<0.05). All extracts showed promising activity against Staphylococcus aureus and Escherichia coli. The size of the inhibition zones ranged between (11.20±0.23) mm to (26.10±2.09) mm (P<0.05) with turmeric and cinnamon being the most effective against Staphylococcus aureus while garlic was least effective against both E. coli and S. aureus.

Conclusions

The present study reveals the presence of potential antioxidant and antimicrobial properties in the extracts of the spices which could be further exploited.     

Anti-obesity and hypoglycemic effect of ethanolic extract of Murraya koenigii (L) leaves in high fatty diet rats

ObjectiveTo evaluate the hypoglycemic and anti-obesity activities of of Murraya koenigii leaves.MethodThe study was performed in high fatty diet induced obesity rats. After 15 days baseline period the treatments animals were received ethanolic extract of Murraya koenigii leaves (300 and 500 mg/kg) in high fatty diet rats. All the treatments were given for one month. On 30th day all the fasted animals received an intraperitoneal injection of glucose (1 g/kg) for glucose tolerance test. At the end of study body weight, total cholesterol, triglycerides, and blood glucose level were measured.ResultsThe results demonstrate clearly that repeated oral administration of Murraya koenigii leaves evoked a potent anti-hyperglycaemic activity in high fat diet obese rats. Postprandial hyperglycaemic peaks were significantly lower in plant-treated experimental groups. In other hand, high fatty diet group increased the both total cholesterol and triglycerides levels as compared to control group. While administration of Murraya koenigii leaves significantly decreased in both cholesterol as well as triglycerides.ConclusionsWe can conclude that Murraya koenigii leaves evokes potent anti-hyperglycaemic and anti-obesity effects. This fact could support their use by the diabetes patient for controlling body weight as well as maintains the glycemic level.     

Antihyperglycemic and antioxidant effects of Solanum xanthocarpum leaves (field grown & in vitro raised) extracts on alloxan induced diabetic rats

ObjectiveTo investigate antidiabetic efficacy of the extract of field grown and in vitro raised leaves of Solanum xanthocarpum (S. xanthocarpum) against alloxan induced diabetic rats.MethodsThe antidiabetic activity of the crude methanol extracts of the field grown and in vitro raised leaves of S. xanthocarpum at different concentrations (100–200 mg/kg bw) was tested against alloxan induced diabetic rats. The antidiabetic efficacy was validated through various biochemical parameters and the antioxidant effect was also determined. The phytochemical analyses of field grown S. xanthocarpum and in vitro rasied S. xanthocarpum leaves were done by estimating their chlorophyll, carotenoids, total sugar, protein, amino acid and minerals contents.ResultsThe results revealed that the methanol extracts of both the leaves (field grown and in vitro raised) of S. xanthocarpum was efficient anti hyperglycemic agents at a concentration of 200 mg/kg bw and posses potent antioxidant activity. However, the extracts of in vitro rasied S. xanthocarpum raised leaves exhibit higher efficacy than the field grown leaves in all tested concentrations. Proximal composition and mineral analysis of S. xanthocarpum revealed higher concentration of contents in in vitro rasied S. xanthocarpum than field grown S. xanthocarpum.ConclusionsFrom the results it can be concluded that the leaves extracts of S. xanthocarpum can be a potential candidate in treating the hyperglycemic conditions and suits to be an agent to reduce oxidative stress.     

The potential role of the three-dimensional-bioprinting model in screening and developing drugs

Recently, we have read with great interest the original article used different spatial configuration models of colorectal cancer (CRC) for validating the anti-tumor efficacy with Diiminoquinone. We feel obliged to provide new insight into the drug screening models by integrating and analyzing the original method and result. These comments may provide comprehensive insights into three-dimensional drug screening models and the difference between pathologic subtypes in CRC.     

Phytochemical composition and in vitro antioxidant activity of aqueous extract of Aerva lanata (L.) Juss. ex Schult. Stem (Amaranthaceae)

