Increasing Extract Concentration Research Articles

USING ONE OF ORGANIC EXTRACTS AS A CORROSION INHIBITOR FOR CARBON STEEL IN ACIDIC ENVIRONMENT

Utilization of mangosteen rind extract as carbon steel inhibitors in the environment of hydrochloric acid (HCl) 0.1M, 0.5M, and 1.0M. Extracts were carried out by extraction using ethanol solvent at a temperature of 600C with a time of 80 minutes. The variation of extract concentration (100 ppm to 1000 ppm in 3 days and the effect of time of corroding the carbon steel with the addition of 1000 ppm extract. Corrosion rate is calculated based on the difference in weight and corrosion products shown by microscope optics. The objective was investigated corrosion inhibition efficiency that could be prevented by mangosteen peel extract as inhibitor. The results showed inhibitory properties of mangosteen peel extract for three (3) days increased with increasing extract concentrations up to 76.53% in 0.1M HCl solution and 28.83% in 1.0M HCl solutions. For the addition of 1000 ppm mangosteen peel extract showed inhibitor efficiency reached about 90% at 3 days of corrosive time in HCl 0, 5 M, 87% in 1.0 M HCl solution, and 81% in 0.1 M HCl solution. The experiment showed that the process of diffusion of compounds in extracts on the surface of carbon steel and react with ferro ions (Fe2 +) to form chemical covalent coordination coordinate with a thickness of 76 µm was successfully done.

Low-Density Polyethylene Films Carrying ferula asafoetida Extract for Active Food Packaging: Thermal, Mechanical, Optical, Barrier, and Antifungal Properties

The physical, thermal, mechanical, optical, microstructural, and barrier properties of low-density polyethylene films (LDPE) containing ferula asafoetida leaf and gum extracts were investigated. Results showed a reduction in elasticity and tensile strength with increasing extract concentration in the polymer matrix. The melting temperature and enthalpy increased with increasing concentration of extracts. The films containing extracts had lower L∗ and a∗ and higher b∗ indices. The films containing leaf extract had more barrier potential to UV than the gum extracts. The oxygen permeability in films containing 5% of leaf and gum extracts increased by 2.3 and 2.1 times, respectively. The morphology of the active films was similar to bubble swollen islands, which was more pronounced at higher concentrations of gum and leaf extracts. FTIR results confirmed some chemical interactions of ferula extracts with the polymer matrix. At the end of day 14th, the growth rate of Aspergillus niger and Saccharomyces cerevisea in the presence of the PE-Gum-5 reduced more than PE-Leaf-5 (3.7 and 2.4 logarithmic cycles, respectively) compared to the first day. Our findings showed that active LDPE films have desire thermo-mechanical and barrier properties for food packaging.

Optimization of Iranian golpar (Heracleum persicum) extract encapsulation using sage (Salvia macrosiphon) seed gum: chitosan as a wall materials and its effect on the shelf life of soybean oil during storage

In this study, total phenolic content (167.25 mg GA/g), total flavonoids (42.37 mg QE/g DM) and tocopherol (4.60 mg αT/g DM) of Iranian golpar which obtained by microwave assisted extraction were measured. Antioxidant activity of 100, 200, 400, 800, 1500 and 2000 ppm concentrations of extract were compared with 100 ppm of TBHQ synthetic antioxidant and antioxidant activity increased with increasing extract concentration. The type and percentage of wall materials (0, 50 and 100%), extract to wall ratio (0.1, 0.25 and 0.4% w/w) and sonication time (2, 4 and 6 min) as independent variable factors and encapsulation efficiency of phenolic compounds, particle size of nanocapsule and zeta potential were considered as the response of encapsulation conditions. Iranian golpar extract was added to soybean oil at 1500 and 2000 ppm of concentration in free and optimum encapsulated form, which had more antioxidant activity than TBHQ during 60 days of storage at 27 ± 2 °C. Concentration of 1500 ppm of Iranian golpar extract (IGE) in the coating of sage seed gum and chitosan can be used as a natural antioxidant to increase the oxidative stability of soybean oil.

