Anti-Helicobacter pylori activity of plants used in Mexican traditional medicine for gastrointestinal disorders

Aim of the study

Helicobacter pylori is the major etiological agent of chronic active gastritis and peptic ulcer disease and is linked to gastric carcinoma. Treatment to eradicate the bacteria failed in many cases, mainly due to antibiotic resistance, hence the necessity of developing better therapeutic regimens. Mexico has an enormous unexplored potential of medicinal plants. This work evaluates the in vitro anti-H. pylori activity of 53 plants used in Mexican traditional medicine for gastrointestinal disorders.

Materials and methods

To test the in vitro antibacterial activity, agar dilution and broth dilution methods were used for aqueous and methanolic extracts, respectively.

Results

Aqueous extracts of Artemisia ludoviciana subsp. mexicana, Cuphea aequipetala, Ludwigia repens,and Mentha × piperita (MIC 125 to <250 μg/ml) as well as methanolic extracts of Persea americana, Annona cherimola, Guaiacum coulteri, and Moussonia deppeana (MIC <7.5 to 15.6 μg/ml) showed the highest inhibitory effect.

Conclusions

The results contribute to understanding the mode of action of the studied medicinal plants and for detecting plants with high anti-Helicobacter pylori activity.     

Davilla elliptica and Davilla nitida: Gastroprotective,anti-inflammatory immunomodulatory and anti-Helicobacter pylori action

Ethnopharmacological relevance

Davilla elliptica and Davilla nitida are species commonly found in the Brazilian Cerrado biome.

Aim of the study

Based on ethnopharmacological and phytochemical analyses, methanolic extracts from leaves of Davilla elliptica (EDE) and Davilla nitida (EDN) were evaluated for their anti-ulcer, anti-inflammatory, immunological and anti-Helicobacter pylori activities.

Materials and methods

The gastroprotective action of both extracts was evaluated in rodent experimental models (HCl/ethanol, ethanol or NSAID). We also evaluated anti-inflammatory (carrageenin-induced rat hind paw edema), immunomodulatory (murine peritoneal macrophages) and antibacterial action of both extracts against a standard strain of Helicobacter pylori.

Results

EDE and EDN (500 mg/kg) were able to protect gastric mucosa against HCl/ethanol solution (EDE 63%; EDN 59%), absolute ethanol (EDE 95%; EDN 88%), and also against injurious effect of NSAID (EDE 77%; EDN 67%). When EDE and EDN were challenged with sulfhydryl depleter compound, the gastroprotective action of both extracts was completely abolished. EDE had gastroprotective effect related to increase of glutathione bioavailability and stimulated higher levels of NO, H₂O₂ and TNF-α production. Otherwise EDN showed better anti-Helicobacter pylori action than EDE. Neither extracts presented anti-inflammatory activity by oral route.

Conclusion

The phytochemical investigation showed that both extracts possess phenolic acid derivatives, acylglycoflavonoids and condensed tannins with evident quantitative variations that probably influenced the pharmacological differences between extracts.     

Screening for polyphenols,antioxidant and antimicrobial activitiesof extracts from eleven Helianthemum taxa (Cistaceae) used in folk medicine in south-eastern Spain

Ethnopharmacological relevance

The Helianthemum genus contains approximately one hundred taxa. Some of them are important medicinal plants used in several countries for many different purposes. However, studies addressing the phytochemistry of many of these species or their biological activities are currently nonexistent.

Aim of the study

To perform a comparative analysis of the qualitative composition of secondary metabolites and biological activities of the leaves of the most commonly distributed and used Spanish Helianthemum taxa in order to find a relationship between chemotype, biological activity and uses.

Materials and methods

water and 80% methanolic extracts derived from 11 different Helianthemum taxa were analyzed for their phytochemical composition using standard methods. Furthermore, HPLC analysis was performed for the estimation of gallic acid, ellagic acid, tannins and flavonols as marker compounds. The antioxidant activity was measured by employing the scavenging activity on DPPH (2,2-diphenyl-1-picrylhydrazyl) and ABTS (2,2′-azinobis-3-ethylbenzothiazoline-6-sulfonate) radicals. The 80% methanolic extracts were evaluated for antibacterial (Gram-positive Staphylococcus aureus, Enterococcus faecalis and Listeria monocytogenes and Gram-negative Escherichia coli and Salmonella enterica) activity using the micro dilution technique.

