The Evaluation of antioxidant, antimicrobial, and lethality Activities of leaf and bark extract of alnus nepalensis D. Don

This study was carried out on phytochemicals and in vitro screening of antibacterial potentials of ethanolic, methanolic and acetonic extracts of stem bark and leaves of Neem plant (<i>Azadirachta indica</i>) by using the methods of AOAC; and agar diffusion technique. The extracts of the leaves and the stem bark were prepared and screened for the presence of different phytochemicals. The results obtained showed that both the leaf and stem bark extracts contain alkaloid, flavonoid, reducing sugar, tannin, saponin and polyphenol. The extracts were tested against selected pathogens; <i>Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Aspergillus niger, Aspergillus fumigatus and Candida albicans </i>by using agar well diffusion technique. In this present research work, the acetonic, ethanolic and methanolic leaves and bark extracts of Neem plant were investigated for antimicrobial activity against these selected pathogens. The Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined. The MIC for the bacterial isolates was 25 mg / ml of the leaf extracts and that for stem bark was 6.25 mg / ml. The MBC was 25 mg / ml. Results showed that the bark extract exhibited strongest antimicrobial activity against bacteria and fungi at different concentrations when compared with the activity of the leaf extract. The acetonic stem bark extract had the highest antibacterial activity with a zone of inhibition of 22 mm, and then followed closely by the stem bark's ethanol extract with a zone of inhibition of 21 mm. More so, the methanolic stem bark extract had the highest antifungal activities with a zone of inhibition of 22.50 mm. Thus, this work showed that both leaf and stem bark extracts had some phytochemicals and antimicrobial activity.

The in vitro antimicrobial activities of crude ethanol, methanol and water extracts of the stem bark of O. gratissimumwere investigated. The extracts exhibited 52 M. R. M. Khoshkholgh Pahlaviani et al antimicrobial activities with zones of inhibition ranging from 10 to 20, 7 to 14 and 2 to 7mm for methanol, ethanol and water extracts respectively. The minimum inhibitory concentration (MIC) of the methanol extract was between 0.5 and 10 mgml -1 while that of ethanol extract ranged from 0.5 to 20 mgml -1 ,while MIC and MBC of streptomycin (Control strain) ranged between 0.065 and 0.5 mgml-1 for all tested bacteria. The minimum bactericidal concentration (MBC) for methanol extract ranged between 2.0 and 12.50 mgml-1, while that of ethanol ranged from 2.0 to 20 mgml-1. Again all the extracts exhibited appreciable activity against all the fungal species investigated. The zones of inhibition exhibited by the extracts against the test fungal species ranged between 2 and 9 for water, ethanol and methanol extracts respectively. Phytochemical screening revealed the presence of saponin, steroids, tannins, glycosides, alkaloids and flavonoids in the extracts. The ability of the crude stem extracts of O. gratissimum to inhibit the growth of bacteria is an indication of its broad spectrum antimicrobial potential which may be employed in the management of microbial infections.

