Recent advances in the therapeutic potential of nobiletin against respiratory diseases.

BACKGROUND: Nobiletin is a natural polymethoxylated flavonoid widely present in citrus fruit peels. It has been demonstrated to exert the effects of anti-tumor, anti-inflammation, anti-oxidative, anti-apoptotic and improve cardiovascular function. Increasing evidences suggest that nobiletin plays an important role in respiratory diseases (RDs) treatment. OBJECTIVE: This review aimed to investigate the therapeutic potential of nobiletin against RDs, such as lung cancer, COPD, pulmonary fibrosis, asthma, pulmonary infection, acute lung injury, coronavirus disease 2019, and pulmonary arterial hypertension. METHODS: We retrieved extensive literature of relevant literatures in English until June 26, 2023 from the database of PubMed, Web of Science, and Scopus databases. The keywords of "nobiletin and lung", "nobiletin and respiratory disease", "nobiletin and chronic respiratory diseases", "nobiletin and metabolites", "nobiletin and pharmacokinetics", "nobiletin and toxicity" were searched in pairs. A total of 298 literatures were retrieved from the above database. After excluding the duplicates and reviews, 53 were included in the current review. RESULTS: We found that the therapeutic mechanisms are based on different signaling pathways. Firstly, nobiletin inhibited the proliferation and suppressed the invasion and migration of cancer cells by regulating the related pathway or key target, like Bcl-2, PD-L1, PARP, and Akt/GSK3ß/ß-catenin in lung cancer treatment. Secondly, nobiletin treats COPD and ALI by targeting classical signaling pathway mediating inflammation. Besides, the available findings show that nobiletin exerts the effect of PF treatment via regulating mTOR pathway. CONCLUSIONS: With the wide range of pharmacological activities, high efficiency and low toxicity, nobiletin can be used as a potential agent for preventing and treating RDs. These findings will contribute to further research on the molecular mechanisms of nobiletin and facilitate in-depth studies on nobiletin at both preclinical and clinical levels for the treatment of RDs.

Residue analysis and dietary risk assessment of picoxystrobin in potato (Solanum tuberosum), citrus fruit (Citrus reticulata Blanco), and Dendrobium officinale Kimura et Migo.

Picoxystrobin is a systemic fungicide widely used on potato, citrus fruit, and Dendrobium officinale. To provide information for the risk assessment of potato, citrus, and Dendrobium officinale, field experiments combined with QuEChERS and HPLC-MS/MS were performed to detect picoxystrobin. Picoxystrobin had good linearity (R2 > 0.99), the average recovery rate was 75 - 102%, and the relative standard deviation was 1 - 11%. Picoxystrobin was utilized as the test agent in field experiments, and samples were evaluated and analyzed at various times after the final application utilizing random sampling. The results showed that picoxystrobin residuals in potato and citrus (orange meat) were ˂ 0.01 mg kg-1, whereas those in citrus whole fruit, D. officinale (fresh), and D. officinale (dried) were < 0.05 - 0.084, 0.16 - 3.82, and 0.34 - 9.05 mg kg-1, respectively. Based on these results, both the acute risk quotient (2.77%) and chronic risk quotient (8.7%) were ˂100%, and the dietary risk assessment indicated that the intake of picoxystrobin residues in potato, citrus fruit, and D. officinale did not pose a health risk. This study can guide the reasonable use of picoxystrobin in potato, citrus fruit, and D. officinale.

Multi-season environmental life cycle assessment of lemons: A case study in south Uruguay.

