Pomelo Research Articles

Anxiolytic, analgesic and anti-inflammatory effects of Citrus maxima (Burm.) Merr. Seed extract in Swiss albino mice model

BackgroundCitrus maxima (Burm.) Merr. is traditionally used for its diverse pharmacological properties. Therefore, there remains a possibility that the seed extract may contain some bioactive compounds. The present study was carried out to evaluate the anxiolytic, analgesic, and anti-inflammatory effects of methanolic seed extract of Citrus maxima (MECM).MethodThe effect of MECM on the rodent central nervous system was evaluated using the hole-board and elevated plus-maze method. Analgesic effect was measured with the acetic acid-induced writhing and formalin-induced paw licking method. The anti-inflammatory effect was examined using a formalin and carrageenan-induced mice paw edema model.ResultsThe MECM at doses of 200 mg/kg and 400 mg/kg significantly (p < 0.01) increased the number of head dipping in the hole-board test. Additionally, the test subjects entered into the open arm and spent more time in it at an increased rate (p < 0.01) in the elevated plus-maze test. In the acetic acid-induced writhing method, the extract showed high potential (p < 0.001) as an analgesic agent. In the case of formalin-induced pain assessment, MECM demonstrated a significant effect (p < 0.01) at the early phase as a centrally acting anti-nociceptive agent and very high potential (p < 0.001) to reduce pain during the late phase as a peripherally acting analgesic. The extract also showed potency (p < 0.01) as an anti-inflammatory agent in formalin and carrageenan-induced mice paw edema test.ConclusionThe findings of the current study indicate that MECM can be a promising new candidate for searching novel anxiolytic, analgesic, and anti-inflammatory compounds through further investigation.

In situ formed and fully integrated laser-induced graphene electrochemical chips for rapid and simultaneous determination of bioflavonoids in citrus fruits

Rapid and sensitive determination of bioflavonoids in agricultural products is an important issue in food production, pharmaceutical industry and modern precision agriculture. In this study, a novel and fully integrated electrochemical chip for simultaneous determination of bioflavonoids in citrus fruits was for the first time developed by in situ formed laser-induced graphene (LIG) at polyimide sheets. Effects of laser power on the surface morphology and structural characteristics as well as electrochemical activity of LIG were investigated. Subsequently, electrocatalysis of naringin and hesperidin at LIG electrodes was realized and kinetic analysis was then conducted to investigate the detail electrode process. Finally, a fully integrated LIG electrochemical chips for rapid determination of naringin and hesperidin were fabricated. As-prepared LIG electrochemical chips demonstrated a low detection limit, large linear range, good selectivity and acceptable reproducibility for both analytes. Furthermore, electrochemical tests on solutions containing Citrus grandis “Tomentosa” (CGT) extract showed that the as-prepared LIG electrochemical chips had a high reliability and validity, as well as an acceptable recovery, and therefore could be used in practical applications.

Effective biosorption of As(V) from polluted water using Fe(III)-modified Pomelo (Citrus maxima) peel: A batch, column, and thermodynamic study

Pomelo, Citrus maxima, peel was chemically modified with lime water and then loaded with Fe(III) to develop anion exchange sites for effective sequestration of As(V) from water. Biosorbent characterizations were done by using FTIR, SEM, XRD, EDX, and Boehm's titration. The batch biosorption studies were carried out at various pHs using modified and non-modified biosorbents and optimum biosorption of As(V) occurred at acidic pH (3.0–5.0) for both the biosorbents. A kinetic study showed a fast biosorption rate and obtained results fitted well with the pseudo-second-order (PSO) model. When isotherm data were modeled using the Langmuir and Freundlich isotherm models, the Langmuir isotherm model fit the data better and produced maximal As(V) biosorption capacities of 0.72 ± 03, 0.86 ± 06, and 0.95 ± 05 mmol/g at temperatures 293± 1K, 298± 1K and 303± 1K, respectively. Desorptionof As(V) was effective using 0.1 M NaOH in batch mode. Negative values of ΔG° for all temperatures with positive ΔH° confirmed the spontaneous and endothermic nature of As(V) biosorption. The existence of co-existing chloride (Cl−), nitrate (NO3−), sodium (Na+), and calcium (Ca2+) showed insignificant interference whereas a high concentration of sulphate (SO42−) and phosphate (PO43−) significantly lowered As(V) biosorption percentage. Arsenic concentrations in actual arsenic polluted groundwater could be reduced to the WHO drinking water standard (10 μg/L) by using only 1 g/L of investigated Fe(III)-SPP. The dynamic biosorption of As(V) in a fixed bed system showed that Fe(III)-SPP was effective also in continuous mode and different design parameters for fixed bed system were determined using Thomas, Adams-Bohart, BDST, and Yoon-Nelson models. Therefore, from all of these results it is suggested that Fe(III)-SPP investigated in this study can be a potential, low cost and environmentally benign biosorbent material for an effective removal of trace amounts of arsenic from polluted water.

