Miracle Fruit (Synsepalum dulcificum) Exhibits as a Novel Anti-Hyperuricaemia Agent

Efficacy and Safety of Habitual Consumption of a Food Supplement Containing Miraculin in Malnourished Cancer Patients: The CLINMIR Pilot Study

Taste disorders (TDs) are common among systemically treated cancer patients and negatively impact their nutritional status and quality of life. The novel food approved by the European Commission (EFSA), dried miracle berries (DMB), contains the natural taste-modifying protein miraculin. DMB, also available as a supplement, has emerged as a possible alternative treatment for TDs. The present study aimed to evaluate the efficacy and safety of habitual DMB consumption in malnourished cancer patients undergoing active treatment. An exploratory clinical trial was carried out in which 31 cancer patients were randomized into three arms [standard dose of DMB (150 mg DMB/tablet), high dose of DMB (300 mg DMB/tablet) or placebo (300 mg freeze-dried strawberry)] for three months. Patients consumed a DMB tablet or placebo daily before each main meal (breakfast, lunch, and dinner). Throughout the five main visits, electrochemical taste perception, nutritional status, dietary intake, quality of life and the fatty acid profile of erythrocytes were evaluated. Patients consuming a standard dose of DMB exhibited improved taste acuity over time (% change right/left side: -52.8 ± 38.5/-58.7 ± 69.2%) and salty taste perception (2.29 ± 1.25 vs. high dose: 2.17 ± 1.84 vs. placebo: 1.57 ± 1.51 points, p < 0.05). They also had higher energy intake (p = 0.075) and covered better energy expenditure (107 ± 19%). The quality of life evaluated by symptom scales improved in patients receiving the standard dose of DMB (constipation, p = 0.048). The levels of arachidonic (13.1 ± 1.8; 14.0 ± 2.8, 12.0 ± 2.0%; p = 0.004) and docosahexaenoic (4.4 ± 1.7; 4.1 ± 1.0; 3.9 ± 1.6%; p = 0.014) acids in erythrocytes increased over time after DMB intake. The standard dose of DMB increased fat-free mass vs. placebo (47.4 ± 9.3 vs. 44.1 ± 4.7 kg, p = 0.007). Importantly, habitual patients with DMB did not experience any adverse events, and metabolic parameters remained stable and within normal ranges. In conclusion, habitual consumption of a standard 150 mg dose of DMB improves electrochemical food perception, nutritional status (energy intake, fat quantity and quality, fat-free mass), and quality of life in malnourished cancer patients receiving antineoplastic treatment. Additionally, DMB consumption appears to be safe, with no changes in major biochemical parameters associated with health status. Clinical trial registered (NCT05486260).

Anti-Hyperlipidemic Components of the Leaves of Synsepalum dulcificum (Miracle Fruit)

Synsepalum dulcificum (Miracle fruit) is a tropical plant in West and Central Africa, which has been historically used for treating diarrhea in humans and animals. Pharmacological research has shown that the leaves of the plant possess anti-hyperlipidemia activity. However, its anti-hyperlipidemic components have not been reported. In this study, the leaves of S. dulcificum were extracted using 95% ethanol and the extract was fractionated using different polar solvents. The anti-hyperlipidemia activity of the extract and fractions were evaluated using the zebrafish model. The results showed that the ethyl acetate (EA) fraction displayed the best anti-hyperlipidemic effect. A comparison of the high-performance liquid chromatography equipped with diode array detector (HPLC-DAD) profiles of the ethanol extract and different fractions at 350 nm indicated that a peak at 37.4 min has the highest intensity in the EA part, relatively. Then the chemical constituents of the extract and the active fraction were extensively identified using UPLC-Q-Exactive-Orbitrap-MS/MS, showing the main peak was quercitrin and other components in the EA part mainly included quercitrin analogs. Furthermore, the quercitrin was isolated from the plant and its contents in the extract and fractions were determined using high-performance liquid chromatography with ultraviolet detector (HPLC-UV) method. The quantitative results showed that the content of quercitrin in the EA fraction was 10.04% (w/w). Further pharmacological study indicated that quercitrin also possessed potent anti-hyperlipidemia activity (improvement rates of liver fat and total cholesterol were 75.6% and 92.5% at 40 μg/mL, respectively). Besides, quercitrin showed little toxicity to zebrafish embryos.