In vitro antibacterial activity of methanol and ethanol leaf extracts of Euphorbia heterophylla and Pterocarpus lucens were investigated against six bacterial clinical isolates using the tube dilution and agar diffusion methods. Salmonella typhi was the most susceptible to methanol leaf extracts of E. heterophylla with a zone of inhibition ranging from 16 to 24 mm for 12.5 to 100 mg/ml concentration. This was followed by Streptococcus lactis, Escherichia coli, Staphylococcus aureus, and Shigella species in that order with Proteus vulgaris not susceptible to the different test concentrations of both plant extracts. E. heterophylla had the least minimum inhibitory concentration (MIC) of 6.25 mg/ml against E. coli and S. typhi while P. lucens extract MIC of 25.00 mg/ml was the least against S. typhi. Since there is an inverse relationship between MIC value and susceptibility of the clinical test isolates, the MIC values also shows that E. heterophylla methanol leaf extracts were more potent to the susceptible test organisms having lower MIC values than the corresponding ethanol leaf extract MIC value. E. heterophylla extract minimum bactericidal concentration (MBC) was 25.00 mg/ml for the sensitive isolates except for methanol extract with 12.50 mg/ml against S. typhi and ethanol extract with 12.50 mg/ml against S. aureus. P. lucens extract MBC was 100.00 mg/ml for the sensitive test isolates except for ethanol leaf extracts with 50.00 mg/ml against S. typhi. The killing rate of E. heterophylla methanol leaf extract MBC shows that E. coli was most rapidly killed at a rate of 4.53 &times; 106 CFU/min with S. aureus as the least killed at a rate of 0.62 &times; 106 CFU/min. S. lactis and E. coli were the most rapidly killed by P. lucens leaf extract MBC at a rate of 1.90 &times; 106 CFU/min. The killing rate of the extracts showed a positive support in the potential use of these plants in curing some infections as done by the traditional herbal healers in Anyigba, Kogi State, Nigeria.&nbsp;&nbsp;&nbsp;&nbsp; &nbsp; Key words: In vitro, antibacteria, extract, inhibitory.In vitro antibacterial activity of methanol and ethanol leaf extracts of Euphorbia heterophylla and Pterocarpus lucens were investigated against six bacterial clinical isolates using the tube dilution and agar diffusion methods. Salmonella typhi was the most susceptible to methanol leaf extracts of E. heterophylla with a zone of inhibition ranging from 16 to 24 mm for 12.5 to 100 mg/ml concentration. This was followed by Streptococcus lactis, Escherichia coli, Staphylococcus aureus, and Shigella species in that order with Proteus vulgaris not susceptible to the different test concentrations of both plant extracts. E. heterophylla had the least minimum inhibitory concentration (MIC) of 6.25 mg/ml against E. coli and S. typhi while P. lucens extract MIC of 25.00 mg/ml was the least against S. typhi. Since there is an inverse relationship between MIC value and susceptibility of the clinical test isolates, the MIC values also shows that E. heterophylla methanol leaf extracts were more potent to the susceptible test organisms having lower MIC values than the corresponding ethanol leaf extract MIC value. E. heterophylla extract minimum bactericidal concentration (MBC) was 25.00 mg/ml for the sensitive isolates except for methanol extract with 12.50 mg/ml against S. typhi and ethanol extract with 12.50 mg/ml against S. aureus. P. lucens extract MBC was 100.00 mg/ml for the sensitive test isolates except for ethanol leaf extracts with 50.00 mg/ml against S. typhi. The killing rate of E. heterophylla methanol leaf extract MBC shows that E. coli was most rapidly killed at a rate of 4.53 &times; 106 CFU/min with S. aureus as the least killed at a rate of 0.62 &times; 106 CFU/min. S. lactis and E. coli were the most rapidly killed by P. lucens leaf extract MBC at a rate of 1.90 &times; 106 CFU/min. The killing rate of the extracts showed a positive support in the potential use of these plants in curing some infections as done by the traditional herbal healers in Anyigba, Kogi State, Nigeria. &nbsp; &nbsp; &nbsp; Key words: In vitro, antibacteria, extract, inhibitory.

