Synergistic effects of baicalein with ciprofloxacin against NorA over-expressed methicillin-resistant Staphylococcus aureus (MRSA) and inhibition of MRSA pyruvate kinase

Ethnopharmacological relevance

Baicalein, the active constituent derived from Scutellaria baicalensis Georgi., has previously been shown to significantly restore the effectiveness of β-lactam antibiotics and tetracycline against methicillin-resistant Staphylococcus aureus (MRSA). With multiple therapeutic benefits, the antibacterial actions of baicalein may also be involved in overcoming other bacterial resistance mechanisms. The aim of the present study was to further investigate antibacterial activities of baicalein in association with various antibiotics against selected Staphylococcus aureus strains with known specific drug resistance mechanisms.

Material and methods

A panel of clinical MRSA strains was used for further confirmation of the antibacterial activities of baicalein. The effect of baicalein on inhibiting the enzymatic activity of a newly discovered MRSA-specific pyruvate kinase (PK), which is essential for Staphylococcus aureus growth and survival was also examined.

Results

In the checkerboard dilution test and time-kill assay, baicalein at 16 μg/ml could synergistically restore the antibacterial actions of ciprofloxacin against the NorA efflux pump overexpressed SA-1199B, but not with the poor NorA substrate, pefloxacin. Moreover, synergistic effects were observed when baicalein was combined with ciprofloxacin against 12 out of 20 clinical ciprofloxacin resistant strains. For MRSA PK studies, baicalein alone could inhibit the enzymatic activity of MRSA PK in a dose-dependent manner.

Conclusion

Our results demonstrated that baicalein could significantly reverse the ciprofloxacin resistance of MRSA possibly by inhibiting the NorA efflux pump in vitro. The inhibition of MRSA PK by baicalein could lead to a deficiency of ATP which might further contribute to the antibacterial actions of baicalein against MRSA.     

Anti-angiogenic activity of methanol extract of Phellinus linteus and its fractions

Aim of the study

The aim of the present study was to investigate the effects of MeOH extract of PL (PLME) and its fractions on angiogenesis.

Materials and methods

PLME and its subsequent fractions (methylene chloride, ethyl acetate, n-butanol and aqueous fractions) were evaluated in vitro. Specifically, the anti-angiogenic activities of PLME and its fractions were investigated by measuring their effects on the proliferation, migration, tube formation and phosphorylation of vascular endothelial growth factor receptor (VEGFR)-2 in human umbilical vein endothelial cells (HUVECs). In addition, the in vivo Matrigel plug model was applied to evaluate new vessel formation.

Results

The results revealed that PLME and its subsequent fractions, except for the aqueous fraction, led to significant inhibition of the proliferation, migration, tube formation and VEGFR-2 phosphorylation of HUVECs as well as in vivo angiogenesis.

Conclusions

These findings indicate the potential for the use of PLME in pathological situations involving stimulated angiogenesis, such as inflammation and tumor development.     

Minimum inhibitory concentrations of medicinal plants used in Northern Peru as antibacterial remedies

Aim

The plant species reported here are traditionally used in Northern Peru to treat bacterial infections, often addressed by the local healers as “inflammation”. The aim of this study was to evaluate the minimum inhibitory concentration (MIC) of their antibacterial properties against Gram-positive and Gram-negative bacteria.

Materials and methods

The antimicrobial activity of ethanolic and water extracts of 141 plant species was determined using a deep-well broth microdilution method on commercially available bacterial strains.

Results

The ethanolic extracts of 51 species inhibited Escherichia coli, and 114 ethanolic extracts inhibited Staphylococcus aureus. In contrast, only 30 aqueous extracts showed activity against Escherichia coli and 38 extracts against Staphylococcus aureus. The MIC concentrations were mostly very high and ranged from 0.008 to 256 mg/ml, with only 36 species showing inhibitory concentrations of <4 mg/ml. The ethanolic extracts exhibited stronger activity and a much broader spectrum of action than the aqueous extracts. Hypericum laricifolium, Hura crepitans, Caesalpinia paipai, Cassia fistula, Hyptis sidifolia, Salvia sp., Banisteriopsis caapi, Miconia salicifolia and Polygonum hydropiperoides showed the lowest MIC values and would be interesting candidates for future research.

