Cone Extract Research Articles

Optimization of Antifungal Properties of Hop Cone Carbon Dioxide Extracts Based on Response Surface Methodology.

Response surface methodology (RSM) was employed to optimize the process parameters of the supercritical carbon dioxide extraction of hop cones in terms of their antifungal properties against Fusarium culmorum and Aspergillus niger. The effects of temperature (40-50 °C), pressure (200-300 bar), and CO2 consumption (25-75 kgCO2/kg) on the extraction yield, content of α- and β-acids, as well as pathogens' growth inhibition were investigated. Both pressure and CO2 consumption had a significant effect on antifungal properties. It was observed that the best results for antifungal properties were obtained when hop cones were extracted with pure carbon dioxide at the temperature of 50 °C, under the pressure of 300 bar with CO2 consumption at the level of 75 kgCO2/kg of feed for extraction. The highest antifungal properties of hop cone supercritical carbon dioxide extracts were analyzed as 100% for Fusarium culmorum and 68% for Aspergillus niger, calculated as the growth inhibition of tested pathogens. The aim of the study was to determine the optimum values of extraction parameters to achieve the maximum response and enable us to investigate the interaction of these parameters on the antifungal properties of hop cone extracts.

Facile green synthesis of a novel NiO and its catalytic effect on methylene blue photocatalytic reduction and sodium borohydride hydrolysis

NiO nanoparticles were synthesized from pine cone extract by green synthesis method, which is a simple, cost-effective, environmentally friendly and sustainable method. The particle size of NiO nanoparticles was determined to be in the range of 10–25 nm by X-diffraction differential and transmission electron microscope analysis, and the bandgap energy of NiO nanoparticles was determined to be 2.66 eV. The catalytic effect of NiO nanoparticles in both microwave-assisted sodium borohydride hydrolysis and photocatalytic reduction of methylene blue was examined and it was determined that they had a high catalytic effect in both applications. It was determined that the hydrogen production rate in sodium borohydride hydrolysis was 1135 mL/g/min. The activation energy of sodium borohydride hydrolysis is 29.69 kJ/mol and 29.59 kJ/mol for the nth-order and Langmuir Hinshelwood kinetic models, respectively. In the photocatalytic reduction of methylene blue with NaBH4, it was determined that the reduction did not occur in the absence of a catalyst, but in the presence of the catalyst, the reduction occurred 98% in 3 min. It was determined that NiO nanoparticles were used five times in the photocatalytic reduction of methylene blue and the reduction efficiency for the fifth time was 93%. It was determined that the photocatalytic reduction of methylene blue was pseudo-first order and the rate constant was 1.63 s−1. It was determined that NiO nanoparticles synthesized by the environmentally friendly green synthesis method can be used as catalysts for two different applications.

UV blocking edible films based on corn starch/moringa gum incorporated with pine cone extract for sustainable food packaging

Corn starch (CS) is a good alternative to synthetic polymers due to its sustainability; nevertheless, because of its weak tensile strength, the matrix requires another polymer. Therefore, 0.5 % (w/v) moringa gum (MG) was added. The purpose of this study was to assess how pine cone extract (PCE) affected the physiochemical and mechanical properties of corn starch and moringa gum (CS/MG) films and their use as UV-blocking composites. The findings suggest that the PCE improved the elongation at break from 3.27 % to 35.2 % while greatly reducing the tensile strength. The hydrogen bonding between CS/MG and PCE was visible in the FTIR spectra. The XRD graph indicated that the films were amorphous. In comparison to CS/MG films, PCE-incorporated edible films demonstrated significant UV-blocking ability indicating their potential as sustainable packaging material for light-sensitive food products.

The Use of Pine Cone Extract in the Production of Albumen Curd

Due to a lack of protein in the human diet, dairy products made from milk proteins have increased in production. The proposed new product was made from cheese whey and curds. The main ingredients were whey proteins and pine cone extract as a natural additive. The relevance of making albumen curd with vegetable extract is scientifically and experimentally justified. Based on this study, the optimal dose of pine cone extract was determined which results in imparting a distinctive taste and aroma characteristic of pine cone, improving the chemical composition, and extending the product’s shelf life.

