Alzheimer’s and Parkinson’s diseases are considered the most common neurodegenerative disorders, representing a major focus of neuroscience research to understanding the cellular alterations and pathophysiological mechanisms involved. Several natural products, including flavonoids, are considered able to cross the blood‐brain barrier and are known for their central nervous system‐related activity. Therefore, studies are being conducted with these chemical constituents to analyze their activities in slowing down the progression of neurodegenerative diseases. The present systematic review summarizes the pharmacological effects of flavonoids in animal models for Alzheimer’s and Parkinson’s diseases. A PRISMA model for systematic review was utilized for this search. The research was conducted in the following databases: PubMed, Web of Science, BIREME, and Science Direct. Based on the inclusion criteria, 31 articles were selected and discussed in this review. The studies listed revealed that the main targets of action for Alzheimer’s disease therapy were reduction of reactive oxygen species and amyloid beta‐protein production, while for Parkinson’s disease reduction of the cellular oxidative potential and the activation of mechanisms of neuronal death. Results showed that a variety of flavonoids is being studied and can be promising for the development of new drugs to treat neurodegenerative diseases. Moreover, it was possible to verify that there is a lack of translational research and clinical evidence of these promising compounds.

Inflammatory diseases result from the body’s response to tissue damage, and if the resolution is not adequate or the stimulus persists, there will be progression from acute inflammation to chronic inflammation, leading to the development of cancer and neurodegenerative and autoimmune diseases. Due to the complexity of events that occur in inflammation associated with the adverse effects of drugs used in clinical practice, it is necessary to search for new biologically active compounds with anti‐inflammatory activity. Among natural products, essential oils (EOs) present promising results in preclinical studies, with action in the main mechanisms involved in the pathology of inflammation. The present systematic review summarizes the pharmacological effects of EOs and their compounds in in vitro and in vivo models for inflammation. The research was conducted in the following databases: PubMed, Scopus, BIREME, Scielo, Open Grey, and Science Direct. Based on the inclusion criteria, 30 articles were selected and discussed in this review. The studies listed revealed a potential activity of EOs and their compounds for the treatment of inflammatory diseases, especially in chronic inflammatory conditions, with the main mechanism involving reduction of reactive oxygen and nitrogen species associated with an elevation of antioxidant enzymes as well as the reduction of the nuclear factor kappa B (NF‐κB), reducing the expression of proinflammatory cytokines. Thus, this review suggests that EOs and their major compounds are promising tools for the treatment of chronic inflammation.

Spondias tuberosa is a plant that produces a fruit crop with high economic relevance at Brazilian Caatinga. Its roots and leaves are used in folk medicine. Chemical composition of a hexane extract from S. tuberosa leaves was evaluated by thin-layer chromatography (TLC), high-performance liquid chromatography (HPLC) and 1H nuclear magnetic resonance (NMR). Antioxidant potential was investigated by DPPH and ABTS assays. Antifungal action on Candida species was evaluated determining the minimal inhibitory concentration (MIC50) and putative mechanisms were determined by flow cytometry analysis. In addition, hemolytic activity on human erythrocytes was assessed and the concentration required to promote 50% hemolysis (EC50) was determined. Phytochemical analysis by TLC showed the presence of flavonoids, hydrolysable tannins, saponins and terpenes. The HPLC profile of the extract suggested the presence of gallic acid (0.28 ± 0.01 g%) and hyperoside (1.27 ± 0.01 g%). The representative 1H NMR spectrum showed saturated and unsaturated fatty acids among the main components. The extract showed weak and moderate antioxidant activity in DPPH (IC50: 234.00 μg/mL) and ABTS (IC50: 123.33 μg/mL) assays, respectively. It was able to inhibit the growth of C. albicans and C. glabrata with MIC50 of 2.0 and 0.078 mg/mL, respectively. The treatment of C. glabrata cells with the extract increased levels of mitochondrial superoxide anion, caused hyperpolarization of mitochondrial membrane, and compromised the lysosomal membrane. Weak hemolytic activity (EC50: 740.8 μg/mL) was detected. The results demonstrate the pharmacological potential of the extract as antioxidant and antifungal agent, aggregating biotechnological value to this plant and stimulating its conservation.

