Activity of essential oils from Brazilian medicinal plants on Escherichia coli

Essential oils obtained from leaves of 29 medicinal plants commonly used in Brazil were screened against 13 different Escherichia coli serotypes. The oils were obtained by water-distillation using a Clevenger-type system and their minimal inhibitory concentration (MIC) were determined by microdilution method. Essential oil from Cymbopogon martinii exhibited a broad inhibition spectrum, presenting strong activity (MIC between 100 and 500 microg/mL) against 10 out of 13 Escherichia coli serotypes: three enterotoxigenic, two enteropathogenic, three enteroinvasive and two shiga-toxin producers. C. winterianus inhibited strongly two enterotoxigenic, one enteropathogenic, one enteroinvasive and one shiga-toxin producer serotypes. Aloysia triphylla also shows good potential to kill Escherichia coli with moderate to strong inhibition. Other essential oils showed antimicrobial properties, however with a more restricted action against the serotypes studied. Chemical analysis of Cymbopogon martinii essential oil performed by gas chromatography (GC) and gas chromatography/mass spectrometry (GC-MS) showed the presence of compounds with known antimicrobial activity, including geraniol, geranyl acetate and trans-cariophyllene, which tested separately, indicated geraniol as antimicrobial active compound. The significant antibacterial activity of Cymbopogon martinii oil suggests that they could serve as a source for compounds with therapeutic potential.     

Antiplasmodial activity of extracts from seven medicinal plants used in malaria treatment in Cameroon

Aim of the study

In a search for new plant-derived biologically active compounds against malaria parasites, we have carried out an ethnopharmacological study to evaluate the susceptibility of cultured Plasmodium falciparum to extracts and fractions from seven Cameroonian medicinal plants used in malaria treatment. We have also explored the inhibition of the Plasmodium falciparum cysteine protease Falcipain-2.

Materials and methods

Plant materials were extracted by maceration in organic solvents, and subsequently partitioned or fractionated to afford test fractions. The susceptibility of erythrocytes and the W2 strain of Plasmodium falciparum to plant extracts was evaluated in culture. In addition, the ability of annonaceous extracts to inhibit recombinant cysteine protease Falcipain-2 was also assessed.

Results and discussion

The extracts showed no toxicity against erythrocytes. The majority of plant extracts were highly active against Plasmodium falciparumin vitro, with IC₅₀ values lower than 5 μg/ml. Annonaceous extracts (acetogenin-rich fractions and interface precipitates) exhibited the highest potency. Some of these extracts exhibited modest inhibition of Falcipain-2.

Conclusion

These results support continued investigation of components of traditional medicines as potential new antimalarial agents.     

Antiparasitic activity of some New Caledonian medicinal plants

Twenty-nine extracts of 18 medicinal plants used in New Caledonia by traditional healers to treat inflammation, fever and in cicatrizing remedies were evaluated in vitro against several parasites (Leishmania donovani, Trypanosoma brucei brucei, Trichomonas vaginalis and Caenorhabditis elegans). Among the selected plants, Scaevola balansae and Premna serratifolia L. were the most active against Leishmania donovani with IC(50) values between 5 and 10microg/ml. The almond and aril extracts from Myristica fatua had an IC(50) value of 0.5-5microg/ml against Trypanosoma brucei brucei. Only Scaevola balansae extract presented a weak activity against Trichomonas vaginalis. The almond extract from Myristica fatua presented significant activity against Caenorhabditis elegans (IC(50) value of 6.6+/-1.2microg/ml).     

Gastroprotective activity of the ethanol extract from the inner bark of Caesalpinia pyramidalis in rats

Ethnopharmacological relevance

Caesalpinia pyramidalis Tul. (Fabaceae), known as “catingueira”, has been used in folk medicine in the treatment of various disorders such as gastritis, heartburn, indigestion, and stomach ache. However, the gastroprotective properties of this species have not yet been studied.

