Bioactives of Melipona rufiventris Propolis: Exploring its Antimicrobial, Anti-Inflammatory, and Antioxidant Activities.

This study explores the potential of propolis, a resinous substance produced by bees, from Melipona rufiventris species. With its composition encompassing resin, wax, pollen, and soil, propolis holds historical significance in traditional medicine within tropical regions. This research is driven by the scarcity of information surrounding M. rufiventris propolis, prompting an investigation into its chemical constituents, in vivo toxicity, and antimicrobial, antioxidant, and anti-inflammatory properties. This exploration could potentially uncover novel applications for this natural product, bolstering both meliponiculture practices and the preservation of native bee populations. The propolis was sampled in Cabo Verde-MG and underwent ethanolic extraction to yield an extract (EEP) for analysis. Chemical assessments (Folin-Ciocalteau, and UHPLC-HRMS) revealed the presence of polyphenols, including flavonoids. The EEP demonstrated higher antimicrobial activity against Gram-positive bacteria and exhibited efficacy against multiresistant strains isolated from complex wounds. Synergistic interactions with commercial antibiotics were also observed. Furthermore, anti-inflammatory evaluations showcased the EEP's potential in reducing NF-kB activation and TNF-α release at non-toxic concentrations. Despite these promising biological activities, the EEP exhibited no antiproliferative effects and demonstrated safety in both the MTS assay and the G. mellonella model. Collectively, these findings highlight the M. rufiventris propolis extract as a valuable reservoir of bioactive compounds with multifaceted potential.

Casearin D inhibits ERK phosphorylation and induces downregulation of cyclin D1 in HepG2 cells.

Cancer is a public health problem which represents the second cause of death in the world. In this framework, it is necessary to identify novel compounds with antineoplastic potential. Plants are an important source for discovering novel compounds with pharmacological potential. In this study, we aimed to investigate the antiproliferative potential of isolated compounds from Casearia sylvestris on tumor cell lines. Crude extract effectively reduced cell viability of 4 tumor cell lines (HepG2, A549, U251-MG, and HT-144) after 48h treatment. HepG2 and HT-144 were the most responsive cells. Three fractions (aqueous ethanol, n-hexane and ethyl acetate) were tested against HepG2 and HT-144 cells and we observed that compounds with antiproliferative activity were concentrated in n-hexane and ethyl acetate fractions. The casearins A, G and J were isolated from n-hexane fraction, while casearin D was obtained from ethyl acetate fraction. We demonstrated that casearin D significantly inhibited the clonogenic capacity of HepG2 cells after 24h exposure indicating its antiproliferative activity. In addition, G1/S transition cell cycle arrest in HepG2 cells was also observed. These effects are related, at least in part, to ability of the casearin D in reducing ERK phosphorylation and cyclin D1 expression levels.

Alkaloids derived from flowers of Senna spectabilis, (-)-cassine and (-)-spectaline, have antiproliferative activity on HepG2 cells for inducing cell cycle arrest in G1/S transition through ERK inactivation and downregulation of cyclin D1 expression.

Cancer is one of the most critical problems of public health in the world and one of the main challenges for medicine in this century. Unfortunately, most patients are diagnosed at advanced stage, when the treatment options are palliative. Consequently, the search for novel therapeutic options is imperative. In the context, the plants represent an important source for discovering of novel compounds with pharmacological potential including antineoplastic agents. Herein, we aimed to investigate in vitro antiproliferative and cytotoxic potentials of an alkaloid mixture derived from Senna spectabilis, (−)-cassine (1) and (−)-spectaline (2). These alkaloids reduced cell viability in a concentration-dependent manner of six tumor cell lines. From initial screening, HepG2 cells were selected for further investigations. We show that alkaloids 1/2 have an important antiproliferative activity on HepG2 cells due to their ability in inducing cell cycle arrest in G1/S transition. This effect was associated to ERK inactivation and down-regulation of cyclin D1 expression. In addition, we evidenced a disruption of the microfilaments and microtubules in a consequence of the treatment. Taken together, the data showed by the first time that alkaloids 1/2 strongly inhibit cell proliferation of hepatocellular carcinoma cells. Therefore, they represent promise antitumor compounds against liver cancer and should be considered for further anticancer in vivo studies.

Anticancer activity of 7-epiclusianone, a benzophenone from Garcinia brasiliensis, in glioblastoma.

BACKGROUND: Glioblastoma is the most common tumor of the central nervous system and one of the hardest tumors to treat. Consequently, the search for novel therapeutic options is imperative. 7-epiclusianone, a tetraprenylated benzophenone isolated from the epicarp of the native plant Garcinia brasiliensis, exhibits a range of biological activities but its prospect anticancer activity is underexplored. Thus, the aim of the present study was to evaluate the influence of 7-epiclusianone on proliferation, clonogenic capacity, cell cycle progression and induction of apoptosis in two glioblastoma cell lines (U251MG and U138MG). METHODS: Cell viability was measured by the MTS assay; for the clonogenic assay, colonies were stained with Giemsa and counted by direct visual inspection; For cell cycle analysis, cells were stained with propidium iodide and analyzed by cytometry; Cyclin A expression was determined by immunoblotting; Apoptotic cell death was determined by annexin V fluorescein isothiocyanate labeling and Caspase-3 activity in living cells. RESULTS: Viability of both cell lines was drastically inhibited; moreover, the colony formation capacity was significantly reduced, demonstrating long-term effects even after removal of the drug. 7-epiclusianone treatment at low concentrations also altered cell cycle progression, decreased the S and G2/M populations and at higher concentrations increased the number of cells at sub-G1, in concordance with the increase of apoptotic cells. CONCLUSION: The present study demonstrates for the first time the anticancer potential of 7-epiclusianone against glioblastoma cells, thus meriting its further investigation as a potential therapeutic agent.

7-Epiclusianone, a Benzophenone Extracted from Garcinia brasiliensis (Clusiaceae), Induces Cell Cycle Arrest in G1/S Transition in A549 Cells.

Lung cancer is the leading cause of cancer deaths in the world. Disease stage is the most relevant factor influencing mortality. Unfortunately, most patients are still diagnosed at an advanced stage and their five-year survival rate is only 4%. Thus, it is relevant to identify novel drugs that can improve the treatment options for lung cancer. Natural products have been an important source for the discovery of new compounds with pharmacological potential including antineoplastic agents. We have previously isolated a prenylated benzophenone (7-epiclusianone) from Garcinia brasiliensis (Clusiaceae) that has several biological properties including antiproliferative activity against cancer cell lines. In continuation with our studies, the present work aimed to investigate the mechanisms involved with antiproliferative activity of 7-epiclusianone in A549 cells. Our data showed that 7-epiclusianone reduced the viability of A549 cells in a concentration-dependent manner (IC50 of 16.13 ± 1.12 µM). Cells were arrested in G1/S transition and apoptosis was induced. In addition, we observed morphological changes with cytoskeleton disorganization in consequence of the treatment. Taken together, the results showed that cell cycle arrest in G1/S transition is the main mechanism involved with antiproliferative activity of 7-epiclusianone. Our results are promising and open up the prospect of using this compound in further anticancer in vivo studies.