Biological Activities of Miracle Berry Supercritical Extracts as Metabolic Regulators in Chronic Diseases

Synsepalum dulcificum (Richardella dulcifica) is a berry fruit from West Africa with the ability to convert the sour taste into a sweet taste, and for this reason, the fruit is also known as the "miracle berry" (MB). The red and bright berry is rich in terpenoids. The fruit's pulp and skin contain mainly phenolic compounds and flavonoids, which correlate with their antioxidant activity. Different polar extracts have been described to inhibit cell proliferation and transformation of cancer cell lines in vitro. In addition, MB has been shown to ameliorate insulin resistance in a preclinical model of diabetes induced by a chow diet enriched in fructose. Herein, we have compared the biological activities of three supercritical extracts obtained from the seed-a subproduct of the fruit-and one supercritical extract obtained from the pulp and the skin of MB. The four extracts have been characterized in terms of total polyphenols content. Moreover, the antioxidant, anti-inflammatory, hypo-lipidemic, and inhibition of colorectal cancer cell bioenergetics have been compared. Non-polar supercritical extracts from the seed are the ones with the highest effects on the inhibition of bioenergetic of colorectal (CRC) cancer cells. At the molecular level, the effects on cell bioenergetics seems to be related to the inhibition of main drivers of the de novo lipogenesis, such as the sterol regulatory element binding transcription factor (SREBF1) and downstream molecular targets fatty acid synthase (FASN) and stearoyl coenzyme desaturase 1 (SCD1). As metabolic reprograming is considered as one of the hallmarks of cancer, natural extracts from plants may provide complementary approaches in the treatment of cancer. Herein, for the first time, supercritical extracts from MB have been obtained, where the seed, a by-product of the fruit, seems to be rich in antitumor bioactive compounds. Based on these results, supercritical extracts from the seed merit further research to be proposed as co-adjuvants in the treatment of cancer.

Miracle fruit seed as a potential supplement for the treatment of learning and memory disorders in Alzheimer's disease

Currently, the treatment of Alzheimer's disease (AD) is still at the stage of symptomatic treatment due to lack of effective drugs. The research on miracle fruit seeds (MFSs) has focused on lipid-lowering and antidiabetic effects, but no therapeutic effects have been reported in AD. The purpose of this study was to provide data resources and a potential drug for treatment of AD. An AD mouse model was established and treated with MFSs for 1 month. The Morris water maze test was used to assess learning memory function in mice. Nissl staining was used to demonstrate histopathological changes. MFSs were found to have therapeutic implications in the AD mouse model, as evidenced by improved learning memory function and an increase in surviving neurons. To explore the mechanism of MFSs in treating AD, network pharmacological approaches, Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and molecular docking studies were carried out. Based on the network pharmacology strategy, 74 components from MFS corresponded to 293 targets related to the AD pathology. Among these targets, AKT1, MAPK3, ESR1, PPARG, PTGS2, EGFR, PPARA, CNR1, ABCB1, and MAPT were identified as the core targets. According to the relevant number of core targets, cis-8-octadecenoic acid, cis-10-octadecenoic acid, 2-dodecenal, and tetradecane are likely to be highly correlated with MFS for AD. Enrichment analysis indicated the common targets mainly enriched in AD and the neurodegeneration-multiple disease signaling pathway. The molecular docking predictions showed that MFSs were stably bound to core targets, specifically AKT1, EGFR, ESR1, PPARA, and PPARG. MFSs may play a therapeutic role in AD by affecting the insulin signaling pathway and the Wnt pathway. The findings of this study provide potential possibilities and drug candidates for the treatment of AD.