Inhibition of Pipeline Steel Corrosion in 0.5 M H<sub>2</sub>SO<sub>4</sub> Using Cotyledon of <i>Chrysophyllum Albidum</i>

The corrosion inhibition characteristics of Chrysophyllum albidum cotyledon extract was studied as a green and sustainable corrosion inhibitors for pipeline steel in acidic environment attemperatures, 303,313 and 323K using gravimetric technique.The results obtained showed that the inhibition efficiency increased with increase in extract concentration but decrease with increase in temperature. The extract attained an inhibition efficiency of 94 % with 5 g/L at 303 K and 52.2 % with 1 g/L at 333K. Also increase in concentration of the extract lead to increase in activation energydepicting an exothermic process.Fourier transform infrared spectroscopy (FT-IR) studies showed the mode of inhibition as adsorption of phytochemicals from the extract on pipeline steel surface. Langmuir adsorption isotherm best fitted into the adsorption process which is spontaneous and physical.
 Keywords: Chrysophyllum albidum, Pipeline steel, Inhibition, Adsorption.

Allelopathic Effects of Castanea henryi Aqueous Extracts on the Growth and Physiology of Brassica pekinensis and Zea mays.

The present study investigated the allelopathic effects of aqueous extracts of Castanea henryi litter on the growth and physiological responses of Brassica pekinensis and Zea mays. Treatment with high concentrations of leaf extract (0.05 g/ml for B. pekinensis and 0.10 g/ml for Z. mays) significantly increased malonaldehyde content and reduced seed germination, seedling growth, chlorophyll content, and the activity levels of antioxidant enzymes. These effects generally increased with increasing extract concentration. However, in Z. mays, low extract concentrations actually promoted seed germination, shoot growth, chlorophyll content, and antioxidant enzyme activity. The allelopathic effects of the various C. henryi extracts decreased as follows: leaf extract > twig extract > shell extract. Eleven potential allelochemicals including rutin, quercetin, luteolin, procyanidin A2, kaempferol, allantoin, propionic acid, salicylic acid, jasmonic acid, methylmalonic acid, and gentisic acid were identified in the leaves of C. henryi which were linked to the strongest allelopathic effects. These findings suggest that the allelopathic effects of C. henryi differ depending on receptor plant species, and that leaves are the most allelopathic litter in C. henryi.

Allelopathic Effect of Chrysanthemum Procumentens on the Seed Germination and Seedling Growth of Beans Phaseolus Vulgaris

The present study was undertaken to assess the allelopathic effect of Chrysanthemum procumentens in relation to germination and growth of bean seedling. C. procumentens reduced germination and suppressed early seedling growth of beans. With increase in extract concentration from 20 mg ml-1 to 60 mg ml-1, a gradual decrease in seed germination evaluated by reduction in the concentration of biomolecules such as total protein, total soluble sugar and amylase activities; and increase in the activities of hydrolytic enzymes such as proteases, Lipases and Arginase occurred. The longest seedling root and shoot lengths were recorded on day 1 at 20 mg ml-1 extract concentration while the shortest seedling root and shoot length were recorded on day 6 at 80 mg ml-1 extract concentrations. It was noted that the reduction in germination and suppression of seedling growth observed in this study were concentration and time dependent. The result suggested that C. procumentens had good allelopathic potential which reduces germination and plant growth.

Haematological Studies of Clarias gariepinus Exposed to Ethanolic Stem Bark Extracts of Ackee, Blighia sapida

