Karwinskia humboldtiana (buckthorn) fruit causes central nervous system damage during chronic intoxication in the rat.

Karwinskia humboldtiana fruit (Kh) causes a neurological disorder 3-4 weeks after ingestion, characterized by flaccid, symmetrical, ascending paralysis, similar to the Guillain-Barre syndrome. In this polyneuropathy the lesion (demyelization) in peripheral nerves has been described in several animal species, both in acute and in chronic intoxication. However, no reports exist about the presence of lesions in the Central Nervous System (CNS), in chronic intoxication.

Bioequivalence of single 100-mg doses of two oral formulations of topiramate: an open-label, randomized-sequence, two-period crossover study in healthy adult male Mexican volunteers.

Background: The proprietary form of topiramate is indicated in Mexico as an antiepileptic agent and in the prophylaxis of migraine headaches. However, before generic topiramate is placed on the market, pharmacokinetic studies investigating the bioequivalence of generic and branded formulations are needed.

Objective: The aim of this study was to compare the bioequivalence and tolerability of a generic (test) and a branded (reference) formulation of topiramate 100 mg in healthy Mexican volunteers.

Evaluation of the bioequivalence of single 100-mg doses of two oral formulations of cyclosporin A microemulsion: a randomized, open-label, two-period crossover study in healthy adult male Mexican volunteers.

Background: Cyclosporin A is widely used in Mexico as immunosuppressive therapy in organ transplantation and in the treatment of autoimmune disorders. Although several generic oral formulations of cyclosporin A are available in Mexico, information concerning the bioequivalence of these formulations in the Mexican population is not available in the published literature.

Objective: The aim of this study was to compare the bioequivalence and tolerability of a generic (test) and a branded (reference) soft-gelatin capsule formulation of cyclosporin A microemulsion 100 mg available in Mexico.

An experimental model of peripheral neuropathy induced in rats by Karwinskia humboldtiana (buckthorn) fruit.

Intoxication by Karwinskia humboldtiana (buckthorn) fruit presents a neurological picture similar to that of Guillain-Barré syndrome. In this report, we describe an experimental animal model of peripheral neuropathy induced by buckthorn fruit. Four groups of Wistar rats received one oral dose of 1.

Bioavailability of two oral formulations of loratadine 20 mg with concomitant ketoconazole: an open-label, randomized, two-period crossover comparison in healthy Mexican adult volunteers.

Background: Loratadine is a long-acting antihistamine with selective peripheral histamine H(1)-receptor antagonistic activity and fewer sedative effects compared with conventional antihistamines, and is widely used in Mexico. Although several generic formulations of loratadine are available in Mexico, based on a literature search, information concerning the bioavailability of each formulation in the Mexican population is not available.

Objective: The aim of this study was to compare the bioavailability and tolerability of 2 oral formulations of loratadine 20 mg (two 10-mg tablets) used in Mexico: Sensibit (test formulation; Laboratorios Liomont S.

Bioavailability of two oral formulations of azithromycin 500 mg: a randomized, open-label, two-period crossover comparison in healthy Mexican adult subjects.

Background: Azithromycin is related to erythromycin but is more active against gram-negative bacteria and less active against streptococci and staphylococci compared with erythromycin. For these reasons, and because of convenience of dosing (QD for 3 days), azithromycin is widely used in Mexico. Although several generic formulations of azithromycin are available in Mexico, information concerning the bioavailability of each formulation in the Mexican population is not available.

In vitro metabolism and toxicity assessment of toxin T-514 (Peroxisomicine A1) of Karwinskia humboldtiana in microsomes and primary cultured hepatocytes.

T-514 (Peroxisomicine A(1)) from Karwinskia humboldtiana is a dimeric hydroxyanthracenone with a highly selective cytotoxic effect on tumor cells. We evaluated the metabolism of this compound in two in vitro systems (liver microsomes and hepatocytes) and assessed the cytotoxicity of its metabolites on normal and tumor cells. Microsomes (12.

Production of reactive oxygen species by toxin T-514 of genus Karwinskia in vitro.

In the present study we have analyzed the production of reactive oxygen species by toxin T-514 of the genus Karwinskia in vitro (primary liver cell cultures and microsomes), as well as their possible role in its cytotoxicity. The role of catalase and superoxide dismutase (SOD) as defense mechanisms against oxidative stress was also studied. Freshly isolated hepatocytes or microsomes were exposed to T-514 in the presence or absence of catalase and SOD.

Effect of meso-2,3-dimercaptosuccinic acid on urinary lead excretion in exposed men.

The efficacy of meso-2,3-dimercaptosuccinic acid (DMSA) was evaluated in workers occupationally exposed to lead (Pb; blood level >50 microg/dL). Ten men were given 600 mg of DMSA per orem daily, for five days. Pb concentrations of whole blood and urine were determined throughout therapy.

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.

In vitro binding studies of the peroxisomicine A1-BSA and -HSA interactions.

