RESUMO
Azorella compacta (A. compacta) is a shrub of the Andean Altiplano of Bolivia, Chile and Peru, consumed by local communities as a traditional medicine for several maladies such as diabetes, hepatic and inflammatory diseases. A. compacta is rich in mulinane- and azorellane-type diterpenoids. For two of these, acute hypoglycemic effects have been described, but the impact of A. compacta diterpenoids on fatty liver disease has not been investigated. Therefore, A. compacta organic fractions were prepared using petroleum ether, dichloromethane and methanol. Their content was characterized by UHPLC/MS, revealing the presence of ten diterpenoids, mainly mulinic acid, azorellanol and mulin-11,13-diene. Next, mice fed with a high-fat diet (HFD), a model of metabolic dysfunction-associated fatty liver disease (MAFLD), received one of the fractions in drinking water for two weeks. After this treatment, hepatic parameters were evaluated. The A. compacta fractions did not reduce hyperglycemia or body weight in the HFD-fed mice but increased the serum levels of hepatic transaminases (AST and ALT), reduced albumin and increased bilirubin, indicating hepatic damage, while histopathological alterations such as steatosis, inflammation and necrosis generated by the HFD were, overall, not ameliorated by the fractions. These results suggest that organic A. compacta extracts may generate hepatic complications in patients with MAFLD.
RESUMO
Mulinane- and azorellane-type diterpenoids have unique tricyclic fused five-, six-, and seven-membered systems and a wide range of biological properties, including antimicrobial, antiprotozoal, spermicidal, gastroprotective, and anti-inflammatory, among others. These secondary metabolites are exclusive constituents of medicinal plants belonging to the Azorella, Laretia, and Mulinum genera. In the last 30 years, more than 95 mulinanes and azorellanes have been reported, 49 of them being natural products, 4 synthetics, and the rest semisynthetic and biotransformed derivatives. This systematic review highlights the biosynthetic origin, the chemistry, and the pharmacological activities of this remarkably interesting group of diterpenoids.
Assuntos
Apiaceae/química , Diterpenos/química , Plantas Medicinais/química , Antibacterianos/síntese química , Antibacterianos/química , Antibacterianos/farmacologia , Diterpenos/síntese química , Diterpenos/farmacologia , Testes de Sensibilidade Microbiana , Modelos Químicos , Estrutura Molecular , Extratos Vegetais/química , Extratos Vegetais/farmacologiaRESUMO
Mulinane diterpenoids isolated from Azorella species have displayed gastroprotective effects in animal models. In this study we have transformed the main constituent, mulin-11,13-dien-20 oic acid from this plant using the filamentous fungus Mucor plumbeus and a ß-cyclodextrin inclusion complex and we have obtained two main products with good yields (33% and 15% for compound 4 and 5, respectively) for further preparation of semisynthetic derivatives to evaluate their gastroprotective effects. In addition, one of the compounds isolated from Azorella cuatrecasasii was new (9-epi-13α-hydroxymulinene 1). Six new derivatives 4a-4c and 5a-5c were then prepared by simple chemical transformations. The structures of all compounds were elucidated by spectroscopic means based on 1D and 2D-NMR techniques. Some 8 diterpenes were evaluated for their gastroprotective effects in the ethanol/HCl-induced ulcer model in mice at 20mg/kg. The highest gastroprotective activity was shown by 7α,16-dihydroxymulin-11,13-dien-20-oic acid 5, which was higher than the reference drug lansoprazole, while 16-hydroxymulin-11,13-dien-20-oic acid 4 was as active as lansoprazole.
Assuntos
Antiulcerosos/farmacologia , Apiaceae/química , Diterpenos/farmacologia , Mucosa Gástrica/efeitos dos fármacos , Úlcera Gástrica/tratamento farmacológico , beta-Ciclodextrinas/farmacologia , Álcoois , Animais , Antiulcerosos/química , Antiulcerosos/isolamento & purificação , Modelos Animais de Doenças , Diterpenos/química , Diterpenos/isolamento & purificação , Relação Dose-Resposta a Droga , Mucosa Gástrica/patologia , Ácido Clorídrico , Camundongos , Conformação Molecular , Úlcera Gástrica/induzido quimicamente , Úlcera Gástrica/patologia , Relação Estrutura-Atividade , beta-Ciclodextrinas/químicaRESUMO
OBJECTIVES: The chemical study of a dichloromethane extract from Azorella compacta was directed to the isolation of characteristic mulinane and azorellane diterpenoids in order to determine their gastroprotective activity. METHODS: Usual chromatographic techniques on the extract led to the isolation of 12 compounds, which were identified by their spectroscopic properties. The HCl/ethanol-induced gastric lesions model in mice was used to determine the gastroprotective activity. KEY FINDINGS: The new diterpenoids, 13ß-hydroxymulinane (1), mulin-11,13-dien-20-ol (2), 13α-methoxyazorellanol (3) and mulin-11,13-dien-18-acetoxy-16,20-dioic acid (12) were isolated from A. compacta. The known diterpenoids mulin-11,13-dien-20-oic acid (4), 13α-hydroxyazorellane (5), 13ß-hydroxyazorellane (6), mulinic acid (7), mulinolic acid (8) and azorellanol (9), and the aromatic compounds 5,7-dihydroxychromone (10) and isoflavonoid biochanin A (11), were also obtained from the extract. Compounds 6, 9 and 12 at 20 mg/kg reduced gastric lesions by 69%, 71% and 73%, respectively, being statistically similar to lansoprazole at the same dose. CONCLUSIONS: The results corroborate the intraspecific chemical variations detected previously in specimens of A. compacta collected at different Chilean latitudes. A high concentration of azorellanol (9) could account in part for some of the therapeutic properties attributed to this species, in particular in ulcer treatment. Most of the mulinane and azorellane diterpenoids isolated in this study showed relevant gastroprotective activity at a low dose in the bioassay.