Citrus Reticulata Peel Research Articles

UJI EFEKTIVITAS DAYA TOLAK UAP EKSTRAK KULIT JERUK LEMON (CITRUS LIMON, SWINGLE) TERHADAP NYAMUK AEDES AEGYPTI (DIPTERA : CULICIDAE)

Citrus reticulata is a plant that is believed to be used as a repellent against mosquito bites. The plant contains several substances that repel mosquitoes. Although quite effective, this type of mosquito repellent is risky because it is presence of active substances in the form of chemical content. Almost all anti-mosquito lotions circulating in Indonesia contain active ingredient DEET (Diethyl toluamide) which is a toxic synthetic chemical when in a concentration of 10-15%. This research is quasi-experimental which aims to find out the ability of citrus reticulata peel extract vapor to repel Aedes aegypti mosquitoes. The research was conducted in the laboratory of Integrated Poltekkes Kemenkes Medan. Starting from May 2018 to October 2018. Research material in the form of orange peel (simplisia) obtained from the market of Fruit Brastagi Karo Regency. Simplisia soaked in organic solvents (alcohol 76%) for 3-5 days to get maserate, and filtered using a fine gauze sieve to get citrus reticulata filtrate. The application process to find out its repulsion, using Aedes mosquito test material. adult aegypti, which is carried out rearing for 5 weeks. From the results 2 times 100% (55.52%) and 75% (35.83%). Using electric mosquito repellent, a combination of both comparisons 1 and 2 adult mosquito displacement by 62%. That difference between comparison and test difference is quite small, which is 6.48% at concentration of filtrate 100%, while at a concentration of 75% difference is 26.17%. Test results based on percentage displacement can be said that a dilution of 100%, 75%, 50%.

Peel Essential Oil Composition and Antibacterial Activities of Citrus x sinensis L. Osbeck ‘Tarocco’ and Citrus reticulata Blanco

Oranges and mandarins in Chongqing, China, are mostly processed for juice and their peels are wasted or landfilled. To add value, it is essential to utilize the peels and extract useful materials, such as citrus essential oils (CEOs). Here, we report the metabolome analysis of the peels of Citrus x sinensis (CS) and Citrus reticulata (CR). In total, 793 metabolites were detected in the CS and CR peels, of which 242 were differentially accumulated. The metabolites were grouped into 12 compound classes. Terpenoids were the highest accumulated class of compounds followed by phenols and alcohols in both fruit peels. CR peels were rich in all types of compounds, whereas CS showed a relatively lower content of the detected compounds. The highest accumulated compounds were β-phellandrene, beta-ocimene, 1,3,6-octatriene,3,7-dimethyl, and d-limonene. Overall, CR showed higher compound diversity than CS. The CS and CR peel extracts showed antibacterial effects against Escherichia coli, Staphylococcus aureus, and Bacillus subtilis. The peel extracts from CR and CS showed similar antibacterial effects against E. coli and B. subtilis, while CS peel extracts were more effective against S. aureus. Overall, our study concludes that both CS and CR peels should not be wasted owing to the CEOs and respective antibacterial activities.

Three polymethoxyflavones from the peel of Citrus reticulata "Chachi" inhibits oxidized low-density lipoprotein-induced macrophage-derived foam cell formation.

Foam cell formation is the hallmark of the development and progression of atherosclerosis. The aim of this study was to investigate the regulatory effects of three polymethoxyflavones (PMFs), namely, tangeretin (TAN), 5,6,7,3′,4′,5′-hexamethoxyflavone (HxMF), and 3,5,6,7,8,3′,4′-heptamethoxyflavone (HpMF) on macrophage-derived foam cell formation and to further explore the molecular mechanisms. The RAW264.7 macrophage-derived foam cell model was successfully induced by oxidized low-density lipoprotein (ox-LDL) (80 μg/ml). It showed that TAN, HxMF, and HpMF alleviated ox-LDL-induced NO release while also inhibiting the expression of IL-1β, IL-6, and TNF-α in RAW264.7 cells. Uptake of excess ox-LDL was inhibited by TAN, HxMF, and HpMF, resulting in the reduction of its foam cell formation. Moreover, TAN, HxMF, and HpMF promoted HDL-mediated cholesterol efflux. Western blot experiment showed that TAN, HxMF, and HpMF inhibited the expression of scavenger receptor class A type I (SRA1) and cluster of differentiation 36 (CD36), while upregulating peroxisome proliferator-activated receptor γ (PPARγ), liver X receptor α (LXRα), phospholipid ATP-binding cassette transporter G1 (ABCG1), and scavenger receptor class B type I (SRB1) expression. Together, our findings suggested that PMFs inhibited foam cell formation might inhibit lipid uptake via downregulating SRA1/CD36 expression and promote cholesterol efflux from foam cells via upregulating PPARγ/LXRα/ABCG1/SRB1 expression. This antiatherosclerotic activity is expected to provide new insights into the development of healthcare uses for PMFs.

