Isolation and identification of antibacterial components in seed extracts of Argemone mexicana L. (Papaveraceae)

ObjectiveThe column chromatographic fractions of chloroform (CH1, CH2, CH3) seed extracts of Argemone mexicana (A. mexicana) were screened for antibacterial activity and phytochemical analysis.MethodsCH3 fraction was isolated and identified by column chromatography, thin layer chromatography, spectral data analysis and phytochemical screening were used for analysis.ResultsCH3 fraction was significantly active at 4 to 64 mg/mL against Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa with minimum inhibitory concentration of 1.5625 to 3.125 mg/mL. The active fraction (CH3) revealed presence of alkaloid with retention factor value of 0.44. The active antibacterial agent in the most potent fraction (CH3) was isolated and identified as N-demethyloxysanguinarine by thin layer chromatography (TLC) and phytochemical screening. The CH1 and CH2 fractions did not show inhibitory activity.ConclusionsThe results support the ethnomedicinal use of seeds of A. mexicana for treatment of bacterial diseases.     

Anti-enteric bacterial activity and phytochemical analysis of the seed kernel extract of Mangifera indica Linnaeus against Shigella dysenteriae (Shiga, corrig.) Castellani and Chalmers

ObjectiveTo evaluate the phytochemical and anti-bacterial efficacy of the seed kernel extract of Mangifera indica (M. indica) against the enteropathogen, Shigella dysenteriae (S. dysenteriae), isolated from the diarrhoeal stool specimens.MethodsThe preliminary phytochemical screening was performed by the standard methods as described by Harborne. Cold extraction method was employed to extract the bioactive compounds from mango seed kernel. Disc diffusion method was adopted to screen antibacterial activity. Minimum inhibitory concentration (MIC) was evaluated by agar dilution method. The crude extracts were partially purified by thin layer chromatography (TLC) and the fractions were analyzed by high performance thin layer chromatography (HPTLC) to identify the bioactive compounds.ResultsPhytochemical scrutiny of M. indica indicated the presence of phytochemical constituents such as alkaloids, gums, flavanoids, phenols, saponins, steroids, tannins and xanthoproteins. Antibacterial activity was observed in two crude extracts and various fractions viz. hexane, benzene, chloroform, methanol and water. MIC of methanol fraction was found to be (95±11.8) μg/mL. MIC of other fractions ranged from 130–380 μg/mL.ConclusionsThe present study confirmed that each crude extracts and fractions of M. indica have significant antimicrobial activity against the isolated pathogen S. dysenteriae. The antibacterial activity may be due to the phytochemical constituents of the mango seed kernel. The phytochemical tannin could be the reason for its antibacterial activity.     

A survey on Hibiscus rosa—sinensis,Alcea rosea L. and Malva neglecta Wallr as antibacterial agents

ObjectiveTo guide for selection of plants with antibacterial activity for further phytochemical works on the isolation and identification of the active compounds.MethodsEthanolic extracts of 3 species from Malvaceae family were evaluated by agar disc diffusion method for antibacterial activity against some gram-positive and gram-negative bacteria (Pseudomonas aeruginosa, Listeria monocytogenes, Staphylococcus epidermidis, Staphylococcus aureus, Klebsiella pneumoniae, Salmonella typhi, Bacillus cereus, Bacillus anthracis, Escherichia coli Streptococcus pyogenes). The extracts were obtained from aerial parts of Hibiscus rosa (H. rosa)-sinensis (leaf and flower), Alcea rosea (A. rosea) L. (leaf and flower) and Malva neglecta (M. neglecta) Wallr (flower).ResultsThese extracts had inhibitory effects at different concentrations (0.05, 0.10, 0.20 and 0.40 g/mL) against above mentioned bacteria. Escherichia coli was the most resistant strain. The highest inhibitory zone was showed by ethanolic extract of M. neglecta against Staphylococcus epidermidis (22 mm) and followed by ethanolic extract from flower of H. rosa against Staphylococcus epidermidis and Staphylococcus aureus (20 mm). The Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) values against Staphylococcus epidermidis were equal (MIC=MBC=5 mg/mL for M. neglecta extract and for H. rosa extract MIC=MBC=20 mg/mL).ConclusionsThese findings suggest that these native plants have good antibacterial properties that can be used for infection control and treatment and could also be as new source for antibiotics discovery and infection treatment.     