Integrated transcriptomic and metabolomic analyses reveal key genes controlling flavonoid biosynthesis in Citrus grandis ‘Tomentosa’ fruits

As a well-recognized traditional Chinese medicine (TCM), immature fruits of Citrus grandis ‘Tomentosa’ (CGT) serve to cure chronic cough in humans. Specialized metabolites including flavonoids may have contribute to this curing effect. Knowledge about the molecular mechanisms underlying flavonoid biosynthesis in ‘Tomentosa’ fruits will, therefore, support the breeding of varieties with improved medicinal properties. Hence, we profiled the transcriptomes and metabolites of the fruits of two contrasting C. grandis varieties, namely ‘Zheng-Mao’ (‘ZM’) used in TCM production, and a locally cultivated pomelo, namely ‘Guang-Qing’ (‘GQ’), at four developmental stages. A total of 39 flavonoids, including 14 flavanone/flavone, 5 isoflavonoids, 12 flavonols, and 6 anthocyanins, were identified, and 16 of which were quantitatively determined in the fruits of the two varieties. We found that ‘ZM’ fruits contain more flavonoids than ‘GQ’. Specifically, rhoifolin levels were significantly higher in ‘ZM’ than in ‘GQ’. We annotated 31,510 genes, including 1,387 previously unknown ones, via transcriptome sequencing of ‘ZM’ and ‘GQ.’ A total of 646 genes were found to be differentially expressed between ‘ZM’ and ‘GQ’ throughout at all four fruit developmental stages, indicating that they are robust expression markers for future breeding programs. Weighted gene co-expression network analysis identified 18 modules. Combined transcriptional and metabolic analysis revealed 25 genes related to flavonoid biosynthesis and 16 transcriptional regulators (MYBs, bHLHs, WD40) that may be involved in the flavonoids biosynthesis in C. grandis ‘Tomentosa’ fruits.

Sweet Orange: Evolution, Characterization, Varieties, and Breeding Perspectives

Among Citrus species, the sweet orange (Citrus sinensis (L.) Osbeck) is the most important in terms of production volumes and cultivated areas. Oranges are particularly appreciated for the organoleptic characteristics and the high nutraceutical value of the fruits (thanks especially to their high content of antioxidants). Recent advances in citrus genetic and genomic resources, such as the release of the reference genomes of several sweet orange cultivars, have contributed to (i) understanding the diversification of C. sinensis and its relation with other citrus species, (ii) assessing the molecular mechanisms underlying traits of interest, (iii) identifying and characterizing the candidate genes responsible for important phenotypic traits, and (iv) developing biotechnological methods to incorporate these traits into different citrus genotypes. It has been clarified that all the genetic diversity within the sweet orange species was derived from subsequent mutations starting from a single ancestor and was derived from complex cycles of hybridization and backcrossing between the mandarin (Citrus reticulata Blanco) and the pummelo (Citrus maxima (Burm.) Merr.). This paper provides an overview of the varietal panorama together with a description of the main driving forces in present and future sweet orange breeding. In fact, for the sweet orange, as well as for other citrus species, the release of novel varieties with improved characteristics is being pursued thanks to the employment of conventional and/or innovative (molecular-based) methods. The state of the art methods together with the innovations in genomics and biotechnological tools leading to the so-called new plant breeding technologies were also reviewed and discussed.

Physiological and Ultrastructural Responses to Excessive-Copper-Induced Toxicity in Two Differentially Copper Tolerant Citrus Species.