The study evaluated effects of sub-lethal concentrations (0.00, 1.6, 3.2, 6.4, 12.8 g/l) of ethanolic stem bark extracts of ackee, Blighia sapida on haematological profile of Clarias gariepinus (mean weight, 6.95± 1.02 g; total length 11.7±1.32 cm). Each concentration was treated in triplicate using a static bioassay system. The exposure period was 21 days. Physico-chemical parameters of water were monitored throughout the study period. Results revealed that haematocrit, red blood cell, haemoglobin and mean corpuscular haemoglobin concentration counts were significantly (p<0.05) depleted with increase in extract concentration while white blood cell counts increased (p<0.05) linearly from 198.2, 198.5, 208.8, 219.4 and 241.53 x 103 cells/µl in 0.00, 1.6, 3.2, 6.4 and 12.8 g/l respectively. The levels of water temperature increased with extract concentrations while dissolved oxygen and pH contents decreased. The implications of these results showed that stem bark extract of ackee had negative effects on the blood of treated fish. This may further explain the decline in wild fishery resources in the locality where the plant parts were collected. In view of this, the direct use of this plant in harvesting fish by local fisher folks in Southern Nigeria should be discouraged until information that aid its application in a sustainable manner is made available through further studies.

Extraction of phenolic compounds from basil (Ocimum americanum L.) leaves with pretreatment using pulsed electric field (PEF)

The study was conducted to determine the role of the pulsed electric field (PEF) as a pretreatment on the extraction of phenolic compounds from basil (Ocimum americanum, L.) leaves. The research used Randomized Block Design (RBD) with two factors, factor 1: exposure time (10, 15, and 20 seconds) and factor 2: voltage (1000, 1500, and 2000 Volts). Extraction was done by maceration using 80% ethanol at 50°C. The results showed that PEF treatment had a significant effect on total phenolic compounds (TPC) and antioxidant activity (IC50) of basil extract. The best treatment at exposure time of 10 seconds and a voltage of 1500 Volts obtains TPC of 260.50 mg GAE/g and IC50 of 35.96 ppm. Whereas the untreated sample (without PEF pre-treatment) obtains TPC of 175.75 mg GAE/g and IC50 of 116.25 ppm. The data showed that PEF treatment before the extraction of basil leaves increased TPC by 1.5 times and antioxidant activity by 3.2 times. FTIR spectra showed that PEF pre-treatment increases absorption or decreases transmittance, which indicates the increase of extract concentration. Scanning electron microscopy (SEM) imaging showed that PEF treatment causes pore formation on the cell membrane, which might facilitate the release of phenolic compounds.

Utilization of mangosteen extract as a corrosion inhibitor of carbon steel in acid environment (HCl)

Utilization of mangosteen rind extract as carbon steel inhibitors in the environment of hydrochloric acid (HCl) 0.1M, 0.5M, and 1.0M. Extracts were carried out by extraction using ethanol solvent at a temperature of 600C with a time of 80 minutes. The variation of extract concentration (100 ppm to 1000 ppm in 3 days and the effect of time of corroding the carbon steel with the addition of 1000 ppm extract. Corrosion rate is calculated based on the difference in weight and corrosion products shown by microscope optics. The objective was investigated corrosion inhibition efficiency that could be prevented by mangosteen peel extract as inhibitor. The results showed inhibitory properties of mangosteen peel extract for three (3) days increased with increasing extract concentrations up to 76.53% in 0.1M HCl solution and 28.83% in 1.0M HCl solutions. For the addition of 1000 ppm mangosteen peel extract showed inhibitor efficiency reached about 90% at 3 days of corrosive time in HCl 0, 5 M, 87% in 1.0 M HCl solution, and 81% in 0.1 M HCl solution. The experiment showed that the process of diffusion of compounds in extracts on the surface of carbon steel and react with ferro ions (Fe2 +) to form chemical covalent coordination coordinate with a thickness of 76 µm was succesfully done.

Effect of ginger, pomegranate and celery extracts on zinc electrodeposition, surface morphology and corrosion inhibition of mild steel