Mechanism of Synsepalum dulcificum Daniell. Inhibiting Lung Adenocarcinoma

Objective: Synsepalum dulcificum Daniell. (SD) is a natural plant fruit and is famous for containing miraculin. It has been reported that SD can be used as an adjuvant treatment to correct patients' loss of taste during the antitumor process, but the effect of SD itself as an antitumor is not clear. In this study, we investigated the mechanism of action of SD on lung adenocarcinoma using network pharmacology. Materials and Methods. The components of SD were identified by liquid chromatography-mass spectrometry, and then the compounds that affect tumor immunity of SD were screened and the related targets were predicted by TCMIO database. At the same time, the results were associated with lung adenocarcinoma targets included in the MalaCards and CTD databases, so as to construct a compound-target action network diagram and explore the mechanism of SD in the treatment of lung adenocarcinoma. In in vitro experiments, cell viability was determined and western blotting was used to detect the related expression of action targets to determine the therapeutic effect of SD. Results. In this experiment, 335 chemical components were identified in SD, and 107 components were related to tumor immunity. After screening by ADME, it was found that 11 compounds might be inhaled into the human body and affect the growth of lung adenocarcinoma. In vitro experiments showed that SD could inhibit the growth of lung adenocarcinoma A549 cells. SD could reduce the expression of PCNA (P < 0.05) and significantly increase the expression of Caspase-3 (P < 0.05). The results of further experiments showed that SD could significantly reduce the phosphorylation of EGFR (P < 0.05), and SD could also effectively inhibit the expression of JAK and STAT3 phosphorylation (P < 0.01) and inhibit the expression of PI3K and AKT phosphorylation (P < 0.01). Conclusion. SD can inhibit the growth of lung adenocarcinoma A549 cells and the potential mechanism was found to be the inhibition of EGFR/JAK/STAT3 and EGFR/PI3K/AKT signaling pathway, and the substance basis for SD to exert antitumor effect may be catechin, taxifolin, betaine, epigallocatechin gallate, erucamide, guanosine, kaempferol, lanosterol, morin, oleanolic acid, and quercetin.

The Chromosome-Level Genome of Miracle Fruit (Synsepalum dulcificum) Provides New Insights Into the Evolution and Function of Miraculin

Miracle fruit (Synsepalum dulcificum) is a rare valuable tropical plant famous for a miraculous sweetening glycoprotein, miraculin, which can modify sour flavors to sweet flavors tasted by humans. Here, we present a chromosome-level high-quality genome of S. dulcificum with an assembly genome size of ∼550 Mb, contig N50 of ∼14.14 Mb, and 37,911 annotated protein-coding genes. Phylogenetic analysis revealed that S. dulcificum was most closely related to Camellia sinensis and Diospyros oleifera, and that S. dulcificum diverged from the Diospyros genus ∼75.8 million years ago (MYA), and that C. sinensis diverged from Synsepalum ∼63.5 MYA. Ks assessment and collinearity analysis with S. dulcificum and other species suggested that a whole-genome duplication (WGD) event occurred in S. dulcificum and that there was good collinearity between S. dulcificum and Vitis vinifera. On the other hand, transcriptome and metabolism analysis with six tissues containing three developmental stages of fleshes and seeds of miracle fruit revealed that Gene Ontology (GO) terms and metabolic pathways of "cellular response to chitin," "plant-pathogen interaction," and "plant hormone signal transduction" were significantly enriched during fruit development. Interestingly, the expression of miraculin (Chr10G0299340) progressively increased from vegetative organs to reproductive organs and reached an incredible level in mature fruit flesh, with an fragments per kilobase of transcript per million (FPKM) value of ∼113,515, which was the most highly expressed gene among all detected genes. Combining the unique signal peptide and the presence of the histidine-30 residue together composed the main potential factors impacting miraculin's unique properties in S. dulcificum. Furthermore, integrated analysis of weighted gene coexpression network analysis (WGCNA), enrichment and metabolite correlation suggested that miraculin plays potential roles in regulating plant growth, seed germination and maturation, resisting pathogen infection, and environmental pressure. In summary, valuable genomic, transcriptomic, and metabolic resources provided in this study will promote the utilization of S. dulcificum and in-depth research on species in the Sapotaceae family.

