Green synthesis of CuO-NiO nanocomposite using Citrus sinensis peel extract and their significant antibacterial properties against a series of pathogenic strains

This paper discusses the green synthesis of a ZnO-NiO nanocomposite using an extract of citrus sinensis peel as a capping and reducing agent. The green synthesized nanocomposite was characterized by X-ray Diffraction (XRD), Energy Dispersive X-ray Spectroscopy (EDX), Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), and Ultraviolet-Visible Spectroscopy (UV-Vis) techniques. XRD is explored for crystallinity, and the crystalline size is found to be 36 nm for the nanocomposite. EDX is utilized for purity, and FTIR is used to establish the composition of the nanocomposites. SEM revealed that ZnO-NiO nanocomposites have a spherical-like surface morphology. The bandgap of the green synthesized nanocomposite is found to be 3.08 eV from reflectance data. By calculating the Zone of inhibition (ZOI) using the agar well diffusion method, the antibacterial activity (ABA) was investigated against three Gram-positive strains and five Gram-negative bacterial strains. The ZOI values for different bacterial strains ranges from 3 ± 0.5 mm to 16 ± 0.5 mm for a 75 µL nanocomposite concentration. The findings in the present work demonstrate that with an increase of the concentration of ZnO-NiO nanocomposite, their antibacterial activity (ABA) also increases, suggesting its merit in showing broad applicability for various uses in medicine.

Nanotechnology has emerged as a rapidly advancing interdisciplinary field with extensive applications in medicine, catalysis, electronics, environmental remediation, agriculture, and material science. Among various metallic nanoparticles, copper nanoparticles (CuNPs) have attracted considerable attention because of their excellent electrical conductivity, catalytic efficiency, antimicrobial activity, optical properties, and cost-effectiveness compared to noble metal nanoparticles. Conventional methods used for the synthesis of copper nanoparticles commonly involve toxic chemicals, hazardous reducing agents, expensive equipment, and high energy consumption, which create environmental and health-related concerns. The present study focuses on the green synthesis of copper nanoparticles using Citrus sinensis (orange) peel extract as a natural reducing and stabilizing agent. Orange peel, generally discarded as agricultural waste, contains several bioactive phytochemicals such as flavonoids, phenolic compounds, ascorbic acid, limonene, terpenoids, and pectin that possess strong antioxidant and reducing capabilities. These phytochemicals facilitate the reduction of copper ions into stable copper nanoparticles. The synthesis process was confirmed by a visible color change in the reaction mixture due to surface plasmon resonance. The synthesized nanoparticles were characterized using UV-Visible spectroscopy, X-Ray Diffraction (XRD), and Scanning Electron Microscopy (SEM). Characterization studies confirmed the successful formation, crystalline nature, and surface morphology of the synthesized copper nanoparticles. The study highlights an economical, environmentally friendly, and sustainable approach for nanoparticle synthesis using agricultural waste materials, with potential applications in antimicrobial activity, catalysis, environmental treatment, and biomedical research.

This study reports a low cost, and scalable method of synthesizing SnO2 -NPs using Citrus sinensis (orange) peel extract, a globally abundant phytochemical-rich agro-waste. The structural properties of SnO2 -NPs were demonstrated by XRD analysis, revealing sharp and intense peaks that confirmed high crystallinity and an average particle size of 15.58 nm. Additionally, the XRD data were refined with Rietveld refinement using FULLPROF and VESTA software, which confirmed that SnO2 -NPs belong to the tetragonal structure. Also, based on UV-Vis absorption spectroscopy, optical properties of SnO2 -NPs were determined, revealing a modified band gap of 3.87 eV. The surface morphology was investigated using SEM coupled with EDX analysis, which revealed NPs are primarily quasi-spherical to slightly polygonal, with some exhibiting distinct faceted edges with high purity, consistent with TEM analysis. Moreover, Fourier transforms infrared spectroscopy spectrum divulge an asymmetric Sn–O–Sn stretching at 621 cm-1. Remarkably, the NPs exhibited excellent photocatalytic activity with a 93.47% degradation of MB dye within 160 min under direct sunlight. Hence, the aim of this study is to foster the use of agricultural waste as a sustainable and eco-friendly resource for the synthesis of NPs and highlight its potential to degrade hazardous dyes in the presence of sunlight.