Conclusions

The presence of antibacterial activity could be confirmed in most species used in traditional medicine in Peru which were assayed in this study. However, the MIC for the species employed showed a very large range, and were mostly very high. Nevertheless, traditional knowledge might provide some leads to elucidate potential candidates for future development of new antibiotic agents.     

Bioactivity-guided fractionation for anti-fatigue property of Acanthopanax senticosus

Ethnopharmacological relevance

The root of Acanthopanax senticosus (also called Eleutherococcus senticosus or Siberian ginseng) has been used extensively in China, Russia and Japan as an adaptogen to fight against stress and fatigue.

Aim of the study

The present study was designed to ascertain the anti-fatigue property of Acanthopanax senticosus by load-weighted swimming test, sleep deprivation test, also to isolate and characterize the active constituents.

Materials and methods

Animals were orally administered with the extract of Acanthopanax senticosus. The anti-fatigue effects of the four fractions with different polarities from the 80% ethanol extract, and the different eluates collected from D101 macroporous resin chromatography and eleutheroside E, were examined based on the weight-loaded swimming capacity (physical fatigue) and the change of biochemical parameters in ICR mice. Moreover, the active fraction was later submitted to sleep-deprived mice (mental fatigue).

Results

The results shown that the n-butanol fraction significant extends the swimming time of mice to exhaustion. Furthermore, the 60% ethanol-water eluate, more purified eleutherosides (including eleutheroside E, E₂ and derivatives), were the exactly active constituents. Two compounds were isolated, which were identified as eleutheroside E, E₂.

Conclusions

The eleutherosides possess the potent abilities to alleviate fatigue both in physical and mental fatigue. Eleutheroside E may be responsible for the pharmacological effect of anti-fatigue. Furthermore, the possible mechanisms were reduced the level of TG by increasing fat utilization, delayed the accumulation of blood urea nitrogen (BUN), and increased the LDH to reduce the accumulation of lactic acid in muscle and then protect the muscle tissue.     

Antidepressant effect of Valeriana wallichii patchouli alcohol chemotype in mice: Behavioural and biochemical evidence

Ethnopharmacological relevance

Valeriana wallichii DC, an ayurvedic traditional medicine has now been shown to exist chemically as three distinct chemotypes. The study aimed to investigate the antidepressant effect of dichloromethane extract of Valeriana wallichii patchouli alcohol chemotype.

Materials and methods

Antidepressant effect of dichloromethane extract of Valeriana wallichii (10, 20 and 40 mg/kg, p.o.) using forced swim test, was determined in both acute and chronic study. The neurotransmitter levels were estimated in mouse forebrain after two weeks of dosing.

Results

Single administration of extract (40 mg/kg) significantly inhibited the immobility period in mice (p < 0.05). Similarly, chronic administration of extract (20 and 40 mg/kg) significantly reduced the immobility period and significantly increased the levels of norepinephrine and dopamine in mouse forebrain (p < 0.05).

Conclusions

The extract demonstrated antidepressant effect and significantly increased the norepinephrine and dopamine levels in forebrain.     

Plants used by native Amazonian groups from the Nanay River (Peru) for the treatment of malaria

Aim of the study

In order to evaluate the antimalarial potential of traditional remedies used in Peru, Indigenous and Mestizo populations from the river Nanay in Loreto were interviewed about traditional medication for the treatment of malaria.

Materials and methods

The survey took place on six villages and led to the collection of 59 plants. 35 hydro-alcoholic extractions were performed on the 21 most cited plants. The extracts were then tested for antiplasmodial activity in vitro on Plasmodium falciparum chloroquine resistant strain (FCR-3), and ferriprotoporphyrin inhibition test was also performed in order to assume pharmacological properties.

Results

Extracts from 9 plants on twenty-one tested (Abuta rufescens, Ayapana lanceolata, Capsiandra angustifolia, Citrus limon, Citrus paradise, Minquartia guianensis, Potalia resinífera, Scoparia dulcis, and Physalis angulata) displayed an interesting antiplasmodial activity (IC₅₀ < 10 μg/ml) and 16 remedies were active on the ferriprotoporphyrin inhibition test.

Conclusions

The results give scientific validation to the traditional medical knowledge of the Amerindian and Mestizo populations from Loreto and exhibit a source of potentially active plants.     