Study’s Excerpt: Ocimum gratissimum extracts showed antibacterial activity against Enterobacteriaceae. Both methanolic and ethanolic extracts contained key phytochemicals. Methanolic extract had lower MICs, indicating stronger antibacterial effect. Inhibition zones ranged from 6.0 mm to 25.5 mm depending on extract and organism. Results support gratissimum as a potential alternative antibacterial agent. Full Abstract: Medicinal plants have bioactive constituents that are used for treating and healing various human ailments. This study aimed to investigate the antibacterial potentials of Ocimum gratissimum leaves against some pathogenic members of Enterobacteriaceae. Fresh leaves of Ocimum gratissimum were collected from a farm in Unguwan Rimi, Kaduna State, Nigeria. The leaves were thoroughly washed, shade-dried at room temperature, and ground into a fine powder. Ethanolic and methanolic extracts were obtained via cold maceration. The phytochemical screening was carried out and the antibacterial activity was determined using agar well diffusion at different concentrations. The result of phytochemical analysis revealed the presence of phenol, tannins, saponins, cardiac glycosides and steroids for both ethanolic and methanolic extracts. The ethanolic extract of Ocimum gratissimum exhibited antibacterial activity against Escherichia coli, with a mean zone of inhibition ranging from 20.8 ± 4.71 mm to 13.8 ± 1.84 mm, while the methanolic extract showed a range of 21.6 ± 4.90 mm to 15.2 ± 1.97 mm. Against Klebsiella spp., the ethanolic extract produced inhibition zones ranging from 25.5 ± 4.40 mm to 18.2 ± 1.50 mm, whereas the methanolic extract showed a more variable range from 20.5 ± 5.00 mm to 6.00 ± 0.00 mm. For Pseudomonas aeruginosa, the zone of inhibition for the ethanolic extract varied from 19.5 ± 2.76 mm to 14.2 ± 1.70 mm, while the methanolic extract ranged from 21.0 ± 7.00 mm to 14.5 ± 5.00 mm. The minimum inhibitory concentration (MIC) of the ethanolic extract against E coli was 250 mg/mL, while that of the methanolic extract was 125 mg/mL. The minimum bactericidal concentration (MBC) for both extracts was 250 mg/mL. For Klebsiella spp., the MIC values were 500 mg/mL for the ethanolic extract and 250 mg/mL for the methanolic extract. Corresponding MBC values were 500 mg/mL (ethanolic) and 250 mg/mL (methanolic). In the case of Pseudomonas aeruginosa, the MICs were 500 mg/mL for the ethanolic extract and 250 mg/mL for the methanolic extract, and MBC followed the same pattern. The result suggests that O. gratissimum could be considered as a good antibacterial agent and can be used as an alternative cure to infections caused by these pathogens. Future studies should explore its therapeutic potential and safety profile.

Background: In healthcare facilities, methicillin-resistant Staphylococcus aureus (MRSA) has long been a common pathogen. Indiscriminate and incomplete uses of antibiotics are creating MRSA more alarming day by day.This study aims to determine the antimicrobial activity of Lannea coromandelica (Jhika or Indian ash tree) bark extract against MRSA.&#x0D; Methods: This experimental study was carried out in Department of Microbiology and Department of Pharmacology, Bangladesh University of Health Sciences, from January to July, 2021. In this study, a bark extract of Lannea coromandelica was prepared by macerating dried powder of the bark of the Jhika or Indian ash tree. Then bark extract was immersed in methanol, ethanol, and water for 48-72 hours, followed by solvent filtering and evaporation. MRSA were identified by biochemical test and then Kibry-Bauer disc diffusion method employed against MRSA isolates using commonly used antibiotics.Then the antibacterial activity of Lannea coromandelica extracts against MRSA was monitored. The microdilution method was used to assess the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of bark extracts. Finally, phytochemical screening was carried out only for methanolic extract.&#x0D; Results: All MRSA isolates were completely resistant to cefoxitin, oxacillin, gentamicin followed by tetracycline. Methanol, ethanol and aqueous extracts of Lannea coromandelica produce maximum zones of inhibition of 14 mm, 13 mm, and 12 mm, respectively, with MIC and MBC values ranging from 3.125 mg/ml to 12.5 mg/ml against MRSA. Phytochemical screening of methanolic extract determined the presence of tannin, saponin, flavonoid, phenol which may be the cause of the highest zone of inhibition against MRSA.&#x0D; Conclusion: It can be concluded that methanol, ethanol and aqueous bark extract of Lannea coromandelica exhibited in vitro antibacterial activity against MRSA by disc diffusion method and detailed pharmacological screening should be carried out for the exploration of effective and natural drugs.&#x0D; BIRDEM Med J 2022; 12(3): 201-206

