Antibacterial and antifungal activity of Flindersine isolated from the traditional medicinal plant, Toddalia asiatica (L.) Lam.

Aim of the study

The leaves and root of Toddalia asiatica (L.) Lam. (Rutaceae) are widely used as a folk medicine in India. Hexane, chloroform, ethyl acetate, methanol and water extracts of Toddalia asiatica leaves and isolated compound Flindersine were tested against bacteria and fungi.

Materials and methods

Antibacterial and antifungal activities were tested against bacteria and fungi using disc-diffusion method and minimum inhibitory concentrations (MICs). The compound was confirmed using X-ray crystallography technique.

Results

Antibacterial and antifungal activities were observed in ethyl acetate extract. One active principle Flindersine (2,6-dihydro-2,2-dimethyl-5H-pyrano [3,2-c] quinoline-5-one-9cl) was isolated from the ethyl acetate extract. The MIC values of the compound against bacteria Bacillus subtilis (31.25 μg/ml), Staphylococcus aureus (62.5 μg/ml), Staphylococcus epidermidis (62.5 μg/ml), Enterococcus faecalis (31.25 μg/ml), Pseudomonas aeruginosa (250 μg/ml), Acinetobacter baumannii (125 μg/ml) and fungi Trichophyton rubrum 57 (62.5 μg/ml), Trichophyton mentagrophytes (62.5 μg/ml), Trichophyton simii (62.5 μg/ml), Epidermophyton floccosum (62.5 μg/ml), Magnaporthe grisea (250 μg/ml) and Candida albicans (250 μg/ml) were determined.

Conclusions

Ethyl acetate extract showed promising antibacterial and antifungal activity and isolated compound Flindersine showed moderate activity against bacteria and fungi.     

In vitro antifungal activity of indirubin isolated from a South Indian ethnomedicinal plant Wrightia tinctoria R. Br.

Ethnopharmacological relevance

Acalypha indica, Cassia alata, Lawsonia inermis, Punica granatum, Thespesia populnea and Wrightia tinctoria are folklore medicines extensively used in the treatment of ringworm infections and skin related diseases in Tamil Nadu, India.

Aim

The present study was designed to investigate the in vitro antifungal activity of certain medicinal plants and the pure compound indirubin isolated from Wrightia tinctoria.

Materials and methods

The hexane, chloroform, methanol and ethanol extracts of six different plants were investigated against dermatophytes, non-dermatophytes and yeasts. Chloroform extract of Wrightia tinctoria leaf was fractionated using column chromatography and the major compound was identified using spectroscopic techniques. Antifungal activity was studied by spore germination test using agar dilution method. The minimum inhibitory concentration (MIC) was determined using broth microdilution method.

Results

Wrightia tinctoria showed promising activity against dermatophytic and non-dermatophytic fungi. Leaf chloroform extract showed activity at 0.5 mg/ml against Trichophyton rubrum, Epidermophyton floccosum, Aspergillus niger and Scopulariopsis brevicaulis. The major compound, identified as indirubin, exhibited activity against dermatophytes such as Epidermophyton floccosum (MIC = 6.25 μg/ml); Trichophyton rubrum and Trichophyton tonsurans (MIC = 25 μg/ml); Trichophyton mentagrophytes and Trichophyton simii (MIC = 50 μg/ml). It was also active against non-dermatophytes (Aspergillus niger, Candida albicans and Cryptococcus sp.) within a MIC range of 0.75-25 μg/ml.

Conclusion

The indole compound indirubin from Wrightia tinctoria showed antifungal activity and may be useful in the treatment of dermatophytosis.     

Antibacterial activity and chemical composition of essential oil of Pamburus missionis

Aim of the study

The aerial parts of Pamburus missionis (Wight) Swingle (Rutaceae) are traditionally used in the treatment of swelling, chronic rheumatism, paralysis, and puerperal diseases.The aim of this work was to investigate the chemical composition and antibacterial activity of essential oil of Pamburus missionis against different bacterial strains.