This study investigates the use of Citrus sinensis (Orange) peel extracts as antibacterial agents against Salmonella typhi and Staphylococcus aureus. The bacteria were isolated from typhoid fever infected patients and diagnosed using various laboratory procedures. The extracts showed antibacterial activity due to the presence of alkaloids, tannins, saponin, glycosides, flavonoids, terpenoids, and phenols. Flavonoids have anti-inflammatory, anti-hepatotoxic, and antimicrobial properties, while saponins and tannins play a role in wound healing and antimicrobial activities. The ethanol extract showed the highest antibacterial effect against the test isolate, with the highest zone of inhibition of 20 mm at 100mg/ml against S. aureus and 19 mm for S. typhi. The aqueous extract had the highest zone of in inhibition of 17 mm at the same concentration for S. typhi and negative bacteria. The study highlights the importance of understanding the potential of Citrus sinensis peel extracts as antibacterial agents. Keywords: Staphylococcus aureus, Citrus Sinensis, S. Typhi, antibacterial activities, flavonoids, Terpenoids, and phenols

In this research study, we reported a convenient and environmentally friendly method for the green synthesis of silver nanoparticles using Citrus sinensis (navel orange) peel. The synthesized silver nanoparticles were identified by colour change from colourless to dark brown due to surface plasmon resonance. The optimal synthesis condition for the AgNPs was determined by varifying different parameters such as peel extract concentration, temperature, AgNO3 concentration, effect of ratio of peel extract to AgNO3 solution, pH and reaction time. The synthesized nanoparticles were identified using the UV-vis spectrophotometer, transmission electron microscopy (TEM), scanning electron microscopy (SEM), and dynamic light scattering (DLS) techniques. The qualitative phytochemical analysis of peel extract was performed to determine the presence of the alkaloids, phenolics, flavonoids, carbohydrates, saponins, triterpenes and tannins. The presence of the phytochemicals were also confirmed by FT-IR spectroscopy analysis. The synthesized silver nanoparticle also revealed good antibacterial activity against some important bacteria Bacillus subtilis, Pseudomonas aeruginosa, Staphylococcus aureus and Escherichia coli.

A synergistic combination of shrimp shell derived chitosan polysaccharide with Citrus sinensis peel extract for the development of colourful and bioactive cellulosic textile

Silver nanoparticles (Ag-NPs) have attracted huge importance due to their distinctive chemical, biological and physical properties. Silver nanoparticles are widely synthesized by the chemical method, which involves the use of toxic chemicals which affects its applications. The bio-reduction method, in comparison with chemical method is more economic and eco-friendly. In the present work, the bio-based production of Ag-NPs was done by using peel extract of orange (citrus sinensis), which played a role of reducing and stabilizing agent. The biosynthesis of silver nanoparticles was optimized by one factor at a time (OFAT) with respect to peel extract concentration, silver nitrate concentration and reaction temperature. The green synthesized silver nanoparticles were characterized by UV-visible spectroscopy, Fourier transforms infrared (FT-IR) spectroscopy, Scanning electron microscopy (SEM) and X-ray diffraction (XRD). Disk diffusion method was used for the study of antibacterial activity of the bio-synthesized silver nanoparticles against the bacteria Escherichia coli and Staphylococcus aureus. The results showed that at a peel extract concentration of 6%, the temperature of 60oC and silver nitrate concentration of 0.1M, the synthesis of Ag-NPs was effective. The orange peel synthesized Ag-NPs showed effective antibacterial activity against both bacteria. However better activity was observed against bacterium Staphylococcus aureus. The results confirmed the synthesis of Ag-NPs using peel extract of citrus sinensis and its role as antibacterial agent.

Citrus sinensis is a rich source of bioactive compounds and has attracted attention due to its medicinal benefits. Historically regarded as agricultural waste, orange peel is rich in flavonoids, polyphenols, tannins, and essential oils with antibacterial, anti-inflammatory, and antioxidant qualities. The phytochemicals in Citrus sinensis peel were used as natural reducing and stabilizing agents in the green synthesis method used in this work to create silver nanoparticles (AgNPs). This method is an environmentally friendly alternative to conventional nanoparticle production, eliminating the need for hazardous chemicals. Based on the study’s results, green-synthesized silver nanoparticles derived from Citrus sinensis peel extract offer a sustainable and biocompatible substitute for biomedical applications. The pharmaceutical and healthcare industries may find therapeutic uses for them due to their exceptional antibacterial, antioxidant, and anticancer properties.

