Robusta Extracts Research Articles

Initial Investigation of the Potential of Robusta Coffee, Arabica Coffee, and Caffeine in Asthma Treatment through the Evaluation of 5-Lipoxygenase Inhibition Activity

Numerous studies have documented the potential of coffee to aid in asthma prevention. Nevertheless, research into how coffee influences asthma management has not been available. One known mechanism by which asthma medications work involves inhibiting 5-lipoxygenase (5-LOX) activity. This study aims to determine the potency of Coffea canephora var. Robusta extract (CRE), Coffea arabica extract (CAE), and caffeine are the primary isolates against 5-LOX activity. Extraction was performed by a reflux procedure using 96% ethanol with a sample-total solvent ratio of 1 : 10, an extraction time of 1 hour, and the extraction was conducted in triplicate. Fractionation was carried out by liquid-liquid partition using a chloroform-water system. Caffeine further purification was performed by the sublimation method, and the inhibition of 5-LOX activity was evaluated using the spectrophotometric method at λ = 234 nm. Apigenin was used as a positive control. From the experiment conducted, the IC50 of the CRE, CAE, caffeine, and apigenin against 5-LOX was 32.2 ± 1.4, 42.1 ± 2.3, 14.3 ± 1.6, and 7.4 ± 1.7 µg/mL, respectively. Continued efforts to isolate bioactive compounds from coffee extract led to the discovery of caffeine, which exhibited a more potent inhibitory effect on 5-LOX. The inhibition of 5-LOX activity by caffeine occurs in a non-competitive manner.

An organic extract from ascidian Ciona robusta induces cytotoxic autophagy in human malignant cell lines.

The last decades have seen an increase in the isolation and characterization of anticancer compounds derived from marine organisms, especially invertebrates, and their use in clinical trials. In this regard, ascidians, which are included in the subphylum Tunicata, represent successful examples with two drugs, Aplidine© and Yondelis© that reached the market as orphan drugs against several malignancies. Here, we report that an organic extract prepared from homogenized tissues of the Mediterranean ascidian Ciona robusta inhibited cell proliferation in HT-29, HepG2, and U2OS human cells with the former being the most sensitive to the extract (EC50 = 250μg/mL). We demonstrated that the ascidian organic extract was not cytotoxic on HT-29 cells that were induced to differentiate with sodium butyrate, suggesting a preference for the mixture for the malignant phenotype. Finally, we report that cell death induced by the organic extract was mediated by the activation of a process of cytotoxic autophagy as a result of the increased expression of the LC3-II marker and number of autophagic vacuoles, which almost doubled in the treated HT-29 cells. In summary, although the detailed chemical composition of the Ciona robusta extract is still undetermined, our data suggest the presence of bioactive compounds possessing anticancer activity.

A Comparative Analysis of Phenolic Content, Antioxidant Activity, Antimicrobial Activity, and Chemical Profile of Coffea robusta Extracts Using Subcritical Fluid Extraction and Supercritical Carbon Dioxide Extraction.

In this study, extracts of Robusta-roasted coffee were obtained using various extraction techniques, including subcritical fluid extractions using HFC-134a and HCFC-22 under room-temperature batch extraction, frozen-temperature batch extraction, and continuous extraction conditions. Additionally, supercritical carbon dioxide (SCCO2) extraction was performed using ethanol and tetrahydrofuran as co-solvents. These extractions were performed due to the presence of potent antioxidants and antibacterial substances in the extracts. Extraction machines were built to process the extraction. The antioxidant potential of the extracts was evaluated using total phenolic content and DPPH and FRAP assays, while antibacterial potential was identified using the disk diffusion method. The results showed that HCFC-22 extraction produced the highest yield compared to other extraction methods, but HFC-134a extraction had the highest antioxidant potential values. The yield and antioxidant potential of the extracts obtained using room-temperature batch extraction were slightly higher than those obtained using frozen-temperature batch extraction and continuous extraction. The yield and antioxidant potential of the extracts obtained using SCCO2 extraction were similar to those obtained using HFC-134a and HCFC-22 extractions, and co-solvents slightly improved the extraction performance. The extracts were found to be more effective as inhibitors of Gram-positive bacteria than Gram-negative bacteria. Caffeine was the most prominent tentative chemical compound in all coffee extracts. This research study provides a better understanding of various extraction techniques using HFC-134a, HCFC-22, and SCCO2 when applied to roasted Robusta coffee beans, with a focus on yield, antioxidant potential, antimicrobial potential, and tentative chemical profiles.

