Effects Of Grapefruit Seed Extract Research Articles

Fungicidal activity of grapefruit seed extract against the pathogenic Candida species causing oral candidiasis

This study aimed to evaluate the antifungal activity of grapefruit seed extract (GSE) against Candida species and to confirm the biological safety. Two-fold serial dilutions of GSE or miconazole were prepared. Cell suspensions of Candida albicans, Candida glabrata, Candida tropicalis, or Candida parapsilosis were added to each diluted solution, and the minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) were determined. The MFC/MIC ratio was calculated to determine whether the substance had a fungistatic or fungicidal activity. Each Candida species treated with GSE were examined using a scanning electron microscope (SEM) and fluorescence microscopy. The effect of GSE on EpiOral™, a three-dimensional tissue model, was assessed by tissue viability assay and histological analysis. GSE was applied to the mandibular gingiva of Japanese white rabbits, and the gingival tissues were histopathologically assessed. GSE demonstrated a fungicidal effect against all tested Candida species, whereas miconazole demonstrated a fungicidal effect against only C. albicans. SEM images showed various cell damage patterns in GSE-treated Candida cells. Fluorescence microscopy revealed that almost all Candida cells were killed by GSE-treated. EpiOral™ treated with GSE showed no effect on the tissue viability and there was no remarkable difference between GSE and control groups in the histological analysis. The histopathological observation in the oral mucosa treated with GSE showed no significant histopathological changes. Taken together, GSE has a fungicidal activity against C. albicans, C. glabrata, C. tropicalis, and C. parapsilosis, and no adverse effects were observed in vitro and in vivo.

Functionalization of cellulose-based nanocomposite hydrogel films with zinc oxide complex and grapefruit seed extract for potential applications in treating chronic wounds

In this study, the influence of grapefruit seed extract (GFSE) was studied on citric acid and zinc oxide incorporated cellulose-based hydrogel films. The effect of GFSE (0.25–1.0%, v/v) on hydrogel films was examined for their physico-chemical, mechanical, thermal, antioxidant and antibacterial properties. The swelling ratio, tensile strength and thermal stability of films decreased with increase in GFSE concentrations. On the other hand, elongation (%) and antioxidant activity of films were found to be 34–60% and 25–79%, respectively for increasing amounts of GFSE. FESEM and FETEM clearly showed that two different types of nanoparticles (50–90 nm and 5–10 nm) were present in GFSE incorporated films. The release of polyphenolic compounds and zinc from films was in sustained manner. Furthermore, the fabricated hydrogel films exhibited antibacterial activity against both E. coli and S. aureus. All these results indicate that the prepared nanocomposite hydrogel films could find their potential applications in wound healing.

Anti-Biofilm Activity of Grapefruit Seed Extract against Staphylococcus aureus and Escherichia coli.

Grapefruit seed extract (GSE) is a safe and effective preservative that is used widely in the food industry. However, there are few studies addressing the anti-biofilm effect of GSE. In this study, the anti-biofilm effect of GSE was investigated against biofilm-forming strains of Staphylococcus aureus and Escherichia coli. The GSE minimum inhibitory concentration (MIC) for S. aureus and E. coli were 25 μg/ml and 250 μg/ml, respectively. To investigate biofilm inhibition and degradation effect, crystal violet assay and stainless steel were used. Biofilm formation rates of four strains (S. aureus 7, S. aureus 8, E. coli ATCC 25922, and E. coli O157:H4 FRIK 125) were 55.8%, 70.2%, 55.4%, and 20.6% at 1/2 × MIC of GSE, respectively. The degradation effect of GSE on biofilms attached to stainless steel coupons was observed (≥ 1 log CFU/coupon) after exposure to concentrations above the MIC for all strains and 1/2 × MIC for S. aureus 7. In addition, the specific mechanisms of this anti-biofilm effect were investigated by evaluating hydrophobicity, auto-aggregation, exopolysaccharide (EPS) production rate, and motility. Significant changes in EPS production rate and motility were observed in both S. aureus and E. coli in the presence of GSE, while changes in hydrophobicity were observed only in E. coli. No relationship was seen between auto-aggregation and biofilm formation. Therefore, our results suggest that GSE might be used as an anti-biofilm agent that is effective against S. aureus and E. coli.

Preparation of antibacterial poly(lactide)/poly(butylene adipate-co-terephthalate) composite films incorporated with grapefruit seed extract

Antimicrobial poly(lactide) (PLA)/poly(butylene adipate-co-terephthalate) (PBAT) blend films incorporated with grapefruit seed extract (GSE) were prepared using a solvent casting method. Effect of GSE on the morphological, water vapor barrier, thermostability, color, optical, and antimicrobial properties of PLA/PBAT composite films was investigated. The composite films showed a yellowish tint after incorporation of GSE and exhibited a high UV-light barrier property. Incorporation of GSE increased the flexibility and tensile strength of the composite films. Films incorporated with 7 wt% of GSE exhibited potent antibacterial activity against Listeria monocytogenes, but they showed only bacteriostatic activity against Escherichia coli. The PLA/PBAT-GSE composite film with UV-light barrier and antibacterial properties has a high potential for an active food packaging application.