This study evaluated the effect of ethanolic extract of Citrus sinensis peel on mercury chloride-induced changes in the prefrontal cortex of adult Wistar rats. Twenty-five Wistar rats were purchased and divided into five groups containing five animals in each group. Group 1 was administered with distilled water, Group 2, Group 3, Group 4, and Group 5 were administered with 5 mg/kg of mercury chloride only, 5 mg/kg of mercury chloride and 140 mg/kg Silymarin, 5 mg/kg mercury chloride and 1000 mg/kg of ethanoic extract of orange peel, and 5 mg/kg mercury chloride and 1500 mg/kg of ethanoic extract of orange peel. All administration was done orally and the administration lasted for 14 days. The animals were sacrificed humanely using 75 mg/kg ketamine intraperitoneally and prefrontal was dissected out. Part was homogenized in 0.1M phosphate buffered saline for the estimation of superoxide dismutase (SOD), and catalase (CAT) activities, and Malondialdehyde (MDA) level and the other part was fixed by immersion in 10 neutral buffered formal-saline for histological evaluation. The chemical structure of sixteen compounds from Citrus sinensis peel obtained from GC-MS analysis reported in the literature were retrieved from the PubChem compound database and the crystal structure of human peroxisome proliferator- activated receptor gamma (PPARγ; PDB:ID: 2P4Y) reported to increase the expression of catalase gene, human extracellular copper-zinc superoxide dismutase enzyme (PDB ID: 2JLP) and mammalian 15-lipoxygenase - 1 enzyme (PDB ID: 2P0M) responsible for the production of lipid peroxidation were retrieved from the PDB database. Ligands and protein preparation, docking and MM-GBSA relative binding free energy calculation were done in Maestro 2023.1. Data obtained was analyzed using the IBM SPSS (version 25) using one-way ANOVA and p-value < 0.05 was considered statistically significant. The results indicate that the MDA level in control Group(13.29±1.183 μmol) is statistically significantly lower compared to the Group 2 (21.88±1.96 μmol), group 3 (27.44±3.52 μmol), Group 4 (22.20±1.16 μmol) and Group 5 (25.40±3.13 μmol). No statistically significant difference was observed in SOD activity. The CAT activities in control group (53.51±6.83 nmol/ml) was statistically significantly lower compared to the group 2 (26.21±3.70 nmol/ml), Group 3 (27.17±5.32 nmol/ml), Group 4 (25.30±4.24 nmol/ml) and Group5 (26.59±4.22 nmol/ml).The present study suggests, ethanolic extract of Citrus sinensis peel have protective effects on mercury-induced changes in prelimbic part of the prefrontal cortex of adult Wistar rats.

Abstract. Batubara WRP, Susilawati TN, Indarto D. 2023. The potency of Berastagi sweet orange (Citrus sinensis) peel extract for obesity treatment: A study in the rats. Nusantara Bioscience 15: 251-257. Obesity is an abnormal accumulation of body fat and is a trigger factor for various degenerative diseases. Obese continues to grow every year in the world. This study aimed to investigate the effects of Orange Peel Extract (OPE) on Body Weight (BW), obesity index (Lee Index), Body Fat Percentage (BFP) and visceral fat in obese-model rats. Thirty male Wistar rats were divided into 5 groups: controls (negative/NC given aquadest and positive/PC given orlistat 12.3 mg/kgBW/day) and interventions (OPE 1-3) given OPE 250, 500 and 750 mg/kgBW/day, respectively. All rats were fed a high-fat, high-fructose (HFHFr) diet for 28 days. Statistical analysis was performed using ANOVA and Friedman test with p<0.05. The average BW in all groups increased significantly after 14 and 28 days of the intervention (p=0.005). A significant decrease in the obesity index average was found in the OPE 2 and 3 groups (p=0.028 and p=0.034) compared to the NC group. The OPE 1-3 and PC group significantly decreased in average BFP compared with the NC group on the 28th day of intervention (p<0.05). In conclusion, OPE can reduce obesity induced by HFHFr. Future research could be directed to evaluate the OPE side effects for obesity treatment.

