[An evaluation of the effect of a bark extract from the cashew (Anacardium occidentale L.) on infection by Leishmania (Viannia) braziliensis]

Antileishmania and immunomodulatory potential of cashew nut shell liquid and cardanol

Conventional treatments for leishmaniasis have caused serious adverse effects, poor tolerance, development of resistant strains. Natural products have been investigated as potential therapeutic alternatives. The cashew nut shell liquid (CNSL) is a natural source of phenolic compounds with several biological activities, where cardanol (CN) is considered one of the most important and promising compounds. This study aimed to evaluate antileishmanial, cytotoxic and immunomodulatory activities of CNSL and CN. Both showed antileishmanial potential, with IC₅₀ for CNSL and CN against Leishmania infantum: 148.12 and 56.74 μg/mL; against Leishmania braziliensis: 85.71 and 64.28 μg/mL; against Leishmania major: 153.56 and 122.31 μg/mL, respectively. The mean cytotoxic concentrations (CC₅₀) of CNSL and CN were 37.51 and 31.44 μg/mL, respectively. CNSL and CN significantly reduced the percentage of infected macrophages, with a selectivity index (SI) >20 for CN. CNSL and cardanol caused an increase in phagocytic capacity and lysosomal volume. Survival rates of Zophobas morio larvae at doses of 3; 30 and 300 mg/kg were: 85%, 75% and 60% in contact with CNSL and 85%, 60% and 40% in contact with CN, respectively. There was a significant difference between the survival curves of larvae when treated with CN, demonstrating a significant acute toxicity for this substance. Additional investigations are needed to evaluate these substances in the in vivo experimental infection model.

Cashew tree (Anacardium occidentale): Possible applications in dermatology

The potential uses of medicinal plants are far from exhausted, and one of the most important tools in the study of medicinal plants is the rescue of traditional knowledge, which, in Brazil, combines Indigenous, African, and European influences. The rich Brazilian ethnobotany, associated with the greatest biodiversity in the planet, constitutes a promising field of studies, albeit rather neglected in the medical community. The investigation of Anacardium occidentale applications in dermatology from the bibliographic survey of the specialty found the following activity: antileishmanial, anti-ophidic, antibiotic, antityrosinase, and antifungal in vitro. Studies associating A occidentale and dermatology in medical literature seem incipient, and there is a lack of studies in humans. In vitro studies are useful as an initial step, but they are irrelevant if they do not develop into viable formulations that can be tested in humans.

Antioxidant, Antimicrobial, and Anticancer Effects of Anacardium Plants: An Ethnopharmacological Perspective

Anacardium plants have received increasing recognition due to its nutritional and biological properties. A number of secondary metabolites are present in its leaves, fruits, and other parts of the plant. Among the diverse Anacardium plants' bioactive effects, their antioxidant, antimicrobial, and anticancer activities comprise those that have gained more attention. Thus, the present article aims to review the Anacardium plants' biological effects. A special emphasis is also given to their pharmacological and clinical efficacy, which may trigger further studies on their therapeutic properties with clinical trials.

Assessment of Phenolic Compounds and Anti-Inflammatory Activity of Ethyl Acetate Phase of Anacardium occidentale L. Bark

The bark of A. occidentale L. is rich in tannins. Studies have described various biological activities of the plant, including antimicrobial, antioxidant, antiulcerogenic and antiinflammatory actions. The objective of this study was to assess the activity of the ethyl acetate phase (EtOAc) of A. occidentale on acute inflammation and to identify and quantify its phenolic compounds by HPLC. The method was validated and shown to be linear, precise and accurate for catechin, epicatechin, epigallocatechin and gallic acid. Swiss albino mice (Mus musculus) were treated with saline, Carrageenan (2.5%), Indomethacin (10 mg/kg), Bradykinin (6 nmol) and Prostaglandine E2 (5 µg) at different concentrations of EtOAc - A. occidentale (12.5; 25; 50; and 100 mg/kg/weight p.o.) for the paw edema test. Challenge was performed with carrageenan (500 µg/mL i.p.) for the doses 50 and 100 mg/kg of EtOAc. Levels of cytokines IL-1, TNF-α, IL-6 and IL-10 were also measured. All EtOAc - A. occidentale concentrations reduced the edema. At 50 and 100 mg/kg, an anti-inflammatory response of the EtOAc was observed. Carrageenan stimulus produced a neutrophil count of 28.6% while 50 and 100 mg/kg of the phase reduced this to 14.5% and 9.1%, respectively. The EtOAc extract reduced levels of IL-1 and TNF-α. These results suggest that the EtOAc plays a modulatory role in the inflammatory response. The chromatographic method can be used for the analysis of the phenolic compounds of the EtOAc phase.