Over-applied copper (Cu)-based agrochemicals are toxic to citrus trees. However, less information is available discussing the ultrastructural alterations in Cu-stressed citrus species. In the present study, seedlings of Citrus sinensis and Citrus grandis that differed in Cu-tolerance were sandy-cultured with nutrient solution containing 0.5 µM Cu (as control) or 300 µM Cu (as Cu toxicity) for 18 weeks. At the end of the treatments, the physiological parameters and ultrastructural features of the citrus leaves and roots were analyzed. The results indicate that Cu toxicity significantly decreased the ratio of shoot biomass to dry weight, the Cu translocation factor and the total chlorophyll of two citrus species. The anatomical and ultrastructural alterations verified that excessive Cu resulted in starch granules accumulated in the leaves and roots of the two citrus species. Under Cu toxicity, increased root flocculent precipitate and thickened root cell wall might reduce the Cu translocation from citrus roots to the shoots. Compared with C. sinensis, C. grandis maintained a relatively integral root cellular structure under Cu toxicity, which provided a structural basis for a higher Cu tolerance than C. sinensis. The present results increase our understanding of the physiological and ultrastructural responses to Cu toxicity in citrus species.

Maintenance of postharvest storability and overall quality of 'Jinshayou' pummelo fruit by salicylic acid treatment.

The loss of postharvest storability of pummelo fruit reduces its commodity value for long run. To maintain its storability, the effects of postharvest dipping treatment by salicylic acid (SA) with different concentrations (0, 0.1, 0.2, or 0.3%) were investigated on pummelo fruit (Citrus maxima Merr. cv. Jinshayou) during the room temperature storage at 20 ± 2°C for 90d. Among all treatments, pre-storage SA treatment at 0.3% demonstrated the most significant ability to reduce fruit decay incidence, decrease weight loss, delay peel color-turned process, and inhibit the declines in total soluble solids (TSS) as well as titratable acid (TA) content. The increases in electrolyte leakage, hydrogen peroxide (H2O2), and malondialdehyde (MDA) content of the 0.3% SA-treated pummelo fruit were reduced compared to the control (dipped in distilled water). Pummelo fruit treated with 0.3% SA exhibited the most outstanding ability to excess reactive oxygen species (ROS) accumulation, as evidenced by promoted the increases in glutathione (GSH), total phenolics and flavonoids contents, delayed the AsA decline, and enhanced the activities of antioxidant enzymes and their encoding genes expression. Pre-storage treatment dipped with SA, particularly at 0.3%, can be used as a useful and safe preservation method to maintain higher postharvest storability and better overall quality of 'Jinshayou' pummelo fruit, and thus delaying postharvest senescence and extend the storage life up to 90d at room temperature.

Fruit quality and volatile constituents of a new very early-ripening pummelo (Citrus maxima) cultivar 'Liuyuezao'.

'Liuyuezao' (LYZ) pummelo (Citrus maxima) originated from a spontaneous bud sport on a 'Guanxi' (GXB) pummelo tree and was released as a new very early-season cultivar. The objective of this study was to present the sensory and nutritional profiles of LYZ fruits, and compare it with other major commercialized pummelo cultivars including GXB, 'Sanhong' (SH) and 'Hongrou' (HR). LYZ had higher contents of organic acids (12.01 mg/g), phenols (669.01 mg/L), vitamin C (75.73 mg/100 mL) and stronger antioxidant capacity (77.65 mg/100 mL) but lower levels of soluble sugars (62.85 mg/g), carotenoids (0.25 mg/L) and flavonoids (46.3 mg/L) when compared to the other pummelos. Moreover, a smaller number (49) and much less content (7.63) of fruit volatiles were detected in LYZ than them in GXB, SH and HR. The relatively high levels of fructose (20.6 mg/g) and organic acids and low levels of volatile compounds in LYZ mainly contributed to its sweet and mildly sour taste and moderate aroma of pummelo note. LYZ is presented as an alternative pummelo cultivar with the potential for commercialization.