Oral Uncaria rhynchophylla (UR) reduces kainic acid-induced epileptic seizures and neuronal death accompanied by attenuating glial cell proliferation and S100B proteins in rats

Aim of the study

Epilepsy is a common clinical syndrome with recurrent neuronal discharges in cerebral cortex and hippocampus. Here we aim to determine the protective role of Uncaria rhynchophylla (UR), an herbal drug belong to Traditional Chinese Medicine (TCM), on epileptic rats.

Materials and methods

To address this issue, we tested the effect of UR on kainic acid (KA)-induced epileptic seizures and further investigate the underlying mechanisms.

Results

Oral UR successfully decreased neuronal death and discharges in hippocampal CA1 pyramidal neurons. The population spikes (PSs) were decreased from 4.1 ± 0.4 mV to 2.1 ± 0.3 mV in KA-induced epileptic seizures and UR-treated groups, respectively. Oral UR protected animals from neuronal death induced by KA treatment (from 34 ± 4.6 to 191.7 ± 48.6 neurons/field) through attenuating glial cell proliferation and S100B protein expression but not GABAA and TRPV1 receptors.

Conclusions

The above results provide detail mechanisms underlying the neuroprotective action of UR on KA-induced epileptic seizure in hippocampal CA1 neurons.     

Tanshinones isolated from the rhizome of Salvia miltiorrhiza inhibit passive cutaneous anaphylaxis reaction in mice

Ethnopharmacological relevance

The rhizome of Salvia miltiorrhiza Bunge (SM, family Labiatae), which contains tanshinones as main constituents, has been used as a cardiovascular and anti-inflammatory agent in Chinese medicine.

Aim of the study

This study aimed to elucidate anti-allergic effects of the root of Salvia miltiorrhiza Bunge (SM, family Labiatae) and its main constituents, tanshinones, against passive cutaneous anaphylaxis (PCA) reaction.

Materials and methods

PCA reaction was induced by IgE-antigen complex (IAC) in ICR mice. Protein expression of IL-4 and TNF-α in rat basophilic leukemia (RBL)-2H3 cells was performed by enzyme-linked immunosorbent assay and NF-κB and c-jun (AP-1) activation assayed by immunoblot.

Results

Tanshinones inhibited the PCA reaction and reduced IL-4 and TNF-α production in mice as well as in IAC-stimulated RBL-2H3 cells. Tanshinones also inhibited NF-κB and AP-1 activation in RBL-2H3 cells stimulated with IAC. Among tested tanshinones, tanshinone I exhibited the most potent inhibition, followed by 15,16-dihydrotanshinone I, tanshinone IIA and cryptotanshinone.

Conclusions

SM and tanshinones may ameliorate the PCA reaction by inhibiting the allergic cytokines IL-4 and TNF-α via NF-κB and AP-1 pathways.     

Comparative ethnobotany and in-the-field antibacterial testing of medicinal plants used by the Bulu and inland Kaulong of Papua New Guinea

Ethnopharmacological relevance

The island of New Britain in Papua New Guinea is an area of great floristic and cultural diversity that has received little attention from ethnobotanists. Here we present the results of a comparative medicinal ethnobotanical survey of the Bulu and inland Kaulong; two distinct people groups inhabiting lowland rainforest on different sides of the island. A high proportion of species are used in the treatment of bacterial infections and plants with antibacterial activity were identified in the field using a specially developed antibacterial assay kit. Follow up testing with human pathogens was used to evaluate active plant material in more detail.

Materials and methods

Rapid appraisal techniques were used to survey both people groups with all data corroborated by three or more separate sources. Plants from both groups were tested in-the-field with a portable antibacterial test kit based on the agar diffusion assay, using a pressure cooker to sterilise glassware and media. Follow up laboratory based tests were carried out using standardised agar dilution protocols for drug resistant and drug sensitive strains of Staphylococcus aureus and Streptococcus pneumoniae.

Results

We find surprisingly little overlap in the plant species used by the two people groups with only 1 out of 70 species used for the same purpose. There is also a difference in emphasis in the conditions treated with 53% of Kaulong medicinal plants dedicated to treating tropical ulcers compared with only 8% of in the Bulu group. In-the-field testing identified Garcinia dulcis bark (a Kaulong tropical ulcer treatment) to have antibacterial activity and follow up tests against a drug resistant strain of Staphylococcus aureus (a pathogen implicated in tropical ulcer pathogenesis) revealed the crude bark extract to be potently active with an MIC of just 1 mg/ml.

