Many natural substances with proven anti-inflammatory activity have been isolated throughout the years. The aim of this review is to review naturally sourced alkaloids with anti-inflammatory effects reported from 2000 to 2010. The assays were conducted mostly in vivo, and carrageenan-induced pedal edema was the most used experimental model. Of the 49 alkaloids evaluated, 40 demonstrated anti-inflammatory activity. Of these the most studied type were the isoquinolines. This review was based on NAPRALERT data bank, Web of Science and Chemical Abstracts. In this review, 95 references are cited.

This review of the current literature aims to study correlations between the chemical structure and gastric anti-ulcer activity of tannins. Tannins are used in medicine primarily because of their astringent properties. These properties are due to the fact that tannins react with the tissue proteins with which they come into contact. In gastric ulcers, this tannin-protein complex layer protects the stomach by promoting greater resistance to chemical and mechanical injury or irritation. Moreover, in several experimental models of gastric ulcer, tannins have been shown to present antioxidant activity, promote tissue repair, exhibit anti Helicobacter pylori effects, and they are involved in gastrointestinal tract anti-inflammatory processes. The presence of tannins explains the anti-ulcer effects of many natural products.

Bidens pilosa L. is a cosmopolitan annual herb, known for its traditional use in treating various diseases and thus much studied for the biological activity of its extracts, fractions and isolated compounds. Polyacetylenes and flavonoids, typical metabolite classes in the Bidens genus, predominate in the phytochemistry of B. pilosa. These classes of compounds have great taxonomic significance. In the Asteraceae family, the acetylene moiety is widely distributed in the Heliantheae tribe and some representatives, such as 1-phenylhepta-1,3,5-triyne, are noted for their biological activity and strong long-wave UV radiation absorbance. The flavonoids, specifically aurones and chalcones, have been reported as good sub-tribal level markers. Natural products from several other classes have also been isolated from different parts of B. pilosa. This review summarizes the available information on the 198 natural products isolated to date from B. pilosa.

Flavonoids are phenolic compounds, secondary metabolites of plants that cause several benefits to our health, including helping the treatment against cancer. These pharmacological properties are associated with the ability of flavonoids in attenuating the generation of reactive oxygen species, acting as chelate compounds or affecting the oxi-redox cycle. In spite of the large number of information in term of SAR and QSAR, no recent review has tabulated and discussed in detail these data. In view of this, we bring here a detailed discussion of the structure-activity relationships (SAR) and quantitative structure-activity relationships (QSAR) models. We have also analyzed the correlation between the chemical structure of flavonoids and analogues to their anticancer activities. A large number of methodologies have been used to identify the characteristics of these compounds with their potential anticancer: multiple linear regression, principal components analysis, comparative molecular field analysis, comparative molecular similarity indices analysis, partial least squares, neural networks, configuration of classification and regression trees, Free-Wilson, docking; using topological, structural and enthalpies’ descriptors. We also discussed the use of docking models, together with QSAR models, for the virtual screening of anticancer flavonoids. The importance of docking models to the medicinal chemistry of anticancer flavonoids has increased in the last decade, especially to help in identifying the structural determinants responsible for the activity. We tabulated here the most important examples of virtual screening determined for anticancer flavonoids and we highlighted the structural determinants. The mode of action, the most potent anticancer flavonoids and hints for the structural design of anticancer flavonoids are revised in details and provided here.

Chemical studies of Praxelis clematidea R.M. King & Robinson resulted in the isolation of six flavones: Apigenine, genkwanine, 7,4’-dimethylapigenin, trimethylapigenin,cirsimaritin and tetramethylscutellarein, which were tested for their toxicity against Staphylococcus aureus SA-1199B, a strain possessing the NorA efflux pump. Efflux pumps are integral proteins of the bacterial membrane and are recognized as one of the main causes of bacterial drug resistance, since they expel antibiotics from the cell. The inhibition of this transporter is one form of modulating bacterial resistance to antimicrobial drugs. The flavones tested did not show any significant antibacterial activity against the Staphylococcus aureus strain used, but were able to modulate bacterial drug resistance. This property might be related to the degree of lipophilicity of the flavones conferred by the methoxyl groups, since 4’,5,6,7 tetramethoxyflavone the most methoxylated compound, reduced the minimal inhibitory concentration of the drug 16-fold.

Since humans cannot synthesize carotenoids, they depend upon the diet exclusively for the source of these micronutrients. It has claimed that they may alleviate chronic diseases such as cancers. The present communication constitutes a global review of the scientific literature on plants and others organisms that biosynthesize carotenoids, which include the series alpha-, beta-, gamma-, delta- and epsilon-carotenes. The results of the literature survey lists more than five hundred sources.