Electrodeposition of Zn on mild steel (MS) within an acid bath consisting of admixed ZnCl2, H3BO3 and KCl solution at specific concentrations of ginger (zingiber officinale), celery (Apium graveolens) and pomegranate (Punica granatum) extracts, and plating time was studied. The surface of electrodeposited MS was analyzed with scanning electron microscope (SEM). Energy dispersive spectroscopy (EDS) was employed for elemental analysis. Results shows the presence and increase in extract concentration is associated with the amount of Zn electrodeposited on MS. Ginger extracts induced the highest weight gain with values between 0.0867 g and 0.1219 g. Morphology studies showed good electrodeposition of Zn on MS, with closely packed Zn particles on the surface with respect to additive concentrations and plating time. EDS results showed pomegranate induced the highest %wt. content of Zn on MS. Corrosion resistance of the unplated and Zn electrodeposited MS with and without extract additives were evaluated with potentiodynamic polarization method. Results showed the presence of ginger, pomegranate and celery extracts improved the corrosion protection of Zn electrodeposited MS with optimal corrosion rates of 2.48 mm/y, 2.78 mm/y and 1.95 mm/y compared to 7.96 mm/y for unplated MS and 6.58 mm/y for Zn electrodeposited MS without additives.

Allelopathic properties of Calliandra haematocephala Hassk. extracts and fractions as an alternative for weed management in quinoa and rice crops

In this study, aqueous extracts of Calliandra haematocephala Hassk. leaves and inflorescences were tested on seeds of quinoa (Chenopodium album L.) and rice (Oryza sativa L.), and on some of the most noxious-associated weeds, Chenopodium album L. and Holcus lanatus L. in quinoa, and Echinochloa crus-galli (L.) P. Beauv., Echinochloa colona L., Eclipta prostrata L. and Rottboellia cochinchinensis (Lou.) W.D. Clayton in rice. The objectives were to identify extract concentrations at which 50 and 90% of germination (GR_{[50,90]}) and radicle elongation (RR_{[50,90]}) were inhibited, to fractionate inflorescence extracts for facilitating identifying the chemical group causing allelopathic effects, and to evaluate the fraction showing the stronger weed suppression effects and the least crop damage. Increasing extract concentration rates (0, 6.25, 12.5, 25, 50 and 100% crude extract) were applied to seeds of target crops and weeds. Flower extracts at rates < 0.30 produced GR_{[50]} and RR_{[50]} on H. lanatus, and GR_{[90]} and RR_{[90]} in C. album, while quinoa seeds were not affected. Rice and its target weeds were minimally affected by flower extracts, whereas radicle elongation of all species was significantly reduced. A concentration rate > 0.52 caused the RR_{[50]} on rice and all its target weeds. Fractions were quantitatively and qualitatively analysed to detect phytochemical groups, using specific chemical reagents and thin-layer chromatography (TLC). The fraction F3 from aqueous flower extract showed a high content of flavonoids, assumed as the potential allelochemical substance. Total flavonoid content in F3 was quantified as 2.7 mg of quercetin per g F3, i.e., 12.8 mg of quercetin per g of inflorescence material. Additionally, field equivalent extract rates obtained from the harvested fresh inflorescence biomass could be determined. These rates ranged between 90 and 143 mL l−1 of F3 aqueous fraction, while for ethanol F3 were 131 mL l−1. Our results are encouraging for finding sustainable and ecologically friendly alternatives for weed management in crops of high nutritional value, contributing also to counteract the growing problem of herbicide resistance.

Bioinsecticidal activity of Vitex negundo L. (Family: Verbenaceae) leaf extracts against Sitophilus granarius L. in stored maize grains

The insecticidal property of dry leaves of Vitex negundo against the Sitophilus granarius in the laboratory at (28±3) 0C and (78±3) % r. h. with Soxhlet extracted extracts of V. negundo leaves in ethanol, methanol, chloroform, acetone and n-Hexane were tested and found very effective to control the store grain insect pest. The biopesticidal effects of extracts in different solvents were compared by calculating LD10, LD50, LD90 and LD99 values for 96 hrs. The Probit analysis of data demonstrated that LD values for ethanol, methanol, chloroform, acetone and n-Hexane extracts were LD10 – 1.216, 1.141, 0.9298, 1.265, 0.5398 ml/Kg; LD50 – 2.997, 3.106, 2.490, 3.727, 1.302 ml/Kg; LD90 – 7.392, 8.457, 6.667, 10.98, 3.142 ml/Kg and LD99 –15.43, 19.14, 14.88, 26.50, 6.439 ml/Kg respectively, for 96 hrs. These results demonstrated that the mortality increased with increase in concentration of extract and exposure time. There was nearly zero fecundity and next generation was not observed in treated grains. The extracts of V. negundo leaf may be of high value in grain storage against S. granarius, especially in subsistence agriculture where the plants are locally available to local farmers. Hence, we conclude that the ethanol, chloroform and n-Hexane extracts from V. negundo leaf are more effective and useful. It served as being a potential insecticidal agent and could be applicable to the management of populations of stored-product insects particularly against the infestation by granary weevil, S. granarius after proper dose formulation.