Preliminary evaluation of in vitro anti-urolithiasic effect of six Algerian plant products

The present paper reports on the preliminary evaluation of in vitro anti-urolithiasic effect (AULE) of six Algerian plant products: lemon (Citrus limon L.), orange (Citrus sinensis L.), grapefruit (Citrus grandis L.), lemon/grapefruit (1/1 ratio, v/v) and tomato (Solanum lycopersicum L.) juices, [and aqueous extract from hairy rupturewort (Herniaria hirsuta L.), the bi-distilled water being taken as reference. The AULE was evaluated, based on the ability of considered plant liquids to prevent the crystallization of calcium oxalate (CaOx) from the mixture of stock solutions of calcium chloride and sodium oxalate. For this, the juices and the aqueous extract to be analyzed were used as solvents to prepare the two stock solutions. The formation of CaOx was assessed by means of microscopic observation and presented in the form of images. A better AULE was observed for citrus juices, compared with bi-distilled water, tomato juice and hairy rupturewort extract. In the case of lemon juice, it was also found that the AULE is more effective when the juice acidity is adjusted to high pH values (6-7). Based on these results, citrus juices may be recommended for the prevention of urinary lithiogenesis. However, in-depth confirmatory studies are always desired, knowing that opinions are not unanimous on this issue.

The functional analysis of sugar transporter proteins in sugar accumulation and pollen tube growth in pummelo (Citrus grandis).

Sugar transporter proteins (STPs) play vital roles in sugar transport and allocation of carbon sources in plants. However, the evolutionary dynamics of this important gene family and their functions are still largely unknown in citrus, which is the largest fruit crop in the world. In this study, fourteen non-redundant CgSTP family members were identified in pummelo (Citrus grandis). A comprehensive analysis based on the biochemical characteristics, the chromosomal location, the exon-intron structures and the evolutionary relationships demonstrated the conservation and the divergence of CgSTPs. Moreover, CgSTP4, 11, 13, 14 were proofed to be localized in plasma membrane and have glucose transport activity in yeast. The hexose content were significantly increased with the transient overexpression of CgSTP11 and CgSTP14. In addition, antisense repression of CgSTP4 induced the shorter pollen tube length in vitro, implying the potential role of CgSTP4 in pummelo pollen tube growth. Taken together, this work explored a framework for understanding the physiological role of CgSTPs and laid a foundation for future functional studies of these members in citrus species.

Effect of H2O2 @CuONPs in the UV Light-Induced Removal of Organic Pollutant Congo Red Dye: Investigation into Mechanism with Additional Biomedical Study.

Hazardous dyes in industrial wastewater are an internationally recognized issue for community health. Nanoparticles synthesized through green protocols are a fascinating research field with numerous applications. The current study mainly aimed to investigate the degradation of Congo red (CR) dye under UV light in the presence of H2O2 and the photocatalytic activity of copper oxide nanoparticles (CuONPs). For CuONP formation, Citrus maxima extract contains a high number of phytochemical constituents. The size of CuONPs ranges between 25 and 90 nm. The photocatalytic activity of CuONPs with the addition of H2O2 was observed and analyzed under UV light to eliminate CR dye. The UV light caused the decomposition of H2O2, which produced ·OH radicals. The results revealed a significant increment in dye degradation during the presence of H2O2. The effect of concentration on the degradation of the CR dye was also studied. The degradation pathway of organic pollutants was reputable from the hydroxy radical medicated degradation of CR. Advanced Oxidation Treatment depends on the in situ production of reactive ·OH species and is presented as the most effective procedure for decontamination. The biological activity of CuONPs was evaluated against Escherichia coli&amp;nbsp;Bacillus subtillis, Staphylococcus aureus, Shigella flexenari, Acinetobacter&amp;nbsp;Klebsiella pneumonia, Salmonella typhi and Micrococcus luteus. The newly synthesised nanomaterials showed strong inhibition activity against Escherichia coli (45%), Bacillus subtilis (42%) and Acinetobacter species (25%). The activity of CuONPs was also investigated against different fungus species such as: Aspergillus flavus, A. niger, Candida glabrata, T. longifusus, M. Canis, C. glabrata and showed a good inhibition zone against Candida glabrata 75%, Aspergillus flavus 68%, T. longifusus 60%. The materials showed good activity against C. glaberata, A. flavus and T. longifusus. Furthermore, CuONPs were tested for antioxidant properties using 2, 2 diphenyl-1-picrylhydrazyl) (DPPH).

