No abstract

Sida rhombifolia L., popularly known in Brazil as "SIDA" or "mata-pasto", is considered a weed; a plant of the American continent and widely distributed in North Africa, belongs to the Malvaceae family. In Brazil, S. rhombifolia L. is scattered throughout the national territory, infesting agricultural crops. Certain species of the genus Sida, including S. rhombifolia, are widely used in Indian, Chinese, African and American medicine. The present study was carried out with the objective of evaluating the nonclinical acute toxicity of crude ethanolic extract (CEE) obtained from S. rhombifolia L. In treated males, there was a statistically significant reduction in water and feed intake. Biochemical analyzes showed statistically significant changes in the parameters of aspartate aminotransferase, alanine aminotransferase and creatinine; hematological parameters showed altered erythrocytes, mean corpuscular volume, mean corpuscular hemoglobin and eosinophil parameters; observed only in treated male animals. The animals' organs showed no significant changes. The results suggest that the ethanolic extract obtained from S. rhombifolia L. presents low acute dose toxicity. However, chronic toxicological studies should be performed to demonstrate the safety of long-term use of the drug.

Considering the relevance of natural products to the development of new drugs, this study focuses on the species Sida rhombifolia (L.), Malvaceae, widely used as a traditional remedy in several countries. The species is used to treat several diseases such as fevers, skin diseases, stomach pain, diarrhea, gum infection, conjunctivitis, urinary infections and inflammation. Many researchers around the word have investigated its pharmacological potential, and many uses have been confirmed. In spite of that, the phytochemical composition of its extracts is still poorly investigated. This research aims to make advances on the understanding of the constituents of S. rhombifolia identifying its alkaloidal compounds using ultra-high performance liquid chromatography coupled to mass spectrometry (UPLC-QTOF-MS/MS). By analyzing its alkaloidal fraction it was possible to identify: 11-cryptolepine carboxylic acid (1), cryptolepine (2), quindoline (3), 11-methoxyquidoline (4), quindolinone (5), cryptolepinone (6), and 11-quindoline methyl ester (7). The alkaloids 1 and 7 are being reported for the first time from Sida genus. Based on the antimicrobial potential of cryptolepinone-type alkaloids, we prepared by semi-synthesis two cryptolepinone derivatives: 10-methylcryptolepinone (8) and the unreported compound 10-ethylcryptolepinone (9). Both derivatives were tested against fungae and bacterial strains and 10-methylcryptolepinone (8) showed strong activity against Cryptococcus neoformans, Candida albicans, C. tropicalis, Aspergillus fumigatus and A. flavus.

Problems in the female reproductive system appear at the beginning of the reproductive cycle and persist until hormonal regulation in menopause. The drug therapies currently used can cause intolerance and susceptibility to other diseases, making it important to search for alternative therapeutic approaches that can be adopted during your reproductive life. Women use several species of plants to treat reproductive disorders. Some species are rich in bioactive molecules, such as flavonoids. The present study evaluated the bioactive in silico profile of three flavonoids: tyroside (Kaempferol-3-O-β-D- (6 ”-Ep-coumaryl) glucopyranoside), Pg-1 (5,7-dihydroxy-3,8, 4'-trimethoxy) and vitexin (5,7,4'-trihydroxyflavone-8-C-β-glucopyranoside). The predictive antineoplastic action on organs of the female reproductive system and the protective activity against pathogens (protozoa, bacteria, fungi and viruses) were addressed. The study showed that vitexin had antiviral activity, tiliroside had a better index of antibacterial and antifungal activity and Pg-1 had antiprotozoal activity. The incidence of neoplasms in the female reproductive system is due to hormonal variation and injuries possibly caused by recurrent infections. Therefore, flavonoids, which are considered phytoestrogens, can regulate hormonal disorder and help fight pathogens. Pg-1 had a better breast, uterine and ovarian anticancer potential, while tiliroside had a greater anticancer effect on the cervical region. Vitexin, despite its lower potential compared to other substances, also demonstrated satisfactory breast and cervical cancer activity. Therefore, these molecules can become important candidates for natural drugs with antimicrobial and anticancer activity, contributing to the use of non-synthetic products.

Phenolic compounds have been related to several beneficial effects on health. Most of them are due the antioxidant activity played by these natural occurring substances. The phenolic compounds are able to inhibit the formation of free radicals, which can induce oxidative damage to cell biomolecules, being related to the etiology of several diseases. Many compounds from secondary metabolism of plants can play relevant role in human health preventing cell oxidative damage. The present study was carried out with the vegetal specie PavoniaglaziovianaGürke (Malvaceae), known as "malva-da-chapada" and "tampa-cabaça". Chemotaxonomic studies on the family indicated that its species are great producers of phenolic substances, such as phenolic acids, flavonoids, tannins and coumarins. From the species P. glazioviana the isolation of flavonoids has already been reported. The present aimed to quantify the total phenolic content in the ethanolic extract of P. glazioviana as well as to evaluate the antioxidant potential of the studied species. For this purpose, the dried aerial parts of the plant were extracted with ethanol, followed by evaporation of the solvent in a rotary evaporator. In order to quantify the total phenolic content in the obtained extract, the Folin-Ciocalteau spectrophotometric method was carried out. The DPPH (2,2-diphenyl-1-picrylhydrazyl) free radical scavenger method was used to evaluate its antioxidant activity. After analysis, the obtained result was 48.4 mg of EAG/g of ethanolic extract of the species. In the evaluation of the antioxidant activity, the EC50 found was 6.36 mg/mL ± 0.02921. The obtained results indicated that the specie P. glazioviana produces SciForum high content of phenolic substances and presents interesting antioxidant activity, being higher than other species of Malvaceaepreviously analyzed.