Guarana powder polysaccharides: Characterisation and evaluation of the antioxidant activity of a pectic fraction

Synthesis of Silver Nanoparticles Using Extracts from Different Parts of the Paullinia cupana Kunth Plant: Characterization and In Vitro Antimicrobial Activity

The green synthesis of silver nanoparticles (AgNPs) can be developed using safe and environmentally friendly routes, can replace potentially toxic chemical methods, and can increase the scale of production. This study aimed to synthesize AgNPs from aqueous extracts of guarana (Paullinia cupana) leaves and flowers, collected in different seasons of the year, as a source of active biomolecules capable of reducing silver ions (Ag+) and promoting the stabilization of colloidal silver (Ag0). The plant aqueous extracts were characterized regarding their metabolic composition by liquid chromatography coupled to high-resolution mass spectrometry (UHPLC-HRMS/MS), phenolic compound content, and antioxidant potential against free radicals. The synthesized AgNPs were characterized by UV/Vis spectrophotometry, dynamic light scattering (DLS), nanoparticle tracking analysis (NTA), transmission electron microscopy (TEM), and scanning electron microscopy coupled to energy-dispersive X-ray spectrometry (EDX). The results demonstrated that the chemical characterization indicated the presence of secondary metabolites of many classes of compounds in the studied aqueous extracts studied, but alkaloids and flavonoids were predominant, which are widely recognized for their antioxidant capabilities. It was possible to notice subtle changes in the properties of the nanostructures depending on parameters such as seasonality and the part of the plant used, with the AgNPs showing surface plasmon resonance bands between 410 and 420 nm using the leaf extract and between 440 and 460 nm when prepared using the flower extract. Overall, the average hydrodynamic diameters of the AgNPs were similar among the samples (61.98 to 101.6 nm). Polydispersity index remained in the range of 0.2 to 0.4, indicating that colloidal stability did not change with storage time. Zeta potential was above -30 mV after one month of analysis, which is adequate for biological applications. TEM images showed AgNPs with diameters between 40.72 to 48.85 nm and particles of different morphologies. EDX indicated silver content by weight between 24.06 and 28.81%. The synthesized AgNPs exhibited antimicrobial efficacy against various pathogenic microorganisms of clinical and environmental interest, with MIC values between 2.12 and 21.25 µg/mL, which is close to those described for MBC values. Therefore, our results revealed the potential use of a native species of plant from Brazilian biodiversity combined with nanotechnology to produce antimicrobial agents.

The effect of ultrasonic power on the physicochemical properties and antioxidant activities of frosted figs pectin

Ultrasound has been widely used in industry due to its high energy and efficiency. This study optimized the ultrasonic-assisted extraction (UAE) process of frosted figs pectin (FFP) using response surface methodology (RSM), and further investigated the effect of ultrasonic power on the structural characteristics and antioxidant activities of FFPs. The UAE method of FFP through RSM was optimized, and the optimal extraction process conditions, particle size of 100 mesh, pH value of 1.95, liquid-solid ratio of 47:1 (mL/g), extraction temperature of 50 °C and extraction time of 65 min, were obtained. The extraction rate of FFP under this condition was 37.97 ± 2.56 %. Then, the four FFPs modified by ultrasound were obtained by changing the ultrasonic power. Research had found that ultrasonic power had little effect on the monosaccharide composition, Zeta potential, as well as the thermal stability and appearance structure of the four FFPs. However, ultrasonic power had a significant impact on other properties of FFP: as the ultrasonic power increased, the DM% and particle size decreased continuously, while the total carbohydrate content increased. Meanwhile, ultrasonic power also had a significant impact on antioxidant activities of FFPs. From the research results, it could be seen that different ultrasonic power had certain changes in its spatial structure and properties, and the structural changes also affected the biological activity of FFP. The study of the effects of ultrasonic power on the physicochemical properties and biological activity of FFP lays the foundation for the development and application of FFP in food additives and natural drug carriers.