Results

The total polyphenolic content and antioxidant capabilities differed significantly among the Helianthemum leaf extracts. A strong correlation between total phenolic content, antioxidant properties and antimicrobial activity was found. The polyphenolic profile was specific for each taxon. Whereas Helianthemum alypoides, Helianthemum cinereum subsp. rotundifolium, Helianthemum hirtum, Helianthemum asperum, and Helianthemum marifolium subsp. marifolium were characterized by the presence of gallic acid, egallic derivatives and ellagitannins; the polyphenolic profile of Helianthemum apenninum subsp. cavanillesianum, Helianthemum syriacum and Helianthemum polygonoides was mostly based on flavonoids. Helianthemum cinereum, Helianthemum alypoides and Helianthemum marifolium consistently presented the strongest radical scavenging activity (in water extracts EC₅₀ ranges from 29.88 to 38.1 against DPPH and from 8.11 to 20.8 against ABTS, and in 80% MeOH extracts from 25.3 to 31.8 against DPPH and from 6.15 to 8.6 against ABTS), total phenol content (>117 mg GAE/l) and antimicrobial activities.

Conclusion

The Helianthemum taxa used in folk medicine did not cluster in a unique section, being equally distributed in two out of the four sections analysed. There was not a clear relationship between the chemotype, based on the polyphenolic composition of the taxa, and their taxonomical classification. However, the composition of the methanolic and water extracts from the leaves of plants belonging to the Helianthemum genus was strongly related to their medicinal uses.     

In vitro bactericidal activity of diterpenoids isolated from Aframomum melegueta K.Schum against strains of Escherichia coli, Listeria monocytogenes and Staphylococcus aureus

Ethnopharmacological relevance

The ethnobotanical use of Aframomum melegueta in the treatment of urinary tract and soft tissue infection suggested that the plant has antimicrobial activity.

Materials and methods

To substantiate the folkloric claims, an acetone, 50:50 acetone:methanol and 2:1 chloroform:methanol extracts were tested against Escherichia coli K12; acetone extract and the fractions of acetone extracts were tested against Listeria monocytogenes. Bioassay-guided fractionation was performed on the extract using L. monocytogenes as the test organism to isolate the bioactive compounds which were then tested against all the other organisms.

Results

Four known labdane diterpenes (G3 and G5) were isolated for the first time from the rhizomes of A. melegueta and purified. These were tested against E. coli, L. monocytogenes, methicillin resistant Staphylococus aureus (MRSA) and S. aureus to determine antibacterial activity. The result showed that two compounds G3 and G5 exhibited more potent antibacterial activity compared to the current clinically used antibiotics ampicillin, gentamicin and vancomycin and can be potential antibacterial lead compounds. The structure of the labdane diterpenes were elucidated using nuclear magnetic resonance (NMR) spectroscopy and Mass spectrometry. A possible mode of action of the isolated compound G3 and its potential cytotoxicity towards mammalian cells were also discussed.

Conclusion

The results confirmed the presence of antibacterial compounds in the rhizomes of A. melegueta with a favourable toxicity profile which could be further optimized as antibacterial lead compounds.     

In vitro pharmacological evaluation of three Barleria species

Ethnopharmacological relevance

Various parts of Barleria prionitis L. (Acanthaceae) are used in traditional medicine to treat infection-related ailments. A comparison of their activities and knowledge of their mechanisms of action are important for drug development and conservation.

Aims of the study

This study investigated the antibacterial effects and underlying mechanisms of action of the anti-inflammatory activities of different parts of three Barleria species of South African origin.

Materials and methods

Crude extracts of different parts of three Barleria species were investigated in vitro for their biological activity. Antibacterial activity was evaluated using the micro-dilution assay against two Gram-positive and two Gram-negative bacteria. Anti-inflammatory activity was evaluated using the cyclooxygenase COX-1 and COX-2 assays.