Substrates and modulators of the multidrug transporter Cdr1p of Candida albicans in antifungal extracts of medicinal plants

The effective treatment of infections caused by the most frequent human fungal pathogens Candida albicans and Candida glabrata is hindered by a limited number of available antifungals and development of resistance. In this study, we identified new extracts of medicinal plants inhibiting the growth of C. glabrata, a species generally showing low sensitivity to azoles. The methanolic extract of Anacardium occidentalis with an MIC of 80 microg ml(-1) proved to be the most active. In contrast to higher azole sensitivity, C. albicans showed increased resistance to several extracts. Investigation of the possible contribution of the multidrug transporter of the ATP-binding cassette superfamily Cdr1p of C. albicans to extract tolerance revealed a differential response upon overproduction of this protein in Saccharaomyces cerevisiae. Whereas the growth inhibitory activity of many extracts was not affected by CDR1 overexpression, increased sensitivity to some of them was observed. In contrast, extracts showing no detectable anticandidal activity including the ethyl acetate extract of Trichilia emetica were detoxified by Cdr1p. The presence of a non-toxic Cdr1p-mediated ketoconazole resistance modulator accompanying growth-inhibitory Cdr1p substrates in this extract was revealed by further fractionation experiments.

Efficacy of the intralesional treatment with Chenopodium ambrosioides in the murine infection by Leishmania amazonensis

AIM OF THE STUDY

Leishmaniasis, caused by protozoan from Leishmania genus, is an endemic disease in the tropical and subtropical regions of the world. The chemotherapy to this disease is not always effective and can cause several side effects. Chenopodium ambrosioides L. (Chenopodiaceae) is used by the native people in the treatment of cutaneous ulcers caused by different species of Leishmania. The aim of this study was to investigate the effect of the treatment with a hydroalcoholic crude extract (HCE) from the leaves of Chenopodium ambrosioides on the murine infection with Leishmania amazonensis.

MATERIAL AND METHODS

The mice were treated for 4-6 weeks post-infection (p.i.) with HCE (5 mg/kg) or meglumine antimoniate (Sb(v)) (28 mg/kg) either by the oral route, once a day, for 15 days or by five intralesional (IL) injections at intervals of 4 days. The thickness of the infected paws was determined weekly and the parasite load evaluated in the draining lymph nodes (LN), the spleen and in the footpad after 7 weeks of infection. The nitric oxide (NO) production was evaluated in cultures with cells from peritoneum or LN.

RESULTS

The IL treatment increased the NO production in the LN and peritoneum cultures and reduced the parasite load from the footpad, spleen and LN. On the other hand, the oral treatment decreased did alter neither the NO production nor the parasite load.

CONCLUSIONS

IL HCE treatment was more efficient than the oral HCE treatment since the former was able to control the dissemination of infection. This effect can be due to either a direct leishmanicidal effect of HCE or the improvement in the NO production by HCE-stimulated macrophages. The results could justify the topical use of the Chenopodium ambrosioides' leaves in the treatment of the ulcers caused by Leishmania.

Some Nigerian plants of dermatologic importance

BACKGROUND

According to the World Health Organization (WHO), 80% of the world's population uses medicinal plants in the treatment of diseases and, in African countries, this rate is much higher. In recent years, however, medicinal plants have represented a primary health source for the pharmaceutical industry. No less than 400 compounds derived from plants are currently used in the preparation of drugs, such as vincristine and vinblastine used in the treatment of cancer. Nigerians still depend largely on crude herbal remedies or traditional medicine. They also use wild plants for cosmetics and perfumery. Some of these herbal remedies have been observed to be effective in certain skin diseases.

