Toxicity of medicinal plants used in traditional medicine in Northern Peru

Ethnopharmacological relevance

The plant species reported here are traditionally used in Northern Peru for a wide range of illnesses. Most remedies are prepared as ethanol or aqueous extracts and then ingested. The aim of this study was to evaluate the potential toxicity of these extracts.

Materials and methods

The toxicity of ethanolic and water extracts of 341 plant species was determined using a brine-shrimp assay.

Results

Overall 24% of the species in water extract and 76% of the species in alcoholic extract showed elevated toxicity levels to brine-shrimp. Although in most cases multiple extracts of the same species showed very similar toxicity values, in some cases the toxicity of different extracts of the same species varied from non-toxic to highly toxic.

Conclusions

Traditional preparation methods take different toxicity levels in aqueous and ethanol extracts into account when choosing the appropriate solvent for the preparation of a remedy.     

Antileishmanial activities associated with plants used in the Malian traditional medicine

Sixty-four extracts issued from twenty-one plants used in the Malian traditional medicine--several of them as antiparasitic drugs--were assayed for their antileishmanial effects against both extracellular and intracellular forms of Leishmania major. Seven extracts from six different plants--Sarcocephalus latifolius, Zanthoxylum zanthoxyloides, Entada africana, Bobgunnia madagascarensis, Pseudocedrela kotschyi and Psorospermum guineense--were found to be significantly active against the intracellular form of the parasite.     

Ethnobotanical survey and antibacterial activity of some plants used in Guinean traditional medicine

A total of 418 healers have been interviewed in Guinea, a coastal country of West Africa, ranging between 7 degrees 30 and 12 degrees 30 of northern latitude and 8 degrees and 15 degrees of western longitude. Plant species used by the local inhabitants to treat infectious diseases were identified using ethnobotanical, ethnographic and taxonomic methods. During these investigations, 218 plants were registered, of which the following were the most frequently used: Erythrina senegalensis, Bridelia ferruginea, Crossopteryx febrifuga, Ximenia americana, Annona senegalensis, Cochlospermum tinctorium, Cochlospermum planchonii, Lantana camara, Costus afer, Psidium guajava, Terminalia glaucescens, Uapaca somon and Swartzia madagascariensis. Most plants, and especially the leaves, were essentially used as a decoction. In order to assess antibacterial activity, 190 recipes were prepared and biologically tested, among which six showed activity (minimal inhibitory concentration<125 microg/ml) against Bacillus cereus, Mycobacterium fortuitum, Staphylococcus aureus, or Candida albicans, i.e., Entada africana, Chlorophora regia, Erythrina senegalensis, Harrisonia abyssinica, Uvaria tomentosa, and a mixture of six plants consisting of Swartzia madagascariensis, Isoberlinia doka, Annona senegalensis, Gardenia ternifolia, Terminalia glaucescens and Erythrina senegalensis.     

Acute toxicity and mutagenic activity of Mexican plants used in traditional medicine

The present work was undertaken to determine safety parameters of selected Mexican medicinal plants chosen on the basis of their frequency of medicinal use and commercial importance. The medicinal herbs included Amphipteryngium adstringens, Hintonia standleyana, Hintonia latiflora, Piper sanctum, Haemathoxylon brasiletto, Iostephane heterophylla, Valeriana procera, Arracacia tolucensis, Brickellia veronicaefolia, Scaphyglottis livida, Exostema caribaeum, Hippocratea excelsa, Ligusticum porteri, Poliomintha longiflora and Gnaphalium sp. In the acute toxicity studies in mice performed according to the Lorke procedure, Exostema caribaeum, Hippocratea excelsa, Ligusticum porteri and Poliomintha longiflora were the most toxic with LD(50) values between 1085 and 2mg/kg. The Ames test revealed that Gnaphalium sp. and Valeriana procera extracts induced mutations of S. typhimurium TA98 with or without the S9 microsomal fraction, and TA100 in the presence of the enzymatic fraction, respectively. The tincture of Valeriana procera, however, was non-mutagenic. Finally, in the Artemia salina lethality test Brickellia veronicaefolia, Arracacia tolucensis, Poliomintha longiflora and Piper sanctum caused significant mortality of the crustacean larvae with LC(50) in the range of 37-227 microg/mL.     

In vitro and in vivo acute antihyperglycemic effects of five selected indigenous plants from Jordan used in traditional medicine

Ethnopharmacological relevance

Achillea santolina L., Pistacia atlantica Desf, Rheum ribes L., Sarcopoterium spinosum (L.) Spach and Teucrium polium L. have traditionally been used as herbal antidiabetic medicines. However their alleged benefits and mechanisms remain elusive.

