Comparison of ABTS/DPPH assays to measure antioxidant capacity in popular antioxidant-rich US foods

To evaluate the comparability of the two most common radical scavenging assays using 2,2′-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, the 50 most popular antioxidant-rich fruits, vegetables and beverages in the US diet were identified and analyzed for their antioxidant capacities, total phenolics and flavonoids content. Spearmans–Rho correlation coefficients were calculated in order to characterize the relationship between antioxidant capacities, total phenolics and flavonoids content. Antioxidant capacity showed a strong positive relationship comparing both assays (ρ = 0.949, p < 0.001). Antioxidant capacity detected by ABTS assay was stronger positively associated with the oxygen radical absorbance capacity (ORAC) from USDA database (for ABTS: ρ = 0.593, p < 0.001; for DPPH: ρ = 0.539, p < 0.001, respectively), phenolics (for ABTS: ρ = 0.946, p < 0.001; for DPPH: ρ = 0.897, p < 0.001, respectively) and flavonoids content (for ABTS: ρ = 0.718, p < 0.001; for DPPH: ρ = 0.708, p < 0.001, respectively). Antioxidant capacity detected by ABTS assay was significantly higher for fruits, vegetables and beverages compared to that by DPPH assay. The high-pigmented and hydrophilic antioxidants were better reflected by ABTS assay than DPPH assay. These data suggest that ABTS assay may be more useful than DPPH assay for detecting antioxidant capacity in a variety of foods.     

Anatomical and cytochemical relationships of adenosine deaminase-containing primary afferent neurons in the rat

The distribution of adenosine deaminase-containing neurons and fibers in the spinal cord and medulla was examined and the relationship of dorsal root ganglia neurons containing this enzyme to those containing somatostatin, substance P, fluoride-resistant acid phosphatase (FRAP) and 5'-nucleotidase was determined using immunohistochemical and histochemical methods. In the spinal cord adenosine deaminase-immunoreactive fibers and neurons were confined to layer I and IIo. A similar localization of these was observed in the spinal trigeminal nucleus. In adult animals treated neonatally with capsaicin adenosine deaminase-positive fibers were totally depleted in layer IIo but only partially depleted in layer I. Analysis of lumbar sensory ganglia revealed that small type-B neurons immunoreactive for adenosine deaminase were also immunoreactive for somatostatin but not substance P. In addition, adenosine deaminase-positive neurons lacked histochemical reaction-product for FRAP and exhibited the lowest activity of 5'-nucleotidase. Examination of the neuronal populations containing the two phosphatase enzymes showed that a proportion of neurons exhibiting 5'-nucleotidase activity were devoid of FRAP activity. It is concluded that dorsal root ganglia neurons immunoreactive for adenosine deaminase and somatostatin constitute a single subpopulation of type-B ganglion cells separate from those containing substance P or FRAP. It appears that the lack of coexistence of adenosine deaminase with either FRAP or 5'-nucleotidase cannot be attributed simply to a coexistence of the two latter enzymes since some 5'-nucleotidase-positive neurons lacking FRAP were also devoid of adenosine deaminase-immunoreactivity. Insofar as these three enzymes may contribute to the regulation of transmission processes in primary sensory neurons, our results indicate a minimal functional relationship between adenine nucleoside and nucleotide degrading enzymes in these neurons. In addition, FRAP appears to have some functional independence from 5'-nucleotidase.     