Performance of different genotypes of pummelo (Citrus grandis L.) for softwood grafting success and growth parameters

Pummelo (Citrus grandis L.) is one of the important tropical fruit crops among the citrus group. Since pummelo is a monoembryonic and crosspollinated crop, vegetative propagation is critical for obtaining true-to-type plants. A study entitled “Performance of different genotypes of pummelo (Citrus grandis L.) for softwood grafting success and growth parameters” was carried out in the Department of Fruit Science, College of Horticulture Bengaluru in 2022. The experiment was laid out in a completely randomised design (CRD) with ten genotypes in three replications to know the response of softwood grafting success on locally gathered scions of elite Devanahalli pummelo genotypes was assessed. In February, they were grafted onto sixmonth-old rangpur lime rootstock. The results revealed that the genotype DSP-8 had recorded the significant minimum days (13) for bud breaking, the maximum graft success (96.67 %) and survivability (100.00 %). The genotype DSP-12 had a significantly maximum graft height at 30, 60, 90 and 120 days after grafting (DAG) (11.60, 14.73, 17.07 and 19.91 cm, respectively) and graft girth at 30, 60, 90 and 120 DAG (3.16, 3.95, 4.95, and 6.01 mm, respectively). Whereas the DSP-5 genotype had recorded significant maximum sprouts at 60, 90 and 120 DAG (3.67, 4.34 and 4.34, respectively) and the DSP-8 genotype had recorded the maximum number of leaves at 30, 60 and 120 DAG i.e., 7.67, 11.67 and 20.34. Among the different genotypes DSP-8 and DSP-12 recorded higher graft success, and these genotypes can be exploited for commercial production.

Construction of Full-Length Infectious cDNA Clones of Citrus Mosaic Virus RNA1 and RNA2 and Infection of Citrus Seedlings by Agrobacterium-Mediated Vacuum-Infiltration

The development of full-length infectious cDNA clones for plant RNA viruses is important for studying their molecular biological characteristics, functional genomics, pathogenesis, and vectorization applications. Citrus mosaic virus (CiMV), a member of the genus Sadwavirus, is of economic importance to the citrus industry and comprises a bipartite, positive-sense, single-stranded RNA genome encapsidated in icosahedral virions. In the present study, full-length cDNA clones of CiMV RNA1 and RNA2 were constructed based on a ternary yeast-Escherichia coli-Agrobacterium tumefaciens shuttle vector, pTY, using transformation-associated recombination (TAR) strategy. Infectivity of cDNA clones of CiMV RNA1 and RNA2 was examined in multiple citrus varieties via Agrobacterium-mediated vacuum-infiltration (AVI) through symptom observation, RT-PCR, and virion detection with an electron microscope. Furthermore, the genome-sized RT-PCR fragments of RNA1 and RNA2 were obtained from symptomatic Jinchengyou (Citrus grandis) plants infected by the cloned virus (CiMV211). In addition, CiMV211 produced typical symptoms of wild-type CiMV in cowpea (Vigna angularis) plants inoculated by Agrobacterium-mediated injection. This is the first report of infectious cDNA clones of CiMV, which may lay the foundation for research on the pathogenesis and vectorization of the virus.

Responses of physiological and morphological characteristics in Thai pummelo cultivars (Citrus maxima (Burm.) Merr.) under drought stress condition

Responses of physiological and morphological characteristics in Thai pummelo cultivars (Citrus maxima (Burm.) Merr.) under drought stress condition

Metabolomic analyses provides insight into the fruit nutritional and sensory attributes among 'Guanxi' pummelo and its bud mutants

The biochemical compositions in pummelo (<italic>Citrus maxima</italic>) fruits are key determining factors for the formation of nutrients and flavor. In this study, sensory (soluble solids, acidity and volatiles) and nutritional (vitamin C, carotenoids, phenols, flavonoids and antioxidant activity) profiles of fruit samples from 'Guanxi' pummelo and its four bud mutants were investigated. 'Guanxi' and 'Hongzuan', two pale-fleshed pummelo cultivars, contained relatively lower levels of carotenoids, vitamin C, phenols and total antioxidant activity compared to the other pummelos with red or yellow flesh. A total of 92 and 167 volatile compounds were detected in the pulp and flavedo of pummelo fruits, respectively. The majority of the different pulp volatiles were ketones, terpenes, alcohols and aldehydes, and were highly accumulated in 'Guanxihuang' pummelo (yellow-fleshed). The contents of volatiles in flavedo (285.85−955.88) were much larger than those in pulp (6.05−26.85) samples. Limonene was the most abundant volatile in flavedo, ranging from 133.28 in 'Hongzuan' to 480.36 in 'Guanxi'. The candidate genes <italic>TPS1</italic> and <italic>LOX2.1</italic> were associated with the amounts of terpenes and aldehydes in pummelo fruits. 'Sanhong' and 'Guanxihuang' fruits were preferred by tasters for their strong aroma, rich sweet and moderately sour taste, and high nutritional constituents. These results may provide insight into understanding the flavor metabolism pathways in pummelo fruits and facilitate further genetic improvement of pummelo fruit quality.

