Evaluation of the immunomodulatory and DNA protective activities of the shoots of Cynodon dactylon

Ethnopharmacological relevance

Fresh juice of Cyanodon dactylon known as ‘durva’ grass is employed in India as a rejuvenator and for wound healing.

Aim of the study

To validate the traditional use of the herb through evaluation of DNA protective activity in vitro and immunomodulatory activity in vivo.

Materials and methods

Fresh juice of the grass was prepared as indicated for use in traditional medicine and standardized for solid content. Its total phenol content was estimated by Folin–Ciocalteau method. Freshly prepared juice was investigated for its effect on doxorubicin-induced DNA damage in vitro. Its immunomodulatory activity was tested on balb/c mice by the humoral antibody response which was determined by haemagglutination antibody titer and spleen cell assay.

Results

Fresh juice of Cyanodon dactylon of 1.46% (w/w) solid content had a phenolic content of 47 ± 0.33 mg/kg GAE. At doses equivalent to 50, 100 and 200 mg total solids/kg body weight the juice protected human DNA against doxorubicin-induced DNA damage as demonstrated in DNA spectral studies, where the ratio of absorbance of DNA at 260 and 280 nm in samples pretreated with the juice was 1.66, 1.53 and 1.63 respectively, while it was 1.37 for DNA treated with doxorubicin only. This indicates nucleic acid purity in the Cynodon dactylon treated samples. Oral administration of the juice at 250 and 500 mg/kg in balb/c mice increased humoral antibody response upon antigen challenge, as evidenced by a dose-dependent, statistically significant increase in antibody titer in the haemagglutination antibody assay and plaque forming cell assay.

Conclusions

The present report demonstrated the DNA protective activity and immunomodulatory property of the fresh juice of Cynodon dactylon validating the traditional use of the herb as a ‘rasayana’ in ayurvedic system of medicine.     

Systematic evaluation of antioxidant capacities of the ethanolic extract of different tissues of jujube (Ziziphus jujuba Mill.) from China

Jujube (Ziziphus jujuba Mill.) has long been used for human consumption and medicinal purposes in China. It is recommended for some diseases in which radical species are produced as a result of oxidative stress. However, the systematic study on the antioxidant capacities of various tissues of jujube is still lacking. In order to address this, various tissues of three jujube varieties were characterized with respect to their antioxidant capacities and antioxidant compounds such as flavonoid, ascorbic acid, anthocyanin and phenolic. Antioxidant capacity was measured using the DPPH (2,2-diphenyl-1-picrylhydrazyl) and FRAP (ferric-reducing antioxidant power) assays. The phenolic acids were analyzed by high-performance liquid chromatography (HPLC). The results show that the peel of all cultivars has the highest antioxidant capacities, reflecting the highest content of total phenolics, flavonoids, and anthocyanins found in this part. In addition, the predominant phenolic acid in jujube was found to be protocatechuic acid, followed by gallic acid, chlorogenic acid and caffeic acid. The results obtained in this study clearly indicate that Chinese jujube has a significant potential to use as a natural antioxidant agent.     

Phenols of virgin olive oil protects nuclear DNA against oxidative damage in HeLa cells

Oxidative DNA damage is an inescapable consequence for cells constantly exposed to oxidative stress derived from normal metabolic processes and from environmental factors. Phenolic compounds, which have strong antioxidant activity, prevent DNA damage by protecting the cells against harmful effects of oxidative stress. In this study, the effect of virgin olive oil phenolic extract (OOPE) was investigated on H₂O₂-induced mitochondrial DNA (mtDNA) and nuclear DNA (nDNA) damage in HeLa cells. DNA damage was assessed in mitochondria and two nuclear regions by using quantitative PCR (QPCR) assay. The cells were pre-treated with non-cytotoxic doses of OOPE for 4 h, and DNA damage was determined. OOPE alone does not change the steady-state level of DNA damage. The oxidative stress generated with 750 μM H₂O₂ caused two times greater damages in mtDNA compared to nDNA, which included the nonexpressed β-globin region (1.507 ± 0.110 lesions/10 kb) and the expressed APEX1 gene (1.623 ± 0.243 lesions/10 kb) with respect to the control region. When cells were preincubated with OOPE for 4 h, nDNA damage under stress condition was completely inhibited; however, mtDNA damage was not affected by this procedure. These results suggest that OOPE has a protective effect against nDNA damage in HeLa cells.     