Background: Adansonia digitata L (Baobab) contains different classes of bioactive compounds which were identified from various parts of the plant such as seed, leaves, and roots and also stem bark. The study was designed to determine the antibacterial activityof Adansonia digitata leaf and stem bark extracts. Methods: The plant material was extracted using aqueous, ethanol and methanol; and their activity against the three clinical isolates Escherichia coli (E. coli), Staphylococcus aureus (S. aureus) and Salmonella typhi (S. typhi) was ascertained using agar well diffusion method. The minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) of the different extracts were also determined. One way analysis of variance was conducted using Stata/SE11.1 and t-test to determine the significant difference between the effects at p ≤ 0.05. Results: The extracts were found to be effective against the tested organisms. The methanolic extracts showed significantly higher activity against the test organisms compared to aqueous and ethanolic extracts (p = 0.000). The result also demonstrated that the leaf extract is more active than the stem bark extract with significant difference (p=0.000). The methanolic and ethanolic leaf extracts exhibited highest inhibitions zone of 19mm and 16mm against E. coli at concentration of 1000mg/mL respectively. The MIC result of the study showed that the methanolic and ethanolic extracts inhibited the growth of the organisms at 25 mg/ml. The methanolic and ethanolic extracts have MBC at 25 mg/mL. Conclusion: The methanolic and ethanolic leaf extracts have significant effect against the test organisms at all concentration tested.

Background:Cassia fistula, is a flowering plant and a member of Fabaceae family. Its leaves are compound of 4 - 8 pairs of opposite leaflets. There are many Cassia species around the world which are used in herbal medicine.Objectives:This study was designed to examine in vitro anti-bacterial activity of methanolic and ethanolic extracts of C. fistula native to Khuzestan, Iran.Materials and Methods:The microbial inhibitory effect of methanolic and ethanolic extracts of C. fistula was tested on 3 Gram positive: Bacillus cereus, Staphylococcus aureus and S. epidermidis and 5 Gram negative: Salmonella Typhi, Kelebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa, and Proteus mirabilis bacterial species using disc diffusion method at various concentrations. The minimum inhibitory and bactericidal concentrations (MIC and MBC) were measured by the tube dilution assay.Results:The extract of C. fistula was effective against B. cereus, S. aureus, S. epidermidis, E. coli and K. pneumoniae. The most susceptible microorganisms to ethanolic and methanolic extracts were E. coli and K. pneumoniae, respectively. Also B. cereus and S. aureus showed the least sensitivity to ethanolic and methanolic extracts, respectively. The MIC (minimum inhibitory concentration) and MBC (minimum bactericidal concentration) of ethanolic extracts against S. aureus, E. coli, S. epidermidis and K. pneumoniae were also determined.Conclusions:With respect to the obtained results and regarding to the daily increase of the resistant microbial strains to the commercial antibiotics, it can be concluded that these extracts can be proper candidates of antibacterial substance against pathogenic bacterial species especially S. aureus, E. coli, K. pneumoniae and S. epidermidis.

Background: Bauhinia tomentosa L. leaves, flower buds or root had been reported to possess anti-diabetic, anti-pyretic, antioxidant, anti-proliferative properties. The seeds and bark of the plant had not still studied for their anti-bacterial properties despite their uses in traditional medicines. Methods: Solvent extraction method was used to prepare crude aqueous, methanol and ethanol extracts of leaf, seed and bark, used for phytochemical screening to determine the classes of metabolites present. Anti-bacterial activity of leaf, seed and bark extracts was evaluated using agar well diffusion assay. Minimum inhibitory concentration (MIC) of extracts was examined using broth dilution assay. Result: Qualitative phytochemical analysis of aqueous seed extract revealed the presence of maximum number of phytochemicals (alkaloids, glycosides, flavonoids, phenols, saponins, tannins, terpenoids and amino acids). Aqueous and methanol seed extracts were observed to be effective against all the tested bacteria viz. Enterobacillus, Micrococcus, Klebsiella pneumoniae, Streptococcus thermophilus and Haemophilus influenza. On the other hand, all the leaf extracts (ethanol, methanol and aqueous) showed inhibition against Enterobacillus, Micrococcus, S. thermophilus and H. influenzae except K. pneumoniae. The aqueous extracts of seed, leaf and bark was observed to be more potent against all the Gram positive and Gram negative bacteria followed by methanol extracts of leaf and seed.