Termiticidal and Biochemical Activity of Combinatorial Essential Oil Ingredients of &amp;lt;i&amp;gt;Tagetes erecta&amp;lt;/i&amp;gt; on Indian White Termite &amp;lt;i&amp;gt;Odontotermes obesus&amp;lt;/i&amp;gt;

In present investigation, various bio-molecular parameters i.e. glycogen, protein, amino acid, DNA, RNA and lipid, were determined for evaluation of anti-termite efficacy of Tagetes erecta essential oil based combinatorial formulations against Indian white termite Odontotermes obesus. For this purpose, 40% and 80% of 24 hrs of LD50 values of various formulations were provided for treatment of termite workers. Observations were taken at 4 hrs time interval up to 16 hrs to know inhibitory activity of these combinatorial mixtures on termite species Odontotermes obesus. Significant (p > 0.05) alterations were observed in the level above mentioned bio-molecules when termites were treated with different combinatorial essential oils ingredients of Citrus maxima. Combinatorial mixtures of Tagetes erecta essential oils have shown synergistic activity against termites. This study will provide an overall sustainable way to termite control in crop field, gardens and houses. It also suggests use of essential oils as better alternative of synthetic termiticides as these are safer for environmental and human health.

Application of Organic Coal Fertilizer and Rabbit Farm Waste on Pumelo (Citrus grandis L. Osbeck) Seed Growth

The pumelo population in Bali is declining one is caused of a lack of good-quality seeds. This research was conducted to determine the effectiveness of organic coal fertilizer and rabbit farm waste as organic fertilizers for the growth of pomelo grafting seedlings. The research design used a nested pattern randomized block design with 3 replications. There are two factors, the first factor is the type of fertilizer, which are Coal fertilizers, Rabbit Farm Waste fertilizers, and Cow Manure fertilizers. The second factor is the dose of each type of fertilizer which consists of 3 levels, namely: 10 tons/ha; 20 tons/ha; and 30 tons/ha. The results showed that the effectiveness of the treatment of the type of organic fertilizer and the dose of the type of organic fertilizer had no significant effect on all observed variables. This shows that both coal fertilizer and rabbit manure have almost the same quality as cow manure in influencing the growth of pomelo seedlings. The effectiveness of fertilizers tested on the average shoot length of grafting tends to show the highest yields obtained at the highest dose (30 tons/ha), namely Coal fertilizer which is 28.80 cm, rabbit manure is 31.87 cm, and cow manure obtained is 28.13 cm.

Reducing aluminum is the key nutrient management strategy for ameliorating soil acidification and improving root growth in an acidic citrus orchard

AbstractAluminum (Al) toxicity is one of the most serious hazards of soil acidification, which limits root formation and hinders crop growth. Soil acidification in orchards has been widely reported. However, there is little information about the effect of Al3+ on citrus roots in acidified red soil. Taking pomelo (Citrus grandis), the main citrus variety in Southeast China, as an example, soil surveys were conducted to analyze the status and characteristics of acidification in pomelo orchards. Subsequently, we explored whether optimized fertilization and liming can effectively reduce Al toxicity in roots and increase yield by three treatments, including farmer fertilization practice (FFP), NPK optimization (OPT), and OPT combined with lime (OPT+L). The results showed that (1) rapid soil acidification occurred in pomelo orchards in the past 40 years (with a decrease of 0.81 units). The severity of soil acidification increases with orchard age. In addition, the soil pH and base saturation (BS) at the drip line (DL; i.e., fertilization site) were the lowest, while the concentration of exchangeable acid (Ex.Acid) and exchangeable Al (Ex.Al), and the ratio of Ex.Al to cation exchange capacity (Ex.Al%) was highest compared to other locations away from DL. Random forest analysis indicated Ex.Al was the most important factor to reflect soil acidification. (2) Under the OPT+L treatment, the concentrations of soil Ex.Acid and Ex.Al decreased, and BS increased, which markedly reduced the Al3+ concentration in the roots and promoted root growth. OPT+L significantly decreased the Al concentrations in soils (by 71.3%) and roots (by 47.8%) but increased root activity, root length, root tips and root surface area by 119.2%, 80.3%, 124.6% and 136.6%, respectively. In addition, structural equation modeling further proved that increasing soil pH and BS while decreasing Ex.Al was beneficial to citrus production in acidic soil, and optimized fertilization and lime application are necessary.