Combined effects of thymol, carvacrol and grapefruit seed extract on lipid oxidation and colour stability of poultry meat preparations

SummaryThe combined effects of thymol, carvacrol and grapefruit seed extract (GFSE) on lipid oxidation and colour stability of poultry meat preparations packaged in air or modified atmospheres (MAP: 5% O2; 30% CO2; 65% N2) were investigated using a simplex centroid mixture design. Lipid oxidation was evaluated through measurement of secondary oxidation products (malonaldehyde, MDA) and general appearance with visual assessment and instrumental measurement of colour. Thymol and carvacrol, as individual antioxidants, retarded the oxidation process by maintaining MDA values below 2 mg kg−1 meat. The effect of GFSE was less than thymol and carvacrol. Redness (a*) decreased in all treatments during storage but this reduction was more evident in the control and in samples containing GFSE than in thymol and carvacrol. Although colour acceptability decreased with time, all meat preparations packaged in air maintained desirable appearance better than samples in MAP. Also, off‐odours developed faster in the samples packaged in MAP than in aerobically packaged samples.

구강질환 원인균에 대한 자몽종자추출물과 법제유황수 함유 치약시제품의 향균효과

구강질환 원인균에 대한 자몽종자추출물(GSE)과 법제유황수(PSS)의 항균활성을 확인하기 위해, 평판배지확산법 및 액체감수성실험법으로 Streptococcus mutans, Prevotella intermedia, Porphyromonas gingivalis 및 Candida albicans에 대한 항균활성을 측정하였다. 평판배지확산법의 경우, GSS의 농도가 40 <TEX>${\mu}l$</TEX>/disk일 때, S. mutans, P. intermedia, P. gingivalis 및 C. albicans에 대한 항균활성은 각각 11.0, 9.5, 8.0, 9.0 mm로 나타났으며, PSS의 농도가 40 <TEX>${\mu}l$</TEX>/disk일 때에는 각각 2.0, 3.5, 0.0, 1.5 mm로 나타났다. 또한 액체배지감수성실험에서 GSE에 대한 MIC 값은 0.24, 0.06, 0.10, 15.63 <TEX>${\mu}l$</TEX>/ml 이었으며, PSS 에 대한 MIC 값은 각각 0.12, 3.91, >125, 7.81 <TEX>${\mu}l$</TEX>/ml이었다. 치약 시제품의 항균효과를 확인하기 위해, GSE와 PSS가 농도별로 함유된 치약시제품 원액과 2배 및 4배 희석액을 제조하여 평판배지확산법을 수행한 결과, 0.5% 치약 시제품의 2배 희석액에서 각각 7.3, 4.3, 2.2 그리고 1.5 mm로 나타났다. 치약 시제품의 물리 화학적 특성을 확인한 결과, pH, 점도, 굴절 및 색도 변화에 있어서 모두 안정성을 보였고, 이상의 결과를 바탕으로 기능성 치약과 같은 구강질환 예방 및 치료제 개발 가능성을 확인하였다. The aim of this study was to assess the effects of dentifrice-contatning grapefruit seed extract (GSE) and processed sulfur solution (PSS) on antimicrobial effects against oral pathogens. We first evaluated the antimicrobial effects of GSE and PSS against oral microbes: Streptococcus mutans (Sm), Prevotella intermedia (Pi), Porphyromonas gingivalis (Pg) and Candida albicans (Ca). When antimicrobial activity against Sm, Pi, Pg and Ca was tested, at 40 <TEX>$\mu$</TEX>l/disk, the inhibition zones of GSE were 11.0, 9.5, 8.0 and 9.0 mm, respectively. With the same method, the inhibition zones of PSS were 2.0, 3.5, 0.0 and 1.5 mm, respectively. In the micro broth dilution method, the MIC values of GSE against Sm, Pi, Pg and Ca were 0.24, 0.06, 0.10 and 15.63 <TEX>$\mu$</TEX>l/rnl, respectively. The MIC values of PSS were 0.12, 3.91,>125 and 7.81 <TEX>$\mu$</TEX>l/ml, respectively. When pH, refractive index, viscosity and color value of dentifrice-containing GSE and PSS were measured, there were no significant changes in these physical properties compared to the control samples. Antimicrobial activities of dentifrice products containing 0.5% GSE and 0.5% PSS against oral pathogens were 7.3, 4.3, 2.2 and 1.5 mm, respectively. According to these results, we conclude that there may be a role for GSE and PSS in the development of new oral supplies.