Antibacterial activity of crude ethanolic extract and solvent fractions of Ficus pseudopalma Blanco leaves

ObjectiveTo investigate the antimicrobial properties of Ficus pseudopalma (F. pseudopalma) leaf extracts.MethodsThe antibacterial properties of F. pseudopalma Blanco crude ethanolic leaf extract, and its solvent fractions chloroform (CF), ethylacetate (EF) and water fractions were evaluated through antibacterial agar disc diffusion method and the minimum inhibitory concentration (MIC) was determined. Five Gram-positive and five Gram-negative bacteria were used for the study.ResultsThe zone of inhibitions obtained from the antibacterial agar diffusion disc method showed that CF, and EF exhibited active (14-19 mm) antibacterial activity against Bacillus subtilis UST CMS 1011, and partially active (10-13 mm) antibacterial properties against both Staphylococcus aureus ATCC 25923 and Staphylococcus epidermidis ATCC 12228. Water exhibited no antibacterial properties against all microorgranisms tested. The MIC values observed for all Gram-positive bacteria tested were >5 mg/mL, except for Bacillus subtilis whose MIC value was 5 mg/mL for CF and EF fractions. All extracts exhibited no antibacterial activity against Gram-negative bacteria.ConclusionsFrom this study, it can be concluded that F. pseudopalma extracts may be a potential antibacterial agent against Gram-positive bacteria. The antibacterial property may be attributed to flavonoids and terpenoids present in the crude ethanolic extract, CF and EF.     

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

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

Antimicrobial and antispasmodic activity of leaf extract and fractions of Stachytarpheta cayennensis

ObjectiveTo investigate the antimicrobial activity of the methanol leaf extract (ME), n-hexane fraction (HF), ethylacetate fraction (EF) and methanol fraction (MF), of Stachytarpheta cayennensis C. Rich (verbenaceae) as well as to ascertain the antispasmodic effects of the ME and the various fractions (HF, EF and MF) on acetylcholine (Ach) and histamine (H) induced contractions on isolated guinea pig ileum.MethodsThe in vitro agar well diffusion method was used for the antimicrobial studies while the isolated tissue method was employed for the antispasmodic test. Organisms used were all clinical isolates of Bacillus subtilis, Staphylococcus aureus, Pseudomonas aeruginosa, Salmonella paratyphi, Candida albicans and Aspergillus niger.ResultsThe extract and fractions exhibited dose dependent inhibition against all the bacteria tested and also exhibited insignificant antifungal activity against Candida albicans and Aspergillus niger. The minimum inhibitory concentration (MIC) of the extract and fractions (mg/mL) on Bacillus subtilis, Staphylococcus aureus, Pseudomonas aeruginosa and Salmonella paratyphi respectively were ME 5.62, 14.12, 22.38, 2.11; EF 1.25, 6.30, 9.40, 9.40 and MF 3.98, 8.81, 39.80, 21.13. The n-hexane fraction exhibited MIC of 1.07 mg/mL against only Bacillus subtilis. The extract and fractions exhibited significant (P< 0.05) dose dependent attenuation of contractions induced by acetylcholine and histamine on isolated guinea pig ileum. Concentrations of the extract and fractions (μg/mL) which evoked 50% inhibition of maximal response exhibited by Ach were ME 0.64, HF 0.16, EF 0.08 and MF 0.15, while that of histamine included ME 5.12, HF 0.16, EF 0.04 and MF 0.64. Preliminary phytochemical studies on the extract and fractions indicated the presence of carbohydrates, alkaloids, saponins, flavonoids, steroids and terpenoids.ConclusionsThe extract and fractions of Stachytarpheta cayennensis possessed both antibacterial and antispasmodic effects confirming the claimed use in folkloric medicine for wound healing and gastrointestinal ulceration.     