Metabolomic profiling and correlations of supercritical extracts of guarana

A previous optimization of supercritical extraction from guarana seeds was performed applying orthogonal array design (OA9(34)). The antioxidant and antimicrobial activities of these extracts, as well as metabolomic profiling and correlations from the compounds by statistical analysis were determined. Extracts 1 (40% ethanol; 20 min; 40 °C and 100 bar), 2 (40% methanol; 60 min; 40 °C and 200 bar), and 8 (40% methanol; 40 min; 60 °C and 100 bar) had the highest combined values of antioxidant capacity for the DPPH, FRAP, ABTS and xanthine oxidase system methods, and were identified by chemometric analysis. Similar chemical profiles of the extracts were obtained by LC-DAD-MS, and were identified: methyl-xanthine, (epi)catechin and dimers and trimers of type A and B proanthocyanidins. The heat map analysis showed positive correlation between antioxidant methods DPPH, FRAP and ABTS and with flavan-3-ols and proanthocyanidins. Extract 3 was active against Gram-negative and -positive bacteria and Candida tropicalis.

Isolation, NMR characterization and bioactivity of a (4-O-methyl-α-D-glucurono)-β-D-xylan from Campomanesia xanthocarpa Berg fruits

Hemicellulose-type polysaccharides were isolated from Campomanesia xanthocarpa fruits by alkaline extraction and submitted to fractionation processes giving rise to eluted (GE-300) and retained (GR-300) fractions. GE-300 presented a mixture of galactoglucomannans (GGM) and glucuronoxylans (MGX), while the GR-300 fraction is composed only of MGX. In this way, the chemical structure of MGX, investigated by 1D ¹H, ¹³C and 2D ¹H-¹³C HSQC, ¹H-¹H COSY and ¹H-¹³C HMBC NMR spectroscopy, revealed that the chemical structure of polysaccharide is a (4-O-methyl-α-D-glucurono)-D-xylan. Deep and precise NMR chemical shift determination of clean and specific ¹H NMR glycosyl units were developed by 1D TOCSY and 1D NOESY analysis. This approach demonstrated unequivocally that 4-O-methyl-α-D-glucopyranosyl uronic acid group is linked to O-2 of a (1 → 4)-β-D-xylan in the main chain. Furthermore, MGX scavenged DPPH radical (0.5 to 1.0 mg mL^-1) and was not cytotoxic to human dermal fibroblasts at concentrations up to 1.0 mg mL^-1, as demonstrated by neutral red and crystal violet assays, evidencing in vitro biocompatibility. The structure elucidation of GR-300 together with its bioactivity assessment contributed to better understand the chemical characteristics of C. xanthocarpa hemicelluloses and may provide structural basis for future structure-property studies.

Production of Lignocellulolytic Enzymes and Phenolic Compounds by Lentinus strigosus from the Amazon Using Solid-State Fermentation (SSF) of Guarana (Paullinia cupana) Residue

The Amazon rainforest has a rich biodiversity, and studies of Basidiomycete fungi that have biomolecules of biotechnological interest are relevant. The use of lignocellulosic biomass in biotechnological processes proposes an alternative use, and also adds value to the material when employed in the bioconversion of agro-industrial waste. In this context, this study evaluate the production of lignocellulolytic enzymes (carboxymethylcellulases (CMCase), xylanase, pectinase, laccase) as well as phenolic compounds and proteases by solid-state fermentation (SSF) using the fungus Lentinus strigosus isolated from Amazon. The guarana (Paullinia cupana) residue was characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). SSF was carried out with 60% humidification of the residue, at 30 °C, for 10 days. The lignocellulosic biomass presented fragmented structures with irregular shapes and porosities, and was mainly constituted by cellulose (19.16%), hemicellulose (32.83%), and lignin (6.06%). During the SSF, significant values of CMCase (0.84 U/g) on the 8th day, xylanase (1.00 U/g) on the 7th day, pectinase (2.19 U/g) on the 6th day, laccase (176.23 U/mL) on the 5th day, phenolic compounds (10.27 μg/mL) on the 1st day, soluble proteins (0.08 mg/mL) on the 5th day, and protease (8.30 U/mL) on the 6th day were observed. In general, the agro-industrial residue used provided promising results as a viable alternative for use as a substrate in biotechnological processes.