Heavy metals possess toxic effects that leads to serious health and environmental problems, anthropogenic activities are chiefly responsible for metal exposure, and they manifest toxic effects on a biological cell. The peels of Citrus sinensis have been reported to have medicinal effect. However, these benefits have not been adequately investigated against metals toxicity. This study evaluated the antioxidant and chelating effect of Citrus sinensis peel extract (CSPE) on wistar rats administered with lead and cadmium. Forty-five (45) rats were separated into nine (9) groups of 5 rats each. The group under control was given distilled water daily, group 2 and 3 received 8mg/kg of cadmium and 15 mg/kg of lead per body weight respectively. Animals in group 4 received 8 mg/kg of cadmium and 100 mg/kg of EDTA treatment per body weight. Group 5 were given 15 mg/kg of lead and treated with 100 mg/kg of EDTA. Group 6 and 7 were respectively treated with CSPE of 250 and 500 mg/kg and administered cadmium-8 mg/kg. Lastly, group 8 and 9 received lead and 250 and 500 mg/kg of CSPE respectively. Administration lasted for 28 days afterwards the rats were sacrificed. The whole blood was separated for analysis of haematological parameters and the liver and kidney tissues harvested for metal analysis. Glutathione Peroxidase (GPx), Malondialdehyde (MDA), Superoxide dismutase (SOD) and Catalase (CAT) were also estimated. Results showed a statistically significant increase (p<0.05) of MDA levels in lead and cadmium and a significant reduction in SOD, CAT and GPx values compared to the control and treated group. The level of cadmium and lead in blood, kidney, and liver tissues of 500 mg/kg CSPE were significantly reduced. CSPE possesses antioxidant properties and exhibits chelating effects on wistar rats administered with lead and cadmium.

Water pollution caused by various natural and artificial sources such as expansion of industrialization, rapid increment in population size, the threat of climate change, and development in urbanization takes a serious attention. Due to this fact, various protocols and techniques were adopted for the treatment of such polluted water. In the present findings, TiO2 nanoparticles (NPs) and TiO2/rGO nanocomposites (NCs) were synthesized using titanium tetra butoxide in the presence of Citrus sinensis (CS) and Musa acuminata (MA) peel waste extract as a capping, reducing, and stabilizing agent. The synthesized NPs and NCs were characterized using thermogravimetric-differential thermal analysis (TGA/DTA), X-ray diffraction (XRD), scanning electron microscope (SEM), high resolution transmission electron microscopy (HR-TEM), selected area electron diffraction (SAED) pattern, ultraviolet diffuse reflectance spectroscopy (UV-DRS), and Fourier transform infrared (FTIR) spectroscopy. The synthesized NPs and NCs were investigated as green alternative photocatalyst for the degradation of methylene blue (MB) dye under visible light irradiation. Thermal analysis results confirmed that the green synthesized TiO2 NPs were found to be too stable above 550°C. XRD analysis result showed that the average crystalline size of CS and MA mediated synthesized TiO2 NPs with various volume ratios was in the range of 7.3–27.3 nm and 13.4–22.4 nm, respectively. The average crystalline size of CS and MA peel extract template synthesized TiO2/rGO NCs was found to be in the range of 7.5–15.3 and 11.2–12.5 nm, respectively. The band gap energy was calculated to be in the range of 3.17–3.29 eV and 3.10–3.38 eV for the CS and MA mediated synthesized TiO2 NPs, respectively. Eg of CS and MA peel extract template formed TiO2/rGO NCs was found to be in the range of 2.85–3.11 eV and 3.07–3.11 eV, respectively. SEM analysis proved that the various synthesized TiO2 NPs and TiO2/rGO NCs were spherical in shape and the absence of any other foreign materials confirmed the purity of the corresponding nanocatalysts. In addition, TEM, HRTEM, and SAED analysis confirmed that the structures of the synthesized nanocatalysts were spherical in shape and the catalysts were too crystalline and the result was found to fit with the XRD result. Among the synthesized various volume ratios of TiO2 nanocatalysts, high percentage of degradation (62% and 58.2%) was achieved using TiO2-2c and TiO2-2 m, respectively. Moreover, 94.28% and 94.25% of MB degradation were achieved in the presence of TiO2/rGO-1.5c and TiO2/rGO-1.5c nanocomposite photocatalysts, respectively.

