Grapefruit Peel Extract Research Articles

Integration of covalent organic frameworks and molecularly imprinted polymers for selective extraction of flavonoid naringenin from grapefruit (Citrus × paradisi Macf.) peels

Grapefruit (Citrus × paradisi Macf.) peel, a by-product of the citrus-processing industry, possesses an important economic value due to the richness of bioactive compounds. In this study, boron-linked covalent organic frameworks integrated with molecularly imprinted polymers (CMIPs) were developed via a facile one-pot bulk polymerization approach for the selective extraction of naringenin from grapefruit peel extract. The obtained CMIPs possessed a three-dimensional network structure with uniform pore size distribution, large surface areas (476 m2/g), and high crystallinity. Benefiting from the hybrid functional monomer APTES-MAA, the acylamino group can coordinate with the boronate ligands of the boroxine-based framework to form B-N bands, facilitating the integration of imprinted cavities with the aromatic skeleton. The composite materials exhibited a high adsorption capacity of 153.65 mg/g, and a short adsorption equilibrium time of 30 min for naringenin, together with favorable selectivity towards other flavonoid analogues. Additionally, the CMIPs captured the template molecules through π–π* interaction and hydrogen bonding, as verified by FT-IR and XPS. Furthermore, they had good performance when employed to enrich naringenin in grapefruit peels extract compared with the common adsorbent materials including AB-8, D101, cationic exchange resin, and active carbon. This research highlights the potential of CMIPs composite materials as a promising alternative adsorbent for naringenin extraction from grapefruit peel.

Development of multifunctional bioactive food packaging based on silver nanoparticles/grape fruit peel extract reinforced PVA composites

Active food packaging based on bio-wastes has gained considerable attention these days due to their ecofriendly and biodegradable behavior. In this study, multifunctional bio-composite films with remarkable anti-oxidant and anti-microbial attributes were synthesized by incorporating biosynthesized silver nanoparticles (AgNPs) and grape fruit peel extract (GFPE) into polyvinyl alcohol (PVA) matrix. Synthesized films were characterized in terms of Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Scanning electron microscopy (SEM), Differential scanning calorimetry (DSC) and Dynamic Mechanical Analyzer (DMA). Antioxidant activity of AgNPs-GFPE/PVA films was determined by %DPPH scavenging ability and Ferric reducing antioxidant power assay while antimicrobial activity was measured by agar diffusion method. XRD analysis revealed the semi-crystalline behavior of synthesized composites with characteristics peak at 38° whereas SEM micrographs confirmed the homogeneous dispersion of reinforcement and porous rough surface structure of AgNPs-GFPE/PVA nano-composites. AgNPs-GFPE/PVA nanocomposite exhibited glass transition temperature (Tg) at ∼116 °C and Tm ∼191 °C along with the storage modulus of 685 MPa, revealing significantly enhanced thermal and mechanical stability of composites compared to pure PVA films. The composite films exhibited remarkable antioxidant potential i.e DPPH scavenging activity ∼50 % and reducing power ∼ 0.58. The AgNPs-GFPE/PVA nano-composite films exhibited remarkable antimicrobial activity in response to food borne pathogens. The results designated that the synthesized composite films have prodigious potential of being cheap, eco-friendlier substitute to conventional materials for application in food packaging, which certify the safety and economical life span of packed food.

Examining the Naringin Content and Sensory Characteristics of Functional Chocolate Fortified with Grapefruit Peel Extract

Grapefruit peel contains a high concentration of naringin- a potent antioxidant with strong bioactive properties. In this study, a new type of functional chocolate fortified with grapefruit peel extract and different concentrations of aqueous methanol and ethanol were evaluated as extraction solvents. A new high-performance liquid chromatography (HPLC) method to analyze the naringin content of the fortified chocolates was developed with a recovery of 107% ± 3.1% and repeatability below 3.5%. A sensory evaluation was conducted to assess the preference for the chocolates among individuals who self-described a preference for bitter flavors. No significant preference was observed in the cases of astringency and aftertaste while the increased bitterness proved to be favorable. However, taste, flavor and overall acceptability were regarded somewhat less favorably. While chocolate proved to be a satisfactory carrier for naringin and had several enjoyable characteristics, further research may focus on improving the organoleptic properties of chocolates fortified by naringin.