Site-Specific Molecular Diffusion in Articular Cartilage Measured using Fluorescence Recovery after Photobleaching

Diffusive transport of solutes is critical to the normal function of articular cartilage. The diffusion of macromolecules through cartilage may be affected by the local composition and structure, which vary with depth from the tissue surface. We hypothesized that the diffusion coefficient of uncharged molecules also varies with depth and molecular size. We used fluorescence recovery after photobleaching (FRAP) to measure site-specific diffusion coefficients of fluorescent dextran molecules (3, 40, 70, and 500 kDa) in porcine articular cartilage. The diffusion coefficients measured using FRAP exhibited an inverse size dependence and were in general agreement with those measured using other techniques. The diffusion coefficients for all molecules varied significantly with depth in a manner that depended upon the size of the diffusing molecule. The diffusion coefficients for the 3 and 500 kDa dextrans were 1.6 and 2.4 times greater, respectively, in the surface zone as compared to the middle and deep zones, whereas the diffusion coefficients of the 40 and 70 kDa dextrans were 0.3 and 0.2 times lower in the surface zone as compared to the middle and deep zones. These differences may reflect variations in the structure and composition of collagen, proteoglycans, and other macromolecules among the zones.© 2003 Biomedical Engineering Society. PAC2003: 8715Vv, 8719Rr, 8764Tt     

Strawberry consumption alleviates doxorubicin-induced toxicity by suppressing oxidative stress

Doxorubicin (Dox), one of the most used chemotherapeutic agents, is known to generate oxidative stress and block DNA synthesis, which result in severe dose-limiting toxicity. A strategy to protect against Dox toxic effects could be to use dietary antioxidants of which fruits and vegetable are a rich source. In this context, strawberry consumption is associated with the maintenance of good health and the prevention of several diseases, thanks to the antioxidant capacities of its bioactive compounds. The aim of the present study was to evaluate the protective effects of strawberry consumption against oxidative stress induced by Dox in rats. Animals were fed with strawberry enriched diet (15% of the total calories) for two months and Dox (10 mg/kg; i.p.) was injected at the end of the experimental period. Strawberry consumption significantly inhibited ROS production and oxidative damage biomarkers accumulation in plasma and liver tissue and alleviated histopathological changes in rat livers treated with Dox. The reduction of antioxidant enzyme activities was significantly mitigated after strawberry consumption. In addition, strawberry enriched diet ameliorated liver mitochondrial antioxidant levels and functionality. In conclusion, strawberry intake protects against Dox-induced toxicity, at plasma, liver and mitochondrial levels thanks to its high contents of bioactive compounds.     

Enamel diffusion modulated by Er:YAG laser (Part 1)--FRAP

Several studies have demonstrated the caries protective effect of lasers by strengthening enamel crystalline structure. However, the effect of laser on enamel diffusion (ED) remains unclear.     

Biochemical and anatomical observations on the degeneration of peptide-containing primary afferent neurons after neonatal capsaicin

Administration of a single dose of capsaicin (50 mg/kg; sc) to two-day-old rats resulted in a loss of between 85 to 95% of the small diameter unmyelinated primary afferent fibres from lumbar dorsal roots. The numbers of myelinated fibres in the dorsal roots were not significantly affected. The substance P and somatostatin contents of the dorsal roots were decreased by 85 to 95%. The extent of depletion of these peptides from the dorsal horn of the spinal cord was somewhat less; substance P was decreased by 55% and somatostatin by 19%. Histochemical studies showed that fluoride-resistant acid phosphatase was virtually absent from the dorsal horn of capsaicin-treated animals. There was also a conspicuous absence of substance P-positive fibres from layers I and II of the dorsal horn and of fibres traversing these layers to deeper regions.Colchicine pretreatment revealed the presence of substance P-containing perikarya within layers III–IV. The plexus of substance P-positive elements which normally surrounded these neurons was absent after capsaicin treatment, suggesting that they receive a substance P-containing primary afferent innervation.The neurotoxicity of capsaicin after a single dose of 50 mg/kg in neonatal animals appears to be restricted largely to unmyelinated primary afferent fibres. The present results suggest that both substance P and somatostatin are contained in primary afferent sensory neurons which give rise to unmyelinated fibres. It can be further concluded that about 50% of substance P and only about 20% of the somatostatin in the dorsal horn appears to be of primary afferent origin.     