Grapefruit Seed Extract is a Powerful in vitro Agent Against Motile and Cystic Forms of Borrelia burgdorferi sensu lato

Lyme borreliosis [1], caused by Borrelia burgdorferi sensu lato, may lead to long-term tissue infection, which may be difficult to cure. The outcome of Lyme borreliosis is highly dependent on the antibiotic treatment [2]. The observation of the ability of B. burgdorferi sensu lato to convert (and reconvert) to cystic forms [3–5] may explain why the infection sometimes is persistent and reactivating. Therefore, it might be important to eradicate all germative forms (not only the motile form) of the bacterium to obtain a proper treatment for Lyme borreliosis. Grapefruit-seed extract (GSE) contains bioactive flavenoids (e.g., hesperitin, resveratrol, and naringenin) and has been shown to possess anti-microbiological effect against bacteria and fungus [6, 7]. Many studies indicate that GSE is a substance whose therapeutic effect ranks equal to or better than other known anti-bacterial agents. Positive effects of GSE are decreased levels of TNF-α, Nuclear factor Kb, NO, protection of the gastrointestinal tract against mechanical stress, and has anti-allergic and other antioxidative properties [8, 9]. Naringenin, hesperidin and other citrus flavones have been found in plasma and tissue after ingestion [10]. Lactobacillus and bifidobacteria in the gut seems to be insignificantly affected by GSE [6], and no severe side effects have been observed. B. burgdorferi sensu lato has a gene for efflux mechanism which may be responsible for antibiotic resistance [11]. GSE is an efflux inhibitor, which can be used to enhance the activity of antibacterial agents [12]. For the reasons mentioned above it is reasonable to test the hypothesis that motile and cystic forms of B. burgdorferi sensu lato will be susceptible to GSE, and this is the aim of our study.

Antibacterial effect of Grapefruit Seed Extract on food-borne pathogens and its application in the preservation of minimally processed vegetables

The application of Grapefruit Seed Extract (GSE) as a sanitizer for reducing the populations of human bacterial pathogens on whole and fresh-cut green vegetables was investigated. Cucumber and lettuce were selected as model green vegetables, and six bacteria strains, including three strains of Salmonella spp. and three strains of Listeria monocytogenes, were selected in our study in order to determine the antibacterial effects of sanitizers. The survival and growth of total aerobes, Salmonella spp ., and L. monocytogenes on whole and fresh-cut cucumber and lettuce during storage (10 and 4 °C) were analyzed by using a classical microbiological enumeration. The antibacterial effects of GSE alone and GSE in combination with nisin and citric acid (Mixture agent II) were significant ( P < 0.05). Treatments with sodium lactate and potassium sorbate (Mixture agent I) were also tested as chemically synthesized agents. Sensory quality was evaluated, and there was no significant difference between GSE and Mixture agent II treatments during storage in terms of organoleptic and visual properties. Our results suggest that GSE could inhibit bacteria significantly ( P < 0.05) and prolong the preservation time; GSE might be applied as an effective and safe preservative for ready-to-eat cucumber and lettuce.

Grapefruit-seed extract attenuates ethanol-and stress-induced gastric lesionsviaactivation of prostaglandin, nitric oxide and sensory nerve pathways

Grapefruit-seed extract (GSE) containing flavonoids, possesses antibacterial and antioxidative properties but whether it influences the gastric defense mechanism and gastroprotection against ethanol- and stress-induced gastric lesions remains unknown. We compared the effects of GSE on gastric mucosal lesions induced in rats by topical application of 100% ethanol or 3.5 h of water immersion and restraint stress (WRS) with or without (A) inhibition of cyclooxygenase (COX)-1 activity by indomethacin and rofecoxib, the selective COX-2 inhibitor, (B) suppression of NO-synthase with L-NNA (20 mg/kg ip), and (C) inactivation by capsaicin (125 mg/kg sc) of sensory nerves with or without intragastric (ig) pretreatment with GSE applied 30 min prior to ethanol or WRS. One hour after ethanol and 3.5 h after the end of WRS, the number and area of gastric lesions were measured by planimetry, the gastric blood flow (GBF) was assessed by H2-gas clearance technique and plasma gastrin levels and the gastric mucosal generation of PGE2, superoxide dismutase (SOD) activity and malonyldialdehyde (MDA) concentration, as an index of lipid peroxidation were determined. Ethanol and WRS caused gastric lesions accompanied by the significant fall in the GBF and SOD activity and the rise in the mucosal MDA content. Pretreatment with GSE (8-64 mg/kg i g) dose-dependently attenuated gastric lesions induced by 100% ethanol and WRS; the dose reducing these lesions by 50% (ID50) was 25 and 36 mg/kg, respectively, and this protective effect was similar to that obtained with methyl PGE2 analog (5 microg/kg i g). GSE significantly raised the GBF, mucosal generation of PGE2, SOD activity and plasma gastrin levels while attenuating MDA content. Inhibition of PGE2 generation with indomethacin or rofecoxib and suppression of NO synthase by L-NNA or capsaicin denervation reversed the GSE-induced protection and the accompanying hyperemia. Co-treatment of exogenous calcitonine gene-related peptide (CGRP) with GSE restored the protection and accompanying hyperemic effects of GSE in rats with capsaicin denervation. GSE exerts a potent gastroprotective activity against ethanol and WRS-induced gastric lesions via an increase in endogenous PG generation, suppression of lipid peroxidation and hyperemia possibly mediated by NO and CGRP released from sensory nerves.