Cucurbitacins are a wide group of natural products found in several plant families, especially in the Cucurbitaceae family. In the last decade, there has been a significant increase in studies aimed at identifying new biological activities of cucurbitacins and describing their mechanisms of action. The most researched pharmacological activities are antineoplastic and anti-inflammatory activity, the first being recently reviewed. The present review explains the anti-inflammatory, antioxidant, and immunomodulatory potential of cucurbitacins, identifying the most studied compounds in this area and exploring their mechanisms of action already studied. A brief report was made about the main structural characteristics of cucurbitacins, in addition to an update on the biological activities attributed to this class in the last 5 years. Cucurbitacin B and cucurbitacin E have been identified as the most investigated when it comes to the immune response, playing roles in both innate and adaptive immunity. The most cited mechanisms were inhibition of COX-2 and NOS, reduction of oxidative stress, suppression of proinflammatory cytokines and modulation of acquired immunity proteins. It was found that cucurbitacins are promising molecules in the search for therapeutic innovation and have wide versatility in the immune response.

Context The emergence of resistant pathogens and toxicity of antifungals have encouraged an active search for novel candidates to manage Candida biofilms. Objective In this study, the little known species Sideroxylon obtusifolium T.D. Penn (Sapotacea) and Syzygium cumini (L.) Skeels (Myrtaceae), from the Caatinga biome in Brazil were chemically characterized and explored for their antifungal potential against C. albicans. Materials and methods We determined the effects of hydroalcoholic extracts/fractions upon fungal growth (minimum inhibitory and fungicidal concentrations, MIC/MFC), biofilm morphology (scanning electron microscopy) and viability (confocal laser scanning microscopy), proposed their mode of action (sorbitol and ergosterol assays), and finally investigated their effects against macrophage and keratinocyte cells in a cell-based assay. Data were analysed using one-way analysis of variance with Tukey-Kramer post-test (α = 0.05). Results The n-butanol (Nb) fraction from S. obtusifolium and S. cumini extract (Sc) showed flavonoids (39.11 ± 6.62 mg/g) and saponins (820.35 ± 225.38 mg/g), respectively, in their chemical composition and demonstrated antifungal activity, with MICs of 62.5 and 125 μg/mL, respectively. Nb and Sc may complex with ergosterol as there was a 4–16-fold increase in MICs in the presence of exogenous ergosterol, leading to disrupted permeability of cell membrane. Deleterious effects were observed on morphology and viability of treated biofilms from concentrations as low as their MICs and higher. Sc was not toxic to macrophages and keratinocytes at these concentrations (p > 0.05), unlike Nb. Conclusions Nb and Sc demonstrated considerable antifungal activity and should be further investigated as potential alternative candidates to treat Candida biofilms.

Aims The aim of this study was to find new eukaryotic sources of the l‐asparaginase (l‐ASNase), since the prokaryotic sources of the enzyme are well‐reported as causing allergic hypersensitivity reactions in a significant number of patients. This report describes screening for l‐ASNase production by filamentous fungi isolated from the Brazilian Caatinga, and the optimization of fermentation parameters to increase fungal growth and improve yield in the production of l‐ASNase. Methods and Results Thirty‐two filamentous fungi were investigated in this study. When Aspergillus terreus strain S‐18 was cultured in a proline‐enriched medium, intracellular l‐ASNase was expressed in concurrence with reduced l‐glutaminase (l‐GLUase) and protease activities. Fermentation conditions were then optimized in a 5‐l bioreactor system to produce a maximum volumetric yield of 108 U total of l‐ASNase activity. Conclusions The work reported here represents the first attempt to produce l‐ASNase by filamentous fungi isolated from Brazil and offers a promising alternative eukaryotic source for l‐ASNase production. Significance and Impact of the study In order to minimize the side effects caused by bacterial l‐ASNase, the search of eukaryotic micro‐organism for l‐ASNase was carried out in fungi. This study demonstrates the diversity of filamentous fungi isolated from the Brazilian Caatinga Biome and the importance of knowledge of the microbial metabolism to obtain high concentrations of biotechnological products.

Bacterial resistance refers to the ability of bacteria to resist the action of some antibiotics due to the development of adaptation and resistance mechanisms. It is a serious public health problem, especially for diseases caused by opportunistic bacteria. In this context, the search for new drugs, used alone or in combination, appears as an alternative for the treatment of microbial infections, and natural products, such as essential oils, are important in this process due to their structural diversity, which increases the probability for antimicrobial action. The objective of this study was to extract and identify the chemical components of the essential oil from Croton conduplicatus (EOCC), to evaluate the antimicrobial activity, to investigate the effect of the interaction between the EOCC and different antibiotics and to evaluate its antibiofilm potential. The EOCC was obtained by hydrodistillation. Based on chemical characterisation, 70 compounds were identified, with 1.8 cineole (13.15%), p-cymene (10.68%), caryophyllene (9.73%) and spathulenol (6.36%) being the major constituents. The minimum inhibitory concentration (MIC) values of EOCC were 256 and 512 µg mL⁻¹ for methicillin-sensitive and -resistant Staphylococcus aureus strains (MSSA and MRSA), respectively. The combinations of EOCC with the antibiotics oxacillin and ampicillin were synergistic (OXA/EOCC and AMP/EOCC combined decreased the OXA MIC and AMP MIC to 0.5 and 0.25 for MSSA, respectively, and OXA/EOCC and AMP/EOCC combined decreased the OXA MIC and the AMP MIC to 1 and 0.5 for MRSA, respectively) and could modify the resistance profile of MSSA and MRSA strains. The results indicated that EOCC was also able to partially inhibit biofilm formation. Our study presents important information about the chemical composition of EOCC and its antimicrobial potential and provides a reference to determine the mechanisms of action of EOCC and its use in pharmaceutical formulations.

Cellulose is among the top 5 excipients used in the pharmaceutical industry. It has been considered one of the main diluents used in conventional and modern dosage forms. Therefore, different raw materials of plant origin have been evaluated as potential alternative sources of cellulose. In this context, Opuntia ficus-indica L. Miller (palma forrageira), a plant of the cactus family that has physiological mechanisms that provide greater productivity with reduced water requirements, is an interesting and unexplored alternative for extracting cellulose. By using this source, we aim to decrease the extraction stages and increase the yields, which might result in a decreased cost for the industry and consequently for the consumer. The aim of this work was to investigate the use of Opuntia ficus-indica L. Miller as a new source for cellulose extraction, therefore providing an efficient, straight forward and low-cost method of cellulose II production. The extraction method is based on the oxidation of the lignins. The obtained cellulose was identified and characterized by spectroscopic methods (FTIR and NMR), X-ray diffraction, thermal analysis (TGA-DTG and DSC) and scanning electron microscopy. The results confirmed the identity of cellulose and its fibrous nature, which are promising characteristics for its use in the industry and a reasonable substrate for chemical modifications for the synthesis of cellulose II derivatives with different physicochemical properties that might be used in the production of drug delivery systems and biomaterials.