Materials and methods

The ethanol extract of Caesalpinia pyramidalis inner bark was used in rats via oral route, at the doses of 30, 100, and 300 mg/kg. The antiulcer assays were performed using the ethanol- and nonsteroidal anti-inflammatory drug-induced ulcer models. Gastric secretion parameters (volume, pH, and total acidity) were also evaluated by the pylorus ligated model, and the mucus in the gastric content was determined. The anti-Helicobacter pylori activity of the ethanol extract of Caesalpinia pyramidalis was performed using the agar-well diffusion and broth microdilution methods.

Results

The ethanol extract (30, 100, and 300 mg/kg) produced dose dependent inhibition (P<0.01) on the ulcer lesion index, the total lesion area, and the percentage of lesion area in the ethanol-induced ulcer model. The ethanol extract (30, 100, and 300 mg/kg) also reduced (P<0.001) the ulcer index in the indomethacin-induced ulcer model. In the model ligature pylorus, the treatment with Caesalpinia pyramidalis ethanol extract failed to significantly change the gastric secretion parameters. However, after treatment with the ethanol extract of Caesalpinia pyramidalis (30, 100, and 300 mg/kg), there was a significant increase (P<0.05) in mucus production. The ethanol extract showed anti-Helicobacter pylori activity, with inhibition halos of 12.0±1.7 mm at 10,000 μg/mL. The minimum inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) values of the ethanol extract were of 625 and 10,000 μg/mL, respectively.

Conclusions

Collectively, the present results suggest that the ethanol extract of Caesalpinia pyramidalis displays gastroprotective actions, supporting the folkloric usage of the plant to treat various gastrointestinal disturbances.     

In vitro antimicrobial activity of extracts and compounds of some selected medicinal plants from Cameroon

Aim of the study

Seven extracts and eight compounds from four selected Cameroonian medicinal plants, Solanecio mannii Hook f. (Asteraceae), Monodora myristica Dunal (Annonaceae), Albizia gummifera (J.F. Gmel) C.A. Smith (Fabaceae/Mimosoideae) and Glyphaea brevis (Spreng) Monachino (Tiliaceae), traditionally used for the treatment of hepatitis, parasites and other infectious diseases, were tested in vitro for their antimicrobial activity against Gram-positive (5 species) and Gram-negative (4 species) bacteria species and pathogenic yeasts (2 Candida species), to establish whether or not they have antimicrobial activity and to validate scientifically their use in traditional medicine.

Materials and methods

The agar disc diffusion and the microbroth dilution methods were used to determine the zone of inhibition between the edge of the filter paper and the edge of the inhibition area (IZ) and the minimal inhibitory concentration (MIC) respectively.

Results

The most active extracts against Candida albicans and Candida krusei were respectively the cyclohexane extract from the fruits of Monodora myristica and the ethyl acetate extract from the stem bark of Albizia gummifera (MIC = 6.3 μg/ml for both extracts). The lowest MIC value (1.6 μg/ml) for purified compounds was obtained on Candida albicans with a mixture of linear aliphatic primary alcohols (n-C24H50O to n-C30H62O), with n-hexacosanol (1b) as major compound and mixture of fatty acid esters of diunsaturated linear 1,2-diols (6).

Conclusion

These results afford ground informations for the potential use of the crude extracts of these species as well as of some of the isolated compounds in bacterial and fungal infections.     

Evaluation of mechanisms involved in the antinociception of the ethanol extract from the inner bark of Caesalpinia pyramidalis in mice

Ethnopharmacological relevance

Caesalpinia pyramidalis Tul. (Fabaceae) is an endemic tree of the Northeast region of Brazil, mainly in the Caatinga region. More commonly, inner bark or flowers are traditionally used to treat many painful and inflammatory processes. A common use of this plant is made by macerating a handful of its stem bark in a liter of wine or sugarcane brandy. It is drunk against stomachache, dysenteries, and diarrheas.