Lemons are a relevant agricultural commodity in Uruguay, mainly exported for fresh consumption. Food eco-labels are on the rise worldwide as consumers and authorities are increasingly demanding them. However, there is a lack of scientific studies estimating the environmental impacts of Uruguayan citrus production. This study aims to assess the environmental performance of lemon production in Uruguay taking into account inter-seasonal variability by applying the Life Cycle Assessment (LCA) methodology and following the Environmental Product Declarations (EPDs) guidelines. A cradle-to-farm gate assessment was carried out based on both mass and spatial functional units. Primary data was gathered from a representative orchard of the region for four harvest seasons (2016-2020). Environmental impact categories recommended by EN 15804 + A2 standard were assessed. Specifically, blue water scarcity was assessed using the AWARE method. In addition, human and freshwater ecotoxicity were assessed using USEtox. Results show that on-field emissions and input production are critical for most of the categories assessed (on average, 84% CC, 88% Ac, 98% MEu, and 85% TEu), whereas blue water consumed for irrigation is the main hotspot in blue water scarcity (86%, on average). As expected, inter-seasonal impacts present higher variability when expressing results per tonne vs. per hectare because, although agricultural inputs applied are the same, climatic variability influences water requirements and also affects yield. Blue water scarcity exhibits the highest variability because water consumption depends strongly on agroclimatic conditions, mainly on rain and irrigated water and on water dynamics in soil. Nitrate leaching is a key emission for freshwater eutrophication and, to a minor degree, for climate change, which also depends on the water dose and timing, either from rain or irrigation. Optimising the N application is crucial to minimise on-field emissions, a hotspot in the present study. Along these lines, improved agricultural practices are suggested to enhance the environmental profile of Uruguayan lemons. Replacement or minimisation of the dose of certain inputs (e.g., copper oxide) through the implementation of complementary agricultural practices is suggested. Finally, up-to-date techniques to decrease blue water scarcity are proposed. Methodological recommendations for future studies include modelling N emissions using mechanistic models, incorporating potential reductions in N emissions due to certain agricultural practices, and harmonizing the methodology to quantify water consumption. This study sets a baseline LCA for Uruguayan citrus fruit production. It highlights inter-seasonal variability as an issue to be considered, even when agricultural practices do not change, and especially relevant in countries with high climatic variability like Uruguay. The study also provides scientific and quantitative evidence to support the environmental decisions of both citrus producers and consumers.

The Effect of a Citrus and Pomegranate Complex on Physical Fitness and Mental Well-Being in Healthy Elderly: A Randomized Placebo-Controlled Trial.

OBJECTIVES: This study investigates whether a citrus and pomegranate complex (CPC) improves physical fitness, mental well-being, and blood biomarkers for oxidative stress and endothelial function in healthy elderly. DESIGN: A randomized placebo-controlled cross-over trial. PARTICIPANTS: The study included 36 healthy elderly aged 60-75 years old. INTERVENTION AND MEASUREMENTS: Participants received four weeks of CPC supplementation and performed the handgrip strength and senior fitness test. Quality of life (QOL) was assessed and blood samples were analyzed for oxidative stress and endothelial function markers. RESULTS: After four weeks of CPC supplementation, handgrip strength significantly improved (p=0.019), compared to placebo. Moreover, the thinking, memory, learning, and concentration facets were improved (p=0.042), compared to placebo, and plasma malondialdehyde decreased, compared to placebo (p=0.033). The intervention did not affect senior fitness and the other QOL domains and blood parameters. CONCLUSION: Four weeks of daily CPC supplementation significantly improves handgrip strength and self-evaluated measures of psychological function in healthy older adults. Further research should focus on mechanisms associated with physical performance.

Upstream processes of citrus fruit waste biorefinery for complete valorization.

Citrus fruit waste (CW) is a useful biomass and its valorization into fuels and biochemicals has received much attention. For economic feasibility, increased efficiency of the preceding extraction and enzyme saccharification processes is necessary. However, at present, there is a lack of systematic reviews addressing these two integral upstream processes in concert for CW biorefinery. Here, the state-of-the-art advancements in enzyme extraction and saccharification processes-using which relevant essential oils, flavonoids, and sugars can be obtained-are reviewed. Specifically, the extraction options for two commercially available CW-derived products, essential oils and pectin, are discussed. With respect to enzyme saccharification, the use of an undefined commercial mixture routinely results in suboptimal sugar production. In this respect, applicable strategies for enzyme mixture customization are suggested for maximizing the hydrolytic efficiency of CW. The enzyme degradation system for CW-derived carbohydrates and its extensive application for sugar production are also discussed.

Ultrasound and high hydrostatic pressure extractions on antioxidant capacity, antiproliferative and apoptosis effects in gastric cancer cells by lemon extract treatment.

The objective of the present study was to investigate the antioxidant and antiproliferative effects of lemon extracts (LE) against human gastric cancer cells (SNU-1) and normal human gastric epithelial cells (GES-1), and their mechanism of inducing cellular death. LE was obtained by three extraction methods: conventional (CE), ultrasound (UAE) and high hydrostatic pressure (HHPE). Experimental results show that the extraction method used to obtain the LE had a significant influence on antioxidant capacity, cellular proliferation, and induction of apoptosis in SNU-1 cells. LE was showed to be cytotoxic with an IC50 of 1747.0 µg mL-1 and 1704.3 µg mL-1, as obtained by UAE and HHPE, respectively. In addition, this extract induces apoptosis as evidenced by confocal microscopy. Our findings indicate that LE would be an attractive source of bioactive compounds with antioxidant and antiproliferative capacity and can improve the functional value of food.