Evaluation of analgesic activity of Shorea robusta extracts in Wistar rats

BACKGROUND: Recent studies have shown presence of flavonoids in Shorea species. Flavanoids halt prostaglandin synthetase. Prostaglandins are involved in pain perception. AIMS AND OBJECTIVES: To evaluate analgesic activity of ethanolic leaf extracts in albino wistar rats. METHODOLOGY: Ethanolic extract of Shorea robusta leaf extract 300mg/kg/bw was prepared . Wistar rats were divided into 3 groups i.e control, test & standard, each group with 6 animals each . SRE 300 mg/kg/ bw was administered orally to test group . Tramadol 10 mg/kg/bw was administered orally to standard group & NS 10ml/kg/bw was administerd to control group. Analgesic activity measured by tailflick method & hot plate method. Reaction time noted. Statistical analysis done. RESULTS: Study showed significant peripheral analgesic activity as evidenced by increase in raction time to tailflick method. CONCLUSION: Shorea robusta leaf extract (300 mg/kg/bw) has good peripheral analgesic action.

Measurement of quality non-specific and specific-parameters of 70% ethanol extract and simplicia from cascara coffee robusta (Coffea canephora L.) and its potency as antioxidant.

Cascara coffee robusta (Coffea canephora L.) has been previously studied and has been reported to have biological activity with potential antibacterial and antioxidant effects. The ethanol extracts of cascara coffee robusta contained secondary metabolites: flavonoids, alkaloids, steroids, terpenoids and tannins. Measuring the quality of natural ingredients is an important means of maintaining the quality and safety of natural medicines. The purpose of the research was to measure the quality of non-specific and specific-parameters of extract and 70% ethanol and simplicia from cascara robusta coffee and evaluate its antioxidant activity. Material and Methods: Samples were soaking with ethanol 70% and evaluated for antioxidant activity using the DPPH method. Results: The results showed that the specific parameters have the same organoleptic properties as simplicia and a 70% ethanol extract of cascara coffee robusta are dark brown, characteristic odor, slightly bitter taste. Water soluble and ethanol soluble 70% ethanol extract of cascara has a total content of 51.98% ± 0.31 and 68.36% ± 1.74. Phytochemical screening results for 70% ethanol extract and simplicial of cascara coffee robusta include alkaloids, flavonoids, saponins, terpenoids, steroids, and tannins. Non-specific parameters of cascara coffee robusta simplicia; total water content of 3.26% ± 0.44; Total ash 4.91% ± 0.16; acid-insoluble ash 0.55% ± 0.33; <1.0 x 100 CFU / gr fungal and yeast contamination; <1.0 x 100 CFU / gr microbial contamination. Non-specific parameters of cascara coffee robusta extract; total water content of 3.55% ± 0.57; total ash of 6.15% ± 0.00; total acid-insoluble ash 0.23% ± 0.02; <1.0 x 10^0 CFU / gr fungal and yeast contamination; <1.0 x 10^0 CFU / gr microbial contamination. Ability the antioxidant activity was demonstrated by the IC50 values of simplicia and the extract, ie 55.14 ± 1.90 μg/mL simplicia and 57.40±0.29 μg/mL extract. Conclusions: Statistical tests show that there is no difference between the values of specific, non-specific parameters and their antioxidant capacity of simplicia and the extract, and all parameters follow standard procedures as a reference requirements. Showed that it meets.