TNF-α inhibition, antioxidant effects and chemical analysis of extracts and fraction from Brazilian guaraná seed powder

Paullinia cupana Kunth., commonly named Guaraná, is a plant from Brazil used as stimulant. The aim of this study was to evaluate the potential of extracts and tannins-rich and methylxanthines-free fraction from guaraná in the anti-inflammatory and antioxidant effect in vitro. Extract 1 obtained good yields of tannins and methylxanthines and was used to identify a type-A procyanidin trimer by LC-ESI-MS. Fraction 4 was rich in tannins and absent of methylxanthines. The extracts and fraction exhibited strong capacity for scavenging DPPH radical with IC₅₀ between 5.88 and 42.75-µg/mL and inhibited TNF-α release by LPS-activated THP-1 cells when compared with control cells and did not present toxicity to THP-1 cells. The fraction 4, rich in tannins, was highly active, with IC₅₀ 5.88 µg/mL by DPPH method and inhibited TNF-α release in 83.50% at 90 µg/mL. These results reinforced potential anti-inflammatory of guaraná and data for new therapeutic approaches.

A Mechanistic Evaluation of Antioxidant Nutraceuticals on Their Potential against Age-Associated Neurodegenerative Diseases

Nutraceuticals have been extensively studied worldwide due to its neuroprotective effects in in vivo and in vitro studies, attributed by the antioxidative properties. Alzheimer (AD) and Parkinson disease (PD) are the two main neurodegenerative disorders that are discussed in this review. Both AD and PD share the similar involvement of oxidative stress in their pathophysiology. Nutraceuticals exert their antioxidative effects via direct scavenging of free radicals, prevent damage to biomolecules, indirectly stimulate the endogenous antioxidative enzymes and gene expressions, inhibit activation of pro-oxidant enzymes, and chelate metals. In addition, nutraceuticals can act as modulators of pro-survival, pro-apoptotic, and inflammatory signaling pathways. They have been shown to be effective particularly in preclinical stages, due to their multiple mechanisms of action in attenuating oxidative stress underlying AD and PD. Natural antioxidants from food sources and natural products such as resveratrol, curcumin, green tea polyphenols, and vitamin E are promising therapeutic agents in oxidative stress-mediated neurodegenerative disease as they have fewer adverse effects, more tolerable, cheaper, and sustainable for long term consumption.

Insoluble-Bound Polyphenols Released from Guarana Powder: Inhibition of Alpha-Glucosidase and Proanthocyanidin Profile

The Brazilian Food Supplement Law recently recognized that guarana (Paullinia cupana) contains bioactive substances, hence supporting its role as a functional food ingredient. The health benefits of guarana are associated, at least in part, to its phenolic compounds. However, to the best of our knowledge, there is no literature addressing the presence of phenolic compounds in the fraction containing insoluble-bound compounds and its contribution in terms of alpha-glucosidase inhibition. The concentration of phenolic extracts released from the insoluble-bound fraction required to inhibit 50% of alpha-glucosidase (IC₅₀) activity was 5.8-fold lower than that present in the soluble counterpart. Both fractions exhibited a mixed inhibition mode. Fourteen proanthocyanidins (dimers to tetramers) present in the insoluble-bound fraction were tentatively identified by MALDi-TOF-MS. Future studies aiming at increasing the concentration of the soluble counterpart are deemed necessary. The results presented here enhance the phenolic database of guarana and have a practical impact on the procurement of nutraceuticals and functional ingredients related to the prevention and/or management of type 2 diabetes. The Brazilian normative on food supplements has been recently revised. This study lends support to the future inclusion of guarana powder in the list of sources of proanthocyanidins for the industry of food supplements.