Conclusions

The results demonstrate extreme differences in medicinal plant use between two people groups living a mere 100 km apart and suggests the two medicinal plant systems have developed in isolation from one another. In-the-field antibacterial testing of plant extracts was found to be a valuable technique that enabled early identification of active plant material.     

An aqueous extract of Poncirus fructus activates the prokinetic activity of 5-HT receptor subtype 4 without hERG interaction

Aim of the study

Poncirus fructus (PF) - also known as the dried, immature fruit of Poncirus trifoliata (L.) Raf. (Rutaceae) - is a natural substance that has long been used for various gastrointestinal disorders in eastern Asia. An aqueous extract of PF (PF-W) has particularly potent gastroprokinetic effects, but its molecular mechanism was not well understood. Identification of the underlying prokinetic mechanism of PF-W was pursued in the present study.

Materials and methods

Changes in in vitro cAMP levels and in vivo intestinal transit rate (ITR) caused by PF-W were measured after pretreatment with GR125487, an antagonist for serotonin receptor subtype 4 (5-HT4R). An [³H] astemizole binding assay and electrophysiology experiments were performed to determine if PF-W has any interaction with the human ether-à-go-go related gene (hERG) potassium channel.

Results

PF-W induced an increase in intracellular cAMP in 5-HT4R-expressing HEK293T cells, indicating that PF-W does activate 5-HT4R. Moreover, pretreatment with GR125487 successfully blocked the increase, suggesting that the response was 5-HT4R-specific. More importantly, pretreatment of GR125487 in rats inhibited the elevation of ITR by PF-W, indicating that the prokinetic effect of PF-W was indeed exerted via 5-HT4R. On the other hand, both [³H]-astemizole binding assay and electrophysiological experiments revealed that PF-W did not interfere at all with the hERG channel.

Conclusion

It was found that PF-W exerts its prokinetic activity through a 5-HT4R-mediated pathway, with no interaction with hERG channels. Therefore, PF-W is a good candidate that might be developed as a prokinetic agent with fewer expected cardiac side effects.     

Gastroprotective activity of hydroalcoholic extract obtained from the leaves of Brassica oleracea var. acephala DC in different animal models

Ethnopharmacological relevance

Brassica oleracea var. acephala DC has been extensively used in Brazilian traditional medicine to treat gastric ulcer.

Aim of the study

This study was conducted to evaluate the antiulcerogenic property of hydroalcoholic extract obtained from the leaves of Brassica oleracea.

Materials and methods

Antiulcer assays were performed using the protocol of ulcer induced by ethanol/HCl, and non-steroidal anti-inflammatory drugs (NSAIDs). Parameters of gastric secretion (volume, pH and [H⁺]) were determined by the pylorus ligation model and mucus in gastric contents.

Results

In the ethanol-induced ulcer model, we observed a significant reduction in all the parameters analyzed, obtaining curative ratios of 58.8 ± 11.5, 86.2 ± 12.2 and 42.8 ± 6.6% for the groups treated with 50 and 100 mg/kg of extract and omeprazole (30 mg/kg), respectively. The dose of 25 mg/kg of hydroalcoholic extract of Brassica oleracea showed no significant results. In the indomethacin-induced ulcer, the percentages of ulcer inhibition were 64.3 ± 9.9, 66.4 ± 12.3 and 81.2 ± 7.5% for the groups treated with 50 and 100 mg/kg extract and positive control (cimetidine, 100 mg/kg), respectively. The results showed a significant increase in pH and mucus production in the groups treated with Brassica oleracea when compared with the control group. No sign of toxicity was observed in the acute toxicity study.

Conclusions

The results of the present study show that hydroalcoholic extract of Brassica oleracea displays antiulcer activity, as demonstrated by the significant inhibition of ulcer formation induced using different models. The data suggest that the effectiveness of the extract is based on its ability to stimulate the synthesis of mucus, increase pH and decrease H⁺ ions in the stomach. This work corroborates the ethnopharmacology use of Brassica oleracea preparations, contributing to its pharmacological validation by suggesting that preparations obtained from Brassica oleracea could be used for the development of new phytopharmaceuticals for the treatment of gastric ulcer.     