Dietary flavonoids-rich Citrus reticulata peel extract interacts with CREB signaling to suppress seizures and linked neurobehavioral impairments in a kindling mouse model

ABSTRACT Objectives: The citrus fruits peel contains a variety of bioactive metabolites that have shown multiple therapeutic effects. However, despite having substantial ethnomedicinal value, citrus peels remained underexplored and regarded as bio-waste. This present study was planned to investigate the effect of a characterized peel extract of Citrus reticulata c.v. (CRE) in pentylenetetrazole (PTZ)-induced kindling and associated cognitive and behavioral impairments in a mouse model. Methods: The kindled animals were treated daily with CRE (100 and 200 mg/kg) and challenged with a sub-effective dose of PTZ every 5th day to record the severity of seizures. In the end, different tests were performed to record behavioral and cognitive performance. Results: CRE-treated kindled animals showed a significant suppression in seizure severity following 20 days of the treatment. In the T-maze test, the extract treatment resulted in a marked increase in the spontaneous alternations, whereas it showed no change in anxiety behavior of kindled animals in the elevated plus-maze test. In both forced swim and tail suspension tests, CRE treatment demonstrated a considerable reduction in immobility time. However, no change in overall locomotion was observed in the open field test among all the groups. An increase in the hippocampal Creb and Bdnf expression and decreased glutamate-to-GABA ratio were observed in the CRE-treated kindled animals. Discussion: The results showed that CRE treatment suppresses epileptic seizures and associated cognitive deficits and depression-like behavior in kindled mice. The gene expression findings supported that the observed protective effects of CRE be due to its interaction with CREB signaling.

The antihyperlipidemic equivalent combinatorial components from peel of Citrus reticulata 'Chachi'.

Since the combinatorial components responsible for the antihyperlipidemic activity of Citrus reticulata 'Chachi' (CRC) peels remains unclear, we herein developed a bioactive equivalence oriented feedback screening method to discover the bioactive equivalent combinatorial components (BECCs) from CRC peels. Using palmitic acid (PA)-stimulated hepatocyte model, a combination of 5 polymethoxyflavones (PMFs) including tangeretin, sinensetin, nobiletin, 5,7,8,4'-tetramethoxyflavone and 3,5,6,7,8,3',4'-heptamethoxyflavone was identified to be responsible for the antihyperlipidemic effect of CRC peels. Via evaluation of combination effect by combination index (CI), these 5 PMFs were found to take effect via a synergistic mode. Our data indicated that the antihyperlipidemic mechanism of PMF combination was associated with the inhibition of fatty acid and cholesterol synthesis, and inflammation. Also, the PMF combination exhibited robust antihyperlipidemic effects in HFD-fed rats in vivo. Our study offers evidence-based data to uncover the pharmacological effect of CRC peels.

Chemical Variation of Chenpi (Citrus Peels) and Corresponding Correlated Bioactive Compounds by LC-MS Metabolomics and Multibioassay Analysis.