Aim of the study

This study aimed to evaluate the effect of water extracts of these plants in in vitro and in vivo experiments.

Materials and methods

In vitro enzymatic starch digestion with aqueous extracts from plants at concentrations of 1, 5, 10, 12.5, 25, 50 and 100 mg/ml was assayed using α-amylase and α-amyloglucosidase. Acarbose was used as control and glucose liberation was determined by glucose oxidase method. Oral starch tolerance test (OSTT) and oral glucose tolerance test (OGTT) were determined for the plant extracts at concentrations 125, 250 and 500 mg/kg b.wt. on Sprague-Dawley rats. Blood glucose levels in rats treated with plant extracts and drugs (acarbose or metformin and glipizide) were measured at −30, 0, 45, 90 and 135 min.

Results

Compared to acarbose (IC₅₀ = 1.2 μg/ml), water extracts of Pistacia atlantica, Rheum ribes and Sarcopoterium spinosum exerted significant dose dependent dual inhibition of α-amylase and α-glucosidase in in vitro enzymatic starch digestion bioassay, with IC₅₀s; 46.98, 58.9 and 49.9 mg/ml, respectively. Comparable in vivo results were obtained for starch-fed rats, exhibiting significant acute postprandial antihyperglycemic efficacies. While Achillea santolina and Teucrium polium extracts lacked any favourable in vitro anti-α-amylase and anti-α-glucosidase effect, other modes of action can possibly explain their substantial acute antihyperglycemic activities in starch-treated rats. Except for Pistacia atlantica extracts, none of the investigated extracts qualified for improving the glucose intolerance in fasted rats on glucose loading.

Conclusions

Pistacia atlantica, Rheum ribes and Sarcopoterium spinosum can be considered as potential candidates for amelioration/management of type 2 diabetes.     

Screening of some Tanzanian medicinal plants from Bunda district for antibacterial, antifungal and antiviral activities

Extracts from 50 plant parts obtained from 39 different plants belonging to 22 families used to treat infectious diseases in Bunda district, Tanzania, were screened against twelve microorganisms, including the bacteria Bacillus cereus, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae and Salmonella typhimurium, the fungi Aspergillus niger, Candida albicans, and the viruses Herpes Simplex Virus type 1, Vesicular Stomatitis Virus T2, Coxsackie B2 and Semliki Forest A7. The highest activity was obtained for the n-hexane extract of Elaeodendron schlechteranum root bark against the Gram-positive bacteria Bacillus cereus (MIC 0.97 microg/ml and MBC 1.95 microg/ml) and Staphylococcus aureus (MIC 3.90 microg/ml and MBC 31.25 microg/ml). Gram-negative bacteria were less sensitive. Only Balanites aegyptiaca stem bark exhibited a high antifungal activity against Candida albicans (MIC 125 microg/ml and MFC 250 microg/ml). Extracts from four plants; Lannea schweinfurthii, Combretum adenogonium, Ficus sycomorus and Terminalia mollis showed strong antiviral activity with RF values of 10(3) and 10(4) against Herpes Simplex Virus type 1 at various concentrations. Our results support, at least in part, the use of most plants as claimed by traditional healers/informants especially against the Gram-positive bacteria Bacillus cereus and Staphylococcus aureus.     

Cytotoxic activity of Brazilian Cerrado plants used in traditional medicine against cancer cell lines

The search for new anti-cancer drugs is one of the most prominent research areas of natural products. Numerous active compounds isolated from Brazilian Cerrado plant species have been studied with promising results.     

Plants used as remedies antirheumatic and antineuralgic in the traditional medicine of Lebanon

Aim of the study

In the present investigation, ethnobotanical and ethnopharmacological research of the traditional use of plants to cure antirheumatic and antineuralgic diseases was carried out in Lebanon.

Materials and methods

The information was collected from different cities and villages of the twenty-six districts “aqdya or qadaa” of the six governorates “mohaafazah” of Lebanon. The knowledge on the medicinal use of plants has been recorded directly on the basis of a detailed survey on herbalists “Attarin or dabbous”, folk healers, on older experienced people and midwives “daye”. This research was carried out for 5 years (2002–2007).