Analgesic and anti-inflammatory activities of 11-O-galloylbergenin

Aims of the study

Current study was designed to explore the analgesic and anti-inflammatory effects of a constituent isolated from Mallotus philippinensis, in order to validate its folk use.

Materials and methods

11-O-galloylbergenin was isolated from ethanolic extract of Mallotus philippinensis. Analgesic and anti-inflammatory activities of the test compound were assessed using formalin test and carrageenan-induced paw edema models.

Results

11-O-galloylbergenin showed significant analgesic activity at doses of 20 and 40 mg/kg against formalin test in rats. Similarly, 11-O-galloylbergenin exhibited significant anti-inflammatory activity in carrageenan-induced paw edema model at doses of 10, 20 and 30 mg/kg.

Conclusion

11-O-galloylbergenin has demonstrated its significant potential to be further investigated for its discovery as a new lead compound for management of pain and inflammation.     

The apoptosis inducing effects of Sutherlandia spp. extracts on an oesophageal cancer cell line

Aim of study

Oesophageal cancer is the ninth most common cancer in the world and the second most common cancer among South African men. It also has one of the lowest possibilities of cure, with the 5-year survival rate estimated to be only 10% overall. Sutherlandia frutescens, or the “cancer bush”, is a medicinal plant indigenous to southern Africa that is believed to have anti-cancer and anti-proliferative properties. The aim of this study was to investigate the potential apoptosis-inducing effects of two S. frutescens extracts and one Sutherlandia tomentosa extract on the SNO oesophageal cancer cell line.

Materials and methods

Cell viability and morphology of SNO cells were evaluated following exposure to the extracts. Apoptotic markers including cytochrome c translocation and phosphatidylserine externalisation were quantified by flow cytometry. The activity of caspases 3 and 7 was evaluated with spectrofluorometry. Apoptosis was evaluated in the presence of the pan-caspase inhibitor, Z-VAD-fmk. The effect of the extracts was compared to non-cancerous peripheral blood mononuclear cells (PBMCs).

Results

Time- and dose-response studies were conducted to establish treatment conditions of 2.5 and 5 mg/ml of crude plant extracts. Microscopy studies revealed that S. frutescens- and S. tomentosa-treated SNO cells had morphological features characteristic of apoptosis. Annexin V/propidium iodide flow cytometry confirmed that the extracts do, in fact, induce apoptosis in the SNO cells. Caspase inhibition studies seem to indicate that extracts A (S. frutescens (L.) R. Br. subsp. microphylla from Colesberg), B (S. frutescens (L.) R. Br. subsp. microphylla from Platvlei) and C (S. tomentosa Eckl. & Zeyh from Stil Bay) are able to induce caspase-dependent as well as -independent cell death. The S. frutescens and S. tomentosa extracts were found to be more cytotoxic to cancerous SNO cells when compared to the PBMCs.

Conclusions

S. frutescens and S. tomentosa extracts show promise as apoptosis-inducing anti-cancer agents.     

Acute and sub-chronic toxicity study of standardized extract of Fumaria indica in rodents

Ethnopharmacological relevance

Despite Fumaria indica (FI) widespread medicinal uses in the Indian traditional medicine, no systematic study of the potential toxicity of the plant has been described.

Aim of the study

To assess acute and sub-chronic toxicity of a 50% ethanolic extract of FI in mice and rats respectively.

Materials and methods

In acute toxicity study, Swiss strain albino mice of either sex were administered orally FI doses of 1, 2.5 and 5 g/kg and observed for behavioural changes and mortality, if any. In sub-chronic toxicity study, Charles Foster albino rats of either sex were administered two doses of FI i.e., 100 and 400 mg/kg, p.o. for 30 consecutive days. During 30 days of treatment, rats were observed for any change in body weight and daily food and water intake. After 30 days, rats were sacrificed for haematological, biochemical and histopathology study. Control animals were administered 0.3% carboxymethyl cellulose (CMC) suspension by oral route.

Results

There was no mortality or abnormal behaviour, observed in acute toxicity study in mice at all the three dose levels. In sub-chronic toxicity study, FI did not produce any significant change in body weight and daily food and water intake of rats when compared to vehicle treated rats. Further, haematological and biochemical parameters were also found normal. Histopathological study revealed normal architecture of kidney and liver of FI treated rats.