Antioxidant Properties of Amazonian Fruits: A Mini Review of In Vivo and In Vitro Studies

Brazil, Colombia, Ecuador, Peru, Bolivia, Venezuela, Suriname, Guyana, and French Guiana share an area of 7,295,710 km² of the Amazon region. It is estimated that the Amazonian forest offers the greatest flora and fauna biodiversity on the planet and on its surface could cohabit 50% of the total existing living species; according to some botanists, it would contain about 16-20% of the species that exist today. This region has native fruit trees in which functional properties are reported as antioxidant and antiproliferative characteristics. Amazon plants offer a great therapeutic potential attributed to the content of bioactive phytochemicals. The aim of this mini review is to examine the state of the art of the main bioactive components of the most studied Amazonian plants. Among the main functional compounds reported were phenolic compounds, unsaturated fatty acids, carotenoids, phytosterols, and tocopherols, with flavonoids and carotenoids being the groups of greatest interest. The main beneficial effect reported has been the antioxidant effect, evaluated in most of the fruits investigated; other reported functional properties were antimicrobial, antimutagenic, antigenotoxic, analgesic, immunomodulatory, anticancer, bronchodilator, antiproliferative, and anti-inflammatory, including hypercholesterolemic effects, leishmanicidal activity, induction of apoptosis, protective action against diabetes, gastroprotective activity, and antidepressant effects.

Thermal decomposition kinetics of guarana seed residue through thermogravimetric analysis under inert and oxidizing atmospheres

This work aims to analyze the thermal decomposition kinetics of guarana seed residue applying inert and oxidizing atmospheres. Thermal decomposition experiments were carried out in a thermogravimetric analyser using heating rates of 5, 10 and 15 °C/min. Three thermal decomposition stages were identified: dehydration; pyrolysis/oxidative pyrolysis, and carbonization/combustion, respectively. In order to obtain the estimation of the activation energies, the isoconversional method proposed by Vyazovkin (1997) was applied. Besides that, three and six independent parallel reactions schemes were applied for respective atmospheres. The ranges of activation energy were of 52-140 kJ/mol and 71-171 kJ/mol for inert and oxidizing atmosphere, respectively. The modeling of conversion rates presented a good agreement in relation to the experimental data (AD < 4%).

Comparison of different Brazilian citrus by-products as source of natural antioxidants

Significant amounts of citrus by-products remain after juice processing, which is then used to obtain pectin. The pectin industry then generates a new waste. No study has characterized this residue or suggested applications for it. The main goal of this study was to compare citrus industrial by-products that remain after juice (CJB) and pectin (CPB) extraction, aiming to obtain bioactive compounds. The residues were evaluated for their chemical composition, antioxidant capacity, and polyphenols content. CJB had 2-fold higher total phenols than CPB. Moreover, CJB exhibited higher antioxidant capacity than CPB. Nine polyphenols were detected; hesperidin was the main compound on both residues. CPB had higher content of polyphenols than CJB, which can be attributed to the industry procedure of pectin extraction. Thus, this study provides support for the reuse of CPB to obtain nutraceutical compounds, converting waste into added-value products.

Diversity of cultivable fungal endophytes in Paullinia cupana (Mart.) Ducke and bioactivity of their secondary metabolites

Paullinia cupana is associated with a diverse community of pathogenic and endophytic microorganisms. We isolated and identified endophytic fungal communities from the roots and seeds of P. cupana genotypes susceptible and tolerant to anthracnose that grow in two sites of the Brazilian Amazonia forest. We assessed the antibacterial, antitumor and genotoxic activity in vitro of compounds isolated from the strains Trichoderma asperellum (1BDA) and Diaporthe phaseolorum (8S). In concert, we identified eight fungal species not previously reported as endophytes; some fungal species capable of inhibiting pathogen growth; and the production of antibiotics and compounds with bacteriostatic activity against Pseudomonas aeruginosa in both susceptible and multiresistant host strains. The plant genotype, geographic location and specially the organ influenced the composition of P. cupana endophytic fungal community. Together, our findings identify important functional roles of endophytic species found within the microbiome of P. cupana. This hypothesis requires experimental validation to propose management of this microbiome with the objective of promoting plant growth and protection.