Materials and methods

The ethanol extract of Caesalpinia pyramidalis inner bark was used in mice via oral route, at the doses of 10, 30, and 100 mg/kg, in behavioral models of nociception and investigates some of the mechanisms underlying this effect.

Results

The ethanol extract (30 and 100 mg/kg, P<0.001), given orally, produced dose dependent inhibition of acetic acid-induced visceral pain. The ethanol extract also caused significant and dose-dependent inhibition of capsaicin-(100 mg/kg, P<0.001) and glutamate-(10, 30, and 100 mg/kg, P<0.01) induced pain. The antinociception caused by the ethanol extract (30 mg/kg) in the abdominal constriction test was significantly attenuated (P<0.001) by intraperitoneal treatment of mice with l-arginine (600 mg/kg).

Conclusions

Collectively, the present results suggest that the ethanol extract of Caesalpinia pyramidalis produced dose-related antinociception in several models of pain through mechanisms that involved both glutamatergic system and/or the l-arginine–nitric oxide pathway, supporting the folkloric usage of the plant to treat various painful processes.     

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.     

In vitro antiplasmodial activity of Brazilian Cerrado plants used as traditional remedies

Twenty-seven species of native Brazilian Cerrado plants commonly used by traditional healers to treat malaria and other diseases were collected and 204 hexanic and ethanolic extracts were obtained by maceration. The antiplasmodial activity of the extracts was tested in vitro against a chloroquine resistant strain (FcB1) of Plasmodium falciparum, and cytotoxicity against the cell lines L-6 of rats and MRC-5 of human was evaluated. Thirty-two extracts showed significant inhibition rates of Plasmodium falciparum growth and of these six showed cytotoxicity against the cell lines. The strongest antiplasmodial activity was found for the hexanic extracts of Xylopia aromatica root wood (IC(50)=4.7 microg/ml), Xylopia emarginata root bark (IC(50)=4.9 microg/ml), Casearia sylvestris var. lingua leaves, stem wood and stem bark, and root wood and root bark (IC(50) values from 0.9 to 2.3 microg/ml), and Cupania vernalis leaves (IC(50)=0.9 microg/ml); and for the ethanolic extract of Aspidosperma macrocarpon root bark (IC(50)=4.9 microg/ml). However, the best selectivity towards Plasmodium falciparum was observed for the hexanic root bark extract of Matayba guianensis (IC(50) on Plasmodium falciparum=6.1 microg/ml, SI=16.4 for MRC-5) and the ethanolic root bark extract of Aspidosperma macrocarpon (IC(50) on Plasmodium falciparum=4.9 micro/ml, SI=16.2 for MRC-5).     

Antifungal activity and cytotoxicity of isolated compounds from leaves of Breonadia salicina

Ethnopharmacological relevance

Breonadia salicina is used traditionally to treat wounds, ulcers, fevers, headaches, and fungal infections. The aim of this study was to investigate the antifungal activity of the plant extract and compounds isolated there from.

Materials and Methods

Leaf extracts of Breonadia salicina were screened for antifungal activity against seven plant pathogens: Aspergillus niger, Aspergillus parasiticus, Colletotrichum gloeosporioides, Trichoderma harzianum, Penicillium expansum, Penicillium janthinellum and Fusarium oxysporum. Bioautography assay was used to determine the presence and number of antifungal compounds of the plant extracts. Bioassay-guided fractionation using column chromatography of the chloroform extract led to the isolation of four antifungal compounds. Nuclear Magnetic Resonance (NMR) spectroscopy, Mass Spectrometry (MS) and Electron Impact Mass Spectrometry (EIMS) were used for the identification of antifungal compounds. Cytotoxicity of the chloroform crude extract and isolated compounds was determined using the MTT (3-(4,5-dimethylthiazol)-2,5-diphenyl tetrazolium bromide) assay against Vero monkey kidney cells.