Results and conclusions

In this survey, 231 species of which 5 are endemic, distributed in 79 botanical families, currently used as antirheumatic herbal remedies, were collected and identified. Among them 53.3% are indigenous, 19.2% are cultivated and 17.5% are imported. Their latin names, local names, local medicinal uses, the used parts of the plant and the preparations and the ways of administration are described. The anti-inflammatory properties due to the plant compounds have been demonstrated and discussed.     

In vitro cytotoxic activity of nine plants used in Mayan traditional medicine

Ethnopharmacological relevance

Plants have been used in folk medicine by Mayan ancient people from the Yucatan Peninsula, Mexico, to treat some diseases considered as cancer diseases such as chronic wounds or tumors.

Aim of the study

We collected a selection of nine plants in order to investigate their cytotoxic activity against cancer cell lines.

Materials and methods

Methanolic extracts were tested for their cytotoxicity using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay on four cancer cell lines; nasopharynx carcinoma (KB), laryngeal carcinoma (Hep-2), cervix adenocarcinoma (HeLa), and cervix squamous carcinoma cells (SiHa) and one normal cell line; canine kidney (MDCK).

Results

All species exhibited some degree of cytotoxic activity. The root bark extract of Hamelia patens exhibited the highest cytotoxic activity on HeLa cells with a CC₅₀ of 13 μg/mL and selectivity index of 13.3, higher than docetaxel. Gossypium schottii and Dioon spinulosum showed similar good cytotoxic activity and selectivity index on HeLa and Hep-2 cells, respectively.

Conclusions

Hamelia patens, Dioon spinulosum and Gossypium schottii demonstrated promising cytotoxic activity and have been selected for future bio-guided fractionation and isolation of active cytotoxic compounds.     

In vivo antigiardial activity of three flavonoids isolated of some medicinal plants used in Mexican traditional medicine for the treatment of diarrhea

Mexican traditional medicine uses a great variety of plants in the treatment of gastrointestinal disorders such as diarrhea. In order to understand the properties of some of their chemical constituents, three flavonoids (kaempferol, tiliroside and (-)-epicatechin) isolated from Geranium mexicanum, Cuphea pinetorum, Helianthemum glomeratum, and Rubus coriifolius, were assayed to demonstrate their in vivo antiprotozoal activity; using an experimental infection of Giardia lamblia in suckling female CD-1 mice. Compounds tested showed antigiardial activity with values of ED(50) (micromol/kg) 0.072 for (-)-epicatechin, 2.057 for kaempferol and 1.429 for tiliroside. The most active flavonoid was the (-)-epicatechin, its activity was higher than metronidazole and emetine, drugs used as positive controls. In the case of kaempferol and tiliroside their potency was close to that of the metronidazole, but far less than emetine.     

Antifungal activity of Paraguayan plants used in traditional medicine

The antifungal activity of aqueous, dichloromethane and methanol extracts from 14 Paraguayan plants used in traditional medicine for the treatment of skin diseases was assayed in vitro by the agar disk diffusion method against 11 fungal strains comprising several filamentous fungi and yeasts. Among them, the dichloromethane extracts of Acanthospermum australe, Calycophyllum multiflorum, Geophila repens and Tabebuia avellanedae, as well as the aqueous and methanol extracts of the latter, showed the highest activity.     

Ethnopharmacological survey of medicinal plants used by traditional healers in Bangladesh for gastrointestinal disorders

Ethnopharmacological relevance

Gastrointestinal diseases are common worldwide, including Bangladesh where majority of the rural people depend on water from unprotected sources. The people from Bangladesh use medicinal plants as their first line of health care to cure and prevent different types of gastrointestinal disorders.

Aim of the study

To compile plants used for the treatment of different gastrointestinal disorders in Bangladesh.

Materials and methods

The field survey was carried out in a period of 18 months. Fieldwork was undertaken in total of eleven districts of Bangladesh. Open-ended and semi structured questionnaire were used to interview a total of 1280 people including traditional healers, Ayurvedic/Unani drug manufacturers and local people.

Results

A total of 250 plant species of 93 families were listed. Leaves were the most cited plant part used against gastrointestinal disorders. Most of the reported species were tree in nature and decoction is the mode of preparation of major portions of the plant species. Most of the plant species were very common and were cultivated or planted in homestead or roadsides. The doses of the plants for different treatments varied widely.

Conclusion

In view of the fact that the plants were selected based on their medicinal usage for treating different kinds of gastrointestinal diseases including diarrhoea, the activities reported here need more works for validation and could be rationalised by the presence of active compounds found in those plants. The documentation represents the preliminary information in need of future phytochemical investigation and is important for the conservation of these plants.     

