Green tea possesses antioxidant, anti-inflammatory, anticancer, and antimicrobial activities, reduces body weight, and slows down aging. These effects are primarily attributed to catechins contained in green tea leaves, particularly epigallocatechin-3-gallate. However, in humans, the realization of green tea’s beneficial effects is limited. In order to summarize and critically analyze the available scientific information about green tea’s health benefits and issues related to its use, we conducted an in-depth literature review in scientific databases. A number of in vitro studies reported that green tea catechins modulate various signaling pathways in cells, which is thought to underlie their beneficial effects. However, data on the effects of catechins in humans are scarce, which is partly due to their low stability and oral bioavailability. Furthermore, catechins may also participate in pharmacokinetic interactions when co-administered with certain drugs such as anticancer agents, drugs for cardiovascular diseases, immunosuppressors, etc. As a result, adverse drug reactions or therapy failure may occur. In conclusion, over the years, various approaches have been investigated to optimize catechin intake and to achieve beneficial effects in humans, but to date, the use of catechins for prophylaxis or disease treatment remains limited. Therefore, future studies regarding the possibilities of catechins administration are needed.

Green tea is one of the most consumed beverages globally. It is very popular due to its specific taste, energizing effect and some health benefits related mainly to the catechins content. Green tea catechins possess antioxidant, anticancer, anti-inflammatory and antimicrobial activity as well as reduce body weight. One of the major and well-studied effects of green tea catechins is their antioxidant effect. However, long-term administration of high doses of antioxidants may result in a pro-oxidant effect and promote cell damage. Therefore, beneficial effects of green tea are directly related to the administered dose of catechins. But it should be noted that consumption of large quantities of green tea beverages or administration of high doses of green tea catechins does not guarantee health benefits and may even lead to adverse effects. This review provides a comprehensive overview of the current knowledge of the antioxidant and pro-oxidant activity of green tea catechins as well as research gaps that require further investigation. In conclusion, despite green tea antioxidant potential, further research is needed to fully understand the benefits and risks associated with the consumption of green tea beverages as well as green tea catechins in different forms and doses.

Knowing the superior biochemical defense mechanisms of sessile organisms, it is not hard to believe the cure for any human sickness might be hidden in nature—we “just” have to identify it and make it safely available in the right dose to our organs and cells that are in need. For decades, green tea catechins (GTCs) have been a case in point. Because of their low redox potential and favorable positioning of hydroxyl groups, these flavonoid representatives (namely, catechin—C, epicatechin—EC, epicatechin gallate—ECG, epigallocatechin—EGC, epigallocatechin gallate—EGCG) are among the most potent plant-derived (and not only) antioxidants. The proven anti-inflammatory, neuroprotective, antimicrobial, and anticarcinogenic properties of these phytochemicals further contribute to their favorable pharmacological profile. Doubtlessly, GTCs hold the potential to “cope” with the majority of today‘s socially significant diseases, yet their mass use in clinical practice is still limited. Several factors related to the compounds’ membrane penetrability, chemical stability, and solubility overall determine their low bioavailability. Moreover, the antioxidant-to-pro-oxidant transitioning behavior of GTCs is highly conditional and, to a certain degree, unpredictable. The nanoparticulate delivery systems represent a logical approach to overcoming one or more of these therapeutic challenges. This review particularly focuses on the lipid-based nanotechnologies known to be a leading choice when it comes to drug permeation enhancement and not drug release modification nor drug stabilization solely. It is our goal to present the privileges of encapsulating green tea catechins in either vesicular or particulate lipid carriers with respect to the increasingly popular trends of advanced phytotherapy and functional nutrition.