Изучение состава фенольных соединений, антирадикальной активности и влияния на фагоцитоз сухого водного экстракта шишек сосны обыкновенной

Pine cone is a new promising type of plant raw material for using in a medical practice. Objective: determination of the phenolic compounds composition of pine cones dry aqueous extract, research of its toxicity, antiradical activity and effect on phagocytosis. Materials and methods. The research object was a collection of pine cones gathered in October 2020. A dry aqueous extract was obtained from the cones by extraction with hot water. The phenolic compounds composition of the pine cones dry aqueous extract was determined by ultra-efficient liquid chromatography/MS on a Waters Acquisition chromatograph with a diode-matrix UV detector and a tandem quadrupole MC detector TQD (Waters). To determine the antiradical activity, a reaction with a stable free radical, 2,2-diphenyl-1-picrylhydrazyl (DPPH), was used. The acute toxicity of the pine cones dry extract was researched by the V.V. Prozorovsky express method on white non-linear mice. The phagocytic activity of peripheral blood leukocytes was determined in vivo by a modified method. Results. The phenolic compounds composition of the extract was analysed. The research identified 12 substances present in the extract, representing at least 1% of the total area on the chromatogram. The following procyanidins were found in the pine cones extract: procyanidin B2, procyanidin B3, procyanidin C1, procyanidin D1. Additionally, flavonoids and phenolic carboxylic acids were identified. The pine cones dry extract demonstrated pronounced antiradical activity, comparable to that of ascorbic acid. The acute toxicity determination revealed that the LD50 of the researched compounds is in doses greater than 1260 mg/kg. Upon examination of the effect of pine cone extract on the phagocytic activity of peripheral blood leukocytes, an increase in the phagocytic index was observed, yet no change was noted in the activity of total leukocyte phagocytosis. Conclusion. The dry aqueous extract of pine cones contains biologically active components of phenolic nature, which suggests that further research into its pharmacological activity may be promising.

Antitoxic activity of spruce cone extract in acute lead acetate poisoning in experiment

Introduction. Lead contamination is continuing worldwide. The development of new effective drugs for lead poisoning is an urgent task. The aim of the work is to evaluate the effectiveness of dry aqueous extract of spruce cones in lead poisoning. Materials and methods. The experiment was carried out on 24 white mongrel rats of both sexes. Animals of the studied groups were administered aqueous solution of lead acetate. The animals of the third group were treated with the extract of cones of common spruce (extract) by intragastric administration 3 times a week for a month. Animals of the fourth group were treated with polypheman by intragastric administration 3 times a week for a month. The elemental composition of tissue samples of animals of the studied groups was determined on energy dispersive X-ray fluorescence spectrometer QUANT’X. The free radical reaction with 2,2-diphenyl-1-picrylhydrazyl was used to determine the antioxidant activity of the extract. Results. In groups of animals injected with lead acetate solution and treated with the extract and the comparison preparation polyphepan, a decrease in lead content in bones and brain tissues was observed compared to the content in animals injected with lead acetate solution without treatment. No effect of the extract on the motor function of the intestine was revealed. When determining the antiradical activity, it was found that the extract showed a pronounced ability to bind free radicals, comparable to the known antioxidant rutin. Discussion. The use of the extract allows effective excretion of lead and prevents its deposition in bone tissue. Due to the ability of procyanidins to penetrate the blood-brain barrier, the extract is effective in brain damage caused by lead. The extract will also be effective in relieving oxidative stress resulting from lead poisoning. Conclusion. The dry aqueous extract of cones of common spruce shows the ability to reduce the lead content in bones and brain tissues in comparison with the group that did not receive treatment for lead acetate poisoning. The extract is able not only to effectively reduce the lead content in the body, but also to fight the consequences of poisoning, due to its pronounced antiradical activity.