Conclusions

FI extract, provisionally standardized on its fumarate contents, seems to fulfill a preclinical criterion necessary for its further development as a clinically useful adaptogen.     

Anti-diabetic activity of Chiliadenus iphionoides

Ethnopharmacological relevance

Chiliadenus iphionoides (Boiss. & Blanche) Brullo (Asteraceae), a small aromatic shrub found throughout Israel, is used traditionally in the treatment of diabetes mellitus. In this study, Chiliadenus iphionoides anti-diabetic activity was characterized using cellular and animal models.

Materials and methods

Pancreatic β cells, adipocytes, and skeletal myotubes were treated with an ethanolic extract of Chiliadenus iphionoides to study the extract's effects on insulin secretion and glucose uptake. The sand rat (Psammomys obesus) was used to study Chiliadenus iphionoides acute and long term effects in vivo. An oral starch tolerance test was performed as well as a 30 day feeding study.

Results

Chiliadenus iphionoides extract increased insulin secretion in β cells as well as glucose uptake in adipocytes and skeletal myotubes. The extract also displayed hypoglycemic activity in the diabetic sand rat.

Conclusions

Chiliadenus iphionoides exhibits considerable anti-diabetic activity, although the mechanism of action remains to be determined.     

Spatholobus suberectus inhibits cancer cell growth by inducing apoptosis and arresting cell cycle at G2/M checkpoint

Aim of the study

Although herbs have long been alternatively applied for cancer treatment in China, its treatment effects and their potential mechanisms have not been sufficiently investigated. The chinese herb Spatholobus suberectus (SS) is commonly prescribed to cancer patients. In this study, the anti-cancer effect of SS and its molecular mechanisms have been investigated.

Materials and methods

The effect of SS on cell proliferation was studied by cell growth assay and flow cytometry on breast cancer cell lines MCF-7 and colon cancer cell line HT-29. The role of SS in apoptosis was studied by flow cytometry, DNA fragmentation assay and mitochondrial membrane potential assay. Expression of proteins associated with cell cycle and apoptosis was determined by Western blot analysis. The in vivo effect of SS was tested in nude mouse cancer xenografts.

Results

Cell growth assay showed that SS effectively inhibits tumor cell growth in a dose-dependent manner. Flow cytometry analysis showed that SS could arrest the cell cycle at G2/M checkpoint, which is associated with DNA damage and activation of phosphor-Chk1/Chk2. The pro-apoptotic effect of SS was demonstrated by Annexin V-PI staining and mitochondrial membrane potential assay. In vivo experiments show that the efficiency of SS alone group was superior to docetaxel or to docetaxel and SS combined. No obvious body weight loss or blood toxicity was observed in SS tested animals.

Conclusions

Our data demonstrates that SS is a potential herb for cancer treatment by inhibiting tumor growth via induction of apoptosis and arrest of the cell cycle at G2/M phase.     

In vitro growth stimulatory and in vivo wound healing studies on cycloartane-type saponins of Astragalus genus

Aim of the study

The present study was undertaken to evaluate the wound healing effects of the four chief saponins of Astragalus species [cycloastragenol (CA), astragaloside IV (AG), cyclocephaloside I (CCI) and cyclocanthoside E (CCE)].

Material and methods

Effects of cell viability and proliferation of the isolated compounds were evaluated by the MTT assay on human keratinocyte. The wound healing activity was studied by using in vitro wound healing, proliferation and migration scratch assay. In order to see in vivo effectiveness of the compounds, an animal study with Sprague-Dawley male rats at the age of 12 weeks was carried out, and then the main histological outcomes were investigated to observe reepithelization, neovascularization, and presence of inflammatory cells, granulation tissue amount and maturation.

Results

All the compounds increased both fibroblast proliferation and migration, but the effects were much superior for CA at 1 ng/ml concentration. Among the compounds, based on the histological findings, 5% CA preparation was found to be the most remarkable in vivo wound healing agent showing greater cell density, more regularly organized dermis and more newly formed blood vessels.

Conclusion

Results of this study indicate that the cycloartane-type saponins are the principal constituents responsible for wound healing activities of the roots of Astragalus species substantiating its use in traditional medicine.     