Peroxisomicine A1 (PA1) is a dimeric hydroxyanthracenone isolated from fruits of plants belonging to the genus Karwinskia. Showing selective toxicity between malignant and benign cell lines, it is currently under screening as an antineoplastic agent. Very little is known about its mechanism of action.

Urinary excretion of trace elements in humans after sodium 2,3-dimercaptopropane-1-sulfonate challenge test.

Objective: To evaluate the effects of intravenous sodium 2,3-dimercaptopropane-1-sulfonate (DMPS, Dimaval) on urinary excretion of essential trace elements in subjects who received this chelating agent as a mercury challenge test.

Subjects: Eleven subjects sought medical attention due to concern with the toxicity of mercury released from dental amalgam fillings.

Design: The subjects were given DMPS 3 mg/kg intravenously.

Peroxisomicine A1 (plant toxin-514) affects normal peroxisome assembly in the yeast Hansenula polymorpha.

Previously we demonstrated that peroxisomicine A1 (T-514), a plant toxin isolated from Karwinskia species, has a deteriorating effect on the integrity of peroxisomes of methylotrophic yeasts. Here we describe two strains of Hansenula polymorpha, affected in the normal utilization of methanol as sole source of carbon and energy due to peroxisomicine A1 treatment. The two strains isolated (L17 and RV31) grew poorly on methanol, apparently due to malfunctioning of their peroxisomes.

Quantitative analysis of liver peroxisomes in rats intoxicated with peroxisomicine-A1.

Peroxisomes are single-membrane-bound organelles present in almost all eukaryotic cells. Hypolipidemic agents such as clofibrate, herbicides and plasticizers induce an increase in the number and size of peroxisomes from mammalian cells. However, there is no evidence of drugs causing a decrease in the number of these organelles.

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.

Studies on the effect of peroxisomicine on catalase activity in albino mice.

Peroxisomicine is a toxic compound isolated from plants of the genus Karwinskia (Rhamnaceae). This toxin produces irreversible and selective damage to the peroxisomes of yeast cells in vivo. Peroxisomicine also inhibits catalase activity in vitro, when using purified enzyme.

Experimental evidence for toxic damage induced by a dimeric anthracenone: diast T-514 (peroxisomicine A2).

Dimeric anthracenones obtained from the genus Karwinskia (Rhamnaceae) are characteristic compounds isolated from the plants of this species. Previous toxicity studies demonstrated Diast T-514 to be toxic to animals in experimental settings. Diast T-514 extracted and characterized from Karwinskia parvifolia, was studied in CD1 mice.

Urinary mercury in twelve cases of cutaneous mercurous chloride (calomel) exposure: effect of sodium 2,3-dimercaptopropane-1-sulfonate (DMPS) therapy.

Objective: To evaluate clinical symptoms and urinary mercury before and after chelation therapy in subjects with chronic cutaneous mercurous chloride (HgCl; calomel) exposure.

Subjects: Twelve women from 19-45 years who had used a facial cream which contained HgCl (5.9%) for 2 to 10 years.

Intravenous self-administration of metallic mercury: report of a case with a 5-year follow-up.

A case of intravenous self-administration of elementary mercury is presented. The increase urinary excretion of mercury after treatment with 2,3-dimercaptopropane-1-sulfonate is reported on a 5-year follow-up. No biochemical abnormalities in hepatic or renal function nor clinical pulmonary malfunction have been detected, despite the persistence of metallic densities in the body.

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.

Evaluation of urinary mercury excretion after administration of 2,3-dimercapto-1-propane sulfonic acid to occupationally exposed men.

The purpose of this study was to determine the clinical efficacy of 2,3-dimercapto-1-propane sulfonic acid, Na salt, on the urinary excretion of mercury as well as its possible adverse effects. Ten men with occupational mercury exposure (urinary level of 50 micrograms/g creatinine or more) were assigned to receive 2,3-dimercapto-1-propane sulfonic acid p.o.

[The incidence of poisoning by Karwinskia humboldtiana in Mexico].

Intoxication produced by Karwinskia humboldtiana presents a neurological picture similar to that of poliomyelitis, Guillain-Barré syndrome or other polyradiculoneuritis with which it is frequently confused. The purpose of this paper is to report the frequency of this intoxication, by means of the antecedent of ingestion of the fruit and the detection of toxins in blood using a thin layer chromatography method. One hundred fifty four samples of cases with acute flaccid paralysis from 18 states of the country were received.

[Familial poisoning with Karwinskia humboldtiana].

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.

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.

In vitro selective toxicity of toxin T-514 from Karwinskia humboldtiana (buckthorn) plant on various human tumor cell lines.

Toxin T-514 is a dimeric anthracenone isolated from the Karwinskia humboldtiana (buckthorn) plant. Its potential anti-neoplastic effect was evaluated in vitro and the results obtained were compared with the effect of other known anti-cancer agents. Normal and malignant continuous cell lines were tested.