Mechanism of antiulcerogenic activity of semi-synthetic crotonin obtained from Croton cajucara Benth

The bark of Croton cajucara Benth. is used in Brazilian folk medicine to treat gastrointestinal disorders. Transdehydrocrotonin (DHC) isolated from the bark of Croton cajucara has antiulcerogenic activity25. The presence of similar activity in semi-synthetic crotonin obtained from dehydrocrotonin from Croton cajucara was observed in gastric ulcer-induced models (HCl/ethanol, ethanol, indomethacin, stress and pylorus ligature). The aim of the present study was to assess the mechanisms involved in the antiulcerogenic activity of semi-synthetic crotonin. We investigated the effects of semi-synthetic crotonin on the response to histamine of right atria isolated from guinea pigs and on the response to carbachol of stomach fundus strips from rats. Semi-synthetic crotonin (3, 10 or 30 mM) induced a shift to the right in the concentrationresponse curves to carbachol in the isolated rat stomach at the pD2 level (pD2: 5.42±0.05, 5.76±0.061, 5.77±0.076, 6.48±0.012, respectively), without any alteration in the maximum response. Semi-synthetic crotonin also induced a shift to the right in the concentration-response curves to histamine in guinea pig right atria, pD2 (5.54±0.06, 6.01±0.06, 5.89±0.06, 5.92±0.03) and ( percent) maximum response (80±6.18, 118±6.18, 114±6.18, 122±1.4), respectively. Thus, the protective effect of semi-synthetic crotonin on induced gastric lesions could be due to antagonism of histaminergic and cholinergic effects on gastric secretion.

Arterite de Takayasu: estudo clínico e angiográfico / Clinical and angiographic features of Takayasu's arteritis

Os autores descrevem os dados clínicos e angiográficos de pacientes com arterite de Takayasu (AT) atendidos no Ambulatório Multidisciplinar de Vasculites da Unifesp/Hospital Säo Paulo entre 1993 e 1997. Foram atendidos 34 pacientes (28 mulheres, 20 de cor branca) com AT. A média de idade por ocasiäo do diagnóstico foi de 27,7 anos e o tempo de doença variou de 2 a 360 meses (mediana de 41 meses). As queixas clínicas por ocasiäo do diagnóstico foram: claudicaçäo de membros superiores em 32 por cento, claudicaçäo de membros inferiores em 23 por cento, emagrecimento em 15 por cento, febre em 15 por cento, insuficiência cardíaca congestiva em 9 por cento, cefaléia em 6 por cento, hipertensäo arterial em 6 por cento e dor precordial em 6 por cento. Durante o seguimento, 60,7 por cento apresentaram ausência ou diminuiçäo de pulso em membro superior, 56 por cento tinham diferença de pressäo arterial > 10 mmHg em membros superiores, 53 por cento tinham sopros arteriais e 29 por cento apresentavam sopros cardíacos. A classificaçäo angiográfica proposta em 1994 para arterite de Takayasu foi aplicada a 28 pacientes com pan-angiografia, que foram classificados como tipo I em 21,4 por cento, tipo IIa em 3,6 por cento, tipo III em 3,6 por cento, tipo IV em 14,3 por cento e tipo V em 57,1 por cento. Nenhum paciente foi classificado como tipo IIb. Três famílias apresentavam mais de um caso de AT: duas famílias com mäe e filha e uma com duas irmäs com AT. Os pacientes com AT atendidos em nosso serviço mostraram grande predomínio da doença em mulheres; 21 por cento dos pacientes apresentavam comprometimento exclusivo dos ramos do arco aórtico (tipo I). Esse padräo de comprometimento é semelhante ao relatado em pacientes japoneses e difere do descrito em pacientes com AT na +ndia

Merging ethnoppharmacology with chemotaxonomy: An approach to unveil bioactive natural products. The case of Psychotria alkaloids as potential analgesics

Psychotria colorata (Will ex R&S) Muell.Arg. flowers are used by "caboclos" in the Amazon as the basis for a homemade analgesic. The study of P. colorata revealed the presence of several pyrrolidinoindoline alkaloids, some with opioid-like analgesic activity in vivo. Neurochemical studies of active alkaloids proved their capability of inhibiting [3H] naloxone binding, confirming the opioid nature of the analgesic activity. These data launched a broader screening of Psychotria species, including P. carthagenensis, P. brachyceras, P. leiocarpa, P. myriantha, P. suterella and P. brachypoda. The analysis of the analgesic activity of several Psychotria species, as well as of specific isolated compounds, allowed a tentative structure/activity relationship and opened a promising research avenue in the search for new analgesic drugs.

Ethnopharmacology and the sustainable development of new plant-derived drugs

This paper presents a reflection based on the experience generated by fifteen years of studies on pharmacology and chemistry of medicinal plants, in a underdeveloped country, Brazil. Although the diversity of the Brazilian flora presents a remarkable opportunity towards the development of new medicinal products, there are only small natural products research groups. Strategies for pharmacological and chemical studies of medicinal plants investigated during this time, major difficulties and ways to bypass them are discussed. The ethnopharmacological approach adopted as a general method by our research team has given good results. Details of our experience in the way to develop new plant durgs are reviewed and updated.

A program for organizing field research data and bibliography on medicinal plants

In the formulation of working hypotheses based on ethnopharmacological information and publications, a rapid access to data is necessary. We present a microcomputer program especially designed for the organization of field data on traditional uses of medicinal plants (data bank 1) and related bibliographic reference (data bank 2). It was developed in Clipper language and turned into an independent executable through compilation, has many help screens (on-line), allows up to 100,000 entries in each data bank, changing and deletion of data, back-up copies, indexed and not indexed searches, and several possibilities of printing or listing data on the screen. Practical routines for the use of the program are presented, handling the existing 300 field work records and 1,000 references.