Effect of ecofriendly grapefruit peel extract on PVC thin films photostabilizing tested under harmful weathering conditions

AbstractExposure to ultraviolet radiation triggers a photooxidative deterioration mechanism in plastics, resulting in bond breakage, release of volatile substances, overall weight reduction, generation of free radicals, and loose crosslinking. The aim of this study was to obtain a plant extract with appropriate concentration and use it to protect polyvinyl chloride (PVC) from photodegradation. PVC films containing different concentrations of naringin that were already extracted and TINUVIN 622 as a commercial stabilizer were investigated in this paper. UV light was used to irradiate PVC films for 300 h to test the photostability. After radiation, infrared spectra, weight loss, molecular weight reduction, and surface morphology examination for PVC films were studied. In comparison to blank film, the photodegradation of PVC films was significantly reduced by the naringin and TINUVIN 622 photostabilizers. The role of photostabilizers includes deactivating excited states (as quenchers), functioning as effective light filters (pigments and absorbers), scavenging radicals, and decomposing hydroperoxides.

Grapefruit peel extract mitigates paroxetine-induced erectile dysfunction in rats through stimulation of erectile response, antioxidant status, and inhibition of key enzymes related with impaired penile erection.

Despite the antidepressant potency of paroxetine, its side effect of erectile dysfunction is burdensome. Grapefruit peels (GFPs) are underutilized cultivar wastes with wide range of therapeutic potentials which have been attributed to their antioxidant behavior and phenolic contents' abilities to effectively inhibit enzymatic activities and manage endothelial dysfunction in cardiovascular disorders. This study aims to investigate the erectogenic potentials of GFP extract in a rat model of paroxetine-induced ED. Experimental rats were sectioned into five groups: [1: control; 2: paroxetine (10mg/kg); 3: paroxetine + sildenafil (5mg/kg); 4: paroxetine + GFP (50 mg/kg); 5: paroxetine + GFP (100 mg/kg)] and treated for 28 days. Sexual behavior of rats was assessed and effect of GFP on ecto-5' nucleotidases, phosphodiesterase-5, and adenosine deaminase (ADA) activities was determined in rats' penile tissues. The levels of malondialdehyde, nitric oxide (NO) as well as superoxide dismutase (SOD) and catalase activities were also determined. HPLC-DAD analysis showed the presence of naringin, rutin, caffeic acid, quercitrin, quercetin, and kaempferol glycoside. Oral administration of paroxetine reduced erectile response as revealed by their low intromission and mounting numbers as well as high intromission and mounting latencies. Paroxetine caused a significant elevation of ADA and phosphodiesterase-5 activities and malondialdehyde levels with drastic reduction in levels of NO, SOD, and catalase activities in rats' penile tissues. However, GFP extract reversed PDE-5, ADA, and antioxidant activities to normal levels, raised the concentration of NO. These results suggest the erectogenic effects and protective potentials of GFP extract against paroxetine-induced erectile dysfunction. PRACTICAL APPLICATION: Grapefruit peels are an environmental menace in many countries and this study showed that the peels can be used in the prevention / management of erectile dysfunction. The therapeutic potentials of the peels are due to the presence of bioactive compounds such as flavonoids and phenolic acids. Therefore, exploring the erectogenic potentials of the peels will translate to conversion of the wastes to therapeutic products.