THE EFFECT OF CHITOSAN ON THE PHYSICOCHEMICAL PROPERTIES OF DERMATOLOGICAL PREPARATIONS CONTAINING HUMULUS LUPULUS L. EXTRACT BASED ON CELUGEL

This study evaluated hydrogels containing Celugel, 3% hop cone extract obtained from Humulus lupulus L. using supercritical carbon dioxide extraction substrate, and 1% and 2% chitosan for dermatological application to treat inflammatory skin conditions. The presence of chitosan significantly affected the rheological properties of the formulations, including their dynamic viscosity, hardness, consistency, cohesiveness, and blurring time. The formulations containing 2% chitosan showed the best application possibilities. The formulations were evaluated for dissolution of cohumulone, which is an analogue of humulone contained in hop cone extract. The concentration of chitosan in the formulations had a significant effect on the dissolution testing parameters of the active ingredient: as the chitosan concentration increased, the desired effect of prolonged release time of the active ingredient was achieved while maintaining the membrane-forming properties of Celugel.

Assessment of the preventive activity of Pinus brutia Ten. (Pinaceae) against in vivo acute lung injury model

Acute lung injury is a crucial inflammation-induced lung complication. Acute respiratory distress syndrome, which has a more severe course and is characterized by diffuse infiltration, develops with the progression of acute lung injury. The incidence of acute lung injury and acute respiratory distress syndrome is high and are both associated with increased mortality and morbidity rates worldwide. The leaves (needles) of Pinus brutia Ten. (Pinaceae) have been traditionally used against bronchitis and asthma. In addition, there are many Turkish folk medicine records regarding the use of its cones in respiratory system diseases such as cough, hoarseness, lung diseases, bronchitis, asthma, tuberculosis, and pneumonia. The present study aims to comparatively investigate the in vivo biological activity of the needles and cones of P. brutia against Acute Lung Injury (ALI) and to evaluate its potential use. The extracts of P. brutia needles and cones were investigated in ALI model in rats. Male Sprague Dawley rats were divided into sham control, lipopolysaccharide (LPS), reference, and six treatment groups. ALI model was induced by intraperitoneal (i.p.) LPS (5 mg/kg) injection. One hour before LPS administration, needle and cone extracts of the P. brutia at doses of 100, 200, and 400 mg/kg were given to the treatment groups. Carboxymethyl cellulose aqueous solution (0.5%) was given to the sham control group and LPS group. Dexamethasone (1.5 mg/kg) was administered to the reference group. In the 4th hour after LPS administration, inflammatory cells were counted in bronchoalveolar lavage fluid (BALF), and the levels of interleukin (IL)− 6 and − 8, and tumor necrosis factor-alpha (TNF-α) were measured by enzyme-linked immunosorbent assay (ELISA). Oxidative stress index (OSI) values and peroxiredoxin (PRDX)− 1 gene expression in lung tissues were calculated by quantitative real time polymer chain reaction (RT-PCR). Histopathological examination was performed by Hematoxylin Eosin (HE) and Masson Trichrome (MT) staining methods. In addition, the amounts of the phenolic compounds were determined by High Performance Liquid Chromatography (HPLC). Catechin hydrate and vanillic acid were determined to be higher; taxifolin was lesser in the cone extract than the needle extract. The best improvement in the macroscopic appearance of the lungs was observed in the cone extract (200 mg/kg) group compared to the other treatment groups. While the percentage of inflammatory cells in BALF was increased in the LPS group, these cells were in the lowest rate in the cone extract (200 mg/kg) group. Both needle and cone extracts decreased the levels of inflammatory cytokines. The OSI values in the treatment groups decreased compared to the LPS group. PRDX-1 levels were the highest in the LPS group, but this level dropped in the treatment groups. The inflammation of the lung tissue in the LPS group was higher than in the other groups. The recovery of inflammation was similar to both needle and cone extracts of P. brutia. These data provide evidence that 200 mg/kg of the cone extract is a potential candidate for the prevention of ALI and warrants further preclinical evaluation.