Toxicity effect of &lt;i&gt;Kigelia africana&lt;/i&gt; aqueous extract on the haematology and histopathology of juvenile Nile Tilapia (&lt;i&gt;Oreochromis niloticus&lt;/i&gt;)

This study examined the toxicity effect of Kigelia africana on Nile tilapia ( Oreochromis niloticus ) juveniles. The corresponding effects of this plant extract on the health status of the O. niloticus were similarly studied using their haematological and histopathological profiles. The experiment was carried out at the Hatchery Unit of the Federal University of Agriculture, Abeokuta fish farm. Fish were acclimatized for one week and fed twice daily at the rate of 3% body weight. Water in the culture medium was replenished daily. A total of 150 juveniles of O. niloticus were exposed to concentrations of 0.00, 1.75, 2.50, 3.75 and 5.00 g L −1 aqueous extract of Kigelia africana set up in three replicates. This toxicity study showed that aqueous bark extract of K. africana caused significant behavioural changes in O. niloticus . Recorded values of the water quality parameters showed significant difference ( p < 0.05) across the treatments. The haematological indices of the fish were also observed to be affected with increasing extract concentration, compared to the control treatment (0.0 g L −1 ). Similarly, histology of the liver and gills showed variations in distortions and damages to the tissues; with observed severity increasing with increase in extract concentrations. This study suggested that the 96-h LC 50 of K. africana could be greater than 5 g L −1 . The study concluded that caution must be taken in the disposal of this plant in water bodies as extended exposure time and at higher concentrations could pose adverse effects on the stock of juvenile Orechromis niloticus . Keywords: toxicity, Kigelia africana , Oreochromis niloticus , haematology, histopathology

Antioxidant Activities of Martynia annua Linn. Root Extract

Background: Antioxidants play a significant role to protect harm caused by oxidative stress (OS). Plants having phenolic substances are reported to possess antioxidant properties. The present study was intended to research the antioxidant potential of aqueous extract, Hydroalcoholic extract and Alcoholic extract from Martynia annua root. Martynia annua (cat’s claw, bichu) belongs to Martyniaceae family. For centuries, extracts of leaves, roots, stems, roots and seeds of M. annua have been used to cure eplilepsy, inflammation, tuberculosis, skin infections etc. Methods: The antioxidant activities of Aqueous, Hydroalcoholic and Alcoholic extractives were evaluated by using DPPH free radical assay. DPPH (1,1-diphenyl-2-picrylhydrazyine) free radical analysis is one of the accurate and frequently employed method for evaluating antioxidant activity. Results: Aqueous, Hydroalcoholic and Alcoholic extracts of Martynia annua root were explored which revealed that with increase in concentration of extracts resulted in increased degree of reduction. The IC50 values were calculated for all three extracts. Ascorbic acid was used as control. Martynia annua exhibited IC50 of 69.58±3.44µg/ml, 70.91±2.91µg/ml &amp; 68.49±3.15µg/ml for Hydro-alcoholic extract, aqueous extract &amp; ethanolic extract respectively while Ascorbic acid exhibited IC 50 of 62.91±2.85µg/ml. Conclusions: Scientific evidence suggests that antioxidants reduce the risk for chronic diseases including cancer and heart disease and infectious diseases. Further evaluation of pharmacological activities and cell line studies of Martynia annua may prove useful in treatment of cancer and heart diseases.&#x0D;