Due to improper use of antibiotics, some pathogenic bacteria that cause serious and deadly infections have become resistant to commonly used broad spectrum antibiotics. This antibiotic resistance has become major global healthcare problem. Therefore, there is an urgent need to develop novel antibacterial agents; hence, much attention has been made on medicinal plants such as Artemisia afra. Thus, the current study was aimed to evaluate the antibacterial activity of ethanolic, methanolic and n-hexane extracts of this plant leaf against four multi-antibiotic resistant clinical pathogens. Crude extracts from A.afra leaf were prepared using ethanol, methanol and n-hexane and the antibacterial effect of each extract was tested against Escherichia coli, Streptococcus pneumoniae, Pseudomonas aeruginosa and Staphylococcus aureus. In addition, minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) were evaluated. Among the crude extracts, the highest zone of inhibition (25.33±0.58mm) was recorded against E. coli when methanolic extract was applied. On the other hand, the lowest inhibition was exhibited when n-hexane extract was applied against S.aureus (5.67±1.56 mm). Concerning MIC values of the different extracts, varied results were obtained. MIC value of 6.25mg/mL was recorded when methanolic extract was applied against all clinical pathogens. Moreover, both methanolic and ethanolic extracts showed MBC value of 12.5mg/mL against the four clinical pathogens. However, the methanolic extract gave MBC value of 6.25mg/mL against E. coli. From this study, it can be concluded that it is possible to develop and formulate of new, efficacious, less toxic and inexpensive herbal medicine from A.afra leaf extract that act against multi-antibiotic resistant clinical pathogens.

Multi-drug resistant is a global public health concern. There has been an increase in infections caused by multidrug resistant micro-organisms in Sub Saharan Africa. This has led to extended illness, expensive health care and deaths. This experimental study was aimed to determine the anti-microbial activity of aqueous and methanol leaf extracts of Warbugia ugandensis, Moringa oleifera and Aloe vera on standard bacteria and multi-drug resistant clinical isolates of Pseudomonas aeruginosa, Staphylococcus aureus, and Escherichia coli. Tetracycline drug was used as the reference drug. The bacteria were treated with extracts at different concentrations to determine the zones of inhibition through Agar Diffusion Assay, minimum inhibitory concentration and minimum bactericidal concentration assays. Raw data was analyzed using one-way and two-way analysis of variance followed by Tukey’s post hoc test. Zones of inhibition ranged from 6.5 mm to 9.98 mm on the multi-drug resistant isolates, while those of the standard bacteria ranged from 6.5 mm to 12.00 mm. Methanol extracts of W. ugandensis, M. oleifera and A. vera at the concentration of 400 mg/ml had higher zones of inhibition against multi-drug resistant S. aureus, P. aeruginosa and E. coli respectively. The antimicrobial activity of the extracts indicated a concentration-dependent response. The minimum bactericidal concentration values obtained were double the minimum inhibitory concentration values. Methanol extracts recorded lower minimum inhibitory and minimum bactericidal concentrations compared to aqueous extracts. Phytochemicals which were present, included alkaloids, cardenolide glycosides, phenols, flavonoids, coumarins, tannins, saponins and anthracin glycosides. These phytochemicals are associated with antimicrobial activities. This study showed potent antimicrobial activities of methanol and aqueous extracts of W. ugandensis, M. oleifera and A. vera against the multi-drug resistant and standard bacteria tested. The extracts, therefore, may be used to develop alternative therapeutics in the management of multi-drug resistant Pseudomonas aeruginosa, Staphylococcus aureus, and Escherichia coli.

Abstract: The incidence of antibiotic resistance is one of the challenges in the treatment of different ailments. Hence, this study focused on the use of V. amygdalina (ethanolic and methanolic) extracts on some selected bacterial isolates. Different concentrations of the extracts were prepared and the residues were re-suspended in the solvents. The zone of inhibition, minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and antibiotic susceptibility patterns were determined according to standard methods. The ethanolic extract appeared to produce better antibacterial effect than methanolic extract. K. pneumoniae and S. marcescens were inhibited by ethanolic extract of 12.5-200mg/ml used. However, only S. aureus was inhibited by all methanolic extract concentrations used. Most of the isolates (83.3%) had lower MIC in ethanolic extract when compared with methanolic extract. The MIC of the isolates in the ethanolic and methanolic extracts ranged from 12.5-100mg/ml and 25-100mg/ml respectively. Two of the isolates, B. cereus and K. pneumoniae did not cease to grow on MBC plates even at the highest concentration of 200mg/ml used. All the isolates showed multiple antibiotic resistance patterns with AMR index range of 0.63-1.0. All the isolates were resistant to augmentin, cefexime, cefuroxime, ceftazidime and nitrofurantoin. The order of susceptibility of the isolates to the antibiotics were gentamicin (83.3%) &gt; ofloxacin (66.7%) &gt; ciprofloxacin (33.3%). It is concluded in this study that the extracts of V. amygdalina inhibited 83% of the isolates at lower concentration of 25mg/ml, were bactericidal at 100-200mg/ml for 66.7% of the isolates and produced higher inhibition zone in comparison with the standard antibiotics on the isolates.