Uji Efek Antioksidan Formulasi Sediaan Sirup Ekstrak Etanol Kulit Buah Jeruk Bali (Citrus Maxima Merr.) Terhadap Malondialdehid Tikus Putih (Rattus Novergicus) Yang Diinduksi Karbon Tetraklorida

Free radicals are any molecule or atom that is unstable because it has one or more unpaired electrons. Free radicals that are formed in the body will produce new free radicals through a chain reaction which eventually increases in number and attacks the body's cells so that tissue damage will occur, therefore antioxidants are needed from outside to neutralize free radicals, the salute is grapefruit peel (Citrus maxima Merr.) This study aims to determine the antioxidant activity of the ethanol extract syrup of grapefruit peel against levels of Malondialdehyde (MDA) blood plasma of male white rats induced by carbon tetrachloride (CCl4). The stages of this study were the first to make a skin extract syrup. grapefruit peel containing 1% extract (F1), 2% extract (F2), 3% extract (F3), and without grapefruit peel extract (F4) as negative control; Furthermore, testing the stability of the syrup preparations before and after storage was accelerated for 12 cycles, and finally the syrup with the best stability was tested for its lipid peroxidation inhibition activity in vivo with blood plasma MDA levels in rats induced by Carbon Tetrachloride. The results showed the results of the syrup stability test. indicates that F3 has the best stability. As for the in vivo test results, F3 showed a decrease in the MDA level of blood plasma in rats which was significantly different from the negative control. The grapefruit peel significantly decreased the MDA level of the rat blood plasma with a value p<0.05. Keywords : Free radicals, Grapefruit Peel, Antioxidant, Syrup Preparation, Malondialdehyde (MDA)

Antibacterial activity of grapefruit peel extracts and green-synthesized silver nanoparticles.

Background and Aim:The gradual loss of efficacy of conventional antibiotics is a global issue. Plant material extracts and green-synthesized nanoparticles are among the most promising options to address this problem. Therefore, the aim of this study was to assess the antibacterial properties of aqueous and hydroalcoholic extracts of grapefruit peels as well as their inclusion in green-synthesized silver nanoparticles (AgNPs).Materials and Methods:Aqueous and hydroalcoholic extracts (80% v/v) were prepared, and the volume and mass yields were determined. The synthesis of AgNPs was done in an eco-friendly manner using AgNO3 as a precursor. The nanoparticles were characterized by ultraviolet–vis spectrometry and photon cross-correlation spectroscopy. The antibacterial activity of the extracts was tested on three Gram-positive bacteria (Staphylococcus aureus ATCC 6538, clinical Enterococcus faecalis, and S. aureus) and two Gram-negative bacteria (two clinical Escherichia coli) using various concentrations of extracts (100, 50, 25, 12, and 5 mg/mL and 5% dimethyl sulfoxide as negative control). Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined using the microdilution method. Modulation of cefazoline and ampicillin on resistant E. coli and S. aureus strains was added to the mixture design response surface methodology with extreme vertices design, with the diameters of inhibition and the fractional inhibitory concentration index as responses and factors, respectively. The antibiotic, the ethanolic extract, and water varied from 0.1 MIC to 0.9 MIC for the first two and from 0 to 0.8 in proportion for the third. Validating the models was done by calculating the absolute average deviation, bias factor, and accuracy factor.Results:The volume yield of the EE and aqueous extract (AE) was 96.2% and 93.8% (v/v), respectively, whereas their mass yields were 7.84% and 9.41% (m/m), respectively. The synthesized AgNPs were very uniform and homogeneous, and their size was dependent on the concentration of AgNO3. The antibacterial activity of the two extracts was dose-dependent, and the largest inhibition diameter was observed for the Gram-positive bacteria (S. aureus ATCC 6538; AE, 12; EE, 16), whereas AgNPs had a greater effect on Gram-negative bacteria. The MICs (mg/mL) of the AEs varied from 3.125 (S. aureus ATCC 6538) to 12.5 (E. coli 1 and E. coli 2), whereas the MICs of the EEs varied from 1.5625 (S. aureus 1, S. aureus ATCC 6538, and E. faecalis) to 6.25 (E. coli 1). There was a significant difference between the MICs of AEs and EEs (p=0.014). The MBCs (mg/mL) of the AEs varied from 12.5 (S. aureus ATCC 6538) to 50 (S. aureus 1), whereas those of the EEs varied from 6.25 (S. aureus 1) to 25 (E. coli 1 and E. faecalis). Ethanolic grapefruit extracts demonstrated an ability to modulate cefazolin on E. coli and S. aureus but were completely indifferent to ampicillin on E. coli.Conclusion:Grapefruit peel extracts and their AgNPs exhibit antibacterial properties that can be exploited for the synthesis of new antimicrobials and their EEs may be efficiently used synergistically with other antibiotics against bacteria with intermediate susceptibility.