The Efficacy and Mechanism of Chinese Herbal Medicines in Lowering Serum Uric Acid Levels: A Systematic Review

Background. Chinese herbal medicines are widely used to lower serum uric acid levels. However, no systemic review summarizes and evaluates their efficacies and the underlying mechanisms of action. Objectives. To evaluate the clinical and experimental evidences for the effectiveness and the potential mechanism of Chinese herbal medicines in lowering serum uric acid levels. Methods. Four electronic databases PubMed, Wed of Science, the Cochrane Library and Embase were used to search for Chinese herbal medicines for their effects in lowering serum uric acid levels, dated from 1 January 2009 to 19 August 2020. For clinical trials, randomized controlled trials (RCTs) were included; and for experimental studies, original articles were included. The methodological quality of RCTs was assessed according to the Cochrane criteria. For clinical trials, a meta-analysis of continuous variables was used to obtain pooled effects. For experimental studies, lists were used to summarize and integrate the mechanisms involved. Results. A total of 10 clinical trials and 184 experimental studies were included. Current data showed that Chinese herbal medicines have promising clinical efficacies in patients with elevated serum uric acid levels (SMD: −1.65, 95% CI: −3.09 to −0.22; p = 0.024). There was no significant difference in serum uric acid levels between Chinese herbal medicine treatments and Western medicine treatments (SMD: −0.13, 95% CI: −0.99 to 0.74; p = 0.772). Experimental studies revealed that the mechanistic signaling pathways involved in the serum uric acid lowering effects include uric acid synthesis, uric acid transport, inflammation, renal fibrosis and oxidative stress. Conclusions. The clinical studies indicate that Chinese herbal medicines lower serum uric acid levels. Further studies with sophisticated research design can further demonstrate the efficacy and safety of these Chinese herbal medicines in lowering serum uric acid levels and reveal a comprehensive picture of the underlying mechanisms of action.

Miracle Berry as a Potential Supplement in the Control of Metabolic Risk Factors in Cancer

The increased incidence of chronic diseases related to altered metabolism has become a social and medical concern worldwide. Cancer is a chronic and multifactorial disease for which, together with genetic factors, environmental factors are crucial. According to the World Health Organization (WHO), up to one third of cancer-related deaths could be prevented by modifying risk factors associated with lifestyle, including diet and exercise. Obesity increases the risk of cancer due to the promotion of low-grade chronic inflammation and systemic metabolic oxidative stress. The effective control of metabolic parameters, for example, controlling glucose, lipid levels, and blood pressure, and maintaining a low grade of chronic inflammation and oxidative stress might represent a specific and mechanistic approach against cancer initiation and progression. Miracle berry (MB) (Synsepalum dulcificum) is an indigenous fruit whose small, ellipsoid, and bright red berries have been described to transform a sour taste into a sweet one. MB is rich in terpenoids, phenolic compounds, and flavonoids, which are responsible for their described antioxidant activities. Moreover, MB has been reported to ameliorate insulin resistance and inhibit cancer cell proliferation and malignant transformation in vitro. Herein, we briefly summarize the current knowledge of MB to provide a scientific basis for its potential use as a supplement in the management of chronic diseases related to altered metabolism, including obesity and insulin resistance, which are well-known risk factors in cancer. First, we introduce cancer as a metabolic disease, highlighting the impact of systemic metabolic alterations, such as obesity and insulin resistance, in cancer initiation and progression. Next, as oxidative stress is closely associated with metabolic stress, we also evaluate the effect of phytochemicals in managing oxidative stress and its relationship with cancer. Finally, we summarize the main biological activities described for MB-derived extracts with a special focus on the ability of miraculin to transform a sour taste into a sweet one through its interaction with the sweet taste receptors. The identification of sweet taste receptors at the gastrointestinal level, with effects on the secretion of enterohormones, may provide an additional tool for managing chronic diseases, including cancer.