ObjectiveTo analyze the phytochemical composition and in vitro antioxidant properties of aqueous extract of Aerva lanata (A. lanata) stem.MethodsDuring the preliminary phytochemical analysis, the aqueous extract of A. lanata was screened for the presence of carbohydrates, proteins, phenolic compounds, oil and fats, saponins, flavonoids, alkaloids, tannins and phytosterols. Antioxidant activity of the extract was determined by 2, 2-diphenyl-1-picrylhydrazyl radical scavenging activity, metal chelating activity, reducing power activity and DNA damage inhibition activity. Analysis of phenolic compounds was performed by Folin-Ciocalteau reagent method and gradient high performance liquid chromatography technique.ResultsPreliminary phytochemical analysis exhibited the presence of phenolic compounds, saponins, flavonoids, tannins and phytosterols as major phytochemical groups. The extract exhibited high 2, 2-diphenyl-1-picrylhydrazyl radical scavenging activity (IC₅₀= 110.74 μg/mL), metal chelating activity (IC₅₀= 758.17 μg/mL), reducing power activity and DNA damage inhibition efficiency. The extract was reported to possess a high amount of total phenolic content and some of them were identified as gallic acid (3,4,5-OH), apigenin-7-O-glucoside (apigetrin), quercetin-3-O-rutinoside (rutin) and myricetin (3,5,7,3,4,5-OH) by high performance liquid chromatography analysis. The extract was found non toxic towards human erythrocytes in the hemolytic assay (IC₅₀ = 24.89 mg/mL).ConclusionsThese results conclud that A. lanata stem possesses high antioxidant activity and can be used for the development of natural and safe antioxidant compounds.     

Analysis of metastatic spread and growth of tumor cells in mice with depressed natural killer activity by anti-asialo GMl antibody or anticancer agents

Summary The mechanism of artificial and spontaneous metastases of tumor was analyzed in B16 melanoma cells and C57BL/6 mice by using anti-asialo GM1 antibody and anticancer agents. Single administrations of 500 g anti-asialo GM1 antibody resulted in significantly decreased NK activity in spleen cells of C57BL/6 mice, lasting 10 days from the day following administration. Treatment with anti-asialo GM1 antibody never decreased the function of T lymphocytes measured by blastogenesis with phytohemagglutinin or T cell growth factor. The tumoricidal functions of activated macrophages but not of resident macrophages were decreased by in vivo treatment with anti-asialo GM1 antibody.The anti-asialo GM1 antibody was evaluated in terms of the enhancing effect on pulmonary metastases with regard to the timing of administration. Treatment with anti-asialo GM1 antibody 1 day before or on the day of tumor inoculation resulted in a substantial increase in the number of artificial pulmonary metastases. In the experimental system of spontaneous metastases, anti-asialo GM1 antibody most effectively increased the number of pulmonary metastases when administered 1–2 weeks before the removal of primary tumor, when the tumor cells are thought to be released into blood circulation from the primary site. In addition, accelerated growth of transplanted tumors at the primary site was observed in mice treated with anti-asialo GM1 antibody. These results strongly suggest that anti-asialo GM1 antibody enhances the incidence of in vivo tumor metastases and the growth of transplanted tumor mainly by suppressing the function of NK cells.The maximum effective dose (MED) of mitomycin C or its derivative (M-83) suppressed NK activity significantly, and pretreatment with these anticancer agents enhanced the growth of the artificial pulmonary and liver metastases. In contrast, the MED of cDDP showed no effect on the NK activity or the numbers of pulmonary and liver metastases. These results indicate that the depression of NK activity induced by chemotherapy results in the promotion of metastatic disease.From these studies it can be concluded that NK cells have a key role in the control of metastases of malignant disease, and that support of NK activity is very important for the prevention of metastases.     

In vitro activities of acetonic extracts from leaves of three forage legumes (Calliandra calotyrsus, Gliricidia sepium and Leucaena diversifolia) on Haemonchus contortus

ObjectiveTo assess ovicidal activity of three acetonic extracts from the leaves of three forage legume, Calliandra calotyrsus (C. calotyrsus), Gliricidia sepium (G. sepium) and Leucaena diversifolia (L. diversifolia) in vitro on Haemonchus contortus (H. contortus).MethodsEggs were exposed for 24 hours to five different concentrations (0.075, 0.15, 0.3, 0.6 and 1.25 mg/mL) of acetonic extracts at room temperature (24 °C). Distilled water and 0.4% Tween were used in the bioassay as negative controls.ResultsThe later did not affect embryonation and egg hatching of H. contortus. Conversively, significant effects were obtained with the acetonic extracts of leaves of all three plants and the maximum activity was observed with the highest concentration (1.25 mg/mL). The acetonic extract of G. sepium was found to be more active (2.9% and 0.0% for embryonation and egg hatching, respectively) than the other substances 16.5% and 33.5%, respectively for C. calothyrsus, 33.7% and 33.3%, respectively for L. diversifolia.ConclusionsThese results suggest that the three forage legumes do possess ovicidal properties and further studies on larvae should be carried out.     

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

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