Soy isoflavones and their relationship with microflora: beneficial effects on human health in equol producers

The bioavailability of soy isoflavones depends on the composition of the microflora for each subject. Bacteria act on different isoflavones with increased or reduced absorption and cause biotransformation of these compounds into metabolites with higher biological activity. S-equol is the most important metabolite and only 25–65 % of the population have the microflora that produces this compound. The presence of equol-producing bacteria in soy product consumers means that the consumption of such products for prolonged periods leads to lower cardiovascular risk, reduced incidence of prostate and breast cancer, and greater relief from symptoms related to the menopause such as hot flushes and osteoporosis

Clovamide and its derivatives as bioactive phenolic compounds of plant origin

W pracy przedstawiono aktualne dane dotyczące aktywności biologicznej klowamidu i jego pochodnych, jako grupy bioaktywnych związków pochodzenia roślinnego. Klowamid jest pochodną kwasu kawowego o strukturze chemicznej podobnej do kwasu rozmarynowego. Właściwości biologiczne pochodnych klowamidu stanowią stosunkowo nowe zagadnienie w naukach o żywności. Wzrasta jednak zainteresowanie naukowców tą grupą substancji. Źródłem klowamidu i jego pochodnych w diecie człowieka są produkty zawierające kakao. Poza kakaowcem (Theobroma cacao) związki te są wytwarzane m.in. przez koniczyny Trifolium pallidum (brak polskiej nazwy) i Trifolium pratense (koniczyna łąkowa), a także rośliny z rodzaju Capsicum (papryka). W literaturze dotyczącej klowamidu i jego pochodnych wskazuje się na ich działanie przeciwutleniające, przeciwpłytkowe (przeciwzakrzepowe), przeciwzapalne, a nawet przeciwnowotworowe. Sugeruje się, że klowamid i jego pochodne mogą być w przyszłości wykorzystane w przemyśle spożywczym, jak również w opracowaniu nowych strategii profilaktycznych i leczniczych chroniących zdrowie człowieka.In the paper, there are presented up to date data on the biological activity of clovamide and its derivatives as a group of bioactive compounds of plant origin. Clovamide is a derivative of caffeic acid and its chemical structure is similar to that of the rosmarinic acid. Biological properties of the clovamide-type compounds are a relatively new issue in the biological and medicinal sciences. However, scientists show a growing interest in that group of substances. In the human diet, products containing cocoa are a source of clovamide and its derivatives. In addition to Theobroma cacao, those compounds are also synthesized, among other things, by Trifolium pallidum clover and Trifolium pratense (red clover), and species of the Capsicum genus. The reference literature on clovamide and its derivatives points to their antioxodative, antiplatelet (antithrombotic), anti-inflammatory, and even anticancer action. It is suggested that, in the future, those properties might be utilized in the food and cosmetic industry as well as when developing new prophylactic and therapeutic strategies to protect human health

Antioxidant activity of caffeic acid and its derivatives

Kwas kawowy jest przedstawicielem kwasów hydroksycynamonowych, stanowiących podgrupę kwasów fenolowych. Syntetyzowany jest przez rośliny jako wtórny metabolit i występuje w postaci pochodnych, takich jak: glikozydy, amidy i estry. Najliczniejszą i najlepiej poznaną grupą pochodnych kwasu kawowego są estry utworzone z kwasem chinowym (kwas chlorogenowy), α-hydroksydihydrokawowym (kwas rozmarynowy) i winowym (kwas kawoilowinowy) oraz ester fenetylowy kwasu kawowego (CAPE). Związki te występują w wielu owocach i warzywach, stąd są naturalnymi składnikami diety. Kwas kawowy oraz jego naturalne pochodne i syntetyczne analogi są silnymi przeciwutleniaczami, które już w niewielkich stężeniach chronią komórki przed stresem oksydacyjnym. W wielu układach doświadczalnych wykazano, że kwas kawowy i jego pochodne skutecznie usuwają reaktywne formy tlenu (RFT) i syntetyczne rodniki, chelatują jony metali oraz wpływają na zahamowanie peroksydacji lipidów. Na szczególną uwagę zasługuje CAPE, wykazujący najsilniejszą aktywność przeciwutleniającą.Caffeic acid is one of the hydroxycinnamic acids, a subgroup of natural phenolic acids. It is synthesized by plants as a secondary metabolite and it naturally occurs in the form of derivatives, such as glycosides, amides, and esters. The largest and best-characterized group of caffeic acid derivatives are its esters formed with chinic (chlorogenic), α-hydroxydihydrocaffeic (rosmarinic), and tartaric (caffeoyltartaric) acids as well as caffeic acid phenethyl ester (CAPE). Those compounds are present in a variety of fruits and vegetables, thus, they are natural components of the diet. Caffeic acid, its natural derivatives, and synthetic analogues are potent antioxidants, which, even in low concentrations, protect cells from oxidativem stress. It was proved in many experimental systems that the caffeic acid and its derivatives effectively scavenge reactive oxygen species (ROS), chelate metal ions, and have an inhibiting effect on lipid peroxidation. CAPE deserves particular attention since it shows the strongest antioxidant activity

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Combination of doxorubicin (DOX) and docetaxel (DTX) is clinically effective against many drug-refractory cancers, nevertheless, enhanced side effects, e.g. cardiotoxicity related to oxidative damage of tissue macromolecules is observed. Nitroxides represent an attractive class of synthetic compounds to ameliorate DOX-DTX toxicity in nontargeted tissues due to their antioxidant and iron-oxidizing properties. The aim of the study was to define the ability of 3-carbamoylpyrroline nitroxyl derivative pirolin (PL) to mitigate oxidative damage to blood plasma proteins and lipids induced by DOX-DTX chemotherapy in Sprague-Dawley rats bearing DMBA-induced mammary tumor. Additionally we also evaluated: i) pro-oxidant and antioxidant activity of pirolin administered as a single agent according to different regimens and ii) differences in biomarkers of the oxidative stress between healthy rats and rats with DMBA-induced mammary tumors. The extent of oxidative stress was evaluated on the basis of its foremost biomarkers: thiol and carbonyl groups, lipid peroxidation products (hydroperoxides, TBARS), activity of antioxidant defense enzyme superoxide dismutase (SOD) and non-enzymatic antioxidant capacity (NEAC). We have found that pirolin alone displayed dual, antioxidant and pro-oxidant activity depending on the regimen of treatment. Daily treatment for 2 weeks increased the amount of thiols, and decreased the protein carbonyl groups. Three administrations of pirolin at 3-week intervals did not influence thiol content but increased hydroperoxides, TBARS and carbonyl groups. Chemotherapy employing DOX-DTX combination caused considerable oxidative stress in the plasma. Significant and dose-dependent oxidative damage to lipids and proteins with concomitant thiol depletion were evident in treated animals. Drugs also increased SOD activity and NEAC. Association of pirolin with DOX-DTX chemotherapy resulted in a partial amelioration of oxidative stress generated by anticancer drugs. This study indicates that a nitroxyl compound pirolin applied as a single agent in vivo can display both antioxidant and pro-oxidant properties but in conjunction with DOX-DTX it is able to protect partially blood plasma against oxidative stress generated by chemotherapy. The outcome, however, seems to be highly dependent on the ratio between the doses of employed anticancer drugs and the nitroxide. K e y w o r d s : chemotherapy, docetaxel, doxorubicin, nitroxide, pirolin, oxidative stress, superoxide dismutase, reactive oxygen specie