Physicochemical characteristics, thermal stability and antioxidant characteristics of

In conducting this study, the extraction of Trichosanthes kirilowii maxim seed oils (TSO) was carried out with the help of cold pressing (CP), hot pressing (HP) and soxhlet extraction (SE). Investigation, together with comparison, was carried out with respect to the physicochemical properties, thermal stability and antioxidant action of TSO. The key ingredients in the seeds consisted of fat, fiber and protein. The physicochemical characteristics of the oils brought to light the fact that CPTSO possessed top oil quality. The findings also suggested that linoleic acid, punicic acid and oleic acid were the leading unsaturated fatty acids in TSO. It was also discovered that TSO had an almost identical chemical composition regardless of the extraction method was used. It was demonstrated by TG/DTG curves that both HPTSO and CPTSO had more thermal stability in comparison with SETSO. Furthermore, the antioxidant activity assessments emphasized that CPTSO had better radical scavenging potential. CP had the ability to deliver an extract with higher quality as well as antioxidant activity in comparison with HP and SE methods and can be taken into consideration as a more suitable method in order to attain high quality oil.

Characterization and physicochemical properties of pectins extracted from agroindustrial by-products

The composition and fine structure of pectins found in plant cell walls are heterogeneous, with striking differences, depending on their source, and this eventually determines their functional and technological properties. The aim of this study was to extract and determine the chemical composition and physicochemical properties of pectins from different sources: passion fruit peel, orange pomace, and soy hull. Pectin extraction was performed with heated hydrochloric acid solution, followed by precipitation with 96% ethanol. Extraction yield, chemical composition, molar mass, physicochemical properties (fat absorption capacity, cation exchange capacity, water holding capacity, and antioxidant activity) of pectin were measured. Pectin extraction efficiency was higher for passion fruit peel and orange pomace (15.71 and 17.96%, respectively). Soy hull had low pectin extraction (5.66%). Galacturonic acid content was 23.21% for passion fruit peel pectin and 16.01% for orange pomace pectin. Water holding capacity, fat absorption capacity, and cation-binding capacity present in pectin extracted from passion fruit peel were higher, suggesting this poorly investigated product could be used as thickening and emulsifying agents in food preparations. Phenolic compounds with antioxidant capacity provide pectins with additional properties and expand their industrial use.

Protein-Bound Polysaccharide from Corbicula fluminea Inhibits Cell Growth in MCF-7 and MDA-MB-231 Human Breast Cancer Cells

A novel protein-bound polysaccharide, CFPS-1, isolated from Corbicula fluminea, is composed predominantly of mannose (Man) and glucose (Glc) in a molar ratio of 3.1:12.7. The polysaccharide, with an average molecular weight of about 283 kDa, also contains 10.8% protein. Atomic force microscopy, high-performance liquid chromatography, Fourier transform infrared spectroscopy, gas chromatography/mass spectrometry, and nuclear magnetic resonance spectroscopy analyses revealed that CFPS-1 has a backbone of 1,6-linked and 1,4,6-linked-α-D-Glc, which is terminated with a 1-linked-α-D-Man residue at the O-4 position of 1,4,6-linked-α-D-Glc, in a molar ratio of 3:1:1. Preliminary in vitro bioactivity tests revealed that CFPS-1 effectively and dose-dependently inhibits human breast cancer MCF-7 and MDA-MB-231 cell growth, with an IC50 of 243 ± 6.79 and 1142 ± 14.84 μg/mL, respectively. In MCF-7, CFPS-1 produced a significant up-regulation of p53, p21, Bax and cleaved caspase-7 and down-regulation of Cdk4, cyclin D1, Bcl-2 and caspase-7. These effects resulted in cell cycle blockade at the S-phase and apoptosis induction. In contrast, in MDA-MB-231, with limited degree of change in cell cycle distribution, CFPS-1 increases the proportion of cells in apoptotic sub-G1 phase executed by down-regulation of Bcl-2 and caspase-7 and up-regulation of Bax and cleaved caspase-7. This study extends our understanding of the anticancer mechanism of C. fluminea protein-bound polysaccharide.