Phenolic Content and Biological Activities of Ethanol Extracts from Medicinal Plants in East Kalimantan, Indonesia

The Dayak tribe are the indigenous people of West Kutai, East Kalimantan, Indonesia, and they have experiences in using plants for traditional medicine and the commonly used plants include Baccaurea macrocarpa (Miq.) Müll.Arg., Entada phaseoloides (L.) Merr., Goniothalamus macrophyllus (Blume) Hook.f. &amp; Thomson, Gynura crepidioides Benth., Helicia robusta (Roxb.) R. Br var. robusta, Litsea elliptica, Pogostemon cablin (Blanco) Benth, and Rhodomyrtus tomentosa (Aiton) Hassk. Therefore, the present study aimed to analyze these plant species for their phenolic content, and antioxidant, antibacterial, anti-tyrosinase, and anticancer activities. The total phenolic content and total antioxidant capacity were analyzed using Folin-Ciocalteu reagent and the phosphomolybdenum method, respectively. The antioxidant activities were evaluated by DPPH and ABTS assays. The antibacterial activity was determined by agar well diffusion and microdilution methods against six bacterial strains. The anticancer activity of the plant extracts was assayed against MDA-MB-231 human breast cancer cells. Based on the ethanol extraction, the highest yield was obtained from L. elliptica (10.42%), while H. robusta extract contained the highest phenolic content, antioxidant capacity, and antioxidant activities. All the extracts exhibited antibacterial activities against all the tested strains of bacteria, with the highest activity found in R. tomentosa extract, which also showed the highest activity against the cancer cells. The ethanol extract from E. phaseoloides exhibited tyrosinase inhibition activity (IC50 = 543.83 ± 51.06 µg/mL). The results herein suggested that the ethanol extracts from some medicinal plants from East Kalimantan have potential as antioxidant, antibacterial, anticancer, and anti-tyrosinase agents.

Robusta Extract Cream Ameliorated Ultraviolet B-induced Wrinkle Skin of Mice by the Regulation of Epidermal Thickness and Inhibition of MMP-1

BACKGROUND: Recently, coffee is widely used for preventing photoaging because of its antioxidant capacity. Among two kinds of coffee, robusta coffee has higher content of antioxidant such as chlorogenic acid (CGA) and caffeine. Researchs about robusta coffee bean effect on photoaging due to UVB radiation is still limited. Therefore, the aim of this study was to examine the effect of robusta extract cream (RE cream) on preventing wrinkle in mice induced by ultraviolet-B (UVB) radiation.METHODS: RE cream was made by mixing RE coffee with moisturizing cream in different concentration (10%, 20%, and 40%). Twenty-five male of Mus musculus Balb/c strain mice aged 4 weeks were divided into five groups; control group, UVB group, UVB + 10% RE group, UVB + 20% RE group, and UVB + 40% RE group. The UVB groups were given UVB radiation three times a week with an exposure duration of 100 seconds per time for ten weeks. At the end of the treatment, skin samples were excised and statined histologically, also were analyzed for their protein expression. Evaluation of wrinkles was carried out using the Bissete method before and after treatment. To evaluate the thickness of the epidermis, HE staining was performed, while masson Trichome staining was performed to determine the collagen content.RESULTS: RE cream-treated groups showed lower wrinkle score compared to the control group. Furthermore, in UVB + 10% RE group, the RE cream application reduce wrinkle formation. In UVB + 10% RE group and UVB + 20% RE group, the RE cream application increased epidermal thickness and collagen content (p=0.00). While collagenase, matrix metalloproteinase-1 (MMP-1) expression was lower in UVB + 20% RE group compared to the UVB group (p&lt;0.05), however the MMP1 expression in UVB + 40% RE group was higher than other treatment group.CONCLUSION: RE cream prevents wrinkle by maintaining epidermal thickness and collagen contain. RE cream also decreases MMP-1 expression in mice.KEYWORDS: coffee, collagen, MMP-1, robusta, wrinkle

Maytenus robusta Reissek, a medicinal plant popularly used to treat digestive diseases, promotes ameliorative effects in colon and liver of mice exposed to dextran sulfate sodium

