Elisa M. Petenatti

Value of the ethnomedical information for the discovery of plants with antifungal properties. A survey among seven Latin American countries.

ETHNOPHARMACOLOGICAL RELEVANCE This study reports the antifungal evaluation of 327 plant species (92 families and 251 genera) from seven Latin American countries which were selected on the basis of their reported ethnomedical uses and compared them with plants selected at random. AIM OF THE STUDY (a) The main aim of this study was to investigate whether the probability of detecting antifungal plants is higher when plants have reports of ethnopharmacological uses related to fungal infections (PAU group) than when they are selected at random (PNAU group). (b) The second objective was to determine, within the PAU group, whether the probability of obtaining a positive result will be higher when the plants are tested against dermatophytes, than against yeasts or Aspergillus spp. (c) The third goal was to investigate, within all MICs<or=1000 microg/mL, if the MICs displayed by the PAU group are comparatively lower than MIC values of the PNAU group; that is to say, if they can be expected more potent antifungal plants within the group of plants that have a history of traditional use related to fungal infections than when they do not have one. MATERIALS AND METHODS A five-stage process of documentation, evaluation and analysis of results was conducted: (1) selection of words that could describe the ethnopharmacological use related to fungal infections; (2) a survey of specialized literature in each country; (3) collection and preparation of an extract of each plant; (4) antifungal evaluation of the selected plants and (5) statistical analysis of the results. 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 eleven human opportunistic and pathogenic fungi. For the statistical analysis the Pearsons Chi Square test and the Scores test were used. RESULTS (a) A significantly higher probability of detecting plants with antifungal activity against at least one fungus was found within the PAU (40.3%) than the PNAU group (21.3%) (p<0.01). (b) A similar higher probability than in (a) (39.6% vs. 20.8%) was found when plants were tested against dermatophytes (p<0.01) but not against yeasts or Aspergillus spp. (p>0.05). (c) Within the detected antifungal plants from both groups, plants of the PAU group displayed higher activities (lower MICs) than those of PNAU group against dermatophytes (p<0.05) but not against yeasts or Aspergillus spp. CONCLUSIONS Considering that dermatophytes are the cause of superficial fungal infections, which can be easily detected and followed by traditional healers, our findings suggest that the ethnopharmacological approach is useful in guiding the detection of antifungal plants in Latin America mainly for infections in which the pathological expression is obvious and, therefore, the cure can be clearly observed.

Evaluation of macro and microminerals in crude drugs and infusions of five herbs widely used as sedatives

It has been determined the concentration of fourteen micro and macrominerals (Al, Ca, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Na, P, Se, and Zn) in both crude drugs and infusions of Melissa officinalis L., Lamiaceae, Nepeta cataria L., Lamiaceae, Passiflora caerulea L., Passifloraceae, Tilia x moltkei Spath ex C.K. Schneid., Tiliaceae, and Valeriana officinalis L., Caprifoliaceae. These herbs are widely consumed by its sedative properties, either alone or in herb mixtures. All measurements were performed using an inductively coupled plasma optical emission spectrometer (ICP-OES). The products were obtained from regional markets, mainly in San Luis province (Argentina). The estimated daily intake was compared with current recommendations. All products and its infusions were included within the upper tolerable limits for minerals, in trace elements such as toxic elements present at low levels.

In vivo antigenotoxic activity of watercress juice (Nasturtium officinale) against induced DNA damage.

The present study was carried out to investigate the genotoxicity as well as possible protective activity against damage induced by cyclophosphamide (CP) of the aqueous juice of watercress (Nasturtium officinale, W.T. Aiton) in vivo. Male and female Swiss mice 7–8 weeks old (N = 48) were treated by gavage with 1 g kg−1 body weight and 0.5 g kg−1 body weight of watercress juice during 15 consecutive days. Genotoxicity and its possible protective effect were tested by the comet assay in peripheral blood cells and the micronucleus test in bone marrow. In addition, biopsies of the bladder, epididymis and testicles of mice were performed to extend the experimental design. Watercress juice per se did not induce genetic damage according to the comet assay and micronucleus study, exhibiting a protective activity against CP (P < 0.05 and P < 0.001, respectively). The comparative analysis of bladder histological changes obtained in the watercress plus CP group against those treated with CP alone suggests a probable protective effect. Further studies are needed in order to establish the protective role of watercress juice against DNA damage. Copyright