A Comparative Study on Ascorbic Acid Concentration, Total Phenol, and Flavonoid Content in Citrus Species Grown in a Different Region of Western Nepal.

Different genetic and environmental factors like altitude, temperature, light radiation, etc. affect the production of phytoconstituents like ascorbic acid, phenol, flavonoid, tannin, etc. So, it is necessary to evaluate phytoconstituents quantitatively and qualitatively because of their different medicinal values. This study is aimed at evaluating and comparing ascorbic acid concentration, total phenol, and flavonoid content in citrus species grown in different places in Western Nepal. For this, fruit collected from Lamjung and Nawalparasi was peeled, and collected juice was extracted with ethanol. Ascorbic acid was estimated using titration with dichlorophenolindophenol dye, and total phenol was estimated using Folin reagent; whereas, flavonoid content was determined by aluminum chloride colorimetric assay. The result showed the maximum ascorbic acid concentration in the fruit juice of Citrus maxima collected from Lamjung, i.e., 2.98 ± 0.161 mg/100 ml, and the least concentration was recorded on extract of Citrus limon collected from Nawalparasi, i.e., 1.005 ± 0.205 mg/100 ml. The total phenol content was comparatively higher in Citrus maxima and Citrus aurantifolia collected from Lamjung, i.e., 12.48 ± 0.40 mg GAE/gm, respectively. Flavonoid content was comparatively higher in Citrus maxima collected from Nawalparasi, i.e., 484.466 ± 3.055 mg QE/gm. This study showed a variation in the concentration of chemical constituents between different places in Western Nepal. This might be due to differences in climatic conditions, environmental factors, altitude, temperature, etc. This study helps to reflect the best-suited altitude for commercial cultivation of the citrus species as these phytochemicals have different medicinal values. Also, this study can help the food industry to use an alternative source of synthetic antioxidant such as ascorbic acid, phenol, and flavonoid. And local people will economically benefit by the commercial cultivation of citrus fruits.

Novel Pectic Polysaccharides Isolated from Immature Honey Pomelo Fruit with High Immunomodulatory Activity

A novel pectic polysaccharide (HPP-1) with high immunomodulatory activity was extracted and isolated from the immature honey pomelo fruit (Citrus grandis). Characterization of its chemical structure indicated that HPP-1 had a molecular weight of 59,024 D. In addition, HPP-1 was primarily composed of rhamnose, arabinose, fucose, mannose, and galactose at a molar ratio of 1.00:11.12:2.26:0.56:6.40. Fourier-transform infrared spectroscopy, periodic acid oxidation, and Smith degradation results showed that HPP-1 had α- and β-glycosidic linkages and 1 → 2, 1 → 4, 1 → 6, and 1 → 3 glycosidic bonds. 13C NMR and 1H NMR analyses revealed that the main glycogroups included 1,4-D-GalA, 1,6-β-D-Gal, 1,6-β-D-Man, 1,3-α-L-Ara, and 1,2-α-L-Rha. Immunomodulatory bioactivity analysis using a macrophage RAW264.7 model in vitro revealed that NO, TNF-α, and IL-6 secretions were all considerably increased by HPP-1. Moreover, RT-PCR results showed that HPP-1-induced iNOS, TNF-α, and IL-6 expression was significantly increased in macrophages. HPP-1-mediated activation in macrophages was due to the stimulation of the NF-κB and MAPK signaling pathways based on western blot analyses. HPP-1 extracted from immature honey pomelo fruit has potential applications as an immunomodulatory supplement.