Identification of antifungal compounds from slender amaranth

Background: Antifungal activity of slender amaranth (Amaranthus viridis L.) is well documented but such studies are scarce in Pakistan, especially against plant pathogens. It was hypothesized that A. viridis has antifungal activity against fungal phyto-pathogens also. Objective: Identification of antifungal constituents from leaf extracts of A. viridis. Methods: Different organic solvent extracts of A. viridis leaves were evaluated against 5 plant pathogenic fungal species viz. Alternaria alternata, Aspergillus flavus, Drechslera australiensis, Fusarium oxysporum and Macrophomina phaseolina. Antifungal activity of A. viridis was determined by serial dilution method. Six levels (0, 5, 10, 15, 20 and 25 mg mL-1) of treatments of each n-hexane, chloroform and ethyl acetate were employed against all fungal species in a Completely Randomised Design (CRD). Results: Generally, all organic solvent extracts reduced the fungal biomass significantly with the increase in extract concentration but ethyl acetate leaf fraction exhibited pronounced activity and reduced the fungal growth up to 44% in A. alternata, 39% in A. flavus, 48% in D. australiensis, 48% in F. oxysporum and 45% in M. phaseolina. Gas Chromatography Mass Spectrometry (GCMS) analysis of ethyl acetate leaf fraction revealed 09 compounds. Out of these 9 compounds, one compound identified as 1,2- Benzenedicarboxylic acid, mono (2-ethylhexyl) ester) showed 58.5% peak value. Conclusions: It was concluded that 1,2- Benzenedicarboxylic acid, mono (2-ethylhexyl) ester) being in the highest concentration in the ethyl acetate leaf fraction of A. viridis may be responsible for antifungal activity. This compound can serve as structural analog to develop ecofriendly fungicides.

Corrosion Inhibition Efficiency of Terminalia Catappa Leaves Extracts on Stainless Steel in Hydrochloric Acid

Corrosion inhibition potential of Terminalia catappa leaves extract was investigated using Grade 304 austenitic stainless steel in 1.0 M HCl solution with a view to finding natural, eco-friendly, low-cost and readily available corrosion inhibitor. The corrosion inhibitory characteristics of the extract were investigated by utilizing gravimetric measurements and microstructural surface changes obtained from scanning electron microscopy (SEM). This study was carried out in the absence and presence of Terminalia catappa inhibitor (0.01-0.09 g/ml) and temperatures (30-50 °C). Data obtained from weight loss experiments and adsorption isotherms (El-Awady, Temkin, and Freundlich) indicated that Terminalia catappa leaf extract repressed the corrosion of stainless steel in acidic media by 96.8 % at 30 °C and conforms to physisorption adsorption mechanism. Inhibition efficiency (% IE) of the extract improved with increasing extract concentration but declined with rising temperature.

Chemical and electrochemical studies of the inhibition performance of hydro-alcoholic extract of used coffee grounds (HECG) for the corrosion of C38 steel in 1M hydrochloric acid

The corrosion protection of C38 steel in 1M HCl solution with hydro-alcoholic used coffee grounds extract (HECG) was studied using measurements of hydrogen gas evolution, potentiodynamic polarization and electrochemical impedance spectroscopy. This work revealed that the HECG studied acts as a mixed type inhibitor. It has also been shown that the corrosion inhibition efficiency (IE) increases with increasing extract concentration, an IE value of 97.4% was reached with 2 g/L HECG. The inhibitory action of the inhibitor was mainly due to the adsorption of HECG molecules on the C38 steel surface. The studies have shown that HECG adsorbs on the C38 steel surface according to Langmuir's isotherm, with a standard free energy (ΔG0ads) of −18,477 KJ mol−1, which means that HECG delays the corrosion process by physical adsorption. The scanning electron microscope (SEM) study confirmed that corrosion inhibition of C38 steel occurs by adsorption of inhibiting molecules on the metal surface. These results show that the HECG can be used as an excellent corrosion inhibitor for C38 steel in a hydrochloric acid medium.