Materials and methods

The essential oil was obtained from fresh leaves by hydro distillation method and its chemical composition was analyzed by GC and GC–MS. The antibacterial activity was determined by disc diffusion and micro broth dilution assay.

Results

GC–MS analysis of the essential oil revealed the presence of 1-tridecanol (38.4%), n-hexadecanoic acid (16.1%), oxygenated monoterpenes (14.4%), monoterpene hydrocarbons (3.1%) and eugenol (1.9%) as the major components. The oil exhibited antibacterial activity at 100 and 450 μg against the test organisms with inhibition zones of 7–25 mm and minimal inhibitory concentrations values in the range of 10–100 and >100 mg/ml.

Conclusion

The present study reveals the antibacterial potency of essential oil of Pamburus missionis. The use of Pamburus missionis in the treatment of various ailments and puerperal diseases can be attributed to its antibacterial property.     

Screening of antifungal activity of plants from the northeast of Mexico

Screening of the antifungal activity of plants from the northeast of Mexico against some of the main etiological agents inducing pulmonary mycoses, Candida albicans, Aspergillus fumigatus, Histoplasma capsulatum, and Coccidioides immitis, was conducted in vitro. We used the M27-A2 and M38-A methods from the National Committee for Clinical Laboratory Standards to screen the antifungal activity. Ten hydroalcoholic extracts from the 15 plants evaluated showed antifungal activity against at least one of these fungi. Following this, a differential extraction was conducted with solvents of different polarities, and 16 extracts showed activity ranging from 16 to 125microg/mL against the different fungi. Toxicity of the extracts was evaluated by means of the test of lethality to Artemia salina, two of which were shown to have toxicity.     

Essential oil of Daucus carota subsp. halophilus: composition, antifungal activity and cytotoxicity

Ethnopharmacological relevance: Essential oils are known to possess antimicrobial activity against a wide spectrum of bacteria and fungi. Daucus carota L. is used since olden times in traditional medicine, due to recognized therapeutic properties, namely the antimicrobial activity of their essential oils. Aim of the study: In the present study the composition and the antifungal activity of the oils of Daucus carota L. subsp. halophilus (Brot.) A. Pujadas (Apiaceae), an endemic plant from Portugal, were evaluated. Moreover, their cytotoxicity in mouse skin dendritic cells at concentration showing significant antifungal activity was also evaluated. Material and methods: The oils were investigated by GC and GC-MS and the antifungal activity (MIC and MLC) were evaluated against yeasts, dermatophyte and Aspergillus strains. Assessment of cell viability was made by the MTT assay. Results: The results showed large variations in the compositions during ontogenesis, particularly in the amounts of elemicin that increased significantly in the ripe umbels (5.9% vs. 31.0%). The results also demonstrated that the oil with high amounts of elemicin, which have stronger antifungal activity, showed no cytotoxic effect, at concentrations ranging from 0.16 to 0.64 mul/ml, for as long as 24h. Conclusion: It is possible to find appropriate doses of Daucus carota oil showing both antifungal activity and very low detrimental effect on mammalian cells.     

Hepatoprotective and toxicological assessment of an ethnomedicinal plant Euphorbia fusiformis Buch.-Ham.ex D.Don

Aim of the study

The tubers of Euphorbia fusiformis Buch.-Ham.ex D.Don (Euphorbiaceae) are traditionally used in India by the Malayali tribes of Chitteri hills, Eastern Ghats, Tamil Nadu to treat liver disorders. The objective of the present study was to assess the hepatoprotective potential and biosafety of Euphorbia fusiformis tuber upon administration thereby justifying the traditional claims.

Materials and methods

The hepatoprotective potential of the ethanol extract of Euphorbia fusiformis tuber against rifampicin induced hepatic damage was investigated in Wistar albino rats. The acute and subchronic toxicity were assessed in mice and rats, respectively.