Results

All the extracts showed broad-spectrum antibacterial activity with minimum inhibitory concentrations ranging from 0.059 to 6.25 mg/ml. Twelve out of 21 crude extracts evaluated showed good activity (>70%) in the COX-1 assay while 10 extracts showed good activity in the COX-2 assay. All the petroleum ether extracts (except B. prionitis stem) exhibited good inhibition of prostaglandin synthesis in COX-1.

Conclusion

The results demonstrated the therapeutic potential of these plants as antibacterial and anti-inflammatory agents. Their anti-inflammatory properties are mediated by the inhibition of the cyclooxygenase enzymes.     

Estimation of anti-inflammatory,antinociceptive and antioxidant activities on Arctium minus (Hill) Bernh. ssp. minus

Ethnopharmacological relevance

Arctium minus (Hill) Bernh. ssp. minus (Asteraceae) leaves are used to alleviate rheumatic pain, against fever and sunstroke with externally application in Turkish folk medicine.

Aim of the study

To evaluate the anti-inflammatory, antinociceptive and antioxidant activities of aqueous and ethanol extracts prepared from the leaves of Arctium minus ssp. minus.

Materials and methods

The ethanolic and aqueous extracts from the leaves of Arctium minus ssp. minus were evaluated in mice for anti-inflammatory activity using carrageenan-induced hind paw edema model and for antinociceptive activity using p-benzoquinone-induced abdominal contractions test. Moreover, the antioxidant power of the extracts has been determined by using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and flow injection analysis-luminol chemiluminescence (FIA-CL). In addition, the total phenolic content in both extracts was determined with spectrophotometric method.

Results

Our results showed that only the ethanol extract exhibited a dose-dependent anti-inflammatory activity ranging between 11.1 and 23.6% at 200 mg/kg dose as well as displayed a significant antinociceptive activity without inducing any gastric damage. Although, both extracts were shown to possess significant DPPH radical-scavenging activity, that of aqueous extract was found to have more pronounced activity. In FIA-CL system, the ethanol extract was shown to possess a significant scavenger activity against H₂O₂ while the aqueous extract was much more potent antioxidant activity against HOCl-luminol CL than ethanol extract.

Conclusion

According to our results, it was concluded that Arctium minus ssp. minus contains potent natural antioxidants. In this study, in vivo experimental results have also supported the folk medicinal utilization of Arctium minus ssp. minus.     

In vitro biological activities of niloticane,a new bioactive cassane diterpene from the bark of Acacia nilotica subsp. kraussiana

Ethnopharmacological relevance

Acacia nilotica subsp. kraussiana was reported in African traditional medicine for the treatment of various ailments. Isolation of an active compound in this study from the bark extract may lead to the validation of its efficiency as a traditional crude drug.

Aims of the study

This study aimed to isolate active compound(s) from an ethyl acetate bark extract of Acacia nilotica subsp. kraussiana and to investigate some of its biological activity.

Materials and methods

The isolation process was carried out using bioassay-guided fractionation. The isolated compound was tested for antibacterial activity using the micro-dilution assay; anti-inflammatory activity using the COX-1 and COX-2 assays and investigated for inhibitory effect against acetylcholinesterase using the microplate assay.

Results

A new bioactive compound was isolated and identified as a cassane diterpene, niloticane. Niloticane showed antibacterial activity against Gram-positive bacteria Bacillus subtilis and Staphylococcus aureus with MIC values of 4 and 8 μg/mL, respectively. With Gram-negative bacteria, niloticane showed weak activity. MIC values obtained were 16 and 33 μg/mL against Klebsiella pneumonia and Escherichia coli, respectively. In the cyclooxygenase test, niloticane possessed activity with IC₅₀ values of 28 and 210 μM against COX-1 and COX-2, respectively. IC₅₀ values observed with indomethacin (positive control) were 3.6 μM for COX-1 and 189 μM for COX-2. In the acetylcholinesterase test, niloticane showed anti-cholinesterase activity with an IC₅₀ value of 4 μM. IC₅₀ values obtained by the galanthamine (positive control) was 2.0 μM.