Anti-inflammatory, antioxidant, anti-tyrosinase and phenolic contents of four Podocarpus species used in traditional medicine in South Africa

Ethnopharmacological relevance

Species of Podocarpus are used traditionally in their native areas for the treatment of fevers, asthma, coughs, cholera, chest complaints, arthritis, rheumatism, venereal diseases and distemper in dogs.

Aims of the study

To investigate the antioxidant, anti-inflammatory and anti-tyrosinase activities of four Podocarpus species, Podocarpus elongatus, Podocarpus falcatus, Podocarpus henkelii and Podocarpus latifolius, used in traditional medicine in South Africa. Phytochemical analysis to determine the phenolic contents was also carried out.

Materials and methods

DPPH, FRAP and β-carotene-linoleic acid assays were used to determine the antioxidant/radical scavenging activities of these species. Anti-inflammatory activity of these species was assayed against two cyclooxygenase enzymes (COX-1 and COX-2). Tyrosinase inhibition activity was analysed using the modified dopachrome method with l-DOPA as the substrate. Phenolics were quantitatively determined using spectrophotometric methods.

Results

Stems of Podocarpus latifolius exhibited the lowest EC₅₀ (0.84 μg/ml) inhibition against DPPH. The percentage antioxidant activity based on the bleaching rate of β-carotene ranged from 96% to 99%. High ferric reducing power was observed in all the extracts. For COX-1, the lowest EC₅₀ value was exhibited by stem extracts of Podocarpus elongatus (5.02 μg/ml) and leaf extract of Podocarpus latifolius showed the lowest EC₅₀ against COX-2 (5.13 μg/ml). All extracts inhibited tyrosinase activity in a dose-dependent manner with stem extract of Podocarpus elongatus being the most potent with an EC₅₀ value of 0.14 mg/ml. The total phenolic content ranged from 2.38 to 6.94 mg of GAE/g dry sample.

Conclusion

The significant pharmacological activities observed support the use of these species in traditional medicine and may also be candidates in the search for modern pharmaceuticals in medicine, food and cosmetic industries.     

Determination of toxic perilla ketone,secondary plant metabolites and antioxidative capacity in five Perilla frutescens L. varieties

Perilla frutescens L. is a traditional Asian crop with multiple uses. Several varieties exist but only little data is available about the content of the toxic perilla ketone and secondary plant metabolites of those genotypes. To estimate the nutritional value of this new vegetable more information about those components is necessary.     

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.     

Geopropolis from Melipona scutellaris decreases the mechanical inflammatory hypernociception by inhibiting the production of IL-1β and TNF-α

Ethnopharmacological relevance

The pharmacological activity of geopropolis collected by stingless bees (important and threatened pollinators), a product widely used in folk medicine by several communities in Brazil, especially in the Northeast Region, needs to be studied.

Objective

The aim of this study was to evaluate the antinociceptive activity of Melipona scutellaris geopropolis (stingless bee) using different models of nociception.

Material and methods

The antinociceptive activity of the ethanolic extract of geopropolis (EEGP) and fractions was evaluated using writhing induced by acetic acid, formalin test, carrageenan-induced hypernociception, and quantification of IL-1β and TNF-α. The chemical composition was assessed by quantification of total flavonoids and phenolic compounds.

Results

EEGP and its hexane and aqueous fractions showed antinociceptive activity. Both EEGP and its aqueous fraction presented activity in the mechanical inflammatory hypernociception induced by the carrageenan model, an effect mediated by the inhibition of IL-1β and TNF-α. The chemical composition of EEGP and its hexane and aqueous fractions showed a significant presence of phenolic compounds and absence of flavonoids.

Conclusion

Our data indicate that geopropolis is a natural source of bioactive substances with promising antinociceptive activity.     

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.