Results

The ethanol extract of tubers (250 mg/kg p.o.) showed remarkable hepatoprotective effect against rifampicin induced hepatic damage in Wistar albino rats. The degree of protection was measured using the biochemical parameters serum glutamate oxaloacetate transaminase (SGOT), serum glutamate pyruvate transaminase (SGPT), gamma glutamyl transpeptidase (GGTP), alkaline phosphatase (ALP), total bilirubin and total protein. Treatment with ethanolic extract prior to the administration of rifampicin significantly (P < 0.05 to P < 0.001) restored the elevated levels of the said parameters on a par with the control group. The single dose LD₅₀ was found to be 10,000 mg/kg bw when administered orally in mice. Subchronic toxicity studies in rats with oral doses of 125, 250 and 500 mg/kg exhibited no significant changes in body weight gain, general behavior, hematological and biochemical parameters. The histological profile of liver and kidney also indicated the non-toxic nature of this drug.

Conclusion

The ethanol extract of Euphorbia fusiformis tubers may have potential therapeutic value in the treatment of liver disorders and is safer to use even at higher doses when taken orally.     

Antimicrobial activity of South African Podocarpus species

ETHNOPHARMACOLOGICAL RELEVANCE: Several species of Podocarpus (Podocarpaceae) are utilized in treating ailments across the world. In Africa, four species are used traditionally in both animal and human health. AIM OF THE STUDY: To investigate the antimicrobial activity of Podocarpus species against Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae and Candida albicans. MATERIALS AND METHODS: Six solvents of varying polarity were used for extraction. Antibacterial activity was assessed using the microdilution bioassay and for antifungal activity, the microdilution bioassay and (M27-P) broth dilution were used. RESULTS: All species exhibited antimicrobial activity with MIC values of less than 1mg/ml. Inhibition against Gram-positive bacteria was stronger with an MIC value of 98mug/ml while for Gram-negative bacteria, the highest inhibition was against Klebsiella pneumoniae with an MIC value of 0.33mg/ml. All species exhibited strong antifungal activity with the best MIC being 30mug/ml after 48h. CONCLUSIONS: All four species exhibited strong inhibition against all tested microbials, based on Aligiannis et al. [Aligiannis, N., Kalpotzakis, E., Mitaku, S., Chinou, I.B., 2001. Composition and antimicrobial activity of the essential oils of two Origanum species. Journal of Agricultural and Food Chemistry 40, 4168-4170] classification they can be classified as strong inhibitors.     

Influence of plant part,season of collection and content of the main active constituent,on the antifungal properties of Polygonum acuminatum Kunth.

Ethnopharmacological relevance

Polygonum acuminatum Kunth. (Polygonaceae) is used to heal infected wounds and as antifungal in the traditional Argentinean medicine.

Aim of the study

The present investigation was carried out to evaluate the antifungal properties of aerial parts of Polygonum acuminatum, in order to give support to its ethnopharmacological use as antifungal agent and to isolate the compound(s) responsible for the antifungal properties. The influence of the plant part used, the season of the year and a study of the correlation of the antifungal activity with the content of the main active constituent were investigated too, with the aim of contributing to determine the most suitable plant extract and season of the year for achieving the best antifungal properties for Polygonum acuminatum traditional use.

Materials and methods

For the antifungal evaluation, the microbroth dilution assay recommended by the Clinical and Laboratory Standards Institute (CLSI, formerly NCCLS) was used against a panel of human opportunistic and pathogenic fungi. Bioassay-guided fractionation allowed us to isolate the compounds responsible for the antifungal activity. GC–MS was used to quantify the main component in the different extracts. For the statistical analysis, ANOVA test for analyses of variance followed by the Tukey test of Multiple Comparisons were used. The correlations between content of the antifungal compound and antifungal activity, were calculated with the Spearman Correlation Coefficient.