Ethnopharmacological relevanceMaytenus robusta Reissek (Celesteraceae), popularly named as cafezinho do mato or coração de bugre, is employed to treat inflammatory digestive diseases in the south of Brazil. However, despite popular usage, the effects of this species on an experimental model of ulcerative colitis are unknown. Aim of the studyTo evaluate the effects of M. robusta extract (HEMR) on colon and liver from mice with colitis induced by dextran sulfate sodium (DSS). Materials and methodsFirstly, the cytotoxicity of HEMR and its effects on ROS and nitrite production in IEC-6 cells were evaluated. The experimental colitis was established by adding 3% DSS on drinking water of mice and the effects of HEMR (1–100 mg/kg, p.o, once a day by 7 days) in colonic and hepatic tissues were analyzed. ResultsThe HEMR (1–100 μg/mL) did not alter the cell viability but reduced nitrite production of IEC-6 stimulated by LPS. Moreover, HEMR (100 mg/Kg) attenuates macro and microscopic alterations in the colon from mice exposed to DSS, as evidenced by a reduction of the colon shortening, attenuation of the epithelial erosion, submucosal edema and preservation of the Goblet cells integrity, as well as the restoration of mucin depletion. The treatment with HEMR increased GSH amount, reduced LOOH levels and normalizes CAT activity in the colon. The group treated with HEMR showed increased GST activity, reduced MPO activity and decreased inflammatory cytokines secretion (TNF and IL-6) in the colonic tissue. In the liver, HEMR increased GST activity, decreased the GPx activity and reduced IL-6 levels. Furthermore, the HEMR treatment reduced AST and ALT serum levels in mice exposed to DSS. Finally, the HEMR was able to reduce intestinal transit. ConclusionsHEMR treatment minimizes inflammation of the colon and maintaining the antioxidant homeostasis. In addition, HEMR may be a potential tool to prevent hepatic injury secondary to ulcerative colitis.

Synthesis of iron nanoparticles from aqueous extract of Eucalyptus robusta Sm and evaluation of antioxidant and antimicrobial activity

In this work we obtained iron nanoparticles (FeNP) from the aqueous extract of the leaves of E. robusta and to evaluate their antimicrobial activity on different pathogenic microorganisms. Different concentration of iron salt and leaf extract were used; the proportion of precursor to leaf extract was 1:1. The results reveled dependence on the particle size of FeNP and synthesis conditions. Subsequently, the antimicrobial activity was evaluated against the microorganisms Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus and Bacillus subtilis, being a close relationship between the conditions of synthesis and the increase or decrease of the antimicrobial activity. Finally, the quantification of flavonoids and total polyphenols was carried out and the antioxidant activity of the E. robusta extract was evaluated, which allowed associating the antimicrobial activity found in the FeNPs with the components present in the extract.

Grevillea juncifolia Hook. and Grevillea robusta A. Cunn. Ex. R. Br. Methanolic Leaf and Flower Extracts Inhibit the Growth of Gram Positive and Gram Negative Bacteria

Introduction: The development of multi-antibiotic resistant strains of bacteria has necessitated the search for new effective antibacterial therapies. Several Grevillea spp. were used traditionally to treat pathogenic illness and are rich in phytocompounds with antibacterial activity. Despite this, the antibacterial activity of Australian Grevillea spp. extracts have not been extensively examined. Methods: The ability of G. juncifolia and G. robusta leaf and flower extracts to inhibit the growth of gram-negative and gram-positive bacterial species and some fungi was investigated by disc diffusion assays. The growth inhibitory activity was further quantified by MIC determination. Toxicity was determined using the Artemia franciscana nauplii bioassay. Results: The G. juncifolia and G. robusta extracts were good inhibitors of the growth of both gram-positive and gram-negative bacteria yet were completely ineffective against all fungal species tested. The leaf extracts generally had better antibacterial activity than the flower extracts. The G. juncifolia leaf extract was a particularly good inhibitor of A. faecalis, P. fluorescens, Y. entercolitica and B. subtilis growth, with MIC values of 62, 533, 736 and 682µg/mL respectively. The G. robusta leaf extract was a potent inhibitor of B. cereus and B. subtilis growth (145 and 83 µg/mL respectively). That extract was also a good inhibitor of A. faecalis, P. fluorescens, S. salford, S. aureus and S. epidermidis growth, albeit with substantially higher MIC values. In contrast, none of the extracts inhibited fungal growth. All extracts were determined to be non-toxic in the Artemia franciscana nauplii bioassay, indicating their safety for the treatment of bacterial infections. Conclusion: The lack of toxicity of the G. juncifolia and G. robusta extracts and their growth inhibitory bioactivity against gram-positive and gram-negative bacteria indicate their potential in the development of new antibiotic chemotherapies.

