RESUMO
Abstract Solvents play important and critical role in natural product chemistry and could generate artefacts during the extraction and purification of metabolites from a biological matrix. This study aimed to correlate the chromatographic profile with biological activity of Ipomoea pes-caprae (L.) R. Br., Convolvulaceae, extracts obtained with hydroethanolic extraction. Thus, aerial parts of I. pes-caprae were extracted with different concentration of ethanol (50, 70 and 90°GL) and the obtained extracts were analysed by HPLC-UV. HPLC data were studied employing chemometrics to discriminate the samples. Moreover these samples were further characterized by using UPLC-QTOF/MS data. The extracts were also biomonitored through the paw-oedema and spontaneous nociception induced by trypsin in mice. Different chromatographic profiles were obtained and the exploratory analysis clearly revealed higher level of ethyl caffeate in extracts of lower strength of ethanol (50°GL). This compound was suggested to be an artefact formed by transesterification of caffeoylquinic acid derivatives present in the plant, once it was not observed when other solvents were employed. During the biological assay, only the extract obtained with ethanol 50°GL presented significant inhibition of inflammation (45 ± 9%) and nociception (24 ± 3%). Ethyl caffeate seems to be linked to the anti-inflammatory effect since it reduced 86 ± 5% of paw-oedema induced by trypsin. Artefacts could contribute to the biological activity of herbal preparations and consequently lead to misinterpretation of the results.
RESUMO
Abstract Aleurites moluccanus L. (Willd.), Euphorbiaceae, is a tree that is native to Indonesia and India. Various parts of this tree are commonly used in traditional medicine to treat pain, fever, inflammation, hepatitis, gastric ulcer and other ailments. An oral suspension containing dried extract of A. moluccanus was developed and in vivo anti-inflammatory activity was evaluated. Extract 100 and 50 mg/ml loaded oral suspensions were prepared using different suspending agents. The formulations were analysed by their appearance, pH, density, redispersion time, rate of settling, rheological behaviour, distribution of particle size and zeta potential. The dose uniformity was determined by measuring the content of total phenolic compounds expressed in swertisin by a validated HPLC method, as well as the dissolution profile. The stability of oral suspensions was analysed in accelerated studies (40 °C for 6 months). The anti-inflammatory activity was analysed using an in vivo paw oedema model. The taste and odour of the suspensions were shown to be characteristic of the extract. Carmellose sodium (CS; 0.5%) and microcrystalline cellulose and carmellose sodium mixture (MCCS; 1%) showed better physical behaviour. The content of total phenolic compounds was 1.6 mg/ml and approximately 100% of the total phenolic compounds dissolved within 10 min. During the stability study, the formulations were approved by their physical–chemical properties and were shown to lose 12–14% of total phenolic compounds at 40 °C after 6 months. Suspensions containing 50 mg/ml of standardised dried extract inhibited around 35 ± 7.6% of paw oedema. Formulations containing CS showed more anti-inflammatory activity. Suspensions containing dry extract of A. moluccanus were successfully obtained and showed physical and physical–chemistry properties that were appropriate and characteristic of this dosage form, suitable for administration in paediatric and elderly populations, making this an alternative to tablets.