Nutritional benefits, phytochemical constituents, ethnomedicinal uses and biological properties of Miracle fruit plant (Synsepalum dulcificum Shumach. & Thonn. Daniell)

Miracle fruit plant or Miracle berry plant (Synsepalum dulcificum) is a peculiar medicinal plant because of the unique taste-modifying property of its fruit which is due to the presence of the glycoprotein, miraculin. This property has been known for centuries to the people of tropical Western and Central Africa who also employ different parts of the plant in the management of various ailments. Scientific investigations have unravelled several pharmacological properties of the plant which include antidiabetic, blood cholesterol-lowering, anti-hyperuricaemia, antioxidant, anticonvulsant and anticancer properties. Also, subacute administration of the plant extract up to 200 mg/kg was not found to be toxic in rats. Apart from miraculin, other pharmacologically active compounds have been identified in the plant including alkaloids (dihydro-feruloyl-5-methoxytyramine, N-cis-caffeoyltyramine, N-cis-feruloyl-tyramine), lignins (+-syringaresinol, +-epi-syringaresinol), phytosterols, triterpenoids, phenolic acids, flavonoids, and amino acids. The plant has also been credited with notable nutritional benefits. Proper documentation of available information on folkloric use, biological activity, constituent phytocompounds, and nutritional benefits of ethnobotanicals will go a long way in affording optimal benefits from their therapeutic potentials. This can also aid in the conservation of species at risk of extinction. This work presents an up-to-date review of the ethnobotany, phytochemistry, biological and nutritional properties of Synsepalum dulcificum.

Antihyperglycemic and hepatoprotective properties of miracle fruit (Synsepalum dulcificum) compared to aspartame in alloxan-induced diabetic mice

OBJECTIVE

This study was undertaken to investigate the antihyperglycemic potential of miracle fruit (MF) as well as its hepatic safety as compared to aspartame in alloxan-induced diabetic mice.

METHODS

MF extracts were prepared and screened for their phytochemical composition using high-performance liquid chromatography (HPLC). Total phenolic, flavonoid and tannin contents and antioxidant potential were also determined. Additionally, MF was evaluated for its sensory attributes. For in vivo work, MF ethanol extract at high (MFH: 500 mg/kg body weight [BW]) and low (MFL: 250 mg/kg BW) doses as well as aspartame were injected intraperitoneally into alloxan-induced diabetic mice. Blood glucose levels were determined following acute and subchronic treatment. At the end of the study, animals were sacrificed, serum was collected for biochemical analysis and liver tissues were obtained for histopathological examination.

RESULTS

MF ethanol extract contained more flavonoids and tannins, and had higher 1,1-diphenyl-1-picrylhydrazyl radical-scavenging activity (79.61%) compared to MF aqueous extract (P < 0.05). HPLC analysis of MF ethanol extract also revealed the presence of 10 antioxidants with quercetin comprising the major polyphenol. Additionally, sensory analysis of MF showed that its intake is effective in masking undesirable sourness. Subchronic administration of MFH proved amelioration of hyperglycemia in mice as compared to aspartame. Moreover, aspartame treatment significantly elevated (P < 0.05) the level of alanine aminotransferase and had destructive effects on the liver histopathology; however, hepatic architecture was restored by low and high doses of MF.

CONCLUSION

MF is an effective antihyperglycemic with hepatoprotective properties that can be used as a healthier alternative sweetening agent in place of aspartame for sour beverages.

Chemical constituents and their antioxidant activities from the leaves of Synsepalum dulcificum

Synsepalum dulcifificum is an evergreen shrub native of tropical West Africa. It is very effective against a variety of diseases. However, the phytochemical investigation on this plant is limited till now. In our current study, seventeen compounds were isolated and identified from the ethyl acetate extract of the leaves. All of the compounds were obtained from S. dulcifificum for the first time. Compounds 4 and 9 were isolated from natural source for the second time. Moreover, the antioxidant activities of compounds 1, 4, 5, 9-11, and 15 were evaluated firstly. Compounds 6, 7, 13, and 14 exhibited significant antioxidant activity in DPPH and ABTS + assays, suggesting their potential application for an antioxidant drug.

