Gastroprotective activity of (E)-ethyl-12-cyclohexyl-4,5-dihydroxydodec-2-enoate, a compound isolated from Heliotropium indicum: role of nitric oxide, prostaglandins, and sulfhydryls in its mechanism of action

Evidence for the efficacy of anti-inflammatory plants used in Brazilian traditional medicine with ethnopharmacological relevance

ETHNOPHARMACOLOGICAL RELEVANCE

When exacerbated, inflammatory processes can culminate in physical and emotional disorders and, if not stopped, can be lethal. The high prevalence of inflammation has become a public health problem, and the need for new drugs to treat this pathology is imminent. The use of medicinal plants has emerged as an alternative, and a survey of data that corroborates its application in inflammatory diseases is the starting point. Furthermore, Brazil harbors a megadiversity, and the traditional use of plants is relevant and needs to be preserved and carefully explored for the discovery of new medicines.

AIM OF THE STUDY

This review sought to survey the medicinal plants traditionally used in Brazil for the treatment of inflammatory processes and to perform, in an integrative way, a data survey of these species and analysis of their phytochemical, pharmacological, and molecular approaches.

MATERIALS AND METHODS

Brazilian plants that are traditionally used for inflammation (ophthalmia, throat inflammation, orchitis, urinary tract inflammation, ear inflammation, and inflammation in general) are listed in the DATAPLAMT database. This database contains information on approximately 3400 native plants used by Brazilians, which were registered in specific documents produced until 1950. These inflammatory disorders were searched in scientific databases (PubMed/Medline, Scopus, Web of Science, Lilacs, Scielo, Virtual Health Library), with standardization of DECS/MESH descriptors for inflammation in English, Spanish, French, and Portuguese, without chronological limitations. For the inclusion criteria, all articles had to be of the evaluated plant species, without association of synthesized substances, and full articles free available in any of the four languages searched. Duplicated articles and those that were not freely available were excluded.

RESULTS

A total of 126 species were identified, culminating in 6181 articles in the search. After evaluation of the inclusion criteria, 172 articles representing 40 different species and 38 families were included in the study. Comparison of reproducibility in intra-species results became difficult because of the large number of extraction solvents tested and the wide diversity of evaluation models used. Although the number of in vitro and in vivo evaluations was high, only one clinical study was found (Abrus precatorius). In the phytochemical analyses, more than 225 compounds, mostly phenolic compounds, were identified.

CONCLUSION

This review allowed the grouping of preclinical and clinical studies of several Brazilian species traditionally used for the treatment of many types of inflammation, corroborating new searches for their pharmacological properties as a way to aid public health. Furthermore, the large number of plants that have not yet been studied has encouraged new research to revive traditional knowledge.

First Evidence of Gastroprotection by Schinus molle: Roles of Nitric Oxide, Prostaglandins, and Sulfhydryls Groups in Its Mechanism of Action

Schinus molle is a plant traditionally used in Mexico to treat gastric disorders. However, no scientific evidence has been reported on its gastroprotective effect. The aim of the current contribution was to conduct a bioassay-guided study on S. molle to evaluate its gastroprotective activity in a model of Wistar rats given ethanol orally to induce gastric lesions. The hexane and dichloromethane extracts from the tested plant showed over 99% gastroprotection at a dose of 100 mg/kg. From the hexane extract, two of the three fractions (F1 and F2) afforded over 99% gastroprotection. The F1 fraction was subjected to column chromatography, which revealed a white solid. Based on the ESI-MS analysis, the two main compounds in this solid were identified. The predominant compound was probably a triterpene. This mixture of compounds furnished about 67% gastroprotection at a dose of 100 mg/kg. Pretreatment with L-NAME, indomethacin, and NEM was carried out to explore the possible involvement of nitric oxide, prostaglandins, and/or sulfhydryl groups, respectively, in the gastroprotective activity of the white solid. We found evidence for the participation of all three factors. No antisecretory activity was detected (tested by pylorus ligation). In conclusion, evidence is herein provided for the first time of the gastroprotective effect of S. molle.