The biochemistry and medical significance of the flavonoids.

https://cyberleninka.org/article/n/132565.pdf

Discovery and resupply of pharmacologically active plant-derived natural products: A review.

The tail suspension test as a model for assessing antidepressant activity: review of pharmacological and genetic studies in mice.

http://www.informaticsjournals.com/index.php/jnr/article/download/232/232

Synergy research: approaching a new generation of phytopharmaceuticals.

Epidemiological studies have revealed that a diet rich in plant-derived foods has a protective effect on human health. Identifying bioactive dietary constituents is an active area of scientific investigation that may lead to new drug discovery. Kaempferol (3,5,7-trihydroxy-2-(4-hydroxyphenyl)-4H-1-benzopyran-4-one) is a flavonoid found in many edible plants (e.g. tea, broccoli, cabbage, kale, beans, endive, leek, tomato, strawberries and grapes) and in plants or botanical products commonly used in traditional medicine (e.g. Ginkgo biloba, Tilia spp, Equisetum spp, Moringa oleifera, Sophora japonica and propolis). Some epidemiological studies have found a positive association between the consumption of foods containing kaempferol and a reduced risk of developing several disorders such as cancer and cardiovascular diseases. Numerous preclinical studies have shown that kaempferol and some glycosides of kaempferol have a wide range of pharmacological activities, including antioxidant, anti-inflammatory, antimicrobial, anticancer, cardioprotective, neuroprotective, antidiabetic, anti-osteoporotic, estrogenic/antiestrogenic, anxiolytic, analgesic and antiallergic activities. In this article, the distribution of kaempferol in the plant kingdom and its pharmacological properties are reviewed. The pharmacokinetics (e.g. oral bioavailability, metabolism, plasma levels) and safety of kaempferol are also analyzed. This information may help understand the health benefits of kaempferol-containing plants and may contribute to develop this flavonoid as a possible agent for the prevention and treatment of some diseases.

A review on the dietary flavonoid kaempferol.

It has been shown recently that a flavonoid fraction (fraction II) obtained from a crude extract of Hypericum perforatum (St John's Wort) was remarkably active in the forced swimming test (FST) Fraction II was further separated using MLCCC to give fractions IIa and IIb Both fractions proved to be active in the FST at different dosages Further separation of fraction IIa by preparative HPLC yielded fraction IIa1 which mainly was composed of hyperoside, isoquercitrin, miquelianin and quercitrin, and fraction IIa2 which contained small amounts of hyperoside and astilbin, while most compounds were not known Both fractions were active after acute treatment in the FST Isolates obtained from these fractions including hyperoside, isoquercitrin, quercitrin, miquelianin, the aglycone quercetin and astilbin, were tested for activity in the FST Except for quercetin, quercitrin and astilbin all compounds were active To exclude false positive results in the FST the validity was checked in open field experiments and in the FST after 12 days of daily treatment

Flavonoids from Hypericum perforatum show antidepressant activity in the forced swimming test.

A commercially available extract of the aerial parts of Hypericum perforatum, LI 160, showed pronounced activity in selected animal bioassays. These include the forced swimming test (FST) and the tail suspension test, used to determine antidepressant activity, and tests indicating activity on the central nervous system, such as body temperature and ketamine induced sleeping time. The counteracting effects of drugs known to interfere with the central dopaminergic system strongly suggested that dopamine mediated activity is important for the activity of the extract. Dose-response experiments of the total extract and of fractions rich in flavonoids and napthodianthrones produced inverted U-shaped dose response curves.

Effects of the total extract and fractions of Hypericum perforatum in animal assays for antidepressant activity.

It has been shown recently that the fraction Ilk of acrude extract of Hypericum per foratum, (St. Johns wort) thatcontained both hypericin (1) and pseudohypericin (2), was re-markably active in the rats forced swimming test (FST) afterPorsolt. However, neither of the naphthodianthrones isolatedfrom this fraction were sufficiently effective when administeredsuspended in water. The solubility of 1 and 2 is remarkably in-creased in the presence of a fraction containing procyanidins, especially procyanidin B2, which is present also in the active Hy- pericum fraction Ilic. The cooperative effect of procyanidins sig-nificantly increased the in vivo effects of 1 and 2, which exhib-ited inverted U-shaped dose response curves, in the FST. Theanti-immobility effect of solubilized 1 and 2 was antagonizedby the dopamine antagonist sulpiride. These data indicate thatnaphthodianthrones are antidepressant constituents of H. per-foratum and suggest that the dopaminergic system is involvedin their action.Phytomedicines based on extracts from the herb of Hypericum

Solubilized hypericin and pseudohypericin from Hypericum perforatum exert antidepressant activity in the forced swimming test.

St. John's wort (Hypericum perforatum L., SJW) contains numerous compounds with documented biological activity. Constituents that have stimulated the most interest include the naphthodianthrones hypericin and pseudohypericin, a broad range of flavonoids, and the phloroglucinols hyperforin and adhyperforin. According to the actual state of scientific knowledge the total extract has to be considered as the active substance. Although there are some open questions, the bulk of data suggests that several groups of active compounds are contributing to the antidepressant efficacy of the plant extract.

St. John's wort: role of active compounds for its mechanism of action and efficacy.

Kidney stone formation or urolithiasis is a complex process that results from a succession of several physicochemical events including supersaturation, nucleation, growth, aggregation, and retention within the kidneys. Epidemiological data have shown that calcium oxalate is the predominant mineral in a majority of kidney stones. Among the treatments used are extracorporeal shock wave lithotripsy (ESWL) and drug treatment. Even improved and besides the high cost that imposes, compelling data now suggest that exposure to shock waves in therapeutic doses may cause acute renal injury, decrease in renal function and an increase in stone recurrence. In addition, persistent residual stone fragments and the possibility of infection after ESWL represent a serious problem in the treatment of stones. Furthermore, in spite of substantial progress in the study of the biological and physical manifestations of kidney stones, there is no satisfactory drug to use in clinical therapy. Data from IN VITRO, IN VIVO and clinical trials reveal that phytotherapeutic agents could be useful as either an alternative or an adjunctive therapy in the management of urolithiasis. The present review therefore critically evaluates the potential usefulness of herbal medicines in the management of urolithiasis.

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Veronika Butterweck

Papers

Flavonoids from Hypericum perforatum show antidepressant activity in the forced swimming test.

Effects of the total extract and fractions of Hypericum perforatum in animal assays for antidepressant activity.

Solubilized hypericin and pseudohypericin from Hypericum perforatum exert antidepressant activity in the forced swimming test.

St. John's wort: role of active compounds for its mechanism of action and efficacy.

Herbal Medicines in the Management of Urolithiasis: Alternative or Complementary?