Antifungal Properties of Pinus eldarica and Pinus longifolia Fruit Extracts against Candida Species Isolated from Vulvovaginal Candidiasis Patients

Introduction:Candidiasis is a disease with serious problems in women. With the increasing drug resistance and risks of the drugs, we investigated the effect of different cone extracts of Pinus eldarica and Pinus longifolia against Candida species isolated from vulvovaginal candidiasis patients.Materials and Methods::Candida species isolated from 50 patients were identified by routine mycological methods, including morphology of corn mil agar, chromium agar, germination, and biochemical methods. The anti-candida properties of the extracts and essential oils of Pinus eldarica and Pinus longifolia were investigated using agar diffusion and microdilution test. The essential oil was then analyzed by Gas chromatography-mass spectrometry (GC-MS).Results:The major constituents of Pinus longifolia essential oil included 23.16% alpha-pinene, 2.59% beta-caryophyllene, 23.61% delta-3-carene, 0.24% carcin-4-hydroxy, 13.56% m-cymene, 0.45% alpha-humulene, and 2.12% junipene. The major constituents of Pinus eldarica essential oil included 29.13% alpha-pinene, 14.22% beta-caryophyllene, 11.70% delta-3-carene, -14.22% carcin-4-hydroxy, 4.29% beta-pinene, 3.59%, alpha humulene, and 8.86% junipene. The results of antifungal tests showed that aqueous, ethanolic, and methanolic extracts had a weak anti-candida effect. By changing the solvent and using petroleum ether solvent, it was found that petroleum ether extract and cone essential oil of Pinus longifolia and Pinus eldarica exhibited a relatively strong anti-candida effect.Discussion and Conclusion:Comparison of Minimum Inhibitory Concentration (MIC) and Minimum Fungicidal Concentration (MFC) of four extracts of Pinus longifolia and Pinus eldarica against different Candida showed that the lowest MIC and MFC were related to essential oil, petroleum ether extract, methanolic extract, ethanolic extract, and aqueous extract, respectively.

Antifungal Activity of Hop Leaf Extracts and Xanthohumol on Two Strains of Venturia inaequalis with Different Sensitivities to Triazoles.

Hop cones are well-known for their antimicrobial properties, attributed to their specialized metabolites. Thus, this study aimed to determine the in vitro antifungal activity of different hop parts, including by-products such as leaves and stems, and some metabolites against Venturia inaequalis, the causal agent of apple scab. For each plant part, two types of extracts, a crude hydro-ethanolic extract and a dichloromethane sub-extract, were tested on spore germination of two strains with different sensitivities to triazole fungicides. Both extracts of cones, leaves and stems were able to inhibit the two strains, whereas rhizomes did not show activity. The apolar sub-extract of leaves appeared as the most active modality tested with half maximal inhibitory concentrations (IC50) of 5 and 10.5 mg·L-1 on the sensitive strain and the strain with reduced sensitivity, respectively. Differences in activity level between strains were noticed for all active modalities tested. Sub-extracts of leaves were then separated into seven fractions by preparative HPLC and tested on V. inaequalis. One fraction, containing xanthohumol, was especially active on both strains. This prenylated chalcone was then purified by preparative HPLC and showed significant activity against both strains, with IC50 of 1.6 and 5.1 mg·L-1. Therefore, xanthohumol seems to be a promising compound to control V. inaequalis.

COMPARISON OF SOME BIOLOGICAL ACTIVITIES AND CATECHIN TANNIN CONTENTS OF TWO JUNIPERUS AND PRUNUS SPECIES

Objective: Qualitative and quantitative determination of catechin in fruits of J. communis var. saxatilis, J. oxycedrus subsp. oxycedrus, P. spinosa, and P. cerasifera was analyzed by LC-MS/MS using standards. Antidiabetic, antimicrobial, and antioxidant activities of fruit and cone extracts of these plants were evaluated. Qualitative analysis of secondary metabolites was also done. Material and Method: Antimicrobial activity was done with MIC. ABTS·+ and DPPH• scavenging activies were used antioxidant activity. α-Amylase and α-glucosidase inhibition assays were done for antidiabetic activity. Result and Discussion: JCS (IC50 = 578 ± 20 μg/ml), JOO (IC50 = 3706 ± 52 μg/ml), and PS (IC50 = 313 ± 7 μg/ml) extracts were observed to show a higher activity than acarbose (IC50 = 4061 ± 146 μg/ml). J. communis var. saxatilis fruit extract was observed with MIC values between (312.5 -2500 µg/ml) against all microorganisms. JCS extract has the highest phenolic composition and JOO has the lowest phenolic composition (µg GAE/ mg extract). JCS extract indicated the highest antioxidant activity. It was determined that plant containing the highest catechin (1173.3±5.77 ng/ml) and epigallocatechin (208±7.21 ng/ml) was JCS. In this research, it can be said that JCS with the highest tannin content shows the highest effects.