IN VITRO ANTI-WRINKLE AND TYROSINASE INHIBITORY ACTIVITIES OF GRAPEFRUIT PEEL and STRAWBERRY EXTRACTS

The research aims to analyse the antioxidant, anti-tyrosinase and anti-wrinkle activities from grapefruit (Citrus Maxima L) and strawberry extracts. Samples were extracted by maceration using 96% ethanol and ethyl acetate, subsequently. The Ferric Reducing Antioxidant Power (FRAP) and β-carotene bleaching (BCB) were used to measure the antioxidant activity. The effect of anti-wrinkle was determined by testing the inhibition of elastase and collagenase enzyme, while anti-tyrosinase activity was analysed using mushroom tyrosinase enzyme. The results showed that strawberry extracts in ethanolic (SE) and ethyl acetate (SEA) have antioxidant activity in FRAP (EC50 = 404.39 ± 3.27 µg / mL and 1978.65 ± 37.25 µg/mL) and BCB (IC50 = 292.30 ± 4.69 µg/mL and 671.11 ± 6.74 µg/mL). Whereas the grapefruit peel extracts both in ethanolic (GPE) and ethyl acetate (GPEA) have antioxidant activity in FRAP (EC50 219.47 ± 71.96 µg / ml and 309.44 ± 95.76 µg/ml) and BCB (EC50 245.19 ± 162.47 µg/ml and 567.54 ± 95.31 µg/ml). As positive standards for FRAP antioxidant analysis were quercetin and vitamin C which has IC50 respectively 18.97 ± 4.50 µg/mL and 24.47 ± 1.44 µg/mL. While in BCB analysis, Butylated Hydroxy Toluene (BHT) used as positive standard (IC50 38.68 ± 5.70 µg/mL). The samples of SE, SEA, GPE and GPEA showed tyrosinase inhibitory activity which the IC50 values were respectively 492.68 ± 1.43; 2658 ± 48.08; 3312.5 ± 222.74; 2985.17 ± 122.80 µg/ml. Kojic acid (IC50 111.52 ± 0.42 µg/ml) is used as positive standard in this study. In addition, SE, SEA, GPE and GPEA were able to inhibit elastase and collagenase enzymes, although their activities were still lower than the positive standard used in this study. Elastastinal in concentration 50 µg/mL giving elastase inhibition about 71.71 ± 0.81 µg/mL, while vitamin C in the same concentration showed collagenase inhibition about 66.79 ± 1.23 µg/mL. It can be concluded that the extract of strawberry and grapefruit peel has antioxidant, anti-tyrosinase and anti-wrinkle activity through inhibition of elastase and collagenase enzymes; thus, they can be used as antiaging cosmetic ingredients.

Activation of grapefruit derived biochar by its peel extracts and its performance for tetracycline removal

A novel adsorbent derived from grapefruit peel (GP) based biochar (GPBC) was synthesized by combined carbonization of GP and subsequent activation by GP extracts. Compared to biochar without extracts activation, the technique granted GPBC-20 (with 1:20 of solid-solution ratio) more abundant surface functional groups, which exerts the adsorbent superior performance for tetracycline (TC) adsorption (37.92 mg/g v.s. 16.64 mg/g). The adsorption kinetics, isotherms and thermodynamics models were further used to evaluate the adsorption behavior of GPBC. The enhanced adsorption was analyzed by characterization of fresh and used GPBC, revealing that the adsorption mechanism was comprised of pore filling, charge interaction and chemical bonding. The comprehensive investigation of using agricultural waste extracts as activator to prepare its raw materials-based adsorbents may be of great significance for enhanced resource utilization.