Preliminary investigation on the antibacterial activity of mango (Mangifera indica L: Anacardiaceae) seed kernel

ObjectiveTo evaluate the antibacterial activity of the methanolic extract of mango (Mangifera indica L.) seed kernel.MethodsChokanan mango seed kernel and seed kernels from assorted mango varieties were collected, cleaned, dried and powered. Crude methanolic extracts of mango seed kernel were analyzed for the phytochemical constituents. The free radical scavenging activity was determined by 2,2-Diphenyl-1-picrylhydrazyl (DPPH) assay. Antibacterial activity was evaluated by disc diffusion assay with three medically important bacterial pathogens such as methicillin resistant Staphylococcus aureus (S. aureus) (MRSA), Escherichia coli (E. coli) and Vibrio vulnificus (V. vulnificus).ResultsQualitative phytochemical analysis indicated the presence of important phytochemical compounds such as glycosides, saponins, flavanoids, tannins and alkaloids. There was no significant difference in the phytochemical content between the single and assorted mango seed kernels. However, the free radical scavenging study indicated that the assorted mango kernels showed slightly higher activity than the single species (P <0.05). The crude methanolic extract of mango seed kernel at a concentration of 100 mg/mL is found to have potential antimicrobial activity against MRSA and E. coli compared to V. vulnificus. Study on the antibacterial activity also indicated that there was no significant difference in the antibacterial activity of the single and assorted mango seed kernel extracts.ConclusionsThe present study conclusively demonstrates the free radical scavenging activity and antibacterial activities of mango seed kernel. In addition, the results also indicated that there is no significant difference in the phytochemical content and biological activity of mango kernels from single and assorted mango varieties.     

Antibacterial activities of some Indian traditional plant extracts

ObjectiveTo evaluate the in vitro antibacterial activity of various solvent extracts of South Indian traditional medicinal plants Ocimum sanctum, Ocimum gratissimum, Aegle marmelos, and Adhatoda vasica leaves against clinical pathogens of human origin.MethodsThe antimicrobial activity of different solvents crude extract of four medicinal plants used in traditional Indian medicine was tested by disc diffusion method against five bacterial pathogens: Escherichia coli, Staphylococcus aureus, Salmonella typhi, Salmonella paratyphi and klebsiella pneumoniae.. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) was determined for evaluating the potential plant extract.ResultsThe antibacterial results showed methanol extracts (0.4 g/ml) of Ocimum gratissimum and Ocimum sanctum showed maximum zone of inhibition (30 mm and 25.5 mm, respectively) against Salmonella typhi. MIC was tested at various concentrations from 0.625 mg/ml to 0.039 mg/ml for all the plant extracts. At the lowest concentration (0.039mg/ml) tested, methanol extracts of Ocimum gratissimum showed higher MIC against Salmonella typhi and Salmonella paratyphi where as the methanolic extracts of Ocimum gratissimum showed potent activity against Staphylococcus aureus at 0.078 mg/ml. Methanol extract (0.4 g/ml) of Aegle marmelos showed significant inhibitory activity of 22.5mm and MIC value of 0.156.mg/ml against E. coli strain. The Klebsiella spp was the most resistant strain of all and various concentrations Adhatoda vasica extract showed less activity against the tested pathogens.ConclusionsThe present screening result demonstrated that the Indian traditional medicinal plants Ocimum sanctum, Ocimum gratissimum, Aegle marmelos methanol leaf extract has potent antibacterial activity and the studied plants may be new source for novel antibacterial compound discovery for treating drugs resistant human pathogens.     

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

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

Antibacterial potential of sponge endosymbiont marine Enterobacter sp at Kavaratti Island, Lakshadweep archipelago

ObjectiveTo isolate antibacterial potential of sponge endosymbiotic bacteria from marine sponges at Lakshadweep archipelago. Also to identify the potent bacteria by 16s rDNA sequencing and determine the antibacterial activity against clinical pathogens by MIC.MethodsSponge samples was collected from sub-tidal habitats at Kavaratti Island and identified. The endosymbiotic bacteria were isolated and selected potential bacteria which show antibacterial activity in preliminary screening against clinical pathogens Staphylococcus aureus (S. aureus), Escherichia coli (E. coli), Salmonella typhi (S. typhi), Klebsiella pneumoniea (K. pneumoniea) and Streptococcus sp. by disc diffusion assay. The crude extracts of potential bacteria LB3 was tested against clinical pathogens by MIC. The LB3 strain was identified by 16s rDNA sequencing, 1 111 bp was submitted in NCBI (HQ589912) and constructed phylogenetic tree.ResultsSponge sample was identified as Dysidea granulosa (D. granulosa) and potential bacteria LB3 identified as Enterobacter sp TTAG. Preliminary screening of sponge isolates against clinical pathogens, LB3 strain was selected as potential producer of secondary metabolites and crude extract was implies on MIC of LB3 have confirmed with lowest concentration of 5.0 mg/mL in broth medium influence of crude extract on growth inhibitory activity after 5 h of incubation period and completed the inhibitory activity at 15 h.ConclusionsThe present study concluded that phylogenetic analysis of endosymbiotic bacteria Enterobacter sp from sponge D. granulosa of Lakshadweep islands showed significant antibacterial activity against clinical bacterial pathogens.     

