Betulin (Bet), the main component of birch tree bark, has been recently reported to exert anticancer activity in several cell lines; however the underlying mechanisms are only partially elucidated. The aims of the present work were to assess the in vivo effects of betulin administered as nanoemulsion (NE) in two experimental models: (i) the chicken embryo chorioallantoic membrane (CAM) assay for the study of anti-angiogenic effects and (ii) the two-stage model of skin carcinoma induced in mice for the study of anti-tumor and anti-inflammatory effects, respectively. On the CAM of the chicken betulin in nanoemulsion (BetNE) shows a good penetrability at extra-embryonic tissue level, affecting both the chorioallantoic membrane as well as the yolk sac by reducing the capillary density. In the animal model, the potential impact of local application of betulin on the respiratory function of isolated liver mitochondria was further assessed. Topical application of betulin nanoemulsion for 12 weeks together with DMBA (7,12-dimethylbenz[a]anthracene) and TPA (12-O-tetradecanoylphorbol 13-acetate), as tumor initiator and promoter, enhanced the active respiration of isolated liver mitochondria. Betulin