The peel of Citrus reticulata “Chachi” (CP) possesses various health-promoting benefits and is not only one of the most famous Chinese herbal medicine, but also an ingredient in fermented foods. In the present study, the effects of storage years (1-, 3-, 4-, 5-, 6-, and 11-years) on the chemical profiling and potential bioactive compounds of CP were compared by metabolomics and in vitro bioactivity analysis. With the increase of storage time, the content of hesperidin significantly decreased, but nobiletin, 3,5,6,7,8,3′,4′-heptamethoxyflavone, and tangeretin were increased. Meanwhile, the antioxidant activity of CP was enhanced. Phenolic acids, flavonol glycosides, fatty acids, and alkyl glycosides were marker compounds that were responsible for distinguishing the storage time of CP. Correlation analysis suggested that some polyphenols including quercetin-glucoside, quinic acid, trihydroxydimethoxyflavone, and rutin were potential antioxidant compounds in CP. The dichloromethane and n-butanol fractions showed the better antioxidant capacity and inhibitory effects on glucose-hydrolysis enzymes. They mainly contained ferulic acid, nobiletin, 3,5,6,7,8,3′,4′-heptamethoxyflavone, kaempferol, and hesperidin.

The Impact of Citrus-Tea Cofermentation Process on Chemical Composition and Contents of Pu-Erh Tea: An Integrated Metabolomics Study.

Ganpu tea, an emerging pu-erh compound tea, which is cofermented with the peel of Citrus reticulata “Chachi,” has been widely favored by Chinese consumers due to its potential health effects and distinct flavor and taste. So far, the influence of this cofermentation procedure on the chemical profile of pu-erh tea has barely been addressed yet. In this work, an ultra-high-performance liquid chromatography-Q Exactive Orbitrap mass spectrometry (UHPLC-QE Orbitrap MS)-based qualitative and quantitative method combined with multivariate analysis was conducted to comprehensively investigate the chemical changes in pu-erh tea after cofermented with Citrus peel. A total of 171 compounds were identified based on a three-level strategy, among which seven phenolic acids, 11 flavan-3-ols, and 27 flavonoids and flavonoid glycosides were identified from pu-erh tea for the first time. Eighty-nine main constituents were selected for further quantitative analysis using a validated method. Both the principal component analysis (PCA) of untargeted metabolomics and orthogonal partial least squares discriminant analysis (OPLS-DA) models of targeted components revealed the significant chemical profile disparity between the raw pu-erh tea and Ganpu tea. It showed that Citrus tea cofermentation process significantly decreased the total contents of phenolic acids, flavan-3-ols, and flavonoid aglycones, while most of the quercetin glycosides and myricetin glycosides as well as the vitexin were significantly increased. In addition, hesperidin, a flavonoid glycoside only existed in Citrus, was first found in pu-erh tea after cofermented with Citrus. This study clearly profiled the chemical composition and content changes of pu-erh tea after cofermented with Citrus peel, which revealed that Citrus tea cofermentation process further accelerated the fermentation of pu-erh tea and improved the unique flavor of tea.

Enzymatically produced pectic-oligosaccharides from fruit waste of Citrus reticulata (mandarin) peels display cytotoxicity against colon cancer cells

Pectin was extracted from Citrus reticulata (mandarin) peels by ultrasound assisted extraction process. The yield of extracted mandarin pectin (EMP) was 21.3 ± 1.2%. EMP after purification (pEMP) by size-exclusion chromatography gave molecular mass, 92.3 kDa. Field-emission scanning electron microscopy image of pEMP showed wrinkled surface and Atomic force microscopy revealed fibrous network. Fourier transform infrared spectroscopic and nuclear magnetic resonance analyses of pEMP showed hetero-polysaccharide nature with 68 ± 2% methylated galacturonic acids. Thermogravimetric analysis showed degradation at 225 ± 5 °C. pEMP treated by recombinant clostridial pectate-lyase (CtPL1B) or a mixture of CtPL1B and pectin-methylesterase (CtPME) produced pectic-oligosaccharides having degree of polymerization, DP2 and DP3. Enzyme assays displayed that CtPME hydrolyzed methyl groups from pEMP and resulting pectate was degraded by CtPL1B. ESI-MS analysis confirmed that the treatment of pEMP by CtPL1B produces methylated unsaturated di-galacturonic and tri-galacturonic acids, which, displayed biocompatibility with normal human kidney (HEK293) cells and cytotoxicity against colon cancer (HT29) cells.

Essential Oils from Citrus reticulata cv. Shatangju Peel: Optimization of Hydrodistillation Extraction by Response Surface Methodology and Evaluation of Their Specific Adhesive Effect to Polystyrene.