İnsan Kanser Hücrelerinde Astragalus elongatus subsp. nucleiferus’ un Antikanser, Antiproliferatif ve Laktat Dehidrojenaz Enzim Aktiviteleri

In this study, potential anticancer and antiproliferative activities of ethanol and water extracts from aerial parts and roots of Astragallus elongatus subsp. nucleiferus were evaluated. In this context, MTT, trypan blue, and LDH enzyme activity assays were performed to determine cytotoxicity and cell proliferation potentials of the plant extracts against human A549, H1299, C6 cancer cells, and non-tumorous HUVECs. Based on cytotoxicity against the cancer cells, the various concentrations of the extracts were selected for in vitro assays. As a result of MTT and trypan blue assays, dose-dependent anticancer and antiproliferative effects were observed on tested human lung and brain carcinoma cells. The water extracts obtained from root of the plant exerted higher anticancer activity with IC50 values ranging from 5.81±0.46 to 18.24±0.12µg/mL than the aerial parts of the extracts. Besides increasing extract concentration lead to decrease the growth rate of the cancer cells, apoptosis was observed in the tested human malignant cells. In contrary anticancer and cytotoxicity results, the ethanol extract of the root was also caused to the highest apoptosis level in a dose dependently. Regarding LDH activity, the plant extracts obtained from aerial parts and roots were demonstrated the highest LDH activity towards H1299 cells, which was followed by A549 cells. The results were found a similar activity profile as observed in MTT and trypan blue assays. These results obtained from this work showed that the roots of the plant are able to inhibit cell growth in cancer cells in a time and concentration dependently.

Phyllanthus reticulatus mediated synthesis and characterization of silver nanoparticles and its antibacterial activity against gram positive and gram negative pathogens

In this study, silver nanoparticles were successfully synthesized by using Phyllanthus reticulatus leaf extract at different concentration (5, 10, 15 mL). The prepared samples were analyzed their optical, structural, surface morphological properties, and along with these properties, the antibacterial properties were analyzed. The UV-vis absorption spectra show SPR band around 450 nm, shift to lower wavelength due to increasing extract concentration. This shift can be ascribing to a decrease in particle size. The crystallinity nature of the prepared samples is observed by the XRD profile; the calculated particles size by Scherrer’s formula displays a decrease in size with respect to leaf extract volume. From the SEM image, it can be seen that irregular and large size particles prepared at 5-10 mL and the smooth spherical shape and tiny particles were observed in the sample prepared at 15 mL. The small and spherical shape nanoparticles show good antibacterial activity against gram positive and negative bacterial pathogens. The activity of large and irregular shape particles may be due to the release of Ag+ ions and generation of ROS. Because of cell wall difference in bacteria, the better activity is observed against gram negative bacteria.

In vitro anti-Helicobacter pylori activity of aqueous extract from Persian Oak testa

ObjectiveGrowing problem of antibiotic resistance in Helicobacter pylori, as a common cause of chronic gastritis and even stomach cancer, demands searching for novel candidates of herbal sources. This study is aimed at assessing the antimicrobial activity of aqueous extract obtained from Quercus brantii var. persica seed coat (Testa) on H. pylori isolated from gastric biopsy specimens. MethodsSuch specimens were collected from 100 patients presenting with endoscopic gastroduodenal findings. Testa extracts were prepared from Persian Oak forests in the province of Kohgiluyeh and Boyer-Ahmad, IRAN. H. pylori isolates were obtained by a series of standard bacteriology tests and cell culture, then were confirmed by PCR. The activity of testa extracts towards 25 H. pylori isolates was assessed by well diffusion method, microdilution assay, and a disk diffusion assay in vitro. Results were analyzed statistically by one-way ANOVA analysis. ResultsAqueous extract of testa demonstrated an antimicrobial activity with zone diameters of inhibition ranged from 0 mm to 40 mm. Its inhibitory activity increased simultaneously with increasing extract concentration. The lowest MIC and MBC were both recorded as 2 µg/mL. Anti-H. pylori activity of testa extract was approximately close to tetracycline and metronidazole and less than amoxicillin. A potent extract of testa possessed significant inhibitory activity (P < 0.05). ConclusionTesta extract is suggested as a natural therapeutic source against the gastric H. pylori infection. However, evaluating the in vivo activity of this extract is necessary too.