Amanita muscaria (L.) Lam., commonly known as fly agaric, remains an uncommon yet clinically important cause of acute mushroom intoxication. Although typically associated with mild to moderate neuropsychiatric disturbances, the mushroom’s toxic profile is highly variable and continues to attract scientific, toxicological, and public health interest. This work provides an integrative review of the biochemical composition, toxicodynamics, and clinical manifestations associated with A. muscaria exposure, with particular emphasis on the pharmacological actions of its principal constituents, ibotenic acid and muscimol. The review is complemented by two contemporaneous cases of severe intoxication in elderly individuals, illustrating the real-world clinical expression of the toxidrome and the challenges in diagnosis and management. Both cases presented with rapid-onset gastrointestinal symptoms, profound central nervous system depression, and cholinergic features, requiring intensive supportive therapy, atropine infusion, and continuous monitoring. Full recovery was achieved in both patients. These clinical observations contextualize the broader toxicological framework discussed in the review and underscore the need for increased clinical vigilance, improved public education, and strengthened diagnostic and therapeutic preparedness regarding psychoactive wild mushroom exposures.

Background: The pharmacological characterization of Bancha green tea requires a preliminary establishment of its phytochemical composition. Objective: The aim of the present study was to develop a simple, sensitive, and environmentally friendly HPLC-UV procedure for the simultaneous quantification of caffeine, (+)-catechin, epigallocatechin gallate and gallic acid in different Bancha green tea isolates. Methods: The chromatographic separation of the four phytochemicals was performed on a Hypersil GOLD aQ column with a mobile phase consisting of acetonitrile/acetic acid/bi-distilled water (8:1:91 v/v/v), in an isocratic mode of elution. The suitability of the proposed procedure was verified by achieved satisfying linearity and specificity. Results: The method was also assessed as accurate and precise, with the obtained limits of quantification of caffeine, (+)-catechin, epigallocatechin gallate, and gallic acid of 0.01, 0.30, 0.50 and 0.03 μg/mL, respectively. As it was expected, the analytical procedure approbation showed the highest epigallocatechin gallate content (16.78 % ± 0.54) in the catechin fraction. On the other hand, the amount of caffeine and epigallocatechin gallate in the total plant extract was almost the same (4.19 % ± 0.14 and 4.12 % ± 0.44, respectively). Conclusion: A reliable HPLC-UV method for phytochemical characterisation of Bancha green tea extracts has been developed. The conducted quantitate assay could be used as a basis for subsequent pharmacological in vivo and in vitro studies of Bancha green tea.

Doxorubicin is an anthracycline antibiotic that is used for the treatment of various types of cancer. However, its clinical usage is limited due to its potential life‐threatening adverse effects, such as cardio‐ and nephrotoxicities. Nonetheless, simultaneous administration of doxorubicin and antioxidants, such as those found in green tea leaves, could reduce cardiac and renal tissue damage caused by oxidative stress. The methylxanthine fraction isolated from Bancha tea leaves were tested in vitro for its antioxidant activity and in vivo for its organoprotective properties against doxorubicin‐induced cardio‐ and nephrotoxicities in a rat model. The in vivo study was conducted on male Wistar rats divided into 6 groups. Methylxanthines were administered at high (5 mg/kg body weight) and low (1 mg/kg body weight) doses, while doxorubicin was administered at a cumulative dose of 20 mg/kg body weight. Serum creatinine, uric acid, and urea concentrations, as well as serum enzyme levels (creatinine kinase (CK), creatinine kinase MB fraction (CK‐MB), aspartate aminotransferase (AST), and lactate dehydrogenase (LDH)) and electrolytes (Na⁺, K⁺, and Cl^-), were analysed. In addition, histological analysis was performed to assess cardiac and renal tissue damage. The concomitant administration of Bancha methylxanthines and doxorubicin showed a dose‐dependent reduction in the serum biochemical parameters, indicating a decrease in the cardiac and renal tissue damage caused by the antibiotic. Histological analysis showed that pretreatment with methylxanthines at the dose of 5 mg/kg resulted in an almost normal myocardial structure and a significant decrease in the morphological kidney changes caused by doxorubicin exposure compared with the group that received doxorubicin alone. The putative mechanism is most likely related to a reduction in the oxidative stress caused by doxorubicin.