Complete chloroplast genome of Synsepalum dulcificum D.: a magical plant that modifies sour flavors to sweet

Synsepalum dulcificum D. belongs to the Sapotaceae family, which is an evergreen shrub native to tropical West Africa. It is a kind of magical plant that has the unique characteristic of modifying sour flavors to sweet. In this study, the chloroplast genome of S. dulcificum was sequenced, assembled, and annotated firstly. Chloroplast genome size of S. dulcificum is 158,463 bp, the circular chloroplast genome consists of four regions: a large single-copy region of 88,256 bp, two inverted repeat regions of 25,958 bp, and a small single-copy region of 18,669 bp, with the GC content of 36.87%. A total of 133 genes were annotated in the S. dulcificum chloroplast genome, of which 88 were protein-coding genes (PCGs), 37 were transfer RNA (tRNA) genes, and eight were ribosomal RNA (rRNA) genes. Phylogenetic analysis showed that Pouteria campechiana was most closely related to S. dulcificum. The study provides important genomic data for further utilization and breeding of S. dulcificum.

The cholesterol-lowering activity of miracle fruit (Synsepalum dulcificum)

Miracle fruit (Synsepalum dulcificum) is famous for its uniqueness of modifying sour taste to sweetness. However, its cholesterol-lowering activity has not been reported. This study investigated the effect of S. dulcificum on the compositional changes of plasma lipids in hamsters fed a high-cholesterol control diet. Six groups of hamsters were fed either a control diet or one of the five experimental diets containing 2% ethanol extract of leaves, 2% water extract of leaves, 2% ethanolic extract of seeds (ES), 2% water extract of seeds, or 2% dry pulp. Results showed that ES decreased the plasma total cholesterol (TC). Two triterpenoids (lupeol acetate and β-amyrin acetate) were isolated from the ES and they added to a diet could decrease TC by 15%-20% in hamsters. It was concluded that ES showed potent TC-lowering activity and triterpenoid was one of the active components of ES. PRACTICAL APPLICATIONS: In recent years, people are more interested in phytochemicals from functional foods treated for hyperlipidemia because they possessed fewer side effects than the synthetic drugs. The triterpenoids isolated from the miracle fruit may be promising candidates for the development of cholesterol-lowering agent, especially for patients whose blood cholesterol level and body weight are high. Meanwhile, the miracle fruit have a good potential as cholesterol-lowering functional food or a natural source of cholesterol-lowering agent.

Effect of high uric acid on the disposition of metformin: in vivo and in vitro studies

Metformin is always used as the baseline antidiabetic therapy for patients with type 2 diabetes mellitus (T2DM) and hyperuricemia. Metformin is excreted into urine through active secretion mediated by rOCTs and rMATE1.The aim of this study was to identify the effects of high uric acid on the disposition and its mechanism. For the in vivo study, a hyperuricemic animal model was induced by intraperitoneal injection of potassium oxonate (250 mg/kg) in rats. Metformin (100 mg/kg) was administered orally to investigate the pharmacokinetics in control and hyperuricemic rats, respectively. For the in vitro study, HEK293 and HepaRG cells were used to investigate the effect of uric acid (15 mg/dl) on the expression of OCT1, OCT2 and MATE1 and the disposition of metformin, respectively. The in vivo study showed that the AUC_0 → 600 of metformin was significantly decreased by 33.3%, whereas the cumulative urinary excretion of metformin was increased by 25.4% in hyperuricemic rats compared with that in control rats. The renal rOCT1, rOCT2 and rMATE1 and hepatic rMATE1 levels were increased in hyperuricemic rats compared with those in control rats, respectively. The in vitro study showed that uric acid could upregulate the expression of OCT2 and MATE1 in HEK293 cells and MATE1 in HepaRG cells and increase the intracellular metformin concentration in these two cell lines. These results demonstrated that a high uric acid level promoted urinary metformin excretion and decreased the plasma metformin concentration; the in vivo and in vitro studies provided a possible explanation being that high uric acid could upregulate the expression of renal metformin transporters OCTs and MATE1.