半枝莲醇提工艺的优化及体外抗氧化活性评价的研究

目的:用正交试验法对半枝莲的乙醇提取工艺进行优化研究,通过体外试验对提取物的抗氧化活性进行评价。方法:以浸膏得率、总黄酮和野黄芩苷从生药中的提取率为评价指标,选择乙醇体积分数(%)、乙醇用量(倍)、提取时间(h)和提取次数(次)为考察因素,利用正交试验L9(34)确定半枝莲的最佳醇提工艺。基于氧化还原反应原理的FRAP法用于总抗氧化能力的评估,DPPH法用于评价自由基清除能力。结果:最佳工艺条件为用药材10倍量的75%乙醇加热回流提取3次,每次1 h。半枝莲提取物以浓度依赖关系发挥着很好的抗氧化作用,对DPPH自由基具有较强的清除和抑制作用。结论:该提取工艺具有较佳的重复性和可行性。半枝莲醇提物显示了较好的抗氧化活性,值得进一步开发研究。     

Pomegranate peel and fruit extracts: A review of potential anti-inflammatory and anti-infective effects

Ethnopharmacological relevance

Punica granatum L. (Punicaceae) has been used for centuries in many cultures for the prevention and treatment of a wide number of health disorders such as inflammation, diabetes, diarrhea, dysentery, dental plaque and to combat intestinal infections and malarial parasites.

Aim of the review

This review aims at providing an up-to-date overview of the chemical constituents, traditional uses, phytochemistry, pharmacology and toxicology of Punica granatum L. Moreover, the focus of this review is the possible exploitation of this species to treat different diseases and to suggest future investigations.

Materials and methods

An extensive and systematic review of the extant literature was carried out, and the data under various sections were identified by using a computerized bibliographic search via PubMed, Web of Science and Google Scholar. All abstracts and full-text articles were examined. The most relevant articles were selected for screening and inclusion in this review.

Key findings

A variety of pomegranate ethnomedical uses have been recorded. Additionally, over the last decade, there has been a dramatic increase of interest in pomegranate as a medicinal and nutritional product due to its n1ewly identified potential health effects, which include treatment and prevention of cancer and cardiovascular diseases. From the toxicological perspective, pomegranate fruit juice, extracts and preparations have been proven to be safe.

Conclusions

The ethnopharmacological relevance of pomegranate is fully justified by the most recent findings indicating the fruit is a medicinal and nutritional agent useful for treating a wide range of human disorders and maladies. Further investigations are needed to fully understand the mode of action of the active constituents and to fully exploit pomegranate’s preventive and therapeutic potential.     

The antimicrobial,antioxidative, anti-inflammatory activity and cytotoxicity of different fractions of four South African Bauhinia species used traditionally to treat diarrhoea

Ethnopharmacological importance

Many Bauhinia species, including those indigenous to South Africa, are used in traditional medicine across the world for treating ailments such as gastrointestinal tract (GIT) disorders, diabetes, infectious diseases and inflammation.

Aims

Several relevant aspects of different fractions of leaf extracts of Bauhinia bowkeri (BAB), Bauhinia galpinii (BAG), Bauhinia petersiana (BAP), and Bauhinia variegata (BAV) used in South African traditional medicine to alleviate diarrhoea related symptoms were evaluated.

Materials and Methods

The antioxidative activities of the extracts were determined using the 2, 2-diphenyl-1-picrylhydrazyl (DPPH), 2, 2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid (ABTS⁺) radical scavenging and ferric reducing antioxidant power (FRAP) methods. In vitro antimicrobial activities of the extracts were determined against bacterial strains (Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli and Enterococcus faecalis) and clinical isolates of the opportunistic fungal strains (Aspergillus fumigatus, Candida albicans, and Cryptococcus neoformans) using a serial dilution microplate method. The polyphenolic contents were quantified using standard methods, and anti-inflammatory activities of the crude extracts were determined using the cyclooxygenase and soybean 15-lipoxygenase enzyme inhibitory assays. The safety of the extracts was evaluated by determining the cytotoxicity against Vero cell lines.