抗骨质疏松症的单味中药及药用植物研究进展

综述了近年来用于治疗骨质疏松症的常用单味中药及药用植物的研究进展以及机制,希望能为新药开发及中药走向世界提供帮助。     

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).     

Antimalarial activity of extracts and alkaloids isolated from six plants used in traditional medicine in Mali and Sao Tome

Methanol and chloroform extracts were prepared from various parts of four plants collected in Mali: Guiera senegalensis (Gmel.) Combretaceae, Feretia apodanthera (Del.) Rubiaceae, Combretum micranthum (Don.) Combretaceae, Securidaca longepedunculata (Fres.) Polygalaceae and two plants -collected in Sao Tome: Pycnanthus angolensis (Welw.) Myristicaceae and Morinda citrifolia (Benth.) Rubiaceae were assessed for their in vitro antimalarial activity and their cytotoxic effects on human monocytes (THP1 cells) by flow cytometry. The methanol extract of leaves of Feretia apodanthera and the chloroform extract of roots of Guiera senegalensis exhibited a pronounced antimalarial activity. Two alkaloids isolated from the active extract of Guiera senegalensis, harman and tetrahydroharman, showed antimalarial activity (IC(50) lower than 4 microg/mL) and displayed low toxicity against THP1. Moreover, the decrease of THP1 cells in S phase of the cell cycle, after treatment with harman and tetrahydroharman, was probably due to an inhibition of total protein synthesis.     

In vitro anticancer screening of South African plants

Aim of the study

The purpose of the present study is to evaluate South African plants for their anticancer activity.

Materials and methods

Plant species were collected throughout South Africa and voucher specimens were deposited and identified at the South African National Biodiversity Institute. Plant extracts were prepared and screened for in vitro anticancer activity against a panel of three human cell lines (breast MCF7, renal TK10 and melanoma UACC62) at the CSIR. Plant extracts that exhibited anticancer activity against these three human cell lines were screened by the NCI against sixty human cancer cell lines organized into sub-panels representing leukaemia, melanoma, cancer of the lung, colon, kidney, ovary, central nervous system, breast and prostate.

Results

A total of 7500 plant extracts were screened for in vitro anticancer activity against breast MCF7, renal TK10 and melanoma UACC62 human cell lines between the period 1999 and 2006. Hits were classified into four categories based on their total growth inhibition of the cell lines. A hit rate of 5.9% was obtained for extracts which showed moderate activity and these were screened by the NCI against a panel of sixty human cancer cell lines. The extracts of plant species with limited published information for their anticancer properties were subjected to bioassay-guided fractionation and the active constituents isolated and identified. The largest number of plant specimens in this study was from the family Asteraceae, which is rich in sesquiterpene lactones.

Conclusions

Although the extracts of the plants were randomly selected, 68% of these plant species which were hits in the screening programme are reported to be used medicinally. Based on our data, it appears that unrelated medicinal use of the source plants may serve as an initial guide to selection of plants for anticancer screening.     

Screening for cytotoxic activity of plants used in traditional medicine

A total of 260 extracts have been prepared from 75 medicinal plant species collected in Africa, Panama and Mauritius. Three different concentrations of each extract have been screened in vitro for cytotoxic activity using a colorimetric assay to determine cell survival of human colon carcinoma Co115 cells. Fifteen plants showed ED50 values between 10.0 and 1.0 micrograms/ml but more significant activities were obtained in 11 (ED50 range 1.0-0.1 micrograms/ml) and 3 (ED50 range 0.1-0.01 micrograms/ml) plant specimens. Identification of new active substances may well be aided by pre-selecting plants known to be used empirically by traditional healers.     

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.     

Medicinal and poisonous diversity of the flora of "Cariri Paraibano", Brazil

A survey of the medicinal and poisonous plant diversity in the flora of the Carirí of the State of Paraíba, Brazil, has been made. Medicinal and poisonous properties of 121 plant species belonging to 96 genera and 45 families were recorded. Of these, 119 species belonging 44 families, representing about 98% of the total, are used for medicinal purposes, and five species are considered as poisonous. The Fabaceae (Leguminosae) family has the highest number (16) of medicinal plants diversity in the area, followed by 11 species of Asteraceae and 9 of Solanaceae. Information on these 121 species are presented together with their medicinal uses. This study aims at emphasizing the importance of setting up conservation priorities, and sustained development of various medicinal plants of semi-arid area of Northeast of Brazil.