Results

Aerial parts (A) of Polygonum acuminatum showed to possess antifungal properties against yeasts as well as dermatophytes but not against Aspergillus spp. From the most active extract (ADCM), polygodial, isopolygodial, drimenol and confertifolin were isolated, possessing polygodial a broader spectrum of action and lower MICs than the rest of compounds. Among the different parts, leaves (L), stems (S) and fruits (F), that constitute the aerial parts of Polygonum acuminatum, (L) showed to possess the best activities, compared to (S) and (F).The analysis of the content of polygodial in the LHex, LDCM, LEtOAC, LMeOH extracts collected in Summer, Autumn, Winter and Spring showed that LDCM of all seasons possessed higher percentages of this sesquiterpene than the rest of extracts. Among the LDCM of different seasons, that of Autumn was the most concentrated in polygodial. The correlation between content of polygodial with antifungal behavior of the different extracts, showed that LDCM of Autumn contains the highest content of polygodial and concomitantly the lowest MICs.

Conclusion

The ethnopharmacological use of Polygonum acuminatum aerial parts in the Argentinean traditional medicine for ailments related to fungal infections is supported by the results obtained in this investigation. From the obtained results, LDCM of Autumn, possessing the highest content of polygodial and the lowest MICs, appeared to be the most suitable extract for being used as antifungal in the traditional medicine. Nevertheless, if some other plant collection of another season different from Autumn is available, a LDCM extract would be the better option, because it contains a higher amount of polygodial compared to LHex, LEtOAc or LMeOH and therefore, a better antifungal activity can be expected.     

傣药腊肠树果实中氨基酸和无机元素分析

目的研究傣药腊肠树果实中的氨基酸和无机元素。方法采用氨基酸分析仪和原子吸收光谱仪对腊肠树果实中的氨基酸和无机元素进行定性定量分析。结果腊肠树果实中主要含氨基酸15种,总量为2.07%;含无机元素13种,其中钾、钙、镁含量较高。结论研究结果,为进一步探讨傣药腊肠树果实的开发应用价值提供了依据。     

Acute and subacute toxicity of Cassia occidentalis L. stem and leaf in Wistar rats

Ethnopharmacological relevance

Cassia occidentalis L. (syn. Senna occidentalis; Leguminosae) has been used as natural medicine in rainforests and tropical regions as laxative, analgesic, febrifuge, diuretic, hepatoprotective, vermifuge and colagogo. Herein, we performed a pre-clinical safety evaluation of hydroalcoholic extract of Cassia occidentalis stem and leaf in male and female Wistar rats.

Materials and methods

In acute toxicity tests, four groups of rats (n = 5/group/sex) were orally treated with doses of 0.625, 1.25, 2.5 and 5.0 g/kg and general behavior, adverse effects and mortality were recorded for up to 14 days. In subacute toxicity assays, animals received Cassia occidentalis by gavage at the doses of 0.10, 0.50 or 2.5 g/kg/day (n = 10/group/sex) for 30 days and biochemical, hematological and morphological parameters were determined.

Results

Cassia occidentalis did not produce any hazardous symptoms or death in the acute toxicity test, showing a LD₅₀ higher than 5 g/kg. Subacute treatment with Cassia occidentalis failed to change body weight gain, food and water consumption and hematological and biochemical profiles. In addition, no changes in macroscopical and microscopical aspect of organs were observed in the animals.

Conclusions

Our results showed that acute or subacute administration of Cassia occidentalis is not toxic in male and female Wistar rats, suggesting a safety use by humans.     

Evaluation of antimicrobial activity of ethanol extract and compounds isolated from Trichodesma indicum (Linn.) R. Br. root

Ethnopharmacological relevance

The roots are reportedly used to treat diarrhoea, dysentery, leprosy, skin diseases and fever.

Aim of study

The aim of present study was to investigate the in vitro antimicrobial potential of ethanol extract of Trichdesma indicum root, and its purified compounds and to validate scientifically its use in traditional medicine.

Material and methods

The root of Trichdesma indicum was extracted with ethanol and subjected to chromatographic separation for isolation of phytochemical compounds. Structures of isolated compounds were elucidated by spectroscopic methods. The antimicrobial activities of the ethanol extract of T. indicum and isolated compounds were primarily evaluated by a disc diffusion test. The anti-microbial efficacy of the ethanol extract or isolated compounds was then assessed in vitro by determining minimal inhibition concentration (MIC) and minimal bactericidal or fungicidal concentration (MBC/MFC).