Background: Herbal medicines have historically been crucial for enhancing human health. Previous studies have highlighted the antioxidant properties of various parts of Citrus sinensis. In light of widespread reliance on plant-based remedies, this study focuses on a particular herbal medicine, Citrus sinensis, known for its rich content of vitamin C, pectins, phenolic compounds, and flavonoids. Objective: This research aims to investigate the hepatoprotective potential of the ethanolic extract of Citrus sinensis peel in vivo, particularly focusing on its antioxidant capabilities. Methods: The study utilized biochemical parameters including aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), bilirubin, and total proteins to assess the hepatoprotective action of the Citrus sinensis peel extract in serum of Wistar albino rats. The rats were divided into five groups, with varying treatments including a control group, a paracetamol-induced hepatotoxicity group, and groups receiving different doses of the Citrus sinensis extract. Results: Treatment with the ethanolic extract of Citrus sinensis peel at doses of 200 mg/kg and 400 mg/kg significantly mitigated the paracetamol-induced elevation of serum levels of AST, ALT, ALP, bilirubin, and total proteins. These improvements were comparable to those observed with the standard drug, silymarin. Conclusion: The study confirms the hepatoprotective effects of Citrus sinensis peel extract against paracetamol-induced liver damage. This protection was evident both biochemically and histopathologically, suggesting the potential therapeutic utility of Citrus sinensis in liver disorders.

The global rise of resistant bacteria threatens the effectiveness of antibiotics, recommending that herbs' natural chemical constituents could provide alternative antimicrobial and insecticidal properties. The study evaluated Citrus sinensis peel extracts' impact on bacterial species isolated from wound samples collected from six hospitals. Quantitative Phytochemical analysis was conducted on the Citrus sinensis peel extracts, Isolates were tested biochemically and molecularly for detection and confirmation of Staphylococcus aureus and Klebsiella pneumonia. The study assessed the antibacterial activity of Citrus sinensis peel extracts using agar disc diffusion method, revealing significant bioactive compounds such as alkaloids, flavonoids, saponins, steroids, glycosides, and tannins. The extracts effectivity against Staphylococcus aureus and Klebsiella pneumonia comes from its bioactive phytochemical components. The result from the morphological and biochemical tests revealed the presence of Staphylococcus aureus, Klebsiella pneumonia, Staphylococcus epidermis, Pseudomonas aeruginosa, Escherichia coli and Enterobacter spp but only Staphylococcus aureus and Klebsiella pneumonia were confirmed by molecular method with a sequence identity of 99.35% and 97.41% respectively when analyzed using the Basic Local Alignment Search Tool (BLAST) of the NCBI package. The study revealed that Citrus sinensis peel extracts showed antibacterial activity against Staphylococcus aureus and Klebsiella pneumonia at different concentrations and Ciprofloxacin as a control. The ethanolic extract showed high activity, while the aqueous extracts showed significant activity. The study suggests Citrus sinensis peel has potential as an antibacterial agent for wound infection treatment, suggesting the need for its phytochemical composition quantification and purification.

The aim of the present study was to investigate histological changes in the kidney of rats induced by cadmium and to evaluate the protective role of jamun (Syzygium cumini) seed and orange (Citrus sinensis) peel extracts.Male Wistar rats were divided into six groups -Group A: Control; Group B: Cadmium (Cd); Group C: Cadmium and jamun seed extract (Cd+ JSE); Group D: Cadmium + orange peel extract (Cd + OPE) ; Group E: Orange peel extract (OPE); Group F: Jamun seed extract (JSE).The Cadmium dose was 10 mg/kg b wt whereas orange peel and jamun seed extract dose was 200 mg/kg b wt/ day for 14 day.For light microscopy kidney were fixed on 7 and 14 day following the treatment.7 day Cd (Group B) treated rats exhibited shrunken glomeruli .In Cd+ JSE (Group C) and Cd + OPE (Group D) treated rats for 7 days, similar changes were noticed but to a lesser extent.Kidney of rats treated for 7 day with OPE and JSE have not shown any remarkable histological change.The kidney of 14 day Cd (Group B) treated rats revealed tubular degeneration and glomerular hypertrophy.In Cd+ JSE (Group C) and Cd + OPE (Group D) treated rats for 14 day, the kidney exhibited changes similar changes (as noticed in Cd treated rats) except degeneration of renal tubules.Kidney of rats treated for 14 day with OPE and JSE have not shown any remarkable histological change.From the present study it can be concluded that Cd caused histological changes in the kidney of rats.These changes can be protected by supplementing with OPE and JSE.