Conclusion

The results obtained support the traditional uses of the bark of Acacia nilotica subsp. kraussiana in African traditional medicine for the treatment of some ailments that relate to microbial diseases, inflammation and central nervous system disorders.     

Antimicrobial activity of Acacia mellifera extracts and lupane triterpenes

Ethnopharmacological relevance

Acacia mellifera (Vahl) Benth (Leguminosae) is a subtropical medicinal plant that is widely used in traditional African medicines against various diseases such as pneumonia and malaria.

Aim of the study

The present study was performed to evaluate the antimicrobial effects of extracts from the stem bark of Acacia mellifera.

Materials and methods

The extracts were examined for antibacterial and antifungal activity using the disc-diffusion method against bacterial strains: Streptococcus pneumoniae (ATCC 25923), Pseudomonas aeruginosa (ATCC 27853), Escherichia coli (ATCC 35218), Escherichia coli (ATCC 25922) and Staphylococcus aureus (ATCC 25923) and fungal strains Candida albicans (ATCC 90028), Candida krusei (ATCC 6255), Cryptococcus neoformans (ATCC 6603) and clinical isolates of Microsporum gypseum and Trichophyton mentagrophytes.

Results

Some of these extracts were found to be active against some bacterial and fungal strains and were further fractionated to give 12 pure compounds. The methanolic and methanol:dichloromethane (1:1) extracts exhibited antibacterial and antifungal activity. The two were active against Staphylococcus aureus (ATCC 25923), Microsporum gypseum, and Trichophyton mentagrophytes. Activity guided fractionation led to isolation of two active compounds: 3-(Z)-cis coumaroylbetulin and 30-hydroxylup-20 (29)-en-3β-ol which were against Staphylococcus aureus (ATCC 25923), Microsporum gypseum, Trichophyton mentagrophytes and Pseudomonas aeruginosa (ATCC 27853).

Conclusions

These results may partly explain and support the use of Acacia mellifera stem barks for the treatment of infectious diseases in traditional Kenya medicine.     

Evaluation of wound healing activity of root of Mimosa pudica

Ethno pharmacological relevance

Mimosa pudica, commonly known as touch-me-not, is used in folklore medicine in arresting bleeding and in skin diseases.

Aim

There was no scientific evidence justifying the use of Mimosa pudica, therefore the present study was aimed at evaluation of wound healing activity of the plant.

Materials and methods

In the present study the roots of Mimosa pudica were studied for wound healing activity by incorporating the methanolic and the total aqueous extract in simple ointment base B.P. in concentration of 0.5% (w/w), 1% (w/w) and 2% (w/w). Wound healing activity was studied in three types of model in rats viz. excision, incision and estimation of biochemical parameter. In case of the excision wound model wound contraction and period of epithelization was studied while in incision wound model was evaluated by determining tensile strength and hydroxyproline content in the scab.

Results

Treatment of wound with ointment containing 2% (w/w) the methanolic and 2% (w/w) the total aqueous extract exhibited significant (P < 0.001) wound healing activity. The methanolic and total aqueous extracts were analyzed for total phenols content equivalent to Gallic acid. The content of total phenols was 11% (w/w) and 17% (w/w) in methanolic and total aqueous extract respectively.

Conclusion

The methanolic extract exhibited good wound healing activity probably due to phenols constituents.     

Chemical constituents and antibacterial property of the essential oil of the roots of Cyathocline purpurea

Ethnopharmacological relevance

Cyathocline purpurea (D. Don.) O. Ktze. (Asteraceae) is a rare existence Indian medicinal plant and traditionally has antimicrobial property.

Aim of the study

The aim of the present study was to identify chemical composition of the essential oil from the roots of Cyathocline purpurea and to screened in vitro antibacterial activity against eight human pathogenic bacteria.

Materials and methods

The essential oil of roots was analyzed by using GC–FID and GC–MS. The antibacterial activity of oil was tested against four Gram-positive and four Gram-negative bacteria and antibacterial activity was determined by the tube dilution method.