A Citrus Fruit Extract High in Polyphenols Beneficially Modulates the Gut Microbiota of Healthy Human Volunteers in a Validated In Vitro Model of the Colon.

The effect of a Citrus Fruit Extract high in the polyphenols hesperidin and naringin (CFE) on modulation of the composition and activity of the gut microbiota was tested in a validated, dynamic in vitro model of the colon (TIM-2). CFE was provided at two doses (250 and 350 mg/day) for 3 days. CFE led to a dose-dependent increase in Roseburia, Eubacterium ramulus, and Bacteroides eggerthii. There was a shift in production of short-chain fatty acids, where acetate production increased on CFE, while butyrate decreased. In overweight and obesity, acetate has been shown to increase fat oxidation when produced in the distal gut, and stimulate secretion of appetite-suppressive neuropeptides. Thus, the data in the in vitro model point towards mechanisms underlying the effects of the polyphenols in CFE with respect to modulation of the gut microbiota, both in composition and activity. These results should be confirmed in a clinical trial.

Citrus hassaku Extract Powder Increases Mitochondrial Content and Oxidative Muscle Fibers by Upregulation of PGC-1α in Skeletal Muscle.

Peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) is expressed in skeletal muscles and regulates systemic metabolism. Thus, nutraceuticals targeting skeletal muscle PGC-1α have attracted attention to modulate systemic metabolism. As auraptene contained in citrus fruits promotes lipid metabolism and improves mitochondrial respiration, it could increase mitochondrial function through PGC-1α. Therefore, we hypothesized that PGC-1α is activated by auraptene and investigated its effect using Citrus hassaku extract powder (CHEP) containing >80% of auraptene. C2C12 myotubes were incubated with vehicle or CHEP for 24 h; C57BL/6J mice were fed a control diet or a 0.25% (w/w) CHEP-containing diet for 5 weeks. PGC-1α protein level and mitochondrial content increased following CHEP treatment in cultured myotubes and skeletal muscles. In addition, the number of oxidative fibers increased in CHEP-fed mice. These findings suggest that CHEP-mediated PGC-1α upregulation induced mitochondrial biogenesis and fiber transformation to oxidative fibers. Furthermore, as CHEP increased the expression of the protein sirtuin 3 and of phosphorylated AMP-activated protein kinase (AMPK) and the transcriptional activity of PGC-1α, these molecules might be involved in CHEP-induced effects in skeletal muscles. Collectively, our findings indicate that CHEP mediates PGC-1α expression in skeletal muscles and may serve as a dietary supplement to prevent metabolic disorders.

A new standardized phytoextract from red orange and lemon wastes (red orange and lemon extract) reduces basophil degranulation and activation.

Citrus fruits are rich sources of bioactive compounds and their consumption is associated to health-promoting effects. Citrus processing wastes contain bioflavonoids and other high added value compounds. The aim of this study was to evaluate the antiallergic properties of a new phytoextract obtained by citrus wastes and peels. Blood orange and lemon processing wastes were used to produce a Red orange and Lemon Extract (RLE). Blood samples from 30 allergic donors were collected and used to evaluate the basophil activation (CD203c) and degranulation (CD63) by stimulation trough allergen with and without the RLE. Reduced basophil expression of CD203c and CD63 were observed in RLE + Allergen treated samples, with -20.21% of CD203c expression (p < 0.0001) and -54.11% of CD63 expression (p < 0.0001), compared to Allergen treated samples. The RLE evidenced a good antiallergic activity, mainly acting on basophils degranulation, and therefore reducing the key event of pro-inflammatory mediators release after allergic stimuli.

Sand bath assisted green synthesis of carbon dots from citrus fruit peels for free radical scavenging and cell imaging.