Essential oil (Eo) from the Citrus reticulata peel has been widely used, and its adhesive effect on polystyrene (PS) was found accidentally. To analyze the essential oils of C. reticulata cv. Shatangju (CrspEos), the extraction of these oils by steam distillation was optimized using the response surface method. The chemical composition of CrspEos was analyzed by gas chromatography–mass spectrometry. Then, the adhesive effect of these essential oils on PS was evaluated. The adhesion area, the influence of adhesion on the thickness of the essential oil on the materials, the effect of adhesion on the transmittance of PS, the strength of adhesion point, and specificity of adhesion were determined. The optimum extraction conditions resulting in the extraction yield of 47.37 μL g–1 were a ratio of liquid-to-solid of 8.94:1, a soaking time of 199.45 min, and an extraction time of 138.71 min. The major component in the essential oils was d-limonene (56.66%), followed by myrcene (6.62%). CrspEos presented a specific adherence effect on PS without influencing the thickness and transmittance of PS but with stronger tenacity than the parent material. CrspEos can be used as an environmentally friendly specific adhesive for PS.

Virtual Screening of Citrus Flavonoid Tangeretin: A Promising Pharmacological Tool for the Treatment and Prevention of Zika fever and COVID-19

It is of great importance for the pharmaceutical industry to find therapeutic substances extracted from natural sources, which are abundant, obtained with low costs and presenting the antiviral potential for the treatment of Zika virus (ZIKV) and COVID-19. Tangeretin (TAN) is a citrus polymethoxyflavone from Citrus reticulata peel oil with known antiviral activities, whose physico-chemical properties are not reported. The present study aimed to investigate by a theoretical screening of electronic, structural properties and pharmacodynamic and pharmacokinetic parameters that characterize TAN as a therapeutic drug in the treatment and prevention of zika fever and COVID-19. The molecule reached its minimum energy-forming state of [Formula: see text]795.85747[Formula: see text]kJ/mol and the HOMO and LUMO boundary orbitals reactivity descriptors suggest that the compound is stable and does not tend to be reactive in intermolecular interactions. The ligand connects to the NS1 ZIKV receptor with strong H-bond interactions, also connects with the NS5 ZIKV receptor in a competitive effect with the SAM inhibitor and acts in a supplementary effect with the N3 inhibitor and the BRT drug in the Mpro SARS-CoV-2 receptor. The properties of ADMET shows that the compound suffers few amounts of drug alterations because it inhibits the metabolic enzymes CYP2C9 and CYP3A4 and penetrates the central nervous system, without accumulation of drug residues in the blood or in the lumen in the gastrointestinal tract, without risk of toxicity to the patient. With the results obtained, it is possible to identify TAN as a promising pharmacological tool for the treatment and prevention of Zika fever and COVID-19.

Supercritical extraction and antioxidant activity of major ingredients in Puerariae lobatae root, Pinus massoniana needle, Citrus reticulata peel and their mixture

The edible herbs Puerariae lobatae root, Pinus massoniana needle, Citrus reticulata peel and their mixture “SGLUAP” were extracted by supercritical CO2 fluid replacing usual ethanol solution. Optimal conditions of the extraction were determined by conducting series of experiments with Box-Benhnken Design of three-variables and three-levels, data fitting and modeling, and analyzing the visual 3D response surface plots. Scavenging free radical rate (DPPH%) and inhibiting xanthine oxidase rate (XO%) of 14 major ingredients in herbs and total phenolic compounds in SGLUAP were assessed. Among them, gallic acid gave DPPH (%) of 94.5 % to be higher than the reference Vitamin C, and daidzein possessed XO (%) of 97.8 % to be much higher than the reference allopurinol. This work has demonstrated a reliable and efficient methodology for extraction optimization, antioxidant activity evaluation and quality assessment of natural products from herbs or plants.

