Therapeutic potential of medicinal plants indicated by the Brazilian public health system in treating the collateral effects induced by chemotherapy, radiotherapy, and chemoradiotherapy: A systematic review.

OBJECTIVE: This study, through a systematic review, evaluated the therapeutic effect of medicinal plants that were of interest to the Unified Health System (SUS) in treating the side effects induced by chemotherapy, radiotherapy and chemoradiotherapy in cancer patients. METHODOLOGY: According to the PRISMA guidelines, a systematic search was conducted in the PubMed, Lilacs and Scopus databases from January 2009 to December 2018, using the groups of descriptors (Cancer OR Neoplasia OR Tumor) and (controlled clinical trial OR randomized clinical trial) associated with the scientific names of the 71 medicinal plants described in RENISUS. The study is registered in PROSPERO CRD42019129927. RESULTS: Of the 29 articles selected, only 17 demonstrated the therapeutic potential of plants included in RENISUS to prevent or treat the side effects induced by chemotherapy, radiotherapy or chemoradiotherapy, either solely or through an adjuvant effect from drugs already used in the medical clinic. The two plant-based therapies that had the most studies exploring their therapeutic potential on side effects were Zingiber officinale and Aloe vera. CONCLUSION: This study showed that some plants listed in RENISUS have shown preventive and curative potential on side effects induced by conventional treatments in patients with different types of cancer. Therefore, the use of scientifically proven herbal products, in conjunction with conventional therapies, can contribute to a better quality of life in cancer patients undergoing conventional treatments.

Synthesis of Quercetin-Metal Complexes, In Vitro and In Silico Anticholinesterase and Antioxidant Evaluation, and In Vivo Toxicological and Anxiolitic Activities.

The level of acetylcholine, a neurotransmitter essential for processing memory and learning, is lower in the brains of patients with Alzheimer's disease due to the higher concentration of the enzyme acetylcholinesterase. The main compounds used for Alzheimer's treatment are acetylcholinesterase inhibitors. Quercetin coordination complexes with the metal ions Cu+2, Zn+2, Ni+2, Co+2, and Fe+2 were synthesized to investigate their potential use against Alzheimer's disease, by evaluating the inhibition of acetylcholinesterase in vitro and in silico, as well as the antioxidant activity, toxicity, and anxiolytic action in the zebrafish (Danio rerio) model. The organic complexes were characterized by UV-Vis and FT-IR. The spectral information suggested that coordination of metals occurs with the carbonyl group and OH linked to the C-3 carbon of quercetin. The quercetin-Fe (QFe) complex presented the best antioxidant and antiacetylcholinesterase actions, and these results were confirmed by molecular docking. In the toxicity and locomotor evaluation, the quercetin molecules and the synthesized complexes, mainly QCu and QZn derivatives, showed the highest degree of inhibition of the fish's locomotor activity, suggesting a possible anxiolytic action. Then, quercetin complexes with metals, mainly with Fe+2, represent valuable compounds and deserve more investigation as promising agents against Alzheimer's disease.