Element composition of extracts of common spruce cones

Trace elements are an integral part of any plant and animal organism.The pharmacological effect of herbal raw materials is due not only to the main active substance, but also to the chemical elements that make up herbal medicinal preparations. Previously, studies were carried out on the wood composition, as well as the polysaccharide complex from spruce cones [1], [2]. The object of this study are common spruce cones harvested on the territory of the Ilyinsky district, Perm Region. The determination of the qualitative and quantitative composition of elements in extracts of common spruce cones was carried out on the X-ray fluorescence QUANT’X spectrometer from Thermo Scientific. The results obtained by the authors demonstrate the content of microelements and ultramicroelements of a fractional extract from the raw material of the studied plant.

Hop (Humulus lupulus L.) Specialized Metabolites: Extraction, Purification, Characterization in Different Plant Parts and In Vitro Evaluation of Anti-Oomycete Activities against Phytophthora infestans

Botanicals represent a promising source of metabolites in the search for new biofungicides. In this context, this study aimed at evaluating the in vitro anti-oomycete activity of hop (Humulus lupulus L.) extracts and metabolites against Phytophthora infestans, an oomycete causing late blight disease in Solanaceae. Crude hydro-ethanolic extracts and dichloromethane sub-extracts of different parts (cones, leaves, stems and rhizomes) were characterized by UHPLC-UV–MS and some cone specialized metabolites were purified by CPC and preparative HPLC. A commercial hop cone essential oil was also analyzed by GC–MS. All extracts succeeded in inhibiting mycelial growth and spore germination with morphological alteration of the mycelium. Extracts of leaves showed a significant anti-oomycete activity compared to the extracts of cones, stems, and rhizomes. Moreover, no difference was noticed between the crude hydro-ethanolic extract and the dichloromethane sub-extract activity, except for leaves, with the apolar sub-extract being more active than the crude one. The extracts of cones succeeded in inhibiting more P. infestans than the essential oil, which appeared to be the less active evaluated modality. Some purified prenylated phenolic compounds also inhibited P. infestans although copper sulfate, a mineral fungicide control, was still more active. This study highlights the potential use of hop by-products as biofungicides to manage P. infestans.

Cones of Coniferous Taxa as a Potential Source of Bioactive Polyphenols

Background: Coniferous cones are a by-product of forestry and wood logging, used for many possible purposes, e.g., the extraction of polyphenols. Objective: The aim of the present article was the comparison of the antioxidant polyphenol content of the differently matured cones of 17 selected conifers, either common in Hungary or yet uninvestigated. Methods: Total polyphenol content, ferric reducing antioxidant power and 2,2-diphenyl-1-picrylhydrazyl assays were used to determine the antioxidant contents. A scoring system was implemented using the three assay results to evaluate and compare the overall antioxidant power of the samples. Result and Conclusion: Highest antioxidant contents were found in green cones, followed by mature and opened cones. Taxa with the highest scores were Tsuga canadensis, Cryptomeria japonica, Chamaecyparis lawsoniana, Thuja orientalis, Metasequoia glyptostroboides and Picea abies. For the samples with the highest overall antioxidant power the high-performance liquid chromatographic/ tandem mass spectrometric polyphenol profiling was carried out (green cones of T. canadensis and P. abies) and 83 compounds have been tentatively identified and described. Results contribute to the future bioactivity testing and evaluation of the cone extracts of T. canadensis and P. abies.

Antioxidant and Antibacterial Activities of Methanol Extracts from Various Plant Parts of Pomegranate and Anatolian Black Pine