Effects of drying temperature on the drying characteristics and volatile profiles of Citrus reticulata Blanco peels under two stages of maturity

Citrus peels are considered as an agricultural waste with negative environmental impacts. In the present study, yellow (ripe) and green (unripe) Citrus reticulata peels were dried in a hot air impingement dryer and the effect of drying temperatures (40, 50, 60, and 70 °C) on the drying characteristics, volatile compounds, and antioxidant capacity were explored. The results showed that the drying time of samples was reduced by more than 50% when the drying temperature was increased from 40 to 70 °C. A total of 56 peaks and 29 volatile components were identified by headspace-gas chromatography-ion mobility spectrometry. Drying caused an obvious reduction in the concentration of linalool oxide, benzaldehyde, (E)-2-heptenal, and 1-pentanol, and an increment in the concentration of pentanal, decanal, linalool, and (E)-2-hexenol. Principal component analysis showed that samples under different treatments were clearly distinguished. Drying resulted in a significant reduction of 2,2‐diphenyl‐1‐picrylhydrazyl and ferric reducing antioxidant power. These findings will contribute to a better understanding of citrus peel drying as well as their volatile profiles and antioxidant capacity changes during drying.

Assessment of α-amylase and α-glucosidase inhibitory potential of Citrus reticulata peel extracts in hyperglycemic/hypoglycemic rats.

Diabetes mellitus is a metabolic disorder of carbohydrate metabolism. The management of Diabetes mellitus with phytochemicals is hallmark of this research. Citrus species are known for their health benefits and are used as traditional food in South East Asia. The total phenolic content of peels was analyzed using different solvents, while Gallic acid was used as standard. Both ethanolic, aqueous extracts of Citrus reticulata peel showed good inhibitory activity against amylase (90.67%, 15.33%) and moderate against glucosidase (70.8%, 14.8%), respectively. Sixteen rats were randomly divided into four groups (G1, G2, G3, and G4); G1 is a negative control (water), G4 is a positive control (Acarbose), while other two are experimental groups like G2 (fed with 100mL and 20mg/mL in hypoglycemic and hyperglycemic trials) and G3 fed with 200mL and 40mg/mL in hypoglycemic and hyperglycemic trials. A significant effect of treatments and value of time was found in hyperglycemic rats. Ethanolic extract showed a significant reduction in blood glucose levels in hypoglycemic (overnight fasting) rats which was comparable to the positive control. These results suggest that C. reticulata peels can contribute as a useful food ingredient as a potential antihyperglycemic agent in managing type 2 diabetes mellitus. In future, C. reticulata peel will be a good candidate for pharmaceutical industry.

Nematicidal potential of Citrus reticulata peel essential oil, isolated major compound and its derivatives against Meloidogyne incognita

Citrus reticulata (Kinnow) peel essential oil, isolated major compound limonene and its derivatives were evaluated for their in vitro nematicidal activity against Meloidogyne incognita. The essential oil was extracted from peels by hydrodistillation . Gas Chromatography-Mass Spectrometry analysis of essential oil revealed limonene as the major compound (51.42%) which was isolated from essential oil. Two derivatives of limonene viz. limonene tetrabromide and carvone were synthesized. Maximum egg hatch inhibition and juvenile mortality was shown by carvone at 1500 µg ml−1 after 96 hours of exposure followed by limonene, limonene tetrabromide and essential oil. The present studies showed that essential oil, major component limonene and its derivatives are effective against M. incognita and can be further explored for nematicidal properties. Further, substitution of carbonyl group in limonene as in carvone helps in enhancement of the nematicidal potential which is useful observation for exploration of these compounds in nematodes management

Antifungal potential of three natural oils and their effects on the thermogravimetric and chromatic behaviors when applied to historical paper and various commercial paper sheets

Three natural extracted oils from Citrus reticulata peels, C. aurantifolia leaves, and Linum usitatissimum (linseeds) were used as antifungal agents against the growth of Aspergillus flavus and Penicillium chrysogenum. The following main compounds (determined via gas chromatography–mass spectrometry) were found. The essential oil (EO) from C. aurantiifolia leaves contained limonene (22.96%), geranyl acetal (13.53%), and geraniol acetate (13.33%); the n-hexane oil from C. reticulata peels contained methyl-13-cyclopentyltridecanoate (16.74%), and D-limonene (16.06%); and linseed oil contained linoleic acid (27.36%), and oleic acid (19.01%). The inhibition of fungal growth significantly was reached 100% against A. flavus at all tested C. aurantifolia leaf EO concentrations and at a concentration of 2000 µL/mL for linseeds oil. The growth inhibition reached 100% against P. chrysogenum with C. aurantifolia leaf EO concentrations of 125-2000 µL/mL. Citrus reticulata peel EO had 100% growth inhibition of P. chrysogenum at concentrations of 2000 µL/mL and 1000 µL/mL, while linseeds oil had 100% growth inhibition at 2000 µL/mL. Thermogravimetric analysis showed that C. aurantifolia EO yielded the greatest thermal stability and color change protection to cotton pulp, while linseed oil was found to protect wood pulp-based and historical papers.