Pemanfaatan Ekstrak dan Serbuk Kulit Jeruk Bali (Citrus Maxima Merr) untuk Mereduksi Kadar Krom(VI) dan Kadmium(II) pada Limbah Cair Artifisial

Limbah artifisial dibuat menggunakan logam krom (K2Cr2O7) dan logam kadmium (CdCl2). Tujuan penelitian ini untuk mengetahui pemanfaatan ekstrak dan serbuk kulit jeruk bali (Citrus Maxima Merr) dalam menurunkan kadar logam krom dan kadmium. Penelitian ini dilakukan dengan menggunakan limbah artifisial yang dicampur dengan ekstrak dan serbuk kulit jeruk bali dengan konsentrasi 0%, 0,5%, 1%, 1,5% dan 2%. Kadar logam diukur menggunakan metode Spektrofotometri Serapan Atom. Hasil penelitian kadar logam krom sebelum perlakuan kadarnya sebesar 46,49 ppm dan setelah perlakuan menggunakan serbuk kadarnya dengan variasi konsentrasi 0,5%; 1%; 1,5% dan 2% yaitu sebesar 29,97 ppm, 33,20 ppm, 31,05 ppm, dan 33,76 ppm, sedangkan pada ekstrak kadarnya sebesar 40,43 ppm, 41,94 ppm, 42,34 ppm dan 48,23 ppm. Hasil penelitian kadar logam kadmium sebelum perlakuan kadarnya sebesar 102,36 ppm dan setelah perlakuan menggunakan serbuk kadarnya dengan variasi konsentrasi 0,5%%; 1%; 1,5% dan 2% yaitu sebesar 33,61 ppm, 20,26 ppm, 13,44 ppm, dan 16,82 ppm, sedangkan pada ekstrak kadarnya sebesar 75,45 ppm, 74,86 ppm, 80,66 ppm dan 85,10 ppm.

Plant extract: safe way for fabrication silver nanoparticles

A safe approach for fabrication silver nanoparticles has established. In this approach a grape fruit peel extract was employed to serve as a capping agent to reduce the aggregation process of Ag nanoparticles. The formation of Ag nanocrystal was confirmed by the color change from yellow to brownish red after 24-hour incubation. The red shift of SPR band position (∼455 nm) compared to the bulk silver (420 nm) indicates the formation of silver nanoparticles. The size and morphology of Ag nanoparticles were characterized by scanning electron microscopy. The SEM images revealed that the prepared Ag nanoparticles have a diameter of 50-70 nm, while the cubic-like shapes are dominated. Fourier Transform Infrared Spectroscopy (FT-IR) was employed to characterize the prepared Ag nanoparticles.

Determination of grapefruit (Citrus paradisi) peel extract bio‐active substances and its application in Caspian white fish (Rutilus frisii kutum) diet: Growth, haemato‐biochemical parameters and intestinal morphology

In this study, total phenolic and flavonoid contents of grapefruit peel extract (GPE) were equal to 117.3 ± 0.3 µg of gallic acid/mg and 39.30 ± 0.1 µg of quercetin/mg respectively. Caspian white fish (n = 180, 4 ± 0.9 g body weight) was fed with supplemented diets, including 0, 6.25, 12.5 and 25 mg of GPE/kg for 60 days at 25 ± 1°C. The growth performance was markedly improved in fish fed with 25 mg/kg of GPE compared to others (p < 0.05). Moreover, fish fed with 25 mg/kg of GPE showed a significant increase in red blood cell (2.65·106 cell/mm3), white blood cell (17.75·103 cell/mm3), packed cell volume (48%) and haemoglobin concentrations (8.75 g/dl) compared to the control (p < 0.05). However, the highest alanine aminotransferase (140 U/L), alanine transaminase (14.5 U/L), and alkaline phosphatase (18.5 U/L) were observed in control group. Morphological analysis of intestine revealed the highest amount of villus width (8.4 µM), height (32.86 µM) and surface area (342.7 µM2) in fish fed with 25 mg/kg of GPE (p < 0.05). In conclusion, supplementing feed with GPE at 25 g/kg can improve growth performance and haemato-biochemical parameters of Caspian white fish fry.