Oxidative stress and bacterial infections threaten human and animal health. Different parts of the plants have a great potential to be used as a source of antioxidant and antibacterial agents for human or animal welfare, because of their active metabolites. This study was conducted to assess the antioxidant and antibacterial activities of methanolic extracts from the leaves, flowers, whole fruits, and woods of pomegranate (Punica granatum L.), and the leaves, cones, and woods of Anatolian black pine [Pinus nigra Arn. subsp. pallasiana (Lamb.) Holmboe]. Antioxidant activity was screened by DPPH and CUPRAC assays. Antimicrobial activity was examined by disc diffusion test against fish pathogens, Aeromonas hydrophila, Vibrio anguillarum, Yersinia ruckeri and Lactococcus garvieae.
 Pomegranate whole fruit extract possessed superior antioxidant activity even higher than ascorbic acid. All parts of pomegranate, except wood, also exhibited significant antibacterial activity against fish pathogens. Black pine cone extract slightly inhibited the growth of fish pathogens while other pine extracts were inactive. This study reveals that the whole fruit of pomegranate is a prominent source of antioxidant and antibacterial metabolites. Cones of Anatolian black pine also seem to be a source of antibacterial compounds against fish pathogens.

Polyphenol contents and free radical scavenging activity of Pinus merkusii cone

This study aimed to investigate the polyphenol contents from the Pinus merkusii cone extract and their antioxidant activity. The cone powder (40 mesh) was extracted with n-hexane, ethyl acetate, and methanol successively for six hours. The cone of n-hexane, ethyl acetate, and methanol soluble extracts was subjected to total tannin content, total phenol content, total flavonoid content, and antioxidant measurements. The polyphenol contents were measured through the colorimetric method, while antioxidant activity was observed by inhibition of the DPPH (1,1-diphenyl-2-picrylhydrazyl) method. The results showed that total tannin content, total phenol content, total flavonoid content, and antioxidant activity of methanol soluble extract was higher than ethyl acetate and n-hexane soluble extracts. In this study, the high antioxidant activity of methanol soluble extract (IC50 of 196.73±13.93 ppm) might due to the high concentration of total phenol content (545.38±54.07 mg GAE/g sample). It was suggested that the P. merkusii cone is potential as the antioxidant source.

Characteristics of the Polyphenolic Profile and Antioxidant Activity of Cone Extracts from Conifers Determined Using Electrochemical and Spectrophotometric Methods.

The aim of the study was to analyze the polyphenolic profile of cone extracts of Douglas fir, Scots pine and Korean fir, and to study their antioxidant activity. The mechanism of electro-oxidation of polyphenols (such as procyanidins and catechins) from cone extracts was investigated using cyclic voltammetry (CV) and differential pulse voltammetry (DPV), as well as spectrophotometric methods—ABTS (2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonate)), DPPH (2,2-diphenyl-1-picrylhydrazyl), FRAP (Ferric Reducing Antioxidant Power ) and CUPRAC (CUPric Reducing Antioxidant Capacity). The scientific novelty of the research is the comprehensive analysis of cone extracts in terms of antioxidant properties. Due to the high polyphenol content, the extracts showed significant ability to reduce oxidative reactions, as well as the ability to scavenge free radicals and transition metal ions. Douglas fir, Scots pine and Korean fir cone extracts can potentially be used as natural stabilizers, preservatives and antimicrobial substances in the food industry and in medications.

Humulus lupulus Cone Extract Efficacy in Alginate-Based Edible Coatings on the Quality and Nutraceutical Traits of Fresh-Cut Kiwifruit.

In this work, an innovative coating strategy that is able to prolong the shelf-life of fresh-cut kiwifruit was proposed, and the effectiveness of the procedure was evaluated for a period of ten days under cold storage (4 °C). Alginate (2% m/v) functionalized with green extracts from hop (Humulus lupulus L.) cones (HE; 0.5 and 1%, v/v) was used as a coating material in order to assess the best performing strategy, leading to the most stable product. At the concentrations used to formulate the edible coatings, no contribution related to hop bitterness on the final product was recorded. The results were compared to control samples (without edible coating and coated only with alginate at 2% m/v). The plant extract was characterized by its main chemical traits and by 1H NMR profiling, revealing the presence of antioxidant and antimicrobial bioactive compounds (i.e., alpha and beta hop acids, xanthohumol). Furthermore, the characteristics of the samples during cold storage were evaluated by physico-chemical (i.e., weight loss, soluble solid content, titratable acidity, pH, color attributes) and nutraceutical (i.e., total polyphenol, ascorbic acid content, total carotenoids, chlorophylls) traits. The results showed that the incorporation of hop extracts into the edible coatings tested was able to preserve the quality and nutraceutical traits of fresh-cut kiwifruit during cold storage, thus prolonging their shelf life and marketability.