In this study, the phytochemical profile of extracts from the flowers of Bromelia laciniosa was characterized. The total phenolic and flavonoids contents were determined and the antioxidant and photoprotective activities were evaluated using in vitro assays. Phytochemical analysis demonstrated that the extracts were found to be positive for the presence of anthracene derivatives, anthraquinones, coumarins, flavonoids and tannins, lignans, mono and diterpenes. The ethanol extract (Bl-EtOH) presented the most significant total phenolic content (53.75 ± 1.25 mg GAE/g). The dichloromethane extract (Bl-CH₂Cl₂) showed the highest flavonoid content (46.06 ± 1.18 mg CE/g). The methanol extract (Bl-MeOH) was the most effective extract in the DPPH (2,2-diphenyl-1-picrylhydrazil) assay (EC₅₀ 141.90 ± 3.01 μg/mL). Bl-EtOH and Bl-MeOH showed higher sun protection factor at a concentration of 100 mg/L (3.38 ± 0.04 and 3.78 ± 0.11, respectively). Therefore, the extracts proved to be interesting for the development of new studies aiming their incorporation into photoprotective cosmetic formulations.

In Brazil, the leather industry is an important economic segment moving around U$ 3 billions of dollars a year. However, high amounts of water are requested to transform skin animals into leather, causing high wastewater amounts to be consequently produced. A major problem is attached to the presence of chromium in the wastewater from the tanning process. Chromium is a heavy metal potentially toxic both to the environment and to the human health. In order to control the levels of chrome dumped into the environment, Brazilian agencies require the treatment of effluents by the generating source. Thus, this study aimed to develop an alternative method to the removal of chromium in wastewater from the leather industry using the Opuntia ficus-indica biomass as eco-friendly biosorbent. Crude waste samples were collected in a tannery stabilization pond for chromium quantification and further treatments. The powdered Opuntia ficus-indica was obtained from species collected in Pernambuco, Brazil, and its physical parameters and pHPCZ were characterized. Adsorptions studies and acute toxicity were also carried out. The biomass remaining after the sorption was analyzed through scanning electron microscopy and Fourier-transform infrared spectroscopy. The chromium content was above the limit allowed by the Brazilian regulatory agency. In sorption studies, biomass was able to remove 74.8% and 84.88% of Cr (III) using 2.0 g and 4.0 g of biomass, respectively. The surface of biomass is very favorable to biosorption and the chemical bindings among oxygen atoms present in the chemical components of this biomass and the heavy metal was confirmed through infrared spectrum. This study proved that Opuntia ficus-indica is effectively biosorbent to chromium, promising and with low costs for the leather industry, able to reduce its ecotoxicity as proven by chemical and biological assays.

The antioxidant and photoprotective activities of dried extracts from the leaves of Encholirium spectabile were investigated. It was also evaluated the total phenolic and flavonoid contents by the Folin-Ciocalteu and aluminum chloride methods, respectively. Antioxidant activities of the extracts were evaluated by using of 2,2-diphenyl-1-picrylhydrazil (DPPH) radical scavenging and β-carotene-linoleic acid bleaching and compared with ascorbic acid, butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) used as reference compounds. The photoprotective effect was evaluated by the spectrophotometric method. The most significant total phenolic and flavonoid contents was of 188.50 ± 27.50 mg of gallic acid equivalent/g and 129.70 ± 4.59 mg of catechin equivalent/g, respectively, for chloroform fraction (Es-CHCl3). The Es-CHCl3 also presented the best antioxidant activity (IC50 25.35 ± 4.35 μg/ml) for DPPH scavenging. The ethanol extract (Es-EtOH), Es-CHCl3 and the fraction ethyl acetate (Es-AcOEt) showed characteristic absorption bands in regions UVB and UVA in a concentration-dependent manner. Es-CHCl3 presented the highest sun protection factor SPF (8.89 ± 2.11). It shows the possibility to use this extract as sunscreen in pharmaceutical preparations.