Results

n-Decanyl laurate (1), n-tetradecanyl laurate (2), n-nonacosanyl palmitate (3), stigmast-5-en-3β-ol-21(24)-olide (4), n-pentacos-9-one (5), n-dotriacont-9-one-13-ene (6), stigmast-5-en-3β-ol-23-one (7) and lanast-5-en-3β-D-glucopyranosyl-21 (24)-olide (8) were isolated from ethanol extract of T.indicum. The ethanol extract and isolated compounds (1–8) showed varying degrees of antimicrobial activities. The ethanol extract exhibited potent growth inhibitory activity against S. aureus, B. subtilis and C. albicans with an MIC value of 19.2 μg/ml. Among all the isolated compounds, lanast-5-en-3β-D-glucopyranosyl-21 (24)-olide (8) displayed strongest antibacterial activity against S. aureus with MIC value of 2.4 μg/ml.

Conclusions

The results of present study provide ground basis for the potential use of the ethanol extract Trichodesma indicum root as well as the some of the isolated compounds in the treatment of infections associated with the studied microorganisms.     

Antimicrobial activity of Ulopterol isolated from Toddalia asiatica (L.) Lam.: a traditional medicinal plant

Ethnopharmacological relevance

The leaves of Toddalia asiatica (L.) Lam. (Rutaceae) are widely used in folk medicine in India to treat various ailments like cough, malaria, indigestion, influenza lung diseases and rheumatism, fever, stomach ailments, cholera and diarrhea. In our earlier communication we have reported the antimicrobial study on the various extracts of the leaves and the isolation and identification of Flindersine, a quinolone alkaloid as the major active principle. In the present study, we report the antibacterial and antifungal activities of Ulopterol, a coumarin isolated as another major active antimicrobial principle.

Materials and methods

The leaves were successively extracted with hexane, chloroform, ethyl acetate, methanol and water. The extracts were studied for their antimicrobial activity against selected bacteria and fungi by using disc-diffusion method. The ethyl acetate extract which was found to possess highest antimicrobial activity was subjected to activity guided fractionation by column chromatography over silica gel. This resulted in the isolation of the coumarin, Ulopetrol, an active principle besides Flindersine which was reported by us earlier. The structure of the compound was elucidated using physical and spectroscopic data. Flindersine and Ulopterol were quantified by HPLC.

Results

Ulopterol showed activity against the bacteria viz. Staphylococcus epidermidis, Enterobacter aerogenes, Shigella flexneri, Klebsiella pneumoniae (ESBL-3967), Escherichia coli (ESBL-3984) and fungi viz. Aspergillus flavus, Candida krusei and Botrytis cinerea. Quantification by HPLC showed the content of Flindersine and Ulopterol to be 0.361% and 0.266% respectively on dry weight basis of the leaves.

Conclusions

Ethyl acetate extract (successive extraction) contained Ulopterol, a coumarin, besides Flindersine, a quinolone alkaloid, as a major active principle in the antimicrobial studies. This is the first report of the antimicrobial activity of Ulopterol and also its first report from the plant.     

Antibacterial, antisecretory and antihemorrhagic activity of Azadirachta indica used to treat cholera and diarrhea in India

Indigenous uses of Azadirachta indica A. juss (Maliaceae) (locally known as neem) leaves in different parts of India for curing gastrointestinal disorder such as diarrhea and cholera is wide spread. The objective of the present study was to evaluate the antibacterial and antisecretory activity of neem extract against Vibrio cholerae, a causative agent of watery diarrhea such as cholera. The methanol extract of neem leaf was tested for its antibacterial, antisecretory and antihemorrhagic activity against Vibrio cholerae. Azadirachta indica extract had significant antibacterial activity against the multi-drug-resistant Vibrio cholerae of serotypes O1, O139 and non-O1, non-O139. The minimum inhibitory concentration reached by 50% (MIC50) and 90% (MIC90), and minimum bactericidal concentration for the extract were 2.5, > 5, and 10 mg/ml, respectively. Neem extract showed antisecretory activity on Vibrio cholerae induced fluid secretion in mouse intestine with inhibition values of 27.7%, 41.1%, 43.3%, 57.0%, and 77.9% at doses of 100, 200, 300, 450 and 1800 mg/kg, respectively. Oral administration of the extract inhibited hemorrhage induced by Vibrio cholerae in mouse intestine at a dose > or = 300 mg/kg. The results obtained in this study give some scientific support to the uses of neem employed by the indigenous people in India employed for the treatment of diarrhea and dreadful disease cholera.     