The ethanol extracts of root, bark and leaf of Bridelia ferruginea was investigated for antibacterial activity against clinical isolate of Staphylococcus aureus and Escherichia coli. The extracts had significant antibacterial activity in vitro at concentration of 25 mg/ml, 50 mg/ml, 100 mg/ml and 200 mg/ml and in vivo at dose of 50 mg/kg and 100 mg/kg. The root extract in vitro had the highest zone of inhibition, followed by the bark extract for both Staphylococcus aureus and Escherichia coli. The concentration of 200 mg/ml had the highest zone of inhibition in vitro. The minimum inhibitory concentration (MIC) showed a decreasing inhibitory effect of the plant extracts for both Staphylococcus aureus and Escherichia coli as the concentration decreases with root having 3.125 mg/ml, bark having 6.25 mg/ml and leaf having 25 mg/ml for Staphylococcus aureus and Escherichia coli. Likewise, the minimum bactericidal concentration (MBC) showed decreasing bactericide effects with decrease concentration with root having 12.5 mg/ml, bark having 12.5 mg/ml and leaf having 25 mg/ml for Escherichia coli while root had 6.25mg/ml, bark had 12.5mg/ml and leaf had 25mg/ml for Staphylococcus aureus. The in vivo investigation showed that the root and bark extract exhibited antibacterial activity on both Staphylococcus aureus and Escherichia coli at doses of 100mg/kg and 50mg/kg; the root extract had higher activity than the bark and root/bark combined. The dose of 100 mg/kg had the highest colonies reduction for Staphylococcus aureus and Escherichia coli in vivo. Preliminary phytochemical screening of root, bark and leaves of Bridelia ferruginea revealed the presence of tannins, flavonoids, carbohydrates, cardiac glycoside (root, bark and leaves), saponins (root and bark). The presence of tannins, saponins, flavonoid, cardiac glycoside and carbohydrate in the bark and root extracts of the plant indicates that the bark and root extracts were pharmacological importance.

The study comprises the results of phytochemical analysis and antimicrobial evaluation of extracts from bark and leaf of Quassia indica (Gaertn). Nooteb. – a medicinal plant used in traditional healing owing to its analgestic, antiinflammatory, antifeedant and antimicrobial properties. A preliminary qualitative analysis was carried out successively in five different solvents with increasing order of polarity-Petroleum ether, Chloroform, Ethyl acetate, Methanol and Water to document the nature and yield of phytochemicals. The extracts were evaluated for antimicrobial effect using two strains of bacteria – Escherichia coli and Staphylococcus aureus and fungi – Aspergillus niger and Candida albicans. Among solvents methanol and water were found as effective extractants in which most of the secondary metabolites - alkaloids, flavonoids, terpenoids, phenolics, tannins, phytosterols were released. Quantitative analysis of the methanolic and aqueous extracts was carried out to estimate the quantity (mg/g tissue) of the phytoconstituents. The alkaloid content was much higher in leaf extract (5.7 mg/g) than in bark (3.5 mg/g). The phenolic content expressed as mg/ g GAE was determined in the methanolic extract, bark (24.38) &gt; leaf (10.44) and the aqueous extract does not show much phenolic content. Flavonoid were maximum in methanolic leaf extract (1.085 mg/g) and minimum in aqueous bark extract (0.305 mg/g) and the terpenoid content was detected in methanolic extracts of leaf (0.4016 mg/g) and bark (0.4224 mg/g). The leaf extract indicated more tannin content (1.536 mg/g) than bark (1.328 mg/g). Evaluation of antimicrobial activity suggested leaf extract as an effective antibacterial and antifungal agent at a concentration of 1000 g/ml with inhibition zones- 24 mm (S.aureus), 22 mm (E.coli) and 14 mm (A.niger), 14 mm(C. albicans). The bark extract was comparatively lesser efficient in resisting microbial growth (E. coli – 20 mm; S. aureus – 22 mm; A. niger – 12 mm; C. albicans – 10 mm).