Results

Compound 1 was identified as ursolic acid, while compounds 2, 3 and 4 were not identified conclusively owing to the presence of mixtures of long chain fatty acids. Compounds 3 and 4 had good antifungal activity against Aspergillus parasiticus and Penicillium janthinellum with MIC values of 10 and 16 µg/ml respectively. Compound 2 and ursolic acid had some activity with MIC values ranging between 20 and 250 µg/ml. The crude extract was less toxic to the Vero cells (LC₅₀=82 µg/ml) than ursolic acid (LC₅₀=25 µg/ml). Compounds 2 and 3 were not toxic at the highest concentration tested (LC₅₀=200 µg/ml). Compound 4 was the most toxic to the cells with an LC₅₀ of 35 µg/ml.

Conclusions

The results support the traditional use of Breonadia salicina for antifungal applications, and demonstrate the potential value of developing antifungal compounds from plant natural products. Indications of toxicity should be evaluated at an early stage as the selectivity of the product in affecting fungi preferentially to plant or mammalian cells should be identified when assessing the potential usefulness of the product.     

Bactericidal activity of medicinal plants,employed for the treatment of gastrointestinal ailments,against Helicobacter pylori

Aim of the study

Helicobacter pylori infection plays a crucial role in the pathogenesis of peptic ulcer, and gastric cancer. The current PPI-based triple regimens for the eradication of Helicobacter pylori faces uprising resistance problem demanding for the search of novel candidates. Medicinal plants have always been a source of lead compounds for drug discovery.In the present study, we evaluated the anti-Helicobacter pylori activity of 50 commonly used Unani (traditional) medicine plants from Pakistan that are extensively utilized for the cure of gastrointestinal disorders to explore the natural source for pilot compounds against Helicobacter pylori.

Materials and methods

Total seven clinical isolates and one standard strain were employed to examine the bactericidal effects of medicinal plants. Helicobacter pylori was isolated from the antral biopsy specimens and confirmed through the standard microbiology procedures. Minimum bactericidal concentration (MBC) of the active plants was determined at the concentration range from 7.8 to 500 μg/ml.

Results

Among the herbs evaluated, more than 50% inhibited the growth of eight strains at the concentration of 500 μg/ml. The 70% aqueous-ethanol extracts of Curcuma amada Roxb., Mallotus phillipinesis (Lam) Muell., Myrisctica fragrans Houtt., and Psoralea corylifolia L. demonstrated strong anti-Helicobacter pylori activity with MBC value ranged from 15.6 to 62.5 μg/ml. The most potent bactericidal activity was exhibited by Mallotus phillipinesis (Lam) Muell. which completely killed the bacteria at the concentration of 15.6–31.2 μg/ml.

Conclusion

The results revealed significant anti-Helicobacter pylori activity of medicinal plants which could be the potential source of new bactericidal agents.     

Hypoglycemic activity and antioxidant potential of some medicinal plants traditionally used in Turkey for diabetes

Cydonia oblonga Mill. (Rosaceae) leaves, Helianthus tuberosus L. (Asteraceae) tubers, and Allium porrum L. (Liliaceae) bulbs are used as a folk remedy for the treatment of diabetes and they are also consumed as food in Turkey. In the present study, the antidiabetic and antioxidant activities of the ethanol extracts of these plants were studied in normal and streptozotocin-induced diabetic rats for 5 days. All extracts were administrated orally to rats at the doses of 250 and 500 mg/kg. Blood glucose level was measured according to glucose oxidase method. In order to determine antioxidant activity, thiobarbituric acid reactive substance (TBARS) and reduced glutathione (GSH) levels in liver, kidney, and heart tissues were measured by using spectrophotometric methods. Oral administration of Cydonia oblonga (500 mg/kg) and Allium porrum (500 mg/kg) extracts for 5 days in diabetic rats caused a decrease in blood glucose levels by 33.8% and 18.0%, respectively. Moreover, Allium porrum and Cydonia oblonga extracts induced significant alleviation on only heart tissue TBARS levels (44.6 and 45.7%), Helianthus tuberosus and Allium porrum extracts showed an inhibitory effect on kidney tissue TBARS levels (24.5 and 14.8%). None of the extracts restored GSH levels in kidney, liver, and heart tissues of diabetic rats.     