Combustion reaction kinetics of guarana seed residue applying isoconversional methods and consecutive reaction scheme

This work aims the study of decomposition kinetics of guarana seed residue using thermogravimetric analyzer under synthetic air atmosphere applying heating rates of 5, 10, and 15°C/min, from room temperature to 900°C. Three thermal decomposition stages were identified: dehydration (25.1-160°C), oxidative pyrolysis (240-370°C), and combustion (350-650°C). The activation energies, reaction model, and pre-exponential factor were determined through four isoconversional methods, master plots, and linearization of the conversion rate equation, respectively. A scheme of two-consecutive reactions was applied validating the kinetic parameters of first-order reaction and two-dimensional diffusion models for the oxidative pyrolysis stage (149.57kJ/mol, 6.97×10(10)1/s) and for combustion stage (77.98kJ/mol, 98.611/s), respectively. The comparison between theoretical and experimental conversion and conversion rate showed good agreement with average deviation lower than 2%, indicating that these results could be used for modeling of guarana seed residue.

Injectable hydrogel from plum pectin as a barrier for prevention of postoperative adhesion

An injectable hydrogel was obtained from the high methyl-esterified plum Prunus domestica L. (PD) pectin and calcium ions (Ca2+). PD hydrogel showed a weak gel-like behavior and could be squeezed out of the syringe with an injection force of ca. 9 N. PD hydrogel was not suitable for the NIH/3T3 fibroblast cell adhesion in vitro. The live/dead fluorescence and MTT (3-(4,5-dimethylthiazol-2yl)-2,5-diphenyltetrazolium bromide) assays indicated that the PD hydrogel had a low cytotoxicity in relation to both the adhered and gel surrounding fibroblasts. PD hydrogel was found to inhibit adhesion formation in the sidewall defect-cecum abrasion rat model. In the control group, the occurrence of adhesion of the cecum to the peritoneal wall was found in seven of the total seven rats operated. Only four of the seven animals that were treated with the PD hydrogel were noted to have any adhesions. These adhesions were of a minimum grade of 1, 2, and 3 and were represented by a thin film that could be easily broken. The protective effect of PD hydrogel was found to be comparable with that of hyaluronic acid hydrogel used as a positive control. PD hydrogel appeared to possess enhanced in vivo residence stability on the injury sites compared to hyaluronic acid hydrogel as measured by staining of healing tissue with periodic acid-Schiff reagent. The data obtained offered the prospect for the development of the pectin-based gels as new barrier materials for surgery.

Depolymerization of polysaccharides from Opuntia ficus indica: Antioxidant and antiglycated activities

The extraction, purification and degradation of polysaccharides from Opuntia ficus indica cladodes, as well as the evaluation of their antioxidant and antiglycated activities in vitro were investigated. The optimization of the extraction showed that extraction by ultrasound at 40 °C presented the best carbohydrates yield. The degradation of the extracted polysaccharides was achieved by free radical depolymerization with H2O2 in the presence of copper(II) acetate for various reaction times. Sugar contents were determined by colorimetric assays. The macromolecular characteristics of the different isolated and degraded carbohydrates were carried by size exclusion chromatography (SEC/MALS/VD/DRI). These experiments showed that all samples are polysaccharides, which are probably pectins and that molecular weight (Mw) has decreased from 6,800,000 to 14,000 g/mol after 3 h of depolymerization without changing the structure. Preliminary antioxidant and antiglycated tests indicated that degraded polysaccharides for 2 and 3 h showed even better antioxidant and antiglycated activities.