Antimicrobial properties of Teucrium polium against some clinical pathogens

ObjectiveTo explore the antibacterial effect of the alcoholic extracts of aerial parts of Teucrium polium, native in Iran on some pathogenic bacteria.MethodsAntibacterial activity of ethanolic extract (50 to 400 mg/mL) and methanolic extract (400 and 600 mg/mL) was evaluated by disc diffusion method.ResultsThe ethanolic extract results showed that Bacillus anthracis was the most sensitive species, while Escherichia coli and Proteus mirabilis were more resistant than others. In the case of the methanolic extract, Bordetella bronchiseptica was the most sensitive and Proteus mirabilis and Arcanobacterium pyogenes were the most resistant species. The hydroalcoholic extract of Teucrium polium had a relatively satisfactory effect on Salmonella typhi. The minimal inhibitory concentration (MIC) of Staphylococcus aureus and Salmonella typhi was 40 mg/mL and Bordetella bronchiseptica and Bacillus anthracis was 10 mg/mL. The minimal bactericidal concentration (MBC) against Bacillus anthracis was 10 mg/mL while against other species were not found (>200 mg/mL). The methanolic extract had also synergistic effect with methicillin, vancomycin against Staphylococcus aureus and with novobiocin against Salmonella typhi.ConclusionsThese results suggest that this plant contains relatively good antibacterial activity and it can be used as a source of antiseptic compounds for medicinal uses.     

Antimicrobial chemical constituents from endophytic fungus Phoma sp.

Objective:To evaluate the antiniicrobial polenlial of different extracts of the endophytic fungus Phoma sp.and the tentative identification of their active constituents.Methods:The extract and compounds were screened for antimicrobial activity using the Agar Well Diffusion Method.Four compounds were purified using column chromatography and tlieir structures were assigned using～1H and～(13)C NMR spectra,DEPT,2D COSY,HMQC and HMBC experiments.Results:The ethyl acetate fraction of Phoma sp.showed good antifungal,antibacterial,and algicidal properties.One new dihydrofuran derivative,named phomafuranol(1),together with tliree known compounds,phomalacton(2),(3R)-5-hydroxymellein(3)and emodin(4)were isolated from the ethyl acetate fraction of Phoma sp.Preliminary studies indicated that phomalacton(2)displayed strong antibacterial,good antifungal and antialgal activities.Similarly(3R)-5-hydroxymellein(3)and emodin(4)showed good antifungal,antibacterial and algicidal properties.Conclusions:Antimicrobial activities of the ethyl acetate fraction of the endophytic fungus Phoma sp.and isolated compounds clearly demonstrate that Phoma sp.and its active compounds represent a great potential for the food,cosmetic and pharmaceutical industries.     

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.     

Efficacy of fresh leaf extracts of Spondias mombin against some clinical bacterial isolates from typhoid patients