In vitro antiprotozoal activities and cytotoxicity of some selected Cameroonian medicinal plants

Eight extracts from seven selected Cameroonian medicinal plants, traditionally used to treat malaria and other protozoal diseases, were tested in vitro for their antiprotozoal activities against Plasmodium falciparum K1 chloroquine-resistant strain, Leishmania donovani, Trypanosoma cruzi and Trypanosoma brucei rhodesiense, protozoa responsible for malaria, visceral leishmaniasis, Chagas disease and African trypanosomiasis, respectively. The most active extract against Plasmodium falciparum K1 strain and Trypanosoma brucei rhodesiense was the methanolic extract of Albizia zygia (Fabaceae) stem bark with IC(50) values of 1.0 microg/ml and 0.2 microg/ml, respectively. Five extracts showed IC(50) values below 5mug/ml against Leishmania donovani, with the methanolic seed extract of Harungana madagascarensis showing the highest activity, but only the methanolic extract of Albizia zygia showed activity against Trypanosoma cruzi. Cytotoxicity and selectivity indexes were estimated for the most active extracts. The best ratio of cytotoxicity to antiplasmodial activity (SI(a)=14) was established for the methanolic leaf extract of Symphonia globulifera (Clusiaceae), while the methanolic stem bark extract of Albizia zygia showed the best ratio of cytotoxicity to antitrypanosomal activity (SI(b)=22.5).     

In vitro and in vivo trypanocidal effect of lipophilic extracts of medicinal plants from Mali and Burkina Faso

AIM OF THE STUDY: To determine the in vitro and in vivo antitrypanosomal activity of extracts of traditionally used plants. MATERIALS AND METHODS: 47 dichloromethane extracts were tested in vitro in the Long-term Viability Assay (LtVA) on Trypanosoma brucei brucei. The most active ones were also tested in vivo using a standardised mouse test. RESULTS: 13 extracts (28%) were active in vitro with MIC-values相似文献   

Antimalarial activity of some plants traditionally used in treatment of malaria in Kwale district of Kenya

Methanolic and water extracts of five medicinal plant species used for treatment of malaria in traditional/cultural health systems of Kwale people in Kenya were tested for antimalarial activity against Plasmodium falciparum and Plasmodium berghei, respectively and for their cytotoxic effects. The most active extracts (IC(50)<10 microg/ml) screened against chloroquine (CQ) sensitive (D6) and resistant (W2) P. falciparum clones, were the water and methanol extracts of Maytenus undata (Thunb.) Blakelock (Celasteraceae), methanol extracts of Flueggea virosa (Willd.) Voigt (Euphorbiaceae), Maytenus putterlickioides (Loes.) Excell and Mendoca (Celastraceae), and Warburgia stuhlmannii Engl. (Canellaceae). These extracts showed various cytotoxic levels on Vero E6 cells with the water extract of M. undata exhibiting least cytotoxicity. At least one of the extracts of the plant species exhibited a high chemo suppression of parasitaemia >70% in a murine model of P. berghei infected mice. These results indicate that there is potential for isolation of a lead compound from the extracts of the five plants. W. stuhlmannii and M. putterlickioides have not been reported before for antiplasmodial activity.     

小叶云实的化学成分及抗菌活性研究

目的:深入研究小叶云实的化学成分及其抗菌活性。方法:利用多种色谱方法对小叶云实根的化学成分进行研究,并对分得的单体化合物进行抗菌筛选。结果:鉴定了6个高异黄酮的化学结构,分别为eucomin(1),intricatinol(2),8-methoxybonducellin(3),bonducellin(4),8-methoxyisobonducellin(5),3-(4-methoxybenzyl)-5,7-dimethoxychroman-4-one(6),并对从小叶云实中获得的单体化合物进行抗菌活性筛选。结论:化合物1～6均为首次从该植物根中分离得到。化合物8-me-thoxyisobonducellin,intricatinol,岩白菜素,金丝桃苷和11-没食子酰岩白菜素对金黄色葡萄球菌、肺炎克雷伯氏菌、乙型链球菌和绿脓杆菌均有不同程度的抑制作用。     