A sand bath assisted strategy for the synthesis of fluorescent carbon dots (CDs) using citrus fruit peels as a renewable green resource is reported in this work. The CDs were synthesized without any alkaline or acidic environment. The synthesized CDs were characterized by various spectroscopic and microscopy techniques. The CDs exhibited excellent water solubility and superior optical properties like excitation dependent emission, and multicolor fluorescence. In addition, the CDs have exhibited remarkable free radical scavenging activity (EC50: 4.7382 µg ml-1).The CDs were highly biocompatible and showed lower toxicity. The CDs when modified with folic acid have shown a significant potential as biological labels for cellular imaging at multiple excitations. Synthesis of CDs from natural fruit peels as an excellent carbon source for versatile applications has been demonstrated.

Genuine Carotenoid Profiles in Sweet Orange [Citrus sinensis (L.) Osbeck cv. Navel] Peel and Pulp at Different Maturity Stages.

The carotenogenesis in the endocarp and flavedo of Navel oranges over four consecutive maturity stages was assessed by high-performance liquid chromatography-diode array detection-atmospheric pressure chemical ionization-multistage mass spectrometry. After optimization of the extraction method, 77 carotenoids, including 26 monoesters and 33 diesters of violaxanthin, ß-citraurin, and antheraxanthin, were characterized. Whereas chloroplast-specific pigments, such as (all-E)-lutein and (all-E)-ß-carotene, predominated in the flavedo of green-ripe fruit, a highly complex pattern of xanthophyll esters was found in the mature oranges. Total carotenoid contents of flavedo were approximately 9-fold higher [12 605 µg/100 g of fresh weight (FW)] than those in the endocarp (1354 µg/100 g of FW) at the fully mature stage. The mature endocarp abundantly contained violaxanthin mono- and diesters, in addition to diverse antheraxanthin esters, which were exclusively detected in this fruit fraction. Likewise, ß-citraurin esters were found to be unique flavedo constituents of mature fruit. Therefore, they may support the detection of fraudulent use of peel fractions during orange juice production.

Mechanism of Cell Wall Polysaccharides Modification in Harvested 'Shatangju' Mandarin (Citrus reticulate Blanco) Fruit Caused by Penicillium italicum.

Modification of cell wall polysaccharide in the plant plays an important role in response to fungi infection. However, the mechanism of fungi infection on cell wall modification need further clarification. In this study, the effects of Penicillium italicum inoculation on 'shatangju' mandarin disease development and the potential mechanism of cell wall polysaccharides modification caused by P. italicum were investigated. Compared to the control fruit, P. italicum infection modified the cell wall polysaccharides, indicated by water-soluble pectin (WSP), acid-soluble pectin (ASP), hemicellulose and lignin contents change. P. italicum infection enhanced the activities of polygalacturonase (PG), pectin methylesterase (PME), and the expression levels of xyloglucanendotransglucosylase/hydrolase (XTH) and expansin, which might contribute to cell wall disassembly and cellular integrity damage. Additionally, higher accumulation of reactive oxygen species (ROS) via decreasing antioxidant metabolites and the activities of antioxidant enzymes including superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX) also contributed to the cell wall polysaccharides modification. Meanwhile, the gene expression levels of hydroxyproline-rich glycoprotein (HRGP) and germin-like protein (GLP) were inhibited by pathogen infection. Altogether, these findings suggested that cell wall degradation/modification caused by non-enzymatic and enzymatic factors was an important strategy for P. italicum to infect 'shatangju' mandarin.

Citrus fruit extracts with carvacrol and thymol eliminated 7-log acid-adapted Escherichia coli O157:H7, Salmonella typhimurium, and Listeria monocytogenes: A potential of effective natural antibacterial agents.

Despite the widespread belief that citrus fruit extracts (CFEs) are microbiologically safe due to their acidity, limited bactericidal effect results in low applicability as antibacterial agent and outbreaks occurred by acid-adapted pathogens. Here, we examined the antibacterial effects of CFEs [lime (Citrus medica), lemon (Citrus limon), calamansi (Citrus microcarpa)] combined with essential oil components (EOCs; carvacrol and thymol) against non-acid-adapted/acid-adapted Escherichia coli O157:H7, Salmonella Typhimurium, and Listeria monocytogenes under 22 °C for 5 min. CFEs (<20%) alone or small amounts of EOCs (2.0 mM; 0.032%) alone could not inactivate the target bacteria effectively. However, combined treatments exhibited marked synergy: CFE + EOCs eliminated all the bacteria (>6.9 log CFU/ml). Among the CFEs tested, the highest synergism was shown by calamansi, an exotic citrus fruit previously unrecognized as an antibacterial agent. Although acid-adaptation improved bacterial survival, calamansi (<20%) + EOCs (<0.032%) completely inactivated even the most resistant pathogen (E. coli O157:H7). Validation test also showed that all tested commercial juice products also eliminated acid-adapted pathogens when used with EOCs. Physicochemical analysis of tested CFEs (pH measurement and HPLC analysis of components) revealed that low pH and flavanone (hesperidin) did not contribute to the synergistic bactericidal effects. Rather, the high citric acid content is likely to contribute to the strong synergistic effect with EOCs by damaging susceptible bacterial membranes. Sensory scores for CFEs were not altered by addition of EOCs at concentrations up to 1.5 mM. This study provides new insight into the utility of CFEs with EOCs to improve not only the microbiological safety of food products containing CFEs but also their applicability as natural antibacterial complex.