Potential of medicinal plants from the Brazilian semi-arid region (Caatinga) against Staphylococcus epidermidis planktonic and biofilm lifestyles

Ethnopharmacological relevance

Medicinal plants from the Caatinga, a Brazilian xeric shrubland, are used in folk medicine to treat infections. These ethnopharmacological data can contribute to obtaining new antimicrobial/antibiofilm extracts and natural product prototypes for the development of new drugs. The aim of this study was to investigate the antibiofilm and antibacterial activities of 45 aqueous extracts from 24 Caatinga plant species.

Materials and methods

The effect of aqueous extracts on planktonic cells and on biofilm formation by Staphylococcus epidermidis was studied by the OD₆₀₀ absorbance and by the crystal violet assay, respectively. Scanning electron microscopy (SEM) was used to generate comparative images of extract-treated and untreated biofilms. Chromatographic analyses were performed to characterize the active extracts.

Results

The in vitro screening, at 0.4 mg/mL and 4.0 mg/mL, showed 20 plants effective in preventing biofilm formation and 13 plants able to inhibit planktonic bacterial growth. SEM images demonstrated distinct profiles of bacterial adhesion, matrix production and cell morphology according to different treatments and surfaces. The phytochemical analysis of the selected active extracts indicates the polyphenols, coumarins, steroids and terpenes as possible active compounds.

Conclusion

This study describes the first antibiofilm and antibacterial screening of Caatinga plants against S. epidermidis. The evaluation presented in this study confirms several ethnopharmacological reports and can be utilized to identify new antibiofilm and antibacterial products against S. epidermidis from traditional Brazilian medicine.     

Modulation of inflammatory markers by the ethanolic extract of Leucas aspera in adjuvant arthritis

Aim of the study

To investigate the anti-inflammatory and antioxidant potential of ethanolic extract of Leucas aspera (EELA) in adjuvant arthritis.

Materials and methods

Complete Freund's adjuvant served to induce arthritis. EELA was administered in two doses along with vehicle control (0.1% carboxymethyl cellulose) and positive control (Diclofenac). Levels of tumour necrosis factor (TNF-)-α, C-reactive protein (CRP), Interleukin-2 (IL-2), Cathepsin D, activities of antioxidant enzymes superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase (CAT) were estimated in plasma/hemolysate and tissue. HPLC analysis of EELA was also performed.

Results

EELA exhibited significant anti-inflammatory (p < 0.001) and antioxidant activity (p < 0.001). It did not show mortality up to 2000 mg/kg body weight. Histopathological studies confirmed complete cartilage regeneration and near normal joint in EELA2 treated arthritic rats.

Conclusion

This study highlighted the antioxidant and anti-inflammatory potential of Leucas aspera. Three major families of compounds present in EELA may explain these activities: catechins (epicatechin, beta epicatechin), flavonoids (procyanidin), phytosterols (beta-sitosterol) apart from glycosides, phenolic compounds and tannins.     

Influences of Fructus evodiae pretreatment on the pharmacokinetics of Rhizoma coptidis alkaloids

Ethnopharmacological relevance

Rhizoma coptidis is a traditional Chinese medicine with pharmacological properties. It is usually prescribed with Fructus evodiae as traditional Chinese medicine (TCM) formulas. Here we report the influences of Fructus evodiae on the pharmacokinetics of the Rhizoma coptidis alkaloids and propose possible mechanisms.

Materials and methods

Pharmacokinetic experiments were performed in rats. In vitro absorption experiments were performed in everted rat gut sacs, while in vitro metabolism experiments and determination of hepatic UDP-glucuronosyltransferase (UGT) 1A1 mRNA expression were performed in rat liver microsomes.

Results

Pretreatment with Fructus evodiae extract for two weeks decreased the systemic exposure of the Rhizoma coptidis alkaloids. This effect was not due to inhibition of absorption or enhanced hepatic phase I metabolism of the Rhizoma coptidis alkaloids. However, Fructus evodiae pretreatment enhanced both the activity and expression of hepatic UGT1A1.

Conclusions

The results showed that Fructus evodiae pretreatment decreased the systemic exposure of the Rhizoma coptidis alkaloids by inducing hepatic UGT1A1.