Results

The main constituents of the oil were thymohydroquinone dimethyl ether (57.4%) and β-selinene (14.0%), among twenty five identified compounds, which represented 90.1% of the total oil. The oil was found active against Gram-positive bacteria with minimal bactericidal concentration (MBC) values in the range of 0.26–0.57 mg/mL.

Conclusions

This is the first report on the chemical composition and antibacterial activity of the essential oil of roots of Cyathocline purpurea. The observation of MBC assay suggested that the Gram positive microorganisms were susceptible to essential oil, while oil was found to be resistant against Gram-negative bacteria, and the oil has bactericidal property.     

Cytotoxic and antibacterial triterpenoids derivatives from Clematis ganpiniana

Ethnopharmacological relevance

The roots and rhizomes of Clematis are commonly used as an analgesic, abirritative, antibacterial, antiphlogistic, anticancer and diuretic agent. The Naxi people traditionally used Clematis ganpiniana's (Lévl. Et Vant.) as a diuretic agent, an anti-inflammatory and anticancer remedy.

Aim of study

To investigate the cytotoxic and antibacterial components from Clematis ganpiniana.

Materials and methods

The aboveground part of Clematis ganpiniana was isolated by chromatographic techniques. Structures of isolated compounds were identified by spectroscopic methods and comparison with published data. Their cytotoxic, apoptosis and antibacterial activities of purified components were also performed.

Results

By bioassay-guided fractionation techniques and chemical characterization, four triterpene glycosides were isolated and their cytotoxicity against cancer cells and antibacterial activity were tested. They showed significant inhibitory activities against MCF-7, MDA-MB-231 with IC50 value of 0.7–16.5 μg/ml, and significant apoptosis for MCF-7 and MDA-MB-231. Moreover, compound 4 showed weak wide-spectrum antibacterial activity.

Conclusion

These results provide promising baseline information for the potential use of Clematis ganpiniana as well as some of the isolated compounds in the treatment of cancer and infectious disease.     

Sesquiterpene lactones with antinociceptive and antipyretic activity from two Centaurea species

Ethnopharmacological relevance

Several Centaurea species are used to alleviate pain and inflammatory symptoms in rheumatoid arthritis, high fever, and head ache in Turkish folk medicine.

Aim of the study

The effectiveness of extracts, fractions and subfractions from dried Centaurea solstitialis L. subsp. solstitialis (CSS) (Asteraceae) roots and aerial parts were studied on mice.

Materials and methods

The antinociceptive and antipyretic effects of Centaurea solstitialis L. subsp. solstitialis have been investigated by using p-benzoquinone-induced writhing reflex for antinociceptive activity and Freund's Complete Adjuvant-induced pyrexia model for antipyretic activity assessment in mice.

Results

The ethanolic extract from the aerial parts of the plant was shown to possess significant antinociceptive (p < 0.01) and antipyretic activities (p < 0.01). The extract was then submitted to subsequent solvent extractions and chromatographic processes. Through bioassay-guided fractionation and isolation procedures two sesquiterpene lactones, solstitialin A and acetyl solstitialin, were isolated and defined as the active components of CSS. On the other hand, a comparative study was conducted on another species, Centaurea depressa Bieb., which has no similar folkloric utilization. Following the same fractionation chart same compounds were defined as the active ingredients.

Conclusion

Results of the present study proved that aerial part of CSS possesses antinociceptive and antipyretic activities supporting the folkloric assertion in Turkish folk medicine. However, these effects seem not limited to CSS, some other Centaurea species, in fact, having no folkloric use might be equally active.     

In vitro and in vivo antimalarial and cytotoxic activity of five plants used in congolese traditional medicine

Aim of the study

The in vitro antiplasmodial activity and cytotoxicity of methanolic and dichloromethane extracts from five Congolese plants were evaluated. The plants were selected following an ethnobotanical survey conducted in D.R. Congo and focusing on plants used traditionally to treat malaria. The in vivo antimalarial activity of aqueous and methanolic extracts active in vitro was also determined in mice infected by Plasmodium berghei berghei.

