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Many diseases have been described to be associated with inflammatory processes. The currently available anti-inflammatory drug therapy is often not successful or causes intolerable side effects. Thus, new anti-inflammatory substances are still urgently needed. Plants were the first source of remedies in the history of mankind. Since their chemical characterization in the 19th century, herbal bioactive compounds have fueled drug development. Also, nowadays, new plant-derived agents continuously enrich our drug arsenal (e.g., vincristine, galantamine, and artemisinin). The number of new, pharmacologically active herbal ingredients, in particular that of anti-inflammatory compounds, rises continuously. The major obstacle in this field is the translation of preclinical knowledge into evidence-based clinical progress. Human trials of good quality are often missing or, when available, are frequently not suitable to really prove a therapeutical value. This minireview will summarize the current situation of 6 very prominent plant-derived anti-inflammatory compounds: curcumin, colchicine, resveratrol, capsaicin, epigallocatechin-3-gallate (EGCG), and quercetin. We will highlight their clinical potential and/or pinpoint an overestimation. Moreover, we will sum up the planned trials in order to provide insights into the inflammatory disorders that are hypothesized to be beneficially influenced by the compound.

The Dictyostelium discoideum NC4 genome harbors approximately 150 individual copies of a retrotransposable element called the Dictyostelium repetitive element (DRE). This element contains nonidentical terminal repeats (TRs) consisting of conserved building blocks A and B in the left TR and B and C in the right TR. Seven different-sized classes of RNA transcripts from these elements were resolved by Northern (RNA) blot analysis, but their combined abundance was very low. When D. discoideum cells were grown in the presence of the respiratory chain blocker antimycin A, steady-state concentrations of these RNA species increased 10-to 20-fold. The D. discoideum genome contains two DRE subtypes, the full-length 5.7-kb DREa and the internally deleted 2.4-kb DREb. Both subtypes are transcribed, as confirmed by analysis of cloned cDNA. Primary transcripts from the sense strand originate at nucleotide +1 and terminate at two dominant sites, located 21 or 28 nucleotides upstream from the 3' end of the elements. The activity of a reasonably strong polymerase II promoter in the 5'-terminal A module is slightly upregulated by the tRNA gene located 50 ± 4 nucleotides upstream and drastically reduced by the adjacent B module of the DRE. Transcripts from the opposite DNA strand (complementary-sense transcripts) were also detected, directed by an internally located polymerase II promoter residing within the C module. This latter transcription was initiated at multiple sites within the oligo(dA12) stretch which terminates DREs.Retrotransposable Dictyostelium repetitive elements (DREs) are present in approximately 150 to 200 copies in the genomes of different Dictyostelium discoideum strains (28-31).Most remarkably, this element always integrates at a distance of 50 ± 4 nucleotides upstream from tRNA genes but in the opposite transcriptional orientation. Upon integration, a 14 + 2-nucleotide target site duplication is created (29). The 5.7-kb DREs contain an internal coding portion with two open reading frames (ORFs) which is flanked by nonidentical terminal repeats (TRs) (see Fig. IA). These TRs are composed of three distinct modules, termed A, B, and C. The 5' TR consists of one or several A modules followed by a 290-bp B module which provides the AUG translation initiation codon. The 3' TR consists of a B module followed by a terminal C module.Approximately half of the DREs in NC4-derived strains show a variant organization (30). They are only 2.4 kb long and are termed DREbs, as opposed to the 5.7-kb DREas (Fig. IA). DREbs carry an extensive internal deletion encompassing nearly the entire ORF2. They also contain several small deletions within the right TR and a variant A module (termed Ab), which always differs from the Aa module of the 5.7-kb DREas by the same three distinct point mutations (30). A similar situation has been described for jockey elements of Drosophila melanogaster, which occur as full-size (5-kb) copies

Medicinal plants represent the oldest source of pharmacotherapy used by mankind. A considerable number of traditional systems of medicine (folk medicine) have emerged over the last millennia under different cultural conditions. Even nowadays, the majority of people in less developed countries have to rely on herbal remedies as primary health care. Based on scientific and technical progress, the options to produce high quality herbal medicinal products have been largely improved in the last decades. The acceptance of phytotherapy as a "natural and mild alternative" to synthetic drugs is very high within the general public in developed countries and, from a global perspective, sales figures of herbal medicines are constantly rising. However, we still face many issues in this field. In contrast to the popularity of herbal medicinal products, physicians and their respective societies often have a very critical view of them. Besides dogmatic obstacles, this is based on the frequently missing clinical trials that clearly demonstrate their efficacy and/or safety. This perspective discusses the reasons and implications of the lack of scientific evidence and also of the wrong understanding of the principles of rational phytotherapy.

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