Daya Hambat Ekstrak Biji Kopi Robusta (Coffea robusta) terhadap Pertumbuhan Fusobacterium nucleatum

Fusobacterium nucleatum is a bacteria found in normal flora of the oral cavity that plays a role in the occurrence of periodontal disease. The prevalence of periodontal disease in Indonesia reaches 70%. One treatment by using medicinal plants is robusta coffee beans. Robusta coffee beans contain volatile acids, chlorogenic acids, caffeine acids, phenols and caffeine suspected to be antibacterial. The objective of this study was to determine the inhibition of coffee robusta extract on growth of Fusobacterium nucleatum. This study used disc diffusion method with 4 samples in each study group. The study group consisted of 6 treatment groups (12,5%, 25%, 50% and 100% coffee robusta extract), positive control group (chlorhexidine gluconate 0,2%), and negative control group (sterile aquades). Data were analyzed using One Way Anova test and LSD (Least Significant Difference) test. Coffee robusta extract has the ability to inhibit the growth of Fusobacterium nucleatum. The concentration of coffe robusta extract 100%, 50%, 25%, 12,5% have same ability to inhibit the growth of Fusobacterium nucleatum.

PENGARUH EKSTRAK KOPI ROBUSTA TERHADAP EKSPRESI OSTEOKALSIN PADA OSTEOBLAS SELAMA PERGERAKAN GIGI ORTODONTI

The objective of research is to determine the expression of osteocalcin on osteoblasts during orthodontic tooth movement after administration robusta coffee extract. Materials and Methods: 16 rats were divided into 2 groups: group K: rats applied with orthodontic mechanical force (OMF) and group P: OMF + coffee robusta extract of 20mg /100 g of BW. OMF was conducted by applying ligature wire on permanent maxillary right first molar and both permanent maxillary incisivus. Subsequently, the permanent maxillary right first molar moved to mesial with Ni-Ti orthodontic closed coil spring. Observations were made on day 15 by immunohistochemical examination to determine the expression of osteocalcin. Results: Robusta coffee extract improved the expression of osteocalcin in the compression and tension areas (p &lt;0.05). Expression of osteocalcin in tension area larger than that in compression area (p &lt;0.05). Conclusion: The administration of Robusta coffee extract increases the expression of osteocalcin, which can increase alveolar bone remodeling.

In vitro anticancer properties of selected Eucalyptus species.

In spite of the recent advancements in oncology, the overall survival rate for pancreatic cancer has not improved over the last five decades. Eucalypts have been linked with cytotoxic and anticancer properties in various studies; however, there is very little scientific evidence that supports the direct role of eucalypts in the treatment of pancreatic cancer. This study assessed the anticancer properties of aqueous and ethanolic extracts of four Eucalyptus species using an MTT assay. The most promising extracts were further evaluated using a CCK-8 assay. Apoptotic studies were performed using a caspase 3/7 assay in MIA PaCa-2 cells. The aqueous extract of Eucalyptus microcorys leaf and the ethanolic extract of Eucalyptus microcorys fruit inhibited the growth of glioblastoma, neuroblastoma, lung and pancreatic cancer cells by more than 80% at 100μg/mL. The E. microcorys and Eucalyptus saligna extracts showed lower GI50 values than the ethanolic Eucalyptus robusta extract in MIA PaCa-2 cells. Aqueous E. microcorys leaf and fruit extracts at 100μg/mL exerted significantly higher cell growth inhibition in MIA PaCa-2 cells than other extracts (p<0.05). Statistically similar IC50 values (p>0.05) were observed in aqueous E. microcorys leaf (86.05±4.75μg/mL) and fruit (64.66±15.97μg/mL) and ethanolic E. microcorys leaf (79.30±29.45μg/mL) extracts in MIA PaCa-2 cells using the CCK-8 assay. Caspase 3/7-mediated apoptosis and morphological changes of cells were also witnessed in MIA PaCa-2 cells after 24h of treatment with the extracts. This study highlighted the significance of E. microcorys as an important source of phytochemicals with efficacy against pancreatic cancer cells. Further studies are warranted to purify and structurally identify individual compounds and elucidate their mechanisms of action for the development of more potent and specific chemotherapeutic agents for pancreatic cancer.