Anti-inflammatory properties from isolated compounds of Cyclolepis genistoides

Context: Cyclolepis genistoides D. Don (Asteraceae) is an Argentinean endemic shrub, known by the vernacular name “palo azul” or “matorro negro”. It is widely used in folk medicine as a diuretic, an antirheumatic, and an antispasmodic agent. Objective: The aim of this work was to describe the activity of two isolated compounds of C. genistoides, oleanolic acid (1) and deacylcynaropicrin (2), using the carrageenan-induced paw edema method in mice. Materials and methods: Aerial parts of C. genistoides were dried, powdered, and extracted with petroleum ether, ethyl acetate, dichloromethane, and methanol for 48 h. The fractions obtained from the ethyl acetate extract yielded oleanolic acid, while deacylcynaropicrin was obtained according to Abdei-Mogib et al. Structures were elucidated by 1H-NMR and 13C-NMR. The products were administered intraperitoneally at doses of 40, 75, and 100 mg/kg. Results and discussion: Compound 1 exhibited significant activity during the first 7 h of the inflammatory phase (at 1, 3, 5, and 7 h), exercising its inhibitory action on inflammation mediated by histamine, prostaglandins, serotonin, and kinins, while compound 2 showed a significant inhibition at 3 and 5 h contributing to this effect, acting in the intermediate phase. Conclusions: According to the results of this work, the intraperitoneal administration of oleanolic acid and deacylcynaropicrin isolated from the aerial parts of C. genistoides produced a significant inhibition of carrageenan-induced inflammation at doses of 75 and 100 mg/kg. These results give support to the use of this plant as an anti-inflammatory in traditional medicine.

The protective effect of Hypericum connatum on stress-induced escape deficit in rat is related to its flavonoid content.

Abstract Context Hypericum perforatum L. (Hypericaceae), used in moderate depression treatment, is active in experimental tests for antidepressant activity. For H. connatum Lam., a South American species lacking hyperforin, antidepressant effects have not been demonstrated. Objective This study evaluates the antidepressant-like effect of H. connatum in rats and identifies the components involved in this activity. Materials and methods First, the effects of acute and 14-d oral administrations of an extract derived from H. connatum aerial parts were studied using the Escape Deficit (ED) test. Next, methanol-extracted flavonoid-enriched fractions B and C and fraction-purified flavonoids (quercetin, rutin and isoquercitrin) were evaluated in the ED test after acute administration. To rule out possible confounding effects of the flavonoids, we examined nociceptive threshold using the tail-flick test and anxious behaviour using the elevated plus maze (EPM) test. Results Hypericum connatum increased reactivity of unavoidable stress-exposed rats after acute (0.5 and 1 g/kg: ED = 18.6/30 and 19.8/30, respectively) and repeated administration (0.5 g/kg twice daily: ED = 17.8/30). Protective effects were observed for fractions B and C (250 mg/kg: ED = 18.1/30 and 18.8/30, respectively), quercetin (2.5, 5 and 10 mg/kg: ED = 15.3/30, 18.3/30 and 21.6/30, respectively), rutin (5 and 10 mg/kg: ED = 15.4/30 and 13.0/30, respectively) and isoquercitrin (2.5 mg/kg: ED = 19.2/30). The flavonoids did not modify nociceptive threshold or performance in the EPM test. Discussion and conclusion Hypericum connatum showed protective activity in the ED test, a correlate of potential antidepressant-like effects that appeared to be related to the flavonoid components of this species.

Antifungal Compounds from Latin American Plants

Latin American region comprises six of the most biologically diverse countries in the world, thus constituting one of the planet areas richest in biodiversity. Some efforts have been made to screen plants of the whole region and also of each country, but the amount of studies in each country is not correlated with its vegetal diversity. Regarding antifungal compounds isolated from this region, many structural types that have demonstrated antifungal properties are presented here. These previous studies are important starting points for the development of new antifungal drugs. However, most studies are preliminary and begin and end with in vitro assays without comparative toxicity studies or in vivo tests. Few of them deepen the mechanisms of action and with rare exceptions, no clinical studies were carried out. A close collaboration among Latin American countries one each other and with the whole world is highly needed and might help in the discovery of new natural antifungal structures from Latin American plants.