Materials and methods

The growth inhibition of Plasmodium falciparum strains was evaluated using the measurement of lactate dehydrogenase activity. The extracts (aqueous, CH₃OH, EtOH and CH₂Cl₂) were prepared by maceration and tested in vitro against the 3D7 (chloroquine sensitive) and W2 (chloroquine resistant) strains of Plasmodium falciparum and against the human normal fetal lung fibroblasts WI-38 to determine the selectivity index. Some extracts were also used at the dose of 300 mg/kg to evaluate their activity in mice infected since 4 days by Plasmodium berghei.

Results

Two plants presented a very high activity (IC₅₀ < 3 μg/ml). These plants were Strychnos icaja roots bark (MeOH and CH₂Cl₂) and Physalis angulata leaves (MeOH and CH₂Cl₂). One plant (Anisopappus chinensis whole plant, MeOH and CH₂Cl₂) presented a high activity (IC50 < 15 μg/ml). The extracts of Anisopappus chinensis and Physalis angulata showed also a good inhibition of parasitemia in vivo. Flavonoids, phenolic acids and terpenes were identified in these plants by a general phytochemical screening method.

Conclusion

Three plants showed a very interesting antiplasmodial activity (Anisopappus chinensis, Physalis angulata and Strychnos icaja) and one of them showed a good selectivity index (>10, Anisopappus chinensis). Anisopappus chinensis and Physalis angulata were also active in vivo.     

Synergistic antibacterial effect of honey and Herba Ocimi Basilici against some bacterial pathogens

Objective

To evaluate the antibacterial activity of the combination of different honey brands and methanolic fraction of Herba Ocimi Basilici using agar well diffusion assay.

Methods

The antibacterial activity was determined against thirteen pathogenic bacterial clinical isolates including six gram negative (Klebsiella pneumonia, Pseudomonas aeroginosa, Escherichia coli, Salmonella typhi, Salmonella typhimirium, Xanthomonas campestris) and six gram positive strains (Enterococcus faecalis faecalis, Bacillus subtilis, Staphylococcus aureus, Clostridium perfringens type C, Clostridium perfringens type D, Clostridium chauvoei). Agar well diffusion method was used while zones of inhibition were measured with vernier scale.

Results

At higher concentration, all the honey brands showed good to significant activity. The highest activity was observed for Hamdard brand honey (27.60±0.40) against Enterococcus faecalis.

Conclusion

These results revealed that combinations of plant extracts of Herba Ocimi Basilici with honey can be used for the development of potent and novel antibacterial agents.     

Eleutherine indica L. accelerates in vivo cutaneous wound healing by stimulating Smad-mediated collagen production

Ethnopharmacological relevance

Eleutherine indica L. has been used for healing of wound, painful and irregular menstruation, dysentery and lesions, and topically used as antiseptic and antimicrobial agent in folk medicine. In the present study, methanolic extracts of Eleutherine indica was subjected to scientific investigation for in-vivo cutaneous wound healing in wistar rat.

Materials and methods

In-vivo wound healing activity of Eleutherine indica was evaluated by using circular excision experimental models, followed by histopathological and western blot analysis. The healing potential was comparatively assessed with a reference gentamicin sulfate hydrogel (0.01% w/w). Wound contraction measurement, hydroxyproline estimation and western blot for COL3A1, bFGF, Smad-2, -3, -4, and -7 were performed.

Results

The methanolic extract of Eleutherine indica showed accelerated wound healing activity as evidenced by fast wound contraction rate and higher hydroxyproline content of granulation tissue. Western blot revealed the Smad-mediated collagen production promoting property of Eleutherine indica methanolic extract. Histopathological examinations also supported the experimental findings.

Conclusion

The study revealed that Eleutherine indica promotes wound healing by augmenting Smad-mediated collagen production in wound granulation tissue.     