Anti-trypanosomal activity of African medicinal plants: A review update

Ethnopharmacological relevance

African trypanosomiasis is one of the neglected tropical diseases caused by different species of trypanosomes that affect both human and livestock with devastating consequences in the continent. Most of the affected populations commonly use traditional medicinal plants for the treatment of the disease. Consequently, this prompted ethnopharmacological research activities on the anti-trypanosomal activity of a number of these African medicinal plants in order to validate their ethnomedicinal use. Furthermore, such studies could lead to the identification of chemical leads for the development of newer anti-trypanosomal agents from those plants. This review aims to provide updated information on the ethnopharmacological evidence of African medicinal plants with anti-trypanosomal activity.

Methods

Literature was collected via electronic search (PubMed, Sciencedirect, Medline and Google Scholar) from published articles that report on the in vitro or in vivo anti-trypanosomal activity of plants that were collected from different parts of Africa.

Results

African medicinal plants investigated for in vitro and in vivo anti-trypanosomal activity from January 1993 to October 2013 are systematically compiled and all the in vivo studies are critically discussed. A total of 264 plant species belonging to 79 families were investigated for anti-trypanosomal activity. However, only 48 bioactive anti-trypanosomal compounds were successfully isolated in pure forms. Furthermore, some of the plants were investigated for possible ameliorative effects on the trypanosome-induced pathological changes out of which 18 plants were reported to be effective while a few others were not. In spite of interesting preclinical ethnopharmacological evidence for anti-trypanosomal activity, not a single African medicinal plant was investigated in a clinical study.

Conclusion

Several African medicinal plants have demonstrated promising anti-trypanosomal effects but the studies on the anti-trypanosomal potentials of these plants are not taken beyond proof of concept stage. It is hoped that the article would stimulate future clinical studies because of the paucity of knowledge in this area.     

Antimutagenic effects of ethanolic extracts from selected Palestinian medicinal plants

Aim of the study

Eryngium creticum, Nigella sativa, and Teucrium polium have been traditionally used for the treatment of inflammations, liver disorders, and arthritis. Various studies on these plants revealed anti-inflammatory, hepatoprotective and antimutagenic activities. Previous results of our research group, however, indicate that aqueous extracts prepared as for the traditional use (tea) have neither cytoprotective nor antimutagenic activity. Instead, there is evidence for a mutagenic potential. Since the described antimutagenic activity may not be present in effective amounts in the aqueous extracts this study focuses on ethanolic extracts.

Materials and methods

Ethanolic extracts of the three plant species were prepared and tested against N-methyl-N′-nitro-N-nitrosoguanidine (MNNG), a directly acting mutagen. Since it cannot be excluded that the active constituents of the plant extracts require biotransformation or induce metabolic enzymes, causing antimutagenic or detoxifying effects, primary cultures of rat hepatocytes were used for this study. Plant ethanolic extracts were applied along with MNNG in three protocols: pre-treatment, combined treatment and post-treatment.

Results and conclusions

The results of this investigation clearly indicate an inhibitory effect of the plant extracts on MNNG mutagenicity, while the extracts had no effect on cytotoxicity indicators such as necrosis and apoptosis. The effects obtained can be attributed to a direct antimutagenic activity and an increased recovery at the chromosomal level. In order to identify the responsible compounds extracts will in a next step have to be fractionated, tested and chemically analyzed.     