Use of Cistus aqueous extracts as botanical fungicides in the control of Citrus sour rot.

In this work, we investigated the in vitro and in vivo antifungal activity of aqueous extracts obtained from eight Cistus plant species against the development of Geotrichum citri-aurantii, the causal agent of citrus sour rot. The results demonstrate the in vitro effectiveness of all tested Cistus species aqueous extracts against G. citri-aurantii, the inhibition of mycelial growth ranged between 80 and 100%. Furthermore, Cistus aqueous extracts totally inhibited germination of G. citri-aurantii arthrospores at a concentration of 5 mg/mL. Among the plant species tested, C. laurifolius, C. salviifolius, C. monspeliensis, C. ladanifer and C. populifolius displayed the best fungistatic activity since the minimum inhibitory concentration (MIC) was <0.625 mg/mL. Under in vivo conditions, incidence of sour rot was lowered to 8.33% when fruits were treated with aqueous extracts of C. populifolius and C. creticus compared to 100% in the control. Disease severity was lowered to 3.74, 4.47 and 5.13% when fruits were treated with C. creticus, C. ladanifer and C. populifolius aqueous extracts, respectively. Using such these biopesticides in a replacement for synthetic fungicides or in combination with other established disease management practices could help control citrus postharvest decay in a more sustainable and eco-friendly way.

Serum ß-cryptoxanthin and ß-carotene derived from Satsuma mandarin and brachial-ankle pulse wave velocity: The Mikkabi cohort study.

BACKGROUND AND AIMS: Findings of observational studies suggest cardioprotective effects of antioxidant vitamins and carotenoids. However, recent meta-analyses failed to show the beneficial effects of supplemental intake of antioxidants on cardiovascular disease (CVD). We aimed to assess the association between CVD risk and ß-cryptoxanthin in Japan, where Satsuma mandarin, a major source of ß-cryptoxanthin, is widely consumed. METHODS AND RESULTS: This was part of the Mikkabi cohort study. Surveys were conducted at baseline, in 2003 and 2005, and on follow-up in 2006, 2009, and 2013. We examined brachial-ankle pulse wave velocity (baPWV) with a high cut-off value set at 18.3 m s(-1). Hazard ratios (HR) and 95% confidence intervals for high baPWV were estimated using a Cox proportional hazards model with adjustment for potential confounders. A total of 635 participants with baPWV of less than 18.3 m s(-1) at baseline were included in the analysis. During the follow-up period of 57,921 person-months, 99 subjects developed high baPWV. After multivariate adjustment, the HR for high baPWV in the highest tertile compared with the lowest tertile was significantly low for ß-cryptoxanthin, ß-carotene, and total carotenoids. Serum concentrations of ß-cryptoxanthin and ß-carotene were higher in people who ate Satsuma mandarin frequently. Compared with <1/d intake of Satsuma mandarin, 3-4/d was associated with a low risk of high PWV. CONCLUSION: This study indicated that ß-cryptoxanthin and ß-carotene derived from Satsuma mandarin are candidate micronutrients for preventing arteriosclerosis development. Further longitudinal and interventional studies will be required to validate the effect on CVD.

Salicylic acid treatment reduces the rot of postharvest citrus fruit by inducing the accumulation of H2O2, primary metabolites and lipophilic polymethoxylated flavones.