Antimicrobial activity of the essential oil and extracts of Cordia curassavica (Boraginaceae)

In traditional Mexican medicine Cordia curassavica (Jacq) Roemer & Schultes is used to treat gastrointestinal, respiratory and dermatological disorders in Zapotitlán de las Salinas, Puebla (México). The aim of this work was to investigate antimicrobial activity of the essential oil, obtained by using Clevenger distillation apparatus, and hexane, chloroform and methanol extracts from aerial parts of Cordia curassavica. Antimicrobial activity was evaluated against 13 bacteria and five fungal strains. The oil and extracts exhibited antimicrobial activity against Gram-positive and Gram-negative bacteria and five fungal strains. Sarcina lutea and Vibrio cholerae were the strains more sensitive to the essential oil effect (MIC=62 microg/mL) and Vibrio cholerae for the hexane extract (MIC=125 microg/mL). Rhyzoctonia solani was the strain more sensitive to the essential oil effect (IC(50)=180 microg/mL) and Trichophyton mentagrophytes for the hexane extract (IC(50)=230 microg/mL). The essential oil was examined by GC and GC-MS. A total 11 constituents representing 96.28% of the essential oil were identified: 4-methyl,4-ethenyl-3-(1-methyl ethenyl)-1-(1-methyl methanol)cyclohexane (37.34%), beta-eudesmol (19.21%), spathulenol (11.25%) and cadina 4(5), 10(14) diene (7.93%) were found to be the major components. The present study tends to confirm the use in the folk medicine of Cordia curassavica in gastrointestinal, respiratory and dermatological diseases.     

New compounds,chemical composition,antifungal activity and cytotoxicity of the essential oil from Myrtus nivellei Batt. & Trab., an endemic species of Central Sahara

Ethnopharmacologic relevance

Myrtus nivellei Batt. & Trab. (Myrtaceae) known as Sahara myrtle is appreciated by the Touaregs as medicinal plant. Infusion of leaves is employed against diarrhea and blennorrhea. Crushed leaves added to oil or to butter ointment have been traditionally used for the treatment of dermatosis. Aim of the study is to consider the traditional medicinal uses and the lack of scientific studies on their biological activities, the present study was designed to elucidate the chemical composition, the antifungal activity of its essential oils against fungi responsible for human infections, as well as, its cytotoxicity in the mammalian keratinocytes.

Materials and methods

Chemical analysis of Myrtus nivellei essential oil isolated by hydrodistillation of aerial parts (leaves and flowers), was carried out using a combination of chromatographic (CC, GC with retention indices) and spectroscopic techniques (MS, ¹³C NMR, 2D NMR). The antifungal activity was evaluated by using broth macrodilution methods for yeasts and filamentous fungi. Cytotoxicity was tested in HaCaT keratinocytes through the MTT assay.

Results

Ten samples coming from two localities of harvest were investigated. The chemical composition was largely dominated by 1,8-cineole (33.6–50.4%) and limonene (17.5–25.0%). The structure of two new compounds bearing the isoamylcyclopentane skeleton has been elucidated. The oil was more active against Cryptococcus neoformans with MIC of 0.16 μL/mL followed by dermatophytes, with MICs of 0.64 and 1.25 μL/mL. Furthermore, evaluation of cell viability showed no cytotoxicity in HaCaT keratinocytes at concentrations up to 1.25 µL/mL.