Hepatoprotective effect of Maytenus robusta Reiss extract on CCl4-induced hepatotoxicity in mice and HepG2 cells

We investigated the hepatoprotective effect of methanolic extract from Maytenus robusta leaves in mice and HepG2 cells. The administration of CCl4 in mice promoted a deep destruction of the histological lobular structure and increased the alanine aminotransferase (ALT) serum levels by 46.25% compared with the control group (p < 0.05). The M. robusta extract reduced the hepatic histological changes and normalization the ALT levels. The antioxidant effect of M. robusta in liver tissue promoted the reduction in 31.5% on lipoperoxides levels (p < 0.05), increased by 101.5% the reduced glutathione content (p < 0.05) and increased the activity of superoxide dismutase, catalase, and glutathione-S-transferase by 21.3% (p < 0.05), 49.3% (p < 0.05), and 27.6% (p < 0.05), respectively, compared with the vehicle group. Moreover, the extract reduced hepatic inflammation by diminishing myeloperoxidase activity, TNF and interleukin-6 levels by 29.4% (p < 0.05), 46.1% (p < 0.01), and 59.5% (p < 0.0001), respectively, compared with the vehicle group. The viability of HepG2 cells after incubation with CCl4 was 29.56± 3.07%, whereas the extract (300 μg/mL) restored the viability to 65.27± 8.75% and aspartate aminotransferase levels to 41.82 ± 4.41 U/L. The extract scavenged DPPH (IC50 = 14.44 μg/mL) and ABTS (IC50 = 3.00 μg/mL) radicals and did not produce acute toxicity in mice at 2000 mg/kg. In conclusion, was confirmed the hepatoprotective potential of M. robusta by its antioxidant effects.

Effect of extraction conditions on the antioxidant and antiglycation capacity of carbohydrates from Opuntia robusta cladodes

SummaryThe extraction and characterisation of six crude polysaccharides from Opuntia robusta cladodes, as well as the assessment of their antioxidant and antiglycation activities in vitro, were examined. In this work, carbohydrates were extracted from defatted cladode's peels and pulps through a sequential extraction method in different aqueous medium (neutral, basic and chelating). The obtained polysaccharides were compared in terms of yield and physicochemical properties. Water‐soluble extracts showed the highest yield, while peel's chelating‐soluble extract gave high galacturonic acid content. Preliminary antioxidant in vitro tests suggested that peel's chelating‐soluble extract presented the highest scavenging activity towards DPPH free radicals and inhibition of linoleic acid peroxidation. Furthermore, all extracted polysaccharides showed good potential in inhibiting the nonenzymatic glycation reaction, particularly on the first 3 days of incubation. The obtained results suggested that Opuntia robusta extracts could be explored as natural antioxidant, especially those extracted with chelating agent.

Modulatory Role of Shorea robusta Bark on Glucose-metabolizing Enzymes in Diethylnitrosamine Induced Hepatocellular Carcinoma in Rats.