METHODS

The data were obtained from history questionnaires completed by patients at the Dermatology Clinic, Lagos State University Teaching Hospital (LASUTH), Ikeja, Lagos, Nigeria, and from oral interviews with vendors and prescribers of herbal preparations at major markets at Lagos and Ijebu-Ode in south-west Nigeria, between July 2004 and July 2006. Photographs of plants were taken at private residences at Lagos, Ibadan, and Ijebu-Ode in south-west Nigeria. A literature search was conducted on 38 of the plants. The data are presented in tabular form.

RESULTS

Sixty-five per cent of patients had applied some form of herbal remedy before attending our clinic. The reasons for consultation included relapses, unsustained relief, incomplete resolution, and post inflammatory hyperpigmentation. Lesions for which herbs were successfully applied included infantile eczema and seborrhoiec dermatitis, atopic eczema, impetigo, impetiginized eczema, tinea capitis, scabies, erythema multiforme, leg ulcers, localized vitiligo, and sexually transmitted diseases. Partial relief was achieved in dermatophytoses, ichthyosis, leprosy, and systemic lupus erythematosus (SLE). Some forms of alopecia, onychomycosis, and vitiligo, as well as allergic dermatoses, were not improved by herbal medicines. The preparation of the remedies was mostly by heating and boiling, infusion, and maceration. In most cases, mixtures of plants or other substances were used. The preparations were applied as poultices, ointments, baths, soaks and soaps, and oral fluids. The plants used included Adansonia digitata, Aframomum melegueta, Aloe species, Azadirachta indica, Cassia alata, Alstonia boonei, Ficus asperifolia, Cocos nucifera, Jatropha gossypyfolia, Ocimum gratissimum, Ricinus communis. A literature search on 38 of the plants used by herbal prescribers revealed the presence of established antimicrobial agents, immune modulating agents, antioxidants, other vitamins and minerals, volatile oils and emollients, and anti-inflammatory agents. Some of the plants may be contaminated by mycotoxins because of poor storage.

CONCLUSION

There appears to be clinical, scientific, and pharmacologic basis for the use of herbal preparations. Nigeria needs to provide effective coordination of the practice of herbal medicine to ensure safety, standardization, and preservation of the flora.

Genotoxicity and antigenotoxicity of cashew (Anacardium occidentale L.) in V79 cells

The use of plants for the treatment of diseases continues to rise although there are few studies providing proof of these effects. One of these plants is the Anacardium occidentale, popularly known as the cashew. The present study evaluated the possible genotoxic and protective activities of cashew stem bark methanolic extract, in vitro, using methyl methanesulfonate (MMS) as a positive control, to compare possible mechanisms of DNA damage induction in the Comet assay. The antigenotoxicity protocols used were pre, simultaneous and post-treatment in relation to MMS. In genotoxicity and antigenotoxicity assessments, besides MMS, PBS was used as the negative control and three concentrations of the A. occidentale extract (500 microg/mL, 1000 microg/mL and 2000 microg/mL) were used on Chinese hamster lung fibroblasts (V79 cells). The Comet assay revealed that the two lowest concentrations tested presented no genotoxic activity, whereas the highest presented genotoxicity. All of the concentrations showed protective activity in simultaneous and post-treatment in relation to MMS. Further studies are required to identify the substances that comprise the extract and more clearly comprehend the antigenotoxic mechanism detected in this study.

Evaluation of mutagenicity and antimutagenicity of cashew stem bark methanolic extract in vitro

Plants remain to be a great source of medicines for humanity. Among them is the Anacardium occidentale L. species, popularly known as the cashew, which has several therapeutic indications, such as cicatrizing, antihypertensive, hypoglycemic and antitumoral properties. The objective of the present work was to assess the mutagenicity and antimutagenicity of cashew stem bark methanolic extract (CSBME) on cell cultures of Chinese hamster lung fibroblasts (V79). The cultures were treated with different concentrations of the CSBME (500, 1000 and 2000 microg/mL) or with the extract associated with doxorubicin (DXR, 0.75 microg/mL) during the cell cycle phases G1, S, and G2 and throughout continuous treatment. Apart from these treatments, the cell cultures were also treated with PBS (negative-control) and DXR (positive-control). The data obtained in the chromosome aberrations (CA) test showed a significant reduction in CA frequency in the cultures treated with DXR and extract in comparison with those that received only DXR during the cell cycle phases G1 and S and throughout the entire cycle, as well as the absence of mutagenicity in all the treatments realized. The antimutagenic effect observed in this work reinforces the presence of the previously described therapeutic properties of cashew and indicates the safe use of this extract.