Guarana: revisiting a highly caffeinated plant from the Amazon

ETHNOPHARMACOLOGICAL RELEVANCE

Guarana (Paullinia cupana Kunth var. sorbilis (Mart.) Ducke) has been traditionally consumed by indigenous communities of the Amazon region. It is valued mainly for its stimulant property because of its high content of caffeine, which can be up to 6% in the seeds.

AIM OF THE REVIEW

The purpose of this review is to revisit this typically Brazilian plant, addressing economic considerations, the chemical makeup of the seeds and pharmacological properties so far investigated.

RESULTS

Guarana is primarily produced in the Brazilian states of Amazonas and Bahia, and approximately 70% of the production is used by the industry of soft and energy drinks. The other 30% becomes guarana powder for direct consumption in capsules or dilution in water, or it serves as a raw material for the pharmaceutical and cosmetics industries. In addition to its stimulant property, guarana has other therapeutic properties, which have aroused the interest of the scientific community.

CONCLUSION

This review shows that other guarana properties may be explored and how scarce are the studies regarding agronomic, plant pathology, physiology and breeding. So far, caffeine has been the main reason to study guarana and still will lead the researches because the demand for this alkaloid by food and pharmaceutical industry, and a strongly growing market related with beauty products. However, guarana has other components and there is great interest in studies designed to elucidate the effects of guarana's bioactive components and their potential pharmacological applications. Significant part of the guarana production in Brazil still comes from Indians tribes in the Amazon State, and any improvement in this plant, in any aspect, may propitiate a positive economic impact in their lives.

Purification, antioxidant activity and antiglycation of polysaccharides from Polygonum multiflorum Thunb

Polysaccharides, one of the most important constituents in Polygonum multiflorum Thunb, a famous Chinese medicinal herb, were isolated by DEAE-52, Sepharose 4B and Sephacryl S-300 column chromatography. Two polysaccharides (PMP-1 and PMP-2) were identified as homogeneous in molecular weight with HPLC. The molecular weights were 4.8 × 10(2) and 6.1 × 10(2) kDa, respectively. Antioxidant activity tests were performed with two polysaccharides at concentrations of 0.1-1.5mg/mL. The results indicated that the inhibitory activity on oxidation and glycation exhibited a dose-dependent response. PMP-2 exhibited a much stronger antioxidant capacity against free radical, lipid oxidation and protein glycation. The IC₅₀ values of PMP-2 were 0.47, 0.6 and 0.93 mg/mL for superoxide anion scavenging, hydroxyl radical scavenging, and hydroxyl peroxide scavenging, respectively. The inhibitory ability of PMP-2 on lipid oxidation was most markedly in rat liver, followed by heart and kidney. Meanwhile, PMP-2 also showed satisfactory suppression of AGEs formation. This suggested that the polysaccharides present in PM can contribute to the biological effects.

Antioxidant activity of penta-oligogalacturonide, isolated from haw pectin, suppresses triglyceride synthesis in mice fed with a high-fat diet

To expand application of hawthorn (Crataegus pinnatifida Bge) fruit, the antioxidant and anti-lipidemic effects of haw pectin penta-oligogalacturonide (HPPS) prepared from hawthorn fruit were investigated in vitro and in mice. HPPS exhibited concentration-dependent scavenging activities against superoxide anion, hydroxyl and DPPH radicals. Additionally, HPPS supplementation significantly enhanced the antioxidant enzyme activities of superoxide dismutase, catalase, glutathione peroxidase, increased the total antioxidant capacity and the levels of glutathione, but lowered the malondialdehyde content in the liver of high-fat fed mice. Furthermore, HPPS significantly decreased the TG levels, the activity and the mRNA and protein levels of glycerol 3-phosphate acyltransferase (GPAT) and phosphatidate phosphohydrolase (PAP) in mice livers. Moreover, liver steatosis of mice associated with diffuse hepatocyte ballooning induced by a high-fat diet was markedly improved by a dose of 300 mg/kg HPPS-consumption. The results revealed that HPPS might be applicable as a dietary supplement for the prevention of fatty liver and oxidative damage.