Introduction:The modulations of glucose-metabolizing enzyme activities play a vital rolein the depletion of energy metabolism and leads to inhibition of cancer growth.Objective:To find the effect of shorearobusta bark extract on glucose-metbolizing enzymes in diethylnitrosamine (DEN) induced hepatocellular carcinoma rats.Materials and Methods:Biochemical evaluation of glucose metabolizing enzyme were done in before and after shorearobusta bark extract (500mg/kg) treatment in DEN induced rats.Results:A significant increasein the activities of the key glycolytic enzymes viz., hexokinase and phosphoglucoisomerase, with a significant decrease in the gluconeogenic enzymes glucose-6-phosphatase and fructose-1,6-bisphosphatasewere observed in HCC bearing rats, when compared with the control. Administration of shorearobusta extract caused a significant decrease in theactivities of glycolytic enzymes and an increase in the gluconeogenic enzymes activities to near normal values.Conclusion:The current findings suggest that the S. robusta extract has a definite modulating role on the key enzymes ofglucose-metabolism in HCC. The modulatory effect may be due to the phytoactive constituents present in the extract of S. robusta.SUMMARY Administration of shorea robusta bark extract caused a significant decrease in the activities of glycolytic enzymes and an increase in the gluconeogenic enzymes activities to near normal values. The S. robusta extract has modulatory activity on the carbohydrate metabolism in DEN-induced HCC bearing rats through a mechanism that which does not provoke any acute biochemical disturbances in the metabolic pathways of glycolysis and gluconeogenesis. The modulatory effect of S. robusta extract may be attributed to the presence of active compounds such as polyphenols and flavonoids. Abbreviations used: HCC: Hepatocellular Carcinoma, SRBE: Shorearobusta bark extract; HEX: Hexokinase; PGI: Phosphoglucoisomerase; DEN: Diethylnitrosamine.

Antibacterial and antibiotic-potentiation activities of some Cameroonian food plants against multi-drug resistant gram-negative bacteria.

To evaluate the in vitro antibacterial properties and the ability to potentiate some common antibiotics effects of the methanol extracts of 11 Cameroonian food plants on 29 Gram-negative bacteria expressing multidrug resistant (MDR) phenotypes. The antimicrobial activity of the extracts was performed using the broth microdilution method. The phytochemical screening of these extracts was also performed using standard methods. Ocimum basilicum, Gnetum africanum and Eucalyptus robusta extracts possessed an antibacterial activity against all the 29 studied bacteria. The extracts from G. africanum and E. robusta were the most active with the lowest minimal inhibitory concentration of 64 μg/mL on Escherichia coli AG100A for both extracts and also against Klebsiella pneumoniae K24 for G. africanum. When tested in the presence of phenylalanine-arginine β-Naphtylamide (PAβN), an efflux pump inhibitor, the extract of Thymus vulgaris and E. Robusta showed the best activities on most tested strains. E. Robusta extract showed good synergistic effects, improving the activity of commonly used antibiotics in about 85% of cases. The overall results obtained provide the baseline information for the use of the tested plants in the treatment of bacterial infections.

Active principles of Grindelia robusta exert antiinflammatory properties in a macrophage model

Plant extracts and/or secondary metabolites are receiving considerable attention as therapeutic agents for treating inflammatory diseases such as periodontitis, which affects the tooth supporting tissues. The aim of this study was to investigate the effect of a Grindelia robusta extract enriched in saponins and polyphenols on Aggregatibacter actinomycetemcomitans lipopolysaccharide (LPS)-induced inflammatory mediator (IL-6, TNF-a, RANTES, MCP-1, PGE(2) ) and matrix metalloproteinase (MMP-1, -3, -7, -8, -9, -13) secretion by macrophages. LPS induced a marked increase in the secretion of all inflammatory mediators and MMPs tested by macrophages, as determined by enzyme-linked immunosorbent assays. At non-cytotoxic concentrations, the G. robusta extract inhibited dose-dependently the secretion of IL-6, RANTES, MCP-1 and, to a lesser extent, PGE(2) and TNF-a. Such inhibition was also observed for MMP-1, -3, -7, -8, -9 and -13 secretion. This ability of G. robusta extract to reduce the LPS-induced secretion of inflammatory mediators and MMPs was associated with a reduction of nuclear factor-kappa B (NF-kB) p65 activation. The results suggest that G. robusta extract possesses an antiinflammatory therapeutic potential through its capacity to reduce the accumulation of inflammatory mediators and MMPs.