In vitro antibacterial effects of Cinnamomum extracts on common bacteria found in wound infections with emphasis on methicillin-resistant Staphylococcus aureus

Ethnopharmacological relevance

Cinnamomum species have been widely used in many traditional systems of medicine around the world. In the Malaysian traditional system of medicine, the leaves, stem bark and stem wood of Cinnamomum iners, Cinnamomum porrectum, Cinnamomum altissimum and Cinnamomum impressicostatum have been used to treat wound infections. To study the antibacterial effects of Cinnamomum iners, Cinnamomum porrectum, Cinnamomum altissimum and Cinnamomum impressicostatum against common bacteria found in wound infections with primary focus on methicillin-resistant Staphylococcus aureus (MRSA).

Materials and methods

The crude extracts from the leaves, stem-bark and stem-wood of Cinnamomum iners, Cinnamomum porrectum, Cinnamomum altissimum and Cinnamomum impressicostatum were obtained using sequential extraction with hexane, ethylacetate, methanol and water. The volatile oils were obtained by hydro-distillation. The antibacterial activities of extracts were investigated using disk diffusion assays and broth microdilution assays.

Results

The volatile oils obtained from the stem-bark of Cinnamomum altissimum, Cinnamomum porrectum and Cinnamomum impressicostatum have shown significant antibacterial activity against a wide range of Gram positive and Gram negative bacteria including MRSA. A few test extracts have shown better activity against MRSA as compared to methicillin sensitive Staphylococcus aureus (MSSA). Amongst all the test extracts, Cinnamomum impressicostatum stem-bark water extract produced the largest inhibition zone of 21.0 mm against MRSA while its inhibition zone against MSSA was only 8.5 mm. The minimum inhibitory concentration (MIC) of this extract against MRSA was 19.5 μg mL⁻¹ and the corresponding minimum bactericidal concentration (MBC) was 39.0 μg mL⁻¹.

Conclusions

This study has scientifically validated the traditional use of Cinnamomum species in treating wound infections. Of high scientific interest was the observation that the antibacterial effect of Cinnamomum impressicostatum stem-bark crude water extract against MRSA was significantly higher than its effect against MSSA, suggesting that the extract contains a compound(s) with higher specific neutralising activity against the drug resistance markers of MRSA.     

Attenuation of inflammatory mediators, oxidative stress and toxic risk evaluation of Aporosa lindleyana Baill bark extract

Ethnopharmacological relevance

Traditionally, Aporosa lindleyana Baill. has been used against various ailments viz. jaundice, fever, headache, seminal loss and insanity. The present study aims to evaluate the anti-inflammatory and anti-oxidant activity of the ethanolic extract of Aporosa lindleyana Baill. bark and its fractions.

Method

The anti-inflammatory activity of ethanolic extract of Aporosa lindleyana Baill. bark and its various fractions at doses of 200 mg/kg and 300 mg/kg b.w. has been carried out by a carrageenan induced hind paw edema method. To establish the probable mechanism of action, TNF-α and NO levels have been estimated by an ELISA method and the effect of active fraction on COX-2 and NF-κB expressions has been evaluated. The effect on the levels of anti-oxidative enzymes (CAT, SOD & GPX) by the ethanolic extract and its fractions has also been investigated. Furthermore, peptic ulcer and hepatotoxic risk evaluation has also been carried out at three times higher dose than that used in inflammatory in vivo model.

Results

Among the extract and its various fractions tested for anti-inflammatory activity, the methanolic fraction at a dose of 300 mg/kg showed significant inhibition in paw edema by 73% as compared to Indomethacin which showed 77% inhibition after 5 h. The same dose of methanolic fraction also caused significant reduction in TNF-α (59.27%) and NO concentration (57.12%) while Indomethacin showed inhibition of 63.91% and 60.12%. The active methanolic fraction was also found to inhibit the expression of NF-κB and COX-2 induced by carrageenan. Histological studies showed that the ethanolic extract and its fractions did not cause any damage to the stomach as well as to liver. Moreover, the active fractions also decreased lipid peroxidation levels and increased the antioxidant enzyme activities (SOD, CAT, GPX).