Phytochemical Study, HPLC Chromatographic Analysis and Antioxidant Activity of Ephedra alata DC. Female Cones Extracts

The aim of this work is a phytochemical study, antioxidant activity and Chromatographic Analysis by HPLC of extracts of the female cones of Ephedra alata DC. Which grows in Oued Souf region (South East of Algeria). According to the results obtained from the estimation of polyphenols and flavonoids content, the methanolic extract has the best content of polyphenols (158.34±2.71mg GAE/g Extract), and the best values of flavonoids (88.50±1.12mg QE/g Extract). The chromatographic analysis by HPLC has identified eight phenolic compounds, which are Gallic Acid, Chlorogenic acid, Vanillic Acid, Vanillin, p-Coumaric acid, Rutin, Naringenin and Quercitin. The antioxidant activity was evaluated by three tests: DPPH• free-radical scavenging, Hemolysis and Reducing power, the results of test scavenging the free-radical DPPH• show the tannins extract had the best scavenging activity capacity than the other extracts (IC50: 14.94±1.34μg/mL), But, in the hemolysis test, all the extracts were proximity except for the aqueous extract that was shown protected of the erythrocytes (50±0.5% of hemolysis percentage). Finally, in the reducing power assay, its results showed that the tannins extract has a best reducing power 27.16±0.25μg/mL in Abs700= 0.5 compared to other extracts.

Bioactivity of Wild Hop Extracts against the Granary Weevil, Sitophilus granarius (L.).

Simple SummaryOne of the outstanding problems in pest control is the extensive use of synthetic compounds characterized by concerns such as risks to non-target organisms, slow degradation, and development of resistance. For these reasons, the interest in more ecofriendly pesticides, such as botanicals, is progressively increased in the last two decades. In this regard, having recently found that essential oil obtained by wild hop has biological activity against Sitophilus granarius, here we checked whether and how three different crude extracts obtained by the same hop ecotype also presented toxicity (contact, ingestion, inhalation) and/or repellent activity against the same insect, which is one of the most damaging pests of stored products. Results reposted here clearly show that, in addition to the essential oil, hop crude extracts (methanol, acetone, and n-hexane) preserve interesting activities against pests. Moreover, since they can be easily obtained and produce high yields, hop crude extracts could represent a valid tool for S. granarius control.The use of bioinsecticides, rather than synthetic compounds, appears a goal to be pursued in pest control, especially for species such as Sitophilus granarius (L.) which attack stored products. Since Humulus lupulus (L.) is a remarkable source of bioactive compounds, this study investigated the bioactivity of hop flower extracts against S. granarius adults by evaluating toxic (contact, inhalation, and ingestion), repellent, antifeedant, and nutritional effects as well as their anticholinesterase activity and olfactory sensitivity. Hop extracts were obtained by soaking dried and ground hop cones in solvents of decreasing polarity: methanol, acetone, and n-hexane. Dried crude extracts were resuspended in each solvent, and used in topical application, ingestion, and fumigation toxicity assays, as well as in contact and short-range repellency tests, in vitro anticholinesterase activity evaluation, and electroantennographic tests. No inhalation toxicity for the extracts was found. On the contrary, all extracts showed adult contact toxicity 24 h after treatment (LD50/LD90 16.17/33.20, 25.77/42.64, and 31.07/49.48 µg/adult for acetone, n-hexane, and methanol extracts, respectively); negligible variations for these values at 48 h were found. The anticholinesterase activity shown by all extracts suggested that the inhibition of this enzyme was one of the mechanisms of action. Interestingly, flour disk bioassays revealed a significant ingestion toxicity for the acetone extract and a lower toxicity for the other two extracts. Moreover, all extracts affected insect nutritional parameters, at the highest dose checked. Filter paper and two-choice pitfall bioassays showed repellent activity and a strong reduction of insect orientation to a highly attractive food odor source, with minor differences among extracts, respectively. Finally, the presence of volatile compounds in the different extracts that are perceived by insect antennae was confirmed by electroantennography. All these findings strongly suggest a possible use of hop cone extracts against S. granarius, thus further confirming this plant as an interesting species for pest control.