To comprehensively analyze the effects of salicylic acid (SA) on the storability of Satsuma mandarin (Citrus unshiu), fruits were treated with 2mM SA. The disease incidence of control/SA-treated fruit at 50d and 120d after treatment was 23.3%/10% and 67.3%/23.3%, respectively, suggesting that SA treatment can significantly reduce the rot rate of postharvest citrus fruit. Fruit quality assays revealed that the treatment can maintain fruit firmness without affecting the inner quality. Furthermore, the contents of H2O2 and some defense-related metabolites, such as ornithine and threonine, in citrus pericarp, were significantly increased by SA treatment. Moreover, it was lipophilic polymethoxylated flavones, rather than flavanone glycosides, that accumulated in SA-treated fruits and these can directly inhibit pathogen development. These results suggest that the effects of SA on postharvest citrus fruit may be attributed to the accumulation of H2O2 and defense-related metabolites.

Antifungal properties of organic extracts of eight Cistus L. species against postharvest citrus sour rot.

UNLABELLED: The effectiveness of methanol and chloroform extracts of eight Cistaceae species to control citrus sour rot decay, caused by Geotrichum citri-aurantii, was investigated in both in vitro and in vivo conditions. Methanol extracts of these plant species exhibited more interesting activity against G. citri-aurantii, in both in vitro and in vivo conditions, compared with chloroforme extracts. Under in vitro trials, obtained results showed that methanol extracts of all tested plants revealed a highest significant antifungal activity with inhibition zones that ranged between 12·33 and 16·33 mm in diameter. All tested methanol extracts totally inhibited spore germination when tested at 10 mg ml(-1) . Incidence of sour rot was significantly lowered to 11·11% when fruits were treated with Cistus populifolius and Cistus ladanifer methanol extracts compared with 100% in the control. The disease severity was lowered to 5·19% and 6·04% when fruits were treated with the same methanol extracts respectively. SIGNIFICANCE AND IMPACT OF THE STUDY: The methanol Cistus extracts had sufficient antifungal activities in vitro and in vivo against G. citri-aurantii to consider its use in the citrus industry after it has been tested under production and natural infection conditions. Such natural products therefore represent a viable alternative approaches for sour rot postharvest management of citrus.

Amelioration of hepatotoxicity induced by aflatoxin using citrus fruit oil in broilers (Gallus domesticus).

This study was conducted to evaluate the efficacy of citrus fruit oil (CFO; 2.5 g kg(-1)) on the clinicopathological changes in broilers fed with diets containing 1 ppm of aflatoxin (AF). A total of 160 Ross 308 broiler chicks of 1-day-old were procured from a commercial hatchery, divided randomly on 7th day of age into four groups with two replicates of 20 birds each and fed with basal diet (group A), basal diet + CFO (group B), basal diet + AF (group C) and CFO + basal diet + AF (group D). The gross and histopathological changes in the liver, kidney, spleen, thymus and bursa of Fabricius were investigated and relative organ weights were calculated. Slight to moderate hydropic degeneration, fatty change with the formation of cyst in some cases, periportal necrosis, infiltration of heterophils and mononuclear cells and bile duct hyperplasia were observed in chicks fed with 1 ppm AF-containing diet. The addition of CFO to AF-containing diet moderately decreased the magnitude and severity of lesions (hydropic degeneration and bile duct hyperplasia) in the liver. The supplementation of CFO to the basal diet did not produce any adverse effects in birds.

Heat treatment enhances the NO-suppressing and peroxynitrite-intercepting activities of kumquat (Fortunella margarita Swingle) peel.

In Taiwan, folk remedies containing dried kumquats (Fortunella margarita Swingle) are used to cure inflammatory respiratory disorders. The induction of inducible nitric oxide (NO) synthase in inflammatory cells and increased airway production of NO and peroxynitrite, its derivative, are key events in such disorders. Although heat is known to affect the antioxidant activity of citrus peels, the effects of dehydration and heating on NO suppression and on the interception of peroxynitrite are unclear. We determined the NO-suppressing activities of freeze-dried, oven-dried, and heat-treated kumquat extracts by measuring their inhibition of NO production in lipopolysaccharide-activated RAW 264.7 macrophages. Furthermore, we evaluated the attenuation of peroxynitrite-mediated nitrotyrosine formation in albumin. Heating, but not oven drying, enhanced the ability of kumquat peels to suppress NO and intercept peroxynitrite, as compared with freeze drying. However, heat treatment and oven drying of kumquat flesh attenuated these activities; these effects were at least partially attributed to heat-susceptible ascorbate.