Anti-gout Potential of Malaysian Medicinal Plants

Gout is a type of arthritis that causes painful inflammation in one or more joints. In gout, elevation of uric acid in the blood triggers the formation of crystals, causing joint pain. Malaysia is a mega-biodiversity country that is rich in medicinal plants species. Therefore, its flora might offer promising therapies for gout. This article aims to systematically review the anti-gout potential of Malaysian medicinal plants. Articles on gout published from 2000 to 2017 were identified using PubMed, Scopus, ScienceDirect, and Google Scholar with the following keyword search terms: “gout,” “medicinal plants,” “Malaysia,” “epidemiology,” “in vitro,” and “in vivo.” In this study, 85 plants were identified as possessing anti-gout activity. These plants had higher percentages of xanthine oxidase inhibitory activity (>85%); specifically, the Momordica charantia, Chrysanthemum indicum, Cinnamomum cassia, Kaempferia galanga, Artemisia vulgaris, and Morinda elliptica had the highest values, due to their diverse natural bioactive compounds, which include flavonoids, phenolics, tannin, coumarins, luteolin, and apigenin. This review summarizes the anti-gout potential of Malaysian medicinal plants but the mechanisms, active compounds, pharmacokinetics, bioavailability, and safety of the plants still remain to be elucidated.

Antihyperuricemic effect of mangiferin aglycon derivative J99745 by inhibiting xanthine oxidase activity and urate transporter 1 expression in mice

A mangiferin aglycon derivative J99745 has been identified as a potent xanthine oxidase (XOD) inhibitor by previous in vitro study. This study aimed to evaluate the hypouricemic effects of J99745 in experimental hyperuricemia mice, and explore the underlying mechanisms. Mice were orally administered 600 mg/kg xanthine once daily for 7 days and intraperitoneally injected 250 mg/kg oxonic acid on the 7th day to induce hyperuricemia. Meanwhile, J99745 (3, 10, and 30 mg/kg), allopurinol (20 mg/kg) or benzbromarone (20 mg/kg) were orally administered to mice for 7 days. On the 7th day, uric acid and creatinine in serum and urine, blood urea nitrogen (BUN), malondialdehyde (MDA) content and XOD activities in serum and liver were determined. Morphological changes in kidney were observed using hematoxylin and eosin (H&E) staining. Hepatic XOD, renal urate transporter 1 (URAT1), glucose transporter type 9 (GLUT9), organic anion transporter 1 (OAT1) and ATP-binding cassette transporter G2 (ABCG2) were detected by Western blot and real time polymerase chain reaction (PCR). The results showed that J99745 at doses of 10 and 30 mg/kg significantly reduced serum urate, and enhanced fractional excretion of uric acid (FEUA). H&E staining confirmed that J99745 provided greater nephroprotective effects than allopurinol and benzbromarone. Moreover, serum and hepatic XOD activities and renal URAT1 expression declined in J99745-treated hyperuricemia mice. In consistence with the ability to inhibit XOD, J99745 lowered serum MDA content in hyperuricemia mice. Our results suggest that J99745 exerts urate-lowering effect by inhibiting XOD activity and URAT1 expression, thus representing a promising candidate as an anti-hyperuricemia agent.

Physicochemical Characterisation of Polysaccharides from the Seeds and Leaves of Miracle Fruit (Synsepalum dulcificum) and Their Antioxidant and α-Glucosidase Inhibitory Activities In Vitro

Miracle fruit (Synsepalum dulcificum) has been well known and studied for its unique taste-modifying ability. In this study, the monosaccharide composition, molecular weight (Mw), and in vitro bioactivities (antioxidant, α-glucosidase inhibition) of polysaccharides from the seeds (MFP-S) and leaves (MFP-L) of miracle fruit were investigated. The results showed that MFP-S was a homogeneous polysaccharide (Mw 2804 Da) with glucose. MFP-L displayed three fractions (92093, 1496, and 237 Da) consisting of rhamnose, arabinose, galactose, glucose, and xylose. Moreover, the antioxidant and α-glucosidase inhibition of MFP-L were significantly greater than those of MFP-S. The α-glucosidase inhibition of MFP-L was remarkably better than the positive control, acarbose (an antidiabetes drug). More specifically, the 50% inhibitory concentration (IC50) values of α-glucosidase activities for MFP-S, MFP-L, and acarbose were 33, 0.01, and 1 mg mL−1, separately. Therefore, MFP-L can be developed as a functional factor with both antioxidant and antidiabetes activities in food applications.