Conclusion

The results of present study demonstrated that significant anti-inflammatory activity of methanolic fraction of Aporosa lindleyana may be attributed to the modulation of pro-inflammatory mediators. Same fraction was also found to be effective against oxidative stress as it was found to elevate the levels of anti-oxidative enzymes. It can therefore be concluded that the methanolic fraction could be explored as a disease modifying agent against inflammation and oxidative stress.     

Exploring the wound healing activity of Arnebia densiflora (Nordm.) Ledeb. by in vivo models

Ethnopharmacological relevance

The roots of Arnebia densiflora (Nordm.) Ledeb. (Boraginaceae), which is an endemic plant for Turkey, have been used for healing of wounds in folk medicine. The extract of the roots in olive oil and mostly the root barks was applied onto open wounds for rapid healing.

Aim of the study

To evaluate the wound healing activity of the roots, extracts were prepared with different solvents; hexane, chloroform, ethyl acetate and methanol, respectively from the roots of Arnebia densiflora.

Materials and methods

Incision by using tensiometer and excision models were employed on mice and rats.

Results

Significant wound healing activity was observed with the ointment formulation prepared by using hexane extract at 1% concentration on the mentioned models. The results of histopathological examination supported the outcome of both incision and excision wound models. The wound healing effect was comparatively evaluated with a reference ointment Madecassol^®.

Conclusion

The experimental data demonstrated that Arnebia densiflora displayed remarkable wound healing activity.     

Monoamine oxidase inhibition by Rhodiola rosea L. roots

Aim of the study

Rhodiola rosea L. (Crassulaceae) is traditionally used in Eastern Europe and Asia to stimulate the nervous system, enhance physical and mental performance, treat fatigue, psychological stress and depression. In order to investigate the influence of Rhodiola rosea L. roots on mood disorders, three extracts were tested against monoamine oxidases (MAOs A and B) in a microtitre plate bioassay.

Materials and methods

Methanol and water extracts gave the highest inhibitory activity against MAOs. Twelve compounds were then isolated by bioassay-guided fractionation using chromatographic methods. The structures were determined by ¹H, ¹³C NMR and HR-MS.

Results

The methanol and water extracts exhibited respectively inhibitions of 92.5% and 84.3% on MAO A and 81.8% and 88.9% on MAO B, at a concentration of 100 μg/ml. The most active compound (rosiridin) presented an inhibition over 80% on MAO B at a concentration of 10⁻⁵ M (pIC₅₀ = 5.38 ± 0.05).

Conclusions

The present investigation demonstrates that Rhodiola rosea L. roots have potent anti-depressant activity by inhibiting MAO A and may also find application in the control of senile dementia by their inhibition of MAO B.     

In vitro activity of Tridax procumbens against promastigotes of Leishmania mexicana

Ethnopharmacological relevance

Tridax procumbens is an active herb against leishmaniasis.

Aim of the study

Leishmaniasis is a group of diseases caused by Leishmania protozoa. We investigated the antileishmanial activity of Tridax procumbens extracts and a pure compound against promastigotes of Leishmania mexicana, the causative agent of cutaneous leishmaniasis in the New World.

Materials and methods

Extracts and (3S)-16,17-didehydrofalcarinol (1) were obtained by chromatographic methods from Tridax procumbens, and the latter identified by spectroscopic analysis. The effect of these extracts and 1 on the growth inhibition of promastigotes of Leishmania mexicana was evaluated. In order to test the safety of extracts and 1, mammalian cells were treated with them, and cell viability was assessed using trypan blue and MTT.

Results

We demonstrated that extracts of Tridax procumbens and 1 showed a pronounced activity against Leishmania mexicana. The methanol extract inhibited promastigotes growth of Leishmania mexicana with a 50% inhibitory concentration (IC₅₀) of 3 μg/ml, while oxylipin 1 exhibited the highest inhibition at IC₅₀ = 0.478 μg/ml.

Conclusions

In this study we report the biological activity of extracts and (3S)-16,17-didehydrofalcarinol (1), obtained from Tridax procumbens, on the promastigote form of Leishmania mexicana, with no effect upon mammalian cells.