Stability of Rosmarinic Acid and Flavonoid Glycosides in Liquid Forms of Herbal Medicinal Products-A Preliminary Study.

Peppermint leaf, sage leaf, thyme herb, and their preparations are common components of herbal medicinal products (HMPs). According to the European Pharmacopoeia guidelines, the above-mentioned plant substances are standardized for the content of essential oils, omitting polyphenols, which also have a significant impact on their activities. The aim of this study was to evaluate the stability of the predominant polyphenols-rosmarinic acid, luteolin-7-O-ß-glucuronide, and eriocitrin-in selected commercial liquid HMPs containing thyme, sage, and peppermint under long-term, intermediate, and accelerated testing conditions. Qualitative and quantitative analyses of these polyphenols were performed by the previously optimized and validated HPLC-DAD method. Rosmarinic acid stability was better in hydroethanolic than in an aqueous solution. The effect of the solvent on the stability of luteolin-7-O-ß-glucuronide and eriocitrin could not be determined and requires further investigation. The present study is the first to analyze the stability of these compounds in commercial herbal medicinal products. The expiration dates proposed by the manufacturers of the tested HMPs did not guarantee stable levels of all analyzed polyphenols throughout the stated period. However, this study is preliminary and requires continuation on a larger number of medicinal products.

Thymol and Thyme Essential Oil-New Insights into Selected Therapeutic Applications.

Thymol (2-isopropyl-5-methylphenol) belongs to the phenolic monoterpenes and mostly occurs in thyme species. It is one of the main compounds of thyme essential oil. Both thymol and thyme essential oil have long been used in traditional medicine as expectorant, anti-inflammatory, antiviral, antibacterial, and antiseptic agents, mainly in the treatment of the upper respiratory system. The current search for new directions of biological or therapeutic activities of natural plant substances with known structures includes thyme essential oil and thymol. Novel studies have demonstrated their antibiofilm, antifungal, antileishmanial, antiviral, and anticancer properties. Also, their new therapeutic formulations, such as nanocapsules containing these constituents, can be beneficial in medicinal practice and create opportunities for their extensive use. Extensive application of thymol and thyme essential oil in the healthcare sector is very promising but requires further research and analysis.

Analysis of Polyphenolic Composition of a Herbal Medicinal Product-Peppermint Tincture.

The pharmacological activity of peppermint leaf (Menthae piperitae folium) for medical use is mainly attributed to the presence of essential oil, which, according to the European Pharmacopoeia (Ph. Eur.), should constitute not less than 12 mL/kg of raw material. The content of polyphenols in peppermint-based preparations, except peppermint leaf dry extract, has not yet been considered as an essential parameter in the pharmacopeial assessment of peppermint quality. This study concerns the evaluation of the presence of representatives of polyphenolic compounds in 23 commercial peppermint tinctures (ethanolic extracts) purchased in pharmacies in Poland. The non-volatile polyphenolic fraction was investigated, and the presence of flavonoids and phenolic acids was quantified. High performance liquid chromatography coupled with a diode-array detector (HPLC-DAD) and an electrospray ionization mass spectrometer (U(H)PLC-ESI-MS) were used in the experiment. The study showed that eriocitrin, luteolin-7-O-rutinoside, and rosmarinic acid were the main polyphenolic components of the peppermint tinctures, as previously reported for peppermint leaf. Despite this, the research shows the extremely diverse content of the mentioned compounds in analyzed commercial medicinal products. In light of these results, it seems that the pharmacopeial assessment for the peppermint leaf (Ph. Eur.) and peppermint tincture (Polish Pharmacopoeia (FP)) requires correction and supplementation.

Insights into novel anticancer applications for apigenin.

Flavonoids, naturally occuring derivatives of 2-phenyl-benzo-γ-pyrone, are widespread in plants as coloring substances. Apigenin (4',5,7,-trihydroxyflavone (5,7-dihydroxy-2-(4-hydroxyphenyl)-4H-1-benzopyran-4-one), molecular formula C15H10O5, is a flavonoid present in many fruits and vegetables, primarily in citrus fruits, apples, parsley and celery leaves. It is also found in some medicinal plants, including chamomile flowers, thyme, oregano, peppermint, lemon balm and yarrow, as a 7-O-glycoside with anti-inflammatory and antioxidant activity. In recent years it has attracted a great deal of interest as a bioactive substance reported to have anticancer properties. According to recent literature data, apigenin is able to reduce cancer cell glucose uptake, inhibit remodeling of the extracellular matrix, inhibit cell adhesion molecules that participate in cancer progression and hinder the development of blood vessels needed by growing tumors. It is reported to protect against a wide variety of cancers. The mechanism of anticancer activity is still under investigation and further research is needed.

CURCUMA LONGA AS MEDICINAL HERB IN THE TREATMENT OF DIABET- IC COMPLICATIONS.

Curcuma longa L. (turmeric) of ginger family (Zingiberaceae) belongs to the group of oldest cultivated spice plants in the south-east Asian countries. For many years rhizome of this plant has been used also as a safe and active drug for the treatment of various.chronic diseases, especially of diabetes mellitus (DM). The active substance of turmeric - curcumin (diferuloylmethane), possesses multiple therapeutic properties. In recent years, many detailed research (tests in vito and in vivo) along with clinical trials have revealed its very valuable biological activities related to its anti-inflammatory, antioxidant and cancer preventive properties, which are presented in numerous publications (1-6). At the molecular level it has been stated that curcumin inhibits cell proliferation, metastasis creation and apoptosis. Currently, great attention has been focused on curcumin as a blocker of TNF-s, which are the principal mediators of most inflammation-related disturbances (7). The main cause of blocking the broadly extended pharmacological and clinical investigations of curcumin is its extremely low solubility in water and in organ fluids. This feature consequently limits its systemic bioavailability and makes use of curcumin as a therapeutic remedy (to date) difficult. The primary aim of presently conducted research is to achieve increased solubilization and bioavailability of this promising nontoxic agent.