Conclusions

The composition of Myrtus nivellei oil differed from that of Myrtus communis. The structure of two di-nor-sesquiterpenoids has been elucidated. It was possible to find appropriate doses of Myrtus nivellei oil with both antifungal activity and very low detrimental effect on keratinocytes. These findings add significant information to the pharmacological activity of Myrtus nivellei essential oils, specifically to its antifungal properties, thus justifying and reinforcing the use of this plant in traditional medicine.     

Antifungal activity of the plant Dodonaea viscosa var. angustifolia on Candida albicans from HIV-infected patients

THE AIM OF THIS STUDY: was to determine the minimum inhibitory concentration (MIC) and the time taken by Dodonaea viscosa var. angustifolia (PLE) a South African medicinal plant, chlorhexidine gluconate (CHX) and triclosan (TRN) to kill Candida albicans. 41 strains of Candida albicans were investigated, 20 from HIV-positive patients, 20 from HIV-negative subjects and Candida albicans ATCC 90028. The MICs of an acetone extract of PLE, CHX and TRN were measured using a microtitre double dilution technique, and the time taken to kill 99.5% of the strains was determined. The MICs of PLE, CHX and TRN were 6.25-25, 0.008-0.16 and 0.0022-0.009 mg/ml, respectively. PLE killed all the test strains within 30s and CHX 40% of the isolates from HIV-positive patients and 20% of strains from HIV-negative subjects in 1 min. During the same time TRN killed 55% and 35% of isolates from HIV-positive and HIV-negative patients. Dodonaea viscosa var. angustifolia has antifungal properties and is more effective than commercially available mouthrinses.     

Antibacterial activity of Helleborus bocconei Ten. subsp. siculus root extracts

Aim of the study

Roots of Helleborus bocconei Ten. subsp. siculus (Schiffner) Merxm. & Podl. are widely used in veterinary folk medicine in Sicily (Italy) to diagnose and cure lower respiratory tract infections in cattle. This study intended to evaluate the in vitro antibacterial activity of the methanolic root extract of Helleborus bocconei Ten. subsp. siculus, and of the bufadienolide and ecdysteroid fractions extracted from its roots, against strains belonging to species commonly associated with respiratory tract infections.

Materials and methods

The phytochemical screening of the previously prepared plant extracts was carried out by chemical, thin-layer chromatography and spectroscopic methods. The in vitro antibacterial activity of the extracts against seven different standard bacterial strains was evaluated by broth microdilution.

Results

According to the present study, Helleborus bocconei Ten. subsp. siculus roots contain bufadienolides and ecdysteroids, and the extracts containing these compounds, as well as the crude methanolic root extract, show antibacterial activity against microorganisms responsible for respiratory infections. In particular, the bufadienolide extract has the highest inhibitory activity against all the tested organisms, and, as the other extracts, shows the lowest MIC values (100 μg/ml) against Moraxella catarrhalis and Streptococcus pneumoniae.

Conclusions

Since the roots of Helleborus bocconei Ten. subsp. siculus contain substances with antibacterial activity, the traditional use of this plant may also derive from its antibacterial properties.     

In vitro antifungal activity of extracts and neolignans from Piper regnellii against dermatophytes

The present study was designated to evaluate the in vitro antidermatophyte activity of extracts from leaves of Piper regnellii as well as of the bioactivity-directed isolation of neolignans. The antifungal assay was performed by microdilution techniques. The hydroalcoholic extract of Piper regnellii leaves presented a strong activity against the dermatophyte fungi Trichophyton mentagrophytes, Trichophyton rubrum, Microsporum canis and Microsporum gypseum with MICs of 15.62, 15.62, 15.62 and 62.5 microg/ml, respectively. On light microscopy and scanning electron microscopy of nail fragments not exposed to hydroalcoholic extract of Piper regnelli leaves, well-formed and extensive mycelial growth was seen. On nail fragments exposed to hydroalcoholic extract at concentrations more than 1.2mg/ml and then inoculated with spore suspension, growth was not seen. The hydroalcoholic extract was fractionated on silica gel in to nine fractions. The active chloroform fraction was lyophilized and chromatographed by column chromatography on silica gel. Structures were established by comparison with literature data and identified as eupomatenoid-3 and eupomatenoid-5. The pure compounds showed strong activity on Trichophyton rubrum with MIC of 50 and 6.2 microg/ml, respectively. Comparing the activity of the active chloroform fraction obtained from hydroalcoholic crude extract with that of isolated compound eupomatenoid-5, it is clear that this showed the same results against Trichophyton rubrum. The results showed that the plant could be explored for possible antifungal agents and provides preliminary scientific validation for the traditional medicinal use of this plant.     