ObjectiveTo evaluate the phytochemical properties and antibacterial activity of methanol, acetone, ethanol and aqueous extracts of fresh leaves of Spondias mombin (S. mombin) on some clinical bacterial isolates.MethodsClean and fresh leaves of S. mombin were collected in Ondo, Southwestern Nigeria. The leaves were blended, extracted with methanol, acetone, ethanol and water. The extracts were evaporated to dryness using rotary evaporator and tested for the presence of saponins, tannins, cardiac glycoside, terpenoids, flavonoids, reducing sugars, volatile oils, alkaloids and glycoside. The extract were tested against Gram-negative bacteria Klebsiella pneumonia, Serratia marcescens, Salmonella typhi and Enterobacter aerogens; Gram-positive bacteria Staphylococcus aureus by observing the zones of inhibition using agar well diffusion assay.ResultsThe study showed that the leaves contained saponins, tannins, flavonoids, alkaloids and glycoside. All the solvent extracts showed activity against all the test bacteria. The methanol extract also showed the highest activity against Enterobacter aerogens, zone of diameter (15.00依1.89) mm, while the ethanol extract showed the highest activity against Staphylococcus aureus with zone of diameter (12.50依1.50) mm. The acetone extract showed the highest activity against Salmonella typhi, zone of diameter (17.50依0.29) mm followed by methanol extract showing zone of diameter (15.67依1.01) mm. The acetone extract showed the highest activity against Klebsiella pneumonia (15.17依0.67) mm, while the aqueous extract shows the highest activity against Serratia marcescens (14.67依2.68) mm. The minimum inhibitory concentration of the leaf extracts ranged between 10-90 mg/mL.ConclusionsThis study showed that the aqueous and organic solvents extract of fresh leaves of S. mombin has anti-microbial activity against all the tested organisms.     

Antibacterial and antioxidant activities of hydroalcoholic stem bark extract of Schotia latifolia Jacq

ObjectiveTo investigate the antibacterial and antioxidant activities of hydroalcoholic extract of Schotia latifolia (S. latifolia) bark commonly used in South Africa traditional medicine for the treatment of various ailments.MethodsThe antibacterial test and MIC was determined by using agar well diffusion and dilution methods respectively against eight strains of bacteria. The total phenol, proanthocyanidin and flavonoid contents of S. latifolia were assessed using standard methods. The antioxidant activity of the extract was evaluated using ferric reducing power and the free radical scavenging activity against 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2’-azino-bis-3-ethylbenzothiazoline-6-sulfonic-acid (ABTS), nitric oxide (NO), hydrogen peroxide (H₂O₂) and lipid oxidation (LO).ResultsThe antibacterial activity demonstrated an appreciable effect against all the gram positive bacteria at MIC between 0.016 and 10 mg/mL while that of gram negative bacteria was above 10 mg/mL. The plant extract exhibited high concentration of proanthocyanidin [(300.00±0.10) mg CE/g], followed by flavonoid [(12.46±0.04 mg) TE/g] and phenol [(11.06±0.03) mg QE/g] contents. Similarly, the extract at 0.5 mg/mL scavenges DPPH, ABTS, H₂O₂, LO and NO by 87.55%, 89.47%, 77.15%, 86.48% and 77.75% of the radicals respectively. The reducing power was also found to be concentration dependent.ConclusionsOur data suggest that S. latifolia extract has antibacterial and antioxidants activity and thus could be used as alternative therapy against antibiotic resistance bacteria and to prevent many radical related diseases.     

Antagonistic activity of Eleutherine palmifolia Linn

ObjectiveThe aim of the present study was to investigate the phytochemical constituent and the in vitro Antimicrobial activity of the wonderful medicinal herb Eleutherine palmifolia.MethodsEleutherine palmifolia bulb was extracted with ethanol. The extract was evaluated for their phytochemical constituent's and their antimicrobial activity against the multidrug resistant pathogens following the standard protocols. The active drug principle present in the extract was analysed by GC-MS.ResultsThe qualitative phytochemical evaluation of the Eleutherine palmifolia bulb revealed the presence of Phenols, Sterols, Phlobatannins, Proteins, Steroids, Tannins and Reducing sugar. The extract showed higher antimicrobial activity in comparison to the standard antibiotics. A promising control over methicillin resistant Staphylococcus aureus and Acinetobacter baumannii was found. GC-MS analysis of the plant extract showed the presence of Decane, Cyclohexane, (1, 2-dimethylbutyl) and Cyclohexanecarbonyl Chloride etc.ConclusionsThe present investigation reveals that the plant Eleutherine palmifolia bulb may act as potent source of antimicrobial agent against methicillin resistant Staphylococcus aureus and Acinetobacter baumannii.     

