ABSTRACT
ABSTRACT Obtaining artemisinin and its derivatives is very costly, which limits access to low-income people. Some hydroalcoholic extract of Artemisia annua L., Asteraceae, which has shown comparable antimalarial activity could be an alternative to the purified compound, especially if the cultivars have higher content of artemisinin. The objective of this study was to evaluate the effects of the extraction parameters (ethanol graduation, previous shaking time in an ultrasound bath and drug/solvent ratio) on the yield of artemisinin in the liquid extract obtained by percolation from A. annua and then optimize the extraction efficiency of this compound. The Box-Behnken (33) factorial design was used in association with response surface methodology. The derivatization reaction of artemisinin was used in an analytical method which was submitted to validation, after reaching the specification of the selectivity, linearity, precision, accuracy and robustness. Detection and quantification limits were 1.3 and 4.0 µg/ml, respectively. The largest amount of this compound of interest was obtained without any ultrasound bath, with an ethanol graduation of 95% and a drug/solvent ratio of 2%. Drug/solvent ratio was the factor which most influenced extraction efficiency. The maximum range of artemisinin yield was 1.21%. Information obtained in this study can be used for future approaches to determining and extracting artemisinin from A. annua.
ABSTRACT
Abstract Pterodon emarginatus Vogel, Fabaceae, is a great source of bioactive compounds. The most known and studied herbal derivative from this species is an ambar-colored oleoresin that contains vouacapane diterpenes and volatile terpenoids, such as β-caryophyllene. Some recent papers aimed to generate nanoemulsions using this oleoresin for biological applications. However, they used high-energy methods that elevate costs of the process or heating procedures, which offer the disadvantage of possible volatile substances loss. Thus, as part of our ongoing studies with nanobiotechnology of natural products, especially regarding preparation of nanoemulsions with promising plant-based oils by low cost and low energy methods, we decided to evaluate the ability of non-heating and solvent-free method to generate P. emarginatus oleoresin-based nanoemulsions. Two non-ionic surfactants were used to generate the nanoemulsions by a simple homogenization method with vortex stirrer. Low mean droplet size (<180 nm) and low polydispersity index (<0.200) were observed even after one day of preparation. The low coefficient of variation for the analyzed parameters of different batches and similar profile for droplet size distribution suggested reproducibility of the method. After 30 days, some degree of droplet growth was observed on nanoemulsion prepared with polyethyleneglycol 400 monooleate, while almost no alteration was observed for nanoemulsion prepared with polysorbate 85. Programmed temperature ramp analysis revealed that no major effects on droplet size and polydispersity index were observed, suggesting the robustness of formed nanoemulsions. Thus, the present study shows for the first time the formation of sucupira-based nanoemulsions by a simple, low cost and ecofriendly method. This study opens new perspectives for bioactive evaluation of this novel nano-product.
ABSTRACT
The dissolution test is an essential tool to assess the quality of herbal medicines in the solid dosage form for oral use. This work aimed to evaluate the dissolution behavior of three herbal medicines in the form of capsules and tablet containing Passiflora, produced with powder or dried extract. Assay of total flavonoids and dissolution methods were validated and obtained results allowed the quantification of flavonoids with precision, accuracy and selectivity. The percentage of total flavonoids found was 2 percent for capsule A (containing only powder), 0.97 percent for capsule B (containing only dried extract) and 5.5 percent for tablet. Although the content was lower, the release of flavonoids present in the capsule containing dried extract was 12 percent higher over 30 min, with dissolved percentage values of 87 and 75, for the capsules containing extract and powder, respectively. The tablet containing dried extract presented dissolution of 76 percent, despite the higher content of flavonoids, which may be due to pharmacotechnical problems. Obtained data demonstrated the need to implement these tests in the quality control of herbal medicines, confirming the release of the active ingredients that underlie the pharmacological action of these medicines.