Evaluation of in vivo wound healing activity of Moroccan Citrus reticulata peel extract

BackgroundCitrus reticulata is one of the most cultivated fruit with great benefits for humans in the world. Citrus reticulata peel has several biological activities within them hypoglycemic, hepatoprotective, antimicrobial and antioxidant. The present study emphasizes on the in vivo wound healing and in vitro antimicrobial and antioxidant activities of Citrus reticulata peel extract.MethodsForty albino mice (23–29 g) of either sex were divided into four groups. The test groups were treated with experimental ointment (0.5% and 10% of methanolic extract), negative control were treated with Vaseline and the positive control were treated with silver sulfadiazine. Burn wounds were induced on dorsal area of mice bodies. Wound area measurement was carried out every day during 22 days. Biochemical screening was performed to identify possible compounds. Antioxidant and antimicrobial activities were also determined.ResultsSignificant wound healing activity was observed with topical application of Citrus reticulata peel extract. Wound area reduction at day 16 of treatment was 100% for both treated groups (0.5% and 10%) when compared to positive and negative control it was 100% and 98.32% respectively at day 22. Furthermore higher rate of wound contraction (100% on 16th day) was observed for both treated groups.The result of biochemical screening showed that C. reticulata peel is characterized by highest amount of total polyphenols (13.19 mg/g), flavonoids (4.07 mg/g), vitamin C (13.20 mg/g), carotenoids (0.032 mg/g) and lowest content of macronutrients (Proteins: 0.40%, reducing sugars: 7.21%; lipids: 1.5%). Additionally C. reticulata peel exhibited remarkable antioxidant activity using DPPH and phosphomolybdate methods as well as the extract possess antimicrobial effect against pathogen bactria.ConclusionThe findings from this research indicated that Citrus reticulata peel extract is effective in inhibiting the growth of pathogen bacteria and could be of therapeutic potentials for wound healing.

Citrus spp. essential oils improve behavioral pattern, repressed cholinesterases and monoamine oxidase activities, and production of reactive species in fruit fly (Drosophila melanogaster) model of Alzheimer's Disease.

Much emphasis has been placed on the biological activities of citrus peel's essential oils (CPEOs) against human ailments. This study investigated the effect of Citrus limon and Citrus reticulata peel's essential oils (EOs) on behavioral and neurochemical imbalance in transgenic and Harwish (Wild) fruit flies. Flies were divided into seven groups comprising of the control and those that were fed with 0.1, 0.5, and 1.0µg/ml of the dietary inclusions of study CPEOs for 7days. Thereafter, behavioral profile was examined using lethality response and negative geotaxis assays. Effect of the EOs on cholinesterase and monoamine oxidase (MAO) activities, and antioxidative parameters were determined. The result showed a significant improvement of behavioral pattern and biochemical parameters of the flies fed with studied CPEOs inclusive diets. Conclusively, both EOs exert neuroprotective capability by reducing cholinesterases and monoamine activities, and also prevent oxidative stress, which are implicated in neuronal dysfunction in humans. PRACTICAL APPLICATIONS: With the growing increase in the search for safer alternatives, having no side effects, for the management of neurodegenerative diseases, a large proportion of the populace is beginning to find solace in the use of natural products. Also, the wide array of similarities between the humans and the dipteran insects, fruit flies is a perfect organism for the study of neurodegenerative diseases. Therefore, this study presents the neuroprotective potentials of lemon and tangerine peels-derived EOs, and the possibility of their exploration as neuroactive agents and alternative in the management of Alzheimer's disease (AD).

Antioxidant and Wound Healing Potential of Essential Oil from Citrus reticulata Peel and Its Chemical Characterization.