In vitro Antimicrobial Activity of Citrus aurantifolia and its Phytochemical screening

ObjectiveTo evaluate the antimicrobial efficacy of Citrus aurantifolia Linn (CA) against some microorganisms – bacteria and fungus were Staphylococcus aureus, Escherichia coli, Klebsiella pneumonia, Pseudomonas spp, Aspergillus niger, Aspergillus fumigates, Mucor spp and Pencillium.Methods100 μl of 10 mg CA were assessed against eight test microorganisms by agar well Diffusion Method. Gentamicin and Ketoconazole 10 mg/ml were used as standards. A different solvent was used to obtain CA leaf extract by using maceration technique.Results%yield obtained for dried leaf extract of CA with chloroform, ethanol, acetone, petroleum ether and aqueous ethanol was approximately 15%, 18%, 09%, 11% and 24% respectively. Due to its high yield value hydroalcoholic extract of CA was used for estimating the antimicrobial activity and its phytochemical screening. Phytochemical screening of CA plant reveals the presence of Alkaloids, carbohydrates, flavonoids, steroids and tannins.ConclusionsThe study demonstrates that the hydroalcoholic extract of CA leaf exhibit antibacterial activity on Klebsiella pneumonia, Pseudomonas sp, Staphylococcus aureus and antifungal activity among Aspergillus niger, Aspergillus fumigates, Mucor species. These recognized a good support to the use of this plant in herbal medicine and as base for the development of new drugs and phytomedicine.     

Preliminary study on the antibacterial activity of some medicinal plants of Khuzestan (Iran)

ObjectiveTo search for antimicrobial agents among natural products.MethodsEthanolic extracts of 4 plant species, including Beta vulgaris L. (Chenopodiaceae), Amaranthus graecizans (A. graecizans) L. (Amaranthaceae), Rumex obtusifolius (R. obtusifolius) L. and Polygonum patulum (P. patulum) M.B. (Polygonaceae), were evaluated for antibacterial activity using agar disc diffusion method against some gram-positive and gram-negative bacteria [Pseudomonas aeruginosa (P. aeruginosa), Listeria monocytogenes (L. monocytogenes), Staphylococcus epidermidis (S. epidermidis), Staphylococcus aureus (S. aureus), Klebsiella pneumoniae (K. pneumoniae), Salmonella typhi (S. typhi), Bacillus cereus (B. cereus), Bacillus anthracis (B. anthracis), Escherichia coli (E. coli) and Streptococcus pyogenes (Str. pyogenes)]. These extracts were obtained from aerial parts of the used plants.ResultsThe majority of these extracts had inhibitory effect at different concentrations (0.05 g/mL, 0.10 g/mL, 0.20 g/mL and 0.40 g/mL) against above mentioned bacteria. E. coli was the most resistant strain. The highest inhibitory zone was showed by ethanolic extract of P. patulum against Str. pyogenes (28 mm) and followed by ethanolic extract of B. vulgaris against S. epidermidis (23 mm). The extract of A. graecizans didn't show inhibitory activity except at 0.40 g/mL against B. cereus. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values of R. obtusifolius extract that was measured against Str. pyogenes were equal (MIC=MBC=5.00mg/mL).ConclusionThe findings of this study could also be as new source for antibiotics discovery and infection treatment.     

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.     

Antimicrobial activity of Algerian propolis in foodborne pathogens and its quantitative chemical composition

ObjectiveTo evaluate the antimicrobial activity of propolis samples collected from different regions of Algeria and their chemical composition.MethodsThe antibacterial activity of ethanolic extract of Algerian propolis against Bacillus cereus (IPA), Staphylococcus aureus (ATCC25923R), Escherichia coli (ATCC25922) and Pseudomonas aeruginosa (ATCC27893R) was evaluated by the disc diffusion method and determined as an equivalent of the inhibition zones diameters after incubation of the cultures at 37 °C for 24 h. The investigation of the polyphenol and flavonoid contents was done spectrophotometrically.ResultsThe ethanolic extract of Algerian propolis samples inhibited the growth of all examined microorganisms with the highest antimicrobial activity against the Gram-positive bacteria. Polyphenol and flavonoids contents were variable, depending on the propolis samples and a positive correlation between antimicrobial activity and chemical composition was observed.ConclusionsAntimicrobial activity, polyphenol and flavonoid contents were variable, depending on the propolis sample. The strong antimicrobial activity of Algerian propolis may be due to high total phenolic and flavonoid contents and this study suggests potential use of propolis in foods.