Acute and subchronic toxicity of Anacardium occidentale Linn (Anacardiaceae) leaves hexane extract in mice

These studies focus on the toxicity leaf hexane extract of A. occidentale L (Anacardiaceae) used in Cameroon traditional medicine for the treatment of diabetes and hypertension. Previous findings on antidiabetic and anti-inflammatory have given support to the ethnopharmacological applications of the plant. After acute oral administration, it was found that doses of the extract less than 6 g/kg are not toxic. Signs of toxicity at high doses were asthenia, anorexia, diarrhoea, and syncope. The LD(50) of the extract, determined in mice of both sexes after oral administration was 16 g/kg. In the subchronic study, mice received A. occidentale at doses of 6, 10 and 14 g/kg (by oral route) for 56 days. At doses of 2, 6 and 10 g/kg of extract, repeated oral administration to mice produced a reduction in food intake, weight gain, and behavioural effects. Liver or the kidney function tests were assessed by determining serum parameters like, creatinine, transaminases, and urea. All these parameters were significantly (p<0.01) abnormal. Histopathological studies revealed evidence of microscopic lesions either in the liver or in the kidney which may be correlated with biochemical disturbances. We conclude that toxic effects of A. occidentale L hexane leaf extract occurred at higher doses than those used in Cameroon folk medicine.

Leishmaniasis phytotherapy. Nature's leadership against an ancient disease

The use of phytotherapy to treat human diseases has its roots in pre-historical times. Despite the modern advances achieved in the field of synthetic chemistry, the most efficient drugs available have their genesis directly or indirectly related with the vegetal kingdom. Indigenous communities have long used plant extracts to treat illnesses. Many of these extracts have shown effective action, with new bioactive compounds being extracted and screened every year. These extracts have also proven to be good sources of therapeutic agents to the treatment of Leishmaniasis. This work highlights some of these agents, while trying to emphasize the importance of plants as a source of new and powerful drugs against this widespread disease.

Plants used in the treatment of leishmanial ulcers due to Leishmania (Viannia) braziliensis in an endemic area of Bahia, Brazil

This paper records the plants used in the treatment of cutaneous leishmaniasis due to Leishmania (Viannia) braziliensis (L(V)b) among the rural population of a cocoa-producing coastal area of Bahia state, Brazil. An enquiry conducted among a hundred patients identified 49 plants species used to treat skin ulceration caused by this Leishmania species. The principal plants used are caju-branco (Anacardium occidentale, Anacardiaceae), used by 65% of the population, folha-fogo (Clidemia hirta,Melastomataceae) 39%, alfavaca-grossa (Plectranthus amboinicus, Lamiaceae) 33%, mastruz (Chenopodium ambrosioides, Chenopodiaceae) 31%, erva-de-santa-maria (Solanum americanum, Solanaceae) (25%) and transagem (Plantago major, Plantaginaceae) 2%.

[Epidemiologic study on tegumentary leishmaniasis in the municipality of Corguinho, Mato Grosso do Sul -- Studies in the human population]

A study on the resident population of 150 inhabitants of Boa Sorte in the Municipality of Corguinho, Mato Grosso do Sul State, Brazil was made, from March 1991 to March 1994, to establish the prevalence of South American Cutaneous Leishmaniasis (SACL), and to characterize the affected population, in an area of recent transmission. Twelve of the inhabitants showed lesions suspected to be SACL, and in 8 cases it was possible to confirm this by biopsy and parasitology. The mucosal form was found in one patient only, the rest showed the following cutaneous forms: ulcerated (3), ulcero-verrucose (1), hyperkeratotic ulcer (1), infiltrated maccule (1), nodule with florid regional adenopathy (1). All patients reacted favorably to treatment with glucantime, with lesion scarring. Side-effects were rare. The parasite isolated from all patients was identified as Leishmania (Viannia) braziliensis. The Montenegro skin test, applied to the 150 inhabitants, showed 32 reactive ones. Of these, six were carriers of the disease, 21 showed sequelae suggestive of the disease and five showed no signs of infection. The age grouping of the cohort ranged from 22 to 78 years, 75% being male. To date, transmission is suspected to be in the peridomicile.