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.

Optimization and validation of an analytical procedure by high-performance liquid chromatography for the quantification of peroxisomicines and isoperoxisomicines.

Peroxisomicine A1 is a potential antineoplastic substance extracted from plants of the genus Karwinskia. An RP-HPLC-DAD method was developed and validated for the separation and quantification of four isomers of this compound. These isomers coelute in the preparative procedure and are present at a proportion ranging between 3 and 5% in the peroxisomicine A1 purified in the laboratory. The desirability coefficient of the method described here was enhanced 140% with respect to the previously reported method.

Effect of peroxisomicine A2 and T 544 of the genus Karwinskia on peroxisomes of Candida boidinii.

Dimeric anthracenones have been isolated from toxic plants of the genus Karwinskia (Rhamnaceae). T 514 or peroxisomicine A1 is one of the anthracenonic compounds which produce irreversible and selective damage on the peroxisomes of yeast cells in vivo. In this paper we describe the effect of two structurally related anthracenones on cell viability and on the peroxisomes of the methylotrophic yeast Candida boidinii. As has been described for peroxisomicine A1, peroxisomicine A2 and T 544 caused a decrease in the viability of C. boidinii at all concentrations tested, and disruption of the peroxisomal membrane, T 544 showing the strongest effect. In C. boidinii cell death and peroxisomal damage seem to be independent events.

Effect of peroxisomicine and related anthracenones on catalase activity.

Dimeric anthracenones were isolated from toxic plants of the genus Karwinskia (Rhamnaceae). T 514 or peroxisomicine A1 is one of these toxic compounds which produces an irreversible and selective damage on the peroxisomes of yeast cells in vivo. In this paper we now report the inhibitory effect in vitro of peroxisomicine A1 and other structurally related anthracenones on liver catalase activity. The peroxisomicine A1 produces a non-competitive inhibition with respect to H2O2 on bovine, dog, and mouse liver catalases. In the three cases Vmax was decreased whereas Km was unaffected. Other dimeric anthracenones of natural origin were also found to be inhibitors of bovine liver catalase. There is a relationship between structure and degree of inhibition of all anthracenonic compounds tested. Peroxisomicine A1 and peroxisomicine A2 caused the highest degree of inhibition (IC50 = 3.34 and 3.64 microM, respectively).

[Familial poisoning with Karwinskia humboldtiana]. / Intoxicación de una familia por Karwinskia humboldtiana (tullidora).

The ingestion of ripe fruit of the Karwinskia humboldtiana, a shrub commonly known as tullidora or coyotillo, produces an intoxication described in the literature as a symmetric flaccid paralysis of the hind limbs, progressive and ascendent, that in severe cases may cause bulbar paralysis and death. The cause of an acute accidental intoxication of an entire family is presented here, wherein ten out of thirteen members ingested the ripe fruit of the tullidora. Three died, the father and two daughters. For the first time the toxins determination in blood by thin layer chromatography method is described. This method supports the diagnosis with other polyradiculoneuritis such as poliomyelitis and the Guillain Barre's syndrome.

Comparison of the hepatotoxicity of toxin T-514 of Karwinskia humboldtiana and its diastereoisomer in primary liver cell cultures.

Toxin T-514 of Karwinskia humboldtiana has been demonstrated to be hepatotoxic in vivo and in vitro. Recently a diastereoisomer of T-514 has been isolated. In the present study we have evaluated and compared the in vitro hepatoxicity of the diastereoisomer of T-514 using primary cultures of rat hepatocytes. Cytotoxicity was evaluated by release of cytoplasmic enzyme lactate dehydrogenase (LDH), and mitochondrial metabolic function (MTT reduction). The diastereoisomer was shown to be almost as hepatoxic in vitro as toxin T-514.