Detection of antifungal compounds in Polygonum ferrugineum Wedd. extracts by bioassay-guided fractionation. Some evidences of their mode of action

Ethnopharmacological relevance

Polygonum ferrugineum Wedd. (Polygonaceae) is used to heal infected wounds and as antiseptic, antibiotic or antifungal in the traditional Argentinean medicine. The present investigation was carried out to evaluate the antifungal properties of different extracts of aerial parts of Polygonum ferrugineum, in order to give support to its ethnopharmacological use and to isolate the compounds responsible for the antifungal properties. The most active compounds were tested for their capacity of producing hyphae malformations, similar to those previously observed for crude extracts.

Materials and methods

Agar Dilution Method (ADM) and Agar Overlay Bioautography (AOB) were used for bioassay-guided fractionation of the aerial part extracts against a panel of human opportunistic pathogenic fungi. The Neurospora crassa assay, followed by Optical Microscopy and Scanning Electron Microscopy observation, was used for studies of mechanisms of action.

Results

MeOH extract and DCM and Hex sub-extracts, but not Aq, EtOAc or BuOH ones possess antifungal activity. Of the seven isolated compounds, cardamonin 2 showed a selective inhibition of Epidermophyton floccosum with a very low MIC (=6.2 μg/mL) and pashanone 1 possessed moderate antifungal activity (MICs = 25-50 μg/mL) but a broader spectrum of action. Chalcone 2, but not 1, induced swelling and shortening of the Neurospora crassa hyphae, similar as those caused by the crude DCM extract.

Conclusions

The bioassay-guided fractionation of Polygonum ferrugineum DCM extract allowed the isolation of five active compounds. Among them, cardamonin 2 showed the highest antifungal activity and selectivity towards Epidermophyton floccosum; in addition, it induced Neurospora crassa malformations that are similar than those produced by the crude DCM extract. These results give additional support to the ethnopharmacological use of Polygonum ferrugineum as antifungal agent.     

决明子水提液对高血压小鼠血压血脂及肾脏结构的影响

目的: 检测决明子水提液对冷激诱导的高血压小鼠血压、血脂及肾脏结构的影响。 方法: 制备决明子水提液备用。实验小鼠分为正常对照组、冷激对照组、冷激决明子饲喂组(5,10,20 mg·kg^-1.BW),对照组相应给予等量生理盐水,连续饲喂18 d。检测各组小鼠血压、血脂含量,切片观察肾脏结构。 结果: 冷激对照组血压显著高于正常对照组( P <0.01),决明子水提液饲喂组小鼠的收缩压、舒张压、平均动脉压与正常对照组相比,差异不显著( P >0.05)。冷激对照组TG含量显著高于正常对照组( P<0.01 ),而冷激饲喂组TG含量明显降低( P<0.05 );冷激饲喂(10 mg·kg^-1,20 mg·kg^-1)组TC含量降低( P<0.05 );冷激饲喂(10 mg·kg^-1)组LDL与HDL含量均降低,其他饲喂组与冷激对照组相比含量虽有降低但无统计学意义。冷激对照组肾小管管壁水肿,内腔极度缩小,肾小球明显胀大,肾小囊腔显著变窄,决明子饲喂组肾小管水肿基本消失,内腔明显增大,肾小球、肾小囊结构趋于正常。 结论: 决明子水提液具有降血压、降血脂、改善病变肾脏结构的作用。