Green synthesis of the Fe3O4@polythiophen-Ag magnetic nanocatalyst using grapefruit peel extract: Application of the catalyst for reduction of organic dyes in water

In this research Fe3O4@polythiophen-Ag magnetic nanocatalyst was synthesized. First Fe3O4 nanoparticles were prepared in the solution and the branched polythiophene was coated on the magnetic particles. This polymer provides enough surface for precipitation of the silver nanocatalyst produced by grapefruit peel extract reduction of AgNO3. The synthesized catalyst was characterized by XRD, FTIR, SEM, FESEM, EDX, TEM, TGA and VSM. Finally, it was used to degrade azo dyes (methyl orange (MO) and methylene blue (MB)) in order to evaluate its catalytic performance. Ratio of the rate constants of the catalytic and non-catalytic reactions was in order of 105 and 104 for reduction reaction of MB and MO respectively. Reaction rate in the presence of catalyst was very high and just 1 min was enough to degrade the MB and MO colorant reagents. The prepared catalyst is able to take part many times in the reaction. It was recovered by a magnet after each experiment and reused 8 times without considerable loss of the activity.

Anticoccidial efficacy of naringenin and a grapefruit peel extract in growing lambs naturally-infected with Eimeria spp.

The current study aimed to determine the anti-Eimeria efficacy of an extract of grapefruit peels (GF) and commercial naringenin (NAR) in naturally-infected lambs, as well as the influence of these flavonoids on the oxidative status during ovine coccidiosis. Pharmacokinetic profiles were also determined. Extracts were administered per os to Eimeria naturally infected growing lambs during 90 consecutive days. The commercial anticoccidial drug toltrazuril (TTZ) was included in this trial as a standard. Twenty-four lambs were divided into four groups: NAR, lambs given a daily dose of 5mg of a commercial naringenin extract of 98% higher purity per kg body weight; GF, lambs that recived a daily dose of 5mg of ethanolic extract of grapefruit peels per kg body weight; TTZ, lambs treated with 20mg of toltrazuril/kg body weight on days 0 and 15 of the experiment; and CTRL, untreated lambs that received daily dose of 30ml of water. Daily doses of GF and NAR were dissolved in 30ml of water and orally given to animals; whereas toltrazuril was administered as a single dose of an undiluted suspension to lambs of the TTZ group. The CTRL group received 30ml of water; as well as the TTZ group for the period after the single dose administration. Fecal and serum samples were collected from all lambs. Anticoccidial efficacy was estimated by coprological techniques. Generation of nitric oxide levels and the antioxidant capacity of the experimental compounds were determined by the Griess and ABTS assays, respectively. The pharmacokinetic parameters of NAR and the GF extract were obtained. On day 30 post-ingestion, anticoccidial efficacy was 91.76% (NAR) and 89.65% (GF); whereas 99.63% of efficacy was achieved with TTZ 15days after treatment. NAR, GF and TTZ significantly reduced oxidative stress in infected animals. The mean daily weight gain for each group was 122g (NAR), 122g (GF), 143g (TTZ) and 98g (CTRL). Following the oral administration of NAR and GF, values in plasma approached maximum concentrations within 2.1 to 2.5h. In conclusion, the administration of NAR and the GF extract reduced Eimeria oocyst output, oxidative stress and promoted higher mean daily weight gains in infected lambs.

Bioactive Flavonoids, Antioxidant Behaviour, and Cytoprotective Effects of Dried Grapefruit Peels (Citrus paradisi Macf.).

Grapefruit (Citrus paradisi Macf.) is an important cultivar of the Citrus genus which contains a number of nutrients beneficial to human health. The objective of the present study was to evaluate changes in bioactive flavonoids, antioxidant behaviour, and in vitro cytoprotective effect of processed white and pink peels after oven-drying (45°C–60°C) and freeze-drying treatments. Comparison with fresh grapefruit peels was also assessed. Significant increases in DPPH, FRAPS, and ABTS values were observed in dried grapefruit peel samples in comparison with fresh peels, indicating the suitability of the treatments for use as tools to greatly enhance the antioxidant potential of these natural byproducts. A total of thirteen flavonoids were quantified in grapefruit peel extracts by HPLC-MS/MS. It was found that naringin, followed by isonaringin, was the main flavonoid occurring in fresh, oven-dried, and freeze-dried grapefruit peels. In vivo assay revealed that fresh and oven-dried grapefruit peel extracts (45°C) exerted a strong cytoprotective effect on SH-SY5Y neuroblastoma cell lines at concentrations ranging within 0.1–0.25 mg/mL. Our data suggest that grapefruit (Citrus paradisi Macf.) peel has considerable potential as a source of natural bioactive flavonoids with outstanding antioxidant activity which can be used as agents in several therapeutic strategies.