Results

The acidified 70% acetone crude extract and their fractions had good antiradical potency against the DPPH and ABTS radicals. The methanol soluble portions of the butanol fractions were more potent (EC₅₀ ranges from 0.64±0.05 to 1.51±0.07 and 0.88±0.18 to 1.49±0.09 μg/ml against DPPH and ABTS radical respectively) compared to the standard, trolox and ascorbic acid (EC₅₀ ranges from 1.47±0.24 to 1.70±0.27 μg/ml) for both DPPH and ABTS. The crude extracts contained variable quantities of phenolic content. The crude extracts and their fractions had weak to good antimicrobial activities, inhibiting the growth of the organisms at concentrations ranging from 39 to 2500 μg/ml. The BAG crude extract and its fractions were the most active against the fungi (MICs ranging from 39 to 625 μg/ml) while the BAB extract and its fractions were the least active with the MICs ranging between 39 and 2500 μg/ml. Aspergillus fumigatus was the least susceptible fungus while Cryptococcus neoformans was the most susceptible.The phenolic-rich crude extracts of BAB, BAG, and BAP had moderate to good dose-dependent cyclooxygenase-1 enzyme inhibitory activity with inhibitions between 22.8% and 71.4%. The extracts were however, inactive against cyclooxygenase-2. The extracts had some level of cytotoxicity towards Vero cell lines, reducing cell viability to less than 10% at concentrations more than 50 μg/ml.

Conclusion

The biological activities observed in Bauhinia species provide a scientific basis for the use of the plants in traditional medicines to treat diseases with multi-factorial pathogenesis such as diarrhoea, with each aspect of activity contributing to the ultimate therapeutic benefit of the plants. However, the use of the phenolic-rich extracts of these plants to treat diarrhoea or any other ailments in traditional medicine needs to be monitored closely because of potential toxic effects and selective inhibition of COX-1 with the associated GIT injury.     

Gastroprotective mechanism of Bauhinia thonningii Schum

Ethnopharmacological relevance

Bauhinia thonningii Schum. (Cesalpiniaceae) is locally known as Tambarib and used to treat various diseases including gastric ulcer.

Aim of the study

The current study aims to evaluate the gastroprotecive mechanism(s) of methanolic (MEBT) and chloroform (CEBT) extracts of Bauhinia thonningii leaves on ethanol-induced gastric ulceration.

Materials and methods

Gastric acidity, quantification and histochemistry of mucus, gross and microscopic examination, nitric oxide, lipid peroxidation, 2D gel electrophoresis, mass spectroscopy and biochemical tests were utilized to assess the mechanism(s) underlying the gastroprotective effects of MEBT and CEBT. Effect of these extracts into lipopolysaccharide/interferon-γ stimulated rodent cells were done in vitro. In vitro and in vivo toxicity studies were also conducted. Antioxidant activities of MEBT and CEBT were examined using DPPH, FRAP and ORAC assays. Phytochemical analyses of MEBT and CEBT were conducted using chemical and spectroscopic methods.

Results

Gross and histological features confirmed the anti-ulcerogenic properties of Bauhinia thonningii. Gastroprotective mechanism of MEBT was observed to be mediated through the modulation of PAS-reactive substances, MDA and proteomics biomarkers (creatine kinase, malate dehydrogenase, ATP synthase, actin and thioredoxin). MEBT and CEBT showed no significant in vitro and in vivo effects on nitric oxide. Methanolic extract (MEBT) showed superior gastroprotective effects, polyphenolic content and antioxidant activities compared to CEBT. The plant extracts showed no in vitro or in vivo toxicity.

Conclusion

It could be concluded that MEBT possesses anti-ulcer activity, which could be attributed to the inhibition of ethanol-induced oxidative damage and the intervention in proteomic pathways but not the nitric oxide pathway.