All these changes occurred after treatment with compound 7 (Figure 5(d)), while compound 5 produced no significant changes compared to the control (data not shown).4. DiscussionMany people living in rural areas have no easy access to conventional SKI-606 allopathic treatments, largely due to the limited availability of health services and their low socioeconomic status. Therefore, plants may provide an important and necessary source of therapeutic medicinal compounds. Flavones and their derivatives, flavonoids and flavonols, are among the most attractive plant derivatives that might enrich the current therapy options, due to their extremely large range of biological properties [14].In this study, in vitro biological activity of nine flavonoid compounds against extracellular and intracellular forms Leishmania spp.

was investigated. This is important as many studies of the activity of compounds against Leishmania spp. are performed on promastigote forms, which are much easier to work in vitro. However, since extracellular forms are not the developed forms of the parasite in vertebrate hosts, evaluations made with these forms are merely indicative of the potential leishmanicidal activity of the compounds tested. Consequently, a preliminary test using extracellular promastigote forms should always be complemented by a subsequent evaluation using intracellular forms (amastigotes in vertebrate host cells), so that a better understanding of the activity may be obtained [4].The petiolaroside-based derivatives (7�C9) presented the lowest IC50 values against extra- and intracellular forms.

Previously, the nine flavonoids investigated here were tested against epimastigote forms of Trypanosoma cruzi, and the most effective compounds were astragalin (1) and two acetylated derivatives (2 and 3). These had significantly lower IC50 values compared with benznidazole [15]. By contrast, in this study, we saw that the astragalin and its derivates were the least effective agents against Leishmania spp.Petiolaroside, 2���-acetylpetiolaroside (7 and 8, resp.), and paeonoside and its derivates (4, 5, and 6) showed the best selectivity indexes. These indexes exceeded the reference drug SI by more than 50 times. The astragalin and its derivates (1, 2, and 3) and petiolaroside decacetate (9) were all more effective than Glucantime.If we compare the results obtained for the infection rate Anacetrapib and the number of amastigotes per infected macrophage cells for both Leishmania species, it can be concluded that 2���-acetylpetiolaroside (8) is clearly the most active. The acetylated derivatives 2���-acetylpetiolaroside (8) and 2���-acetylpaeonoside (5) are more active than petiolaroside (7) and paeonoside (4), respectively.