Fruit peels are considered as waste and contribute to a major proportion of the biomass. They can be a good source of various therapeutic benefits. Peels biomass of citrus fruits is usually considered as garbage. Such peels may have many important and valuable medicinal components with pharmacological activities. Citrus reticulata, (Rutaceae family, local name tangerine) is a local seasonal fruit in Pakistan, a very good example of wastage of its peels. The study is based on the exploration of a citrus fruit peel derived essential oil, its chemical characterization, identification of various bioactive components and the exploration of pharmacological potentials (antibacterial and wound healing activity). Essential oil was recovered by hydro-distillation of freshly collected peels. Chemical constituents of oil were determined by Gas Chromatography-Mass Spectroscopy (GC-MS) analysis. Antioxidant activities were evaluated by total phenolic contents, total flavonoid content, DPPH scavenging activity and reducing power assay. Antibacterial activity was determined using disc diffusion assay. In vivo wound healing potential was determined in rabbits after topical administration of oil. Wound scoring was calculated followed by histological study. GC-MS analysis showed the presence of various components with the greatest proportion of D-Limonene (89.31%). Total flavonoid and phenolic contents were found to be 14.63 ± 0.95 mg CE/g and 17.03 ± 3.24 mg GAE/g respectively, while DPPH activity was found to be 73.32%. A better antibacterial activity was shown against E. coli. In vivo studies showed significant reduction in wound diameter in essential oil treatment groups. Further, the essential oil was found non-irritant in draize scoring. The study concluded that essential oil of this fruit peel might be used for antibacterial and wound healing purposes.

Potency of Citrus reticulata Peel Extract as Active Compound of NonAlcohol Based Gel Hand Sanitizer

Hand sanitizer is nowadays known as a part of one’s personal hygiene kit because of its practical use andeffectivity against skin microbes, such as Staphylococcus aureus. The common commercial hand sanitizers are madefrom alcohol which may have negative side effect like skin irritation. Utilization of active compounds from a plantthat has antibacterial compounds might be applied to the substitution of alcohol in the formulation of hand sanitizer.In this study, phytochemical compounds from Citrus reticulata and Citrus aurantifolia peel extracts were testedqualitatively and their antibacterial acitivity on Staphylococcus aureus were tested using disk diffusion method. Theresults showed that Citrus reticulata peel extract at the concentration of 70% was the most effective concentration ininhibiting Staphylococcus aureus. This certain concentration of Citrus reticulata peel extract was then chosen in the gelhand sanitizer formulation. Application of gel hand sanitizer with Citrus reticulata peel extract as its active compoundon the hands of respondents were also observed to inhibit bacterial growth. The use of peel extracts from Citrusspp, especially from Citrus reticulata might be potential in the formulation of non-alcohol based gel hand sanitizer.

Synthesis of bio-based nickel nanoparticles composite, characterization and corrosion in hibition in simulated oilfield microbial and acidizing environments

Aqueous extract of Citrus reticulata peels (CRE) mediated synthesis of nickel nanoparticles (CRE-NiNPs), characterization and application of the obtained composite as microbial and acid corrosion inhibitor is reported. The CRE-NiNPs were stable, non-agglomerated, monodispersed, round-shaped and of 40 − 55 nm size. With surfaces rich in O and N sites, CRE-NiNPs efficiently adsorbs on and inhibits X80 steel corrosion in I M HCl solution with efficiency of 87.3% and 80.6% at 30 and 60 °C, respectively. The nanoparticle also affords 3-log reduction in Desulfovibrio sp population and 73.2% inhibition efficiency at 3.21 mg/L minimum inhibitory concentration. Potentiation with D-tyrosine increases the efficiency to 79.7% and 5-log reduction in microbial population. Microbial corrosion inhibition is attributed to ease of penetration through bacteria cells to subdue their metabolic via physical and chemical adsorption mechanisms. Compared to the crude, CRE-NiNPs is more thermally stable, more efficient and affords better surface protection at high temperature. Highlights Citrus reticulata peels extract (CRE) mediated nickel nanoparticles (CRE-Ni NPs) were synthesized and characterized. CRE-Ni NPs richer in N and O sites, more stable and efficiently inhibits corrosion at high temperatures than CRE Small size enhances high efficiency against Desulfovibrio sp with over 3-log population reduction Adsorption of CRE-Ni NPs is by combined physisorption and chemisorption enabled by C=C, C=O, C–O, O–H and N–H sites