Effect of different extraction methods on the recovery of chlorogenic acids, caffeine and Maillard reaction products in coffee beans

Water and ethanolic extracts were obtained from green and roasted (3 different roast degrees) Arabica and Robusta coffee beans. Three types of water extracts were prepared from the examined, finely ground material through: (a) brewing with boiling water, (b) boiling in water, and (c) boiling in water under elevated pressure. All these extracts were lyophilized. Two types of ethanolic extracts were derived from the examined material through (a) extraction of the finely ground coffee beans and (b) extraction of the solid residue that remained after boiling the coffee beans in water under elevated pressure. These ethanolic extracts were dried. Both water and ethanolic extracts were analyzed for concentration of potential antioxidants such as chlorogenic acids and caffeine (by HPLC) and Maillard reaction products (measurements of absorbance at 420 nm). Concentration of chlorogenic acids in Robusta extracts varied between 0.4 and 36.0 g × 100 g−1 dry extract weight (db.), while in Arabica extracts it ranged from 0.1 to 22.4 g × 100 g−1 db. Extracts of dark roasted Arabica contained more chlorogenic acids than those of Robusta. Concentration of caffeine, which in green and roasted coffee beans is maintained at the similar level, tended to increase in Robusta extracts with the roast degree and temperature of extraction with water, while in case of Arabica extracts there was no noticeable tendency. Caffeine concentrations varied between 0.12 and 8.41 g × 100 g−1 db. and between 0.03 and 6.53 g × 100 g−1 db. in Robusta and Arabica extracts, respectively. Ethanolic extracts were characterized by relatively higher caffeine concentrations and lower contents of brown pigments and chlorogenic acids as compared to water extracts. The richest in antioxidants were extracts of green Robusta coffee beans derived through boiling in water under elevated pressure.

Evaluation of the antiulcerogenic activity of Maytenus robusta (Celastraceae) in different experimental ulcer models

Maytenus robusta (Celastraceae) is used in folk medicine for the treatment of stomach ulcers and is very well adapted to the South of Brazil. Maytenus ilicifolia is the main species of the Celastraceae family, and is used in the treatment of gastric ulcers. However, Maytenus ilicifolia is presently at the stage of extinction, due to indiscriminate use in Brazil. Thus, the use of Maytenus robusta in phytotherapeutic preparations, instead of Maytenus ilicifolia, is suggested. However, there have been no reports regarding the antiulcer activity of Maytenus robusta extract. Therefore, this study was carried out to evaluate the antiulcerogenic property of the hydroalcoholic extract of aerial parts of Maytenus robusta. The antiulcer assays were performed using the following protocols: nonsteroidal anti-inflammatory drug (NSAID)-induced ulcer, ethanol-induced ulcer, and stress-induced ulcer. The effects of the extract on gastric content volume, pH and total acidity, using the pylorus ligated model, were also evaluated. In the ethanol-induced ulcer model, it was observed that the treatment with Maytenus robusta extract significantly reduced the lesion index in 75.1 ± 8.6, 85.0 ± 9.2, 86.6 ± 7.4 and 75.5 ± 5.3 for the groups treated with 50, 250 and 500 mg/kg of Maytenus robusta and positive control (omeprazole 30 mg/kg), respectively. Also were observed significant inhibition in lesion index in the indomethacin-induced ulcer model, being the decrease of the 62.5 ± 7.1, 62.5 ± 6.1, 63.6 ± 5.5 and 96.2 ± 3.6 for groups treated with 50, 250 and 500 mg/kg of Maytenus robusta and positive control (cimetidine 100 mg/kg), respectively. Results similar were observed in the stress-induced ulcer model, where the inhibition of ulcer lesions were 71.3 ± 5.5, 72.7 ± 6.3, 76.5 ± 7.1 and 92.3 ± 7.5 for the groups treated with 50, 250 and 500 mg/kg of Maytenus robusta and positive control (cimetidine 100 mg/kg), respectively. Regarding the model of gastric secretion, a reduction in the volume of gastric juice volume and total acidity was observed, as well as an increase in gastric pH. The results of the present study showed that Maytenus robusta hydroalcoholic extract displays gastroprotective activity. These results were similar to those obtained in studies carried out with Maytenus ilicifolia, which indicate that this species could be used in phytotherapeutic preparations as a substitute for Maytenus ilicifolia. This work also corroborates the traditional indication of Maytenus robusta, contributing to its pharmacological validation.