忍冬科药用植物DNA条形码通用序列的筛选

目的:从4条DNA片段(psbA-trnH,matK,rbcL,和ITS2)中筛选可用于忍冬科药用植物鉴定的DNA条形码通用序列。方法:通过比较各序列的PCR扩增成功率、测序效率、种内和种间变异、barcoding gap和鉴定成功率等指标评价不同序列在忍冬科植物中的鉴定能力。结果:对忍冬科13个属,33个物种,58个样本进行分析,ITS2序列在属水平上的鉴定成功率为100.0%,物种水平上的鉴定成功率为96.6%。结论:ITS2序列可以作为忍冬科植物的DNA条形码候选序列,同时推荐psbA-trnH序列作为ITS2序列的补充序列。     

Antifungal study of the resinous exudate and of meroterpenoids isolated from Psoralea glandulosa (Fabaceae)

Ethnopharmacological relevance

Psoralea glandulosa L. (Fabaceae) is a medicinal resinous shrub used in Chilean folk medicine as antiseptic in treatment of infections and skin diseases caused by bacteria and fungus.

Aim of the study

To evaluate the in vitro antifungal activity of the resin and the active components from P. glandulosa against clinical yeast isolates.

Materials and methods

Active compounds were obtained of the resinous exudate from aerial parts of P. glandulosa. Eight species of yeast were exposed to the resin and two major compounds. Minimum inhibitory concentration (MIC₈₀) was determined according to the standard broth microdilution method.

Results

Bakuchiol and 3-hydroxy-bakuchiol demonstrated potent activity with the MIC₈₀ ranging from 4 to >16 and 0.125 to 16 μg/mL, respectively. The resin had some degree of antifungal activity.

Conclusions

The overall results provided important information for the potential application of the 3-hydroxy-bakuchiol from P. glandulosa in the therapy of serious infection and skin diseases caused by clinical yeast.     

Comparative “in vitro” evaluation of the antiresorptive activity residing in four Ayurvedic medicinal plants. Hemidesmus indicus emerges for its potential in the treatment of bone loss diseases

Ethnopharmacological relevance

Four Indian plants, traditionally used in Ayurvedic medicine: Asparagus racemosus Willd., Emblica officinalis Gaertn., Hemidesmus indicus R. Br., and Rubia cordifolia L. were selected on the basis of their ethnobotanical use and of scientific evidence that suggests a potential efficacy in the treatment of bone-loss diseases. The antiresorptive properties of the four plants have been investigated. The aim was to provide adequate evidence for the exploitation of natural compounds as alternative therapeutics for the treatment of diseases caused by increased osteoclast activity.

Materials and methods

Decoctions were prepared from dried plant material according to the traditional procedure and standardization by HPLC was performed using marker compounds for each species. Total polyphenols, flavonoids and radical scavenging activity of the decoctions were also determined. The bioactivity of the plant decoctions was evaluated in subsequent phases. (1) A cytotoxicity screening was performed on the mouse monocytic RAW 264.7 cell line to define the concentrations that could be utilized in the following step. (2) The antiresorptive properties of plant decoctions were compared with that of a “gold standard” drug (alendronate) by measuring osteoclastogenesis inhibition and osteoclast apoptosis. (3) The toxic effect on bone forming cells was excluded by evaluating the impact on the proliferation of osteogenic precursors (mesenchymal stem cells, MSC).

Results

All the decoctions inhibited osteoclastogenesis similarly to alendronate at the highest doses, but Hemidesmus indicus and Rubia cordifolia were also effective at lower concentrations. Apoptosis increased significantly when cells were exposed to the highest concentration of Emblica officinalis, Hemidesmus indicus, and Rubia cordifolia. All concentrations of Emblica officinalis tested inhibited the proliferation of osteogenic precursors, while only the highest doses of Asparagus racemosus and Rubia cordifolia were toxic. On the contrary, Hemidesmus indicus did not affect osteogenic precursor growth at any concentration tested.

Conclusion

Among the medicinal plants included in the study, Hemidesmus indicus showed the greatest antiosteoclastic activity without toxic effect on osteogenic precursors. Therefore, Hemidesmus indicus exhibits the properties of an antiresorptive drug and represents the ideal candidate for further clinical investigations.