English

The effects of ethanolic extracts of five different citrus peels on mean body and liver weight and serum lipid content were investigated in albino rats. Six groups (n=8 each) were fed with a high fat diet for seven days ad libitum before oral daily administration of the peel extracts of orange (OR), lemon (LE), lime (LI), tangerine (TA), grapefruit (GR) and synergistic combination of equal ratios (w/w), that is, (SY), respectively at a dose of 500 mg / kg body weight for 14 days. The positive control group received only the high fat diet (HFD), while the negative control group received only a standard diet (STD). The body weights of the animals were monitored every two days and the animals were sacrificed after the 7th and 14th days of or following the administration of the extracts. All the parameters increased in the positive control group (HFD) compared to the negative control (STD) group. Body and liver weights decreased in all treated groups, as well as serum cholesterol and triglycerides, which decreased significantly in SY and GR groups, p &lt; 0.05. All extracts contained mainly flavonoids and alkaloids while the grapefruit peel extract contained additional saponins that could contribute to the reduction in both body weight and serum lipid content. Conclusively, peel extract from different types of Nigerian citrus which ordinarily serve as waste may synergistically be used to control and manage obesity and associated pathologies. &nbsp; Key words: Citrus peel, high fat diet, obesity, serum lipids, liver and body weight.

Protective effect of orange and grapefruit peel extracts against testicular toxicity induced by sulfasalazine in male albino rats

Protective effect of orange and grapefruit peel extracts against testicular toxicity induced by sulfasalazine in male albino rats

Hydrolysis of Flavanone Glycosides by β-Glucosidase from Pyrococcus furiosus and Its Application to the Production of Flavanone Aglycones from Citrus Extracts

The hydrolytic activity of the recombinant β-glucosidase from Pyrococcus furiosus for the flavanone glycoside hesperidin was optimal at pH 5.5 and 95 °C in the presence of 0.5% (v/v) dimethyl sulfoxide (DMSO) and 0.1% (w/v) Tween 40 with a half-life of 88 h, a Km of 1.6 mM, and a kcat of 68.4 1/s. The specific activity of the enzyme for flavonoid glycosides followed the order hesperidin > neohesperidin > naringin > narirutin > poncirin > diosmin > neoponcirin > rutin. The specific activity for flavanone was higher than that for flavone or flavonol. DMSO at 10% (v/v) was used to increase the solubility of flavanone glycosides as substrates. The enzyme completely converted flavanone glycosides (1 g/L) to flavanone aglycones and disaccharides via one-step reaction. The major flavanone in grapefruit peel, grapefruit pulp, or orange peel extract was naringin (47.5 mg/g), naringin (16.6 mg/g), or hesperidin (18.2 mg/g), respectively. β-Glucosidase from P. furiosus completely converted naringin and narirutin in 100% (w/v) grapefruit peel extract to 22.5 g/L naringenin after 12 h, with a productivity of 1.88 g L(-1) h(-1); naringin and narirutin in 100% (w/v) grapefruit pulp extract to 8.1 g/L naringenin after 9 h, with a productivity of 0.90 g L(-1) h(-1); and hesperidin in 100% (w/v) orange peel extract to 9.0 g/L hesperetin after 9 h, with a productivity of 1.00 g L(-1) h(-1). The conversion yields, concentrations, and productivities of flavanone aglycones in this study are the highest among those obtained from citrus extracts. Thus, this enzyme may be useful for the industrial hydrolysis of flavanone glycosides in citrus extracts.