Objectives: The main objective of this study was to evaluate antimicrobial activity of ethanolic extract of spices along with determination of its synergistic effect against few selected pathogens.&#x0D; Methods: In this study, ethanolic extract of 5 different spices; Zingiber officinale (Ginger), Allium sativum (Garlic), Curcuma longa (Turmeric), Capsicum annum (Chili) and Allium cepa (Onion) were obtained by using Soxhlet apparatus. The ethanolic extract was concentrated by evaporation and different concentrations of extract were prepared in Dimethy Sulphoxide (DMSO) solvent. Test organisms included mainly pathogens i.e. Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumoniae. The antimicrobial activities of the extracts were determined by well diffusion technique both individually and in combination. On the other hand, Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) was determined by serial dilution technique. The result were interpreted on the basis of the fact that the growth occurs in positive control and other tubes with inadequate amount of extract whereas the lowest concentration of agent that inhibits growth of organism, detected by lack of visible turbidity by inhibition of 99% is designed as the MIC. The MBC is identified by determining the lowest concentration of extract solution that reduces the viability of the initial bacterial inoculum by a predetermined reduction such as ≥99.9%. Likewise, for determination of Fractional Inhibitory Concentration Index (FICI), two extracts were combined along with standardized inoculum of bacterial strain. Tubes without visible turbidity were streaked on agar plate and observed for 99.9% killing. &#x0D; Results: All the tested extract of spices were found effective against S. aureus and K. pneumoniae only. The highest zone of inhibition (ZOI) was found in chili extract (ZOI=26 mm) against S. aureus whereas lowest zone of inhibition was found in garlic extract against K. pneumoniae (ZOI=12mm). Similarly, highest ZOI was produced by combined extract of both Turmeric and Ginger (ZOI= 26 mm). Turmeric extract was found to be effective against S. aureus (MIC value = 62.5 mg /ml and MBC value = 31.25 mg/ml) and K. pneumoniae (MIC value 125 mg/ml and MBC value = 62.5 mg/ml). The Fractional Inhibitory Concentration (FIC) values of combined extract suggested synergistic and additive effect (0.5&lt;FIC&lt;1). Chili and ginger were effective with FIC value of 0.25.&#x0D; Conclusion: To recapitulate, the extract of spices can be used to prevent the pathogenic organism.

Psidium guajava (guava tree plant) is widely used in Nigerian communities as food and for medicinal purposes to treat some bacterial and non-bacterial related diseases. Increase in the rate at which pathogenic bacteria develop resistance to some available synthetic drugs calls for urgent action to turn the search lights on natural products such as plants for bioactive compounds needed to develop novel antimicrobials. This study evaluated the antibacterial activity of ethanolic and methanolic crude leaf and bark extracts of P. guajava against pathogenic strains of Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, Pseudomonas aeruginosa and Streptococcus pneumoniae by the agar well diffusion technique. Ethanolic and methanolic leaf extracts of P. guajava produced inhibitory zones of 15-22 mm and 13-20 mm against the test bacteria Original Research Article Ifeanyichukwu et al.; EJMP, 7(1): 26-30, 2015; Article no.EJMP.2015.064 27 respectively. Inhibitory zones of 16-19 mm and 13-23 mm was recorded against the test bacteria for methanolic and ethanolic bark extracts respectively. The observed antibacterial activities of P. guajava further explain the use of guava tree plant for medicinal purposes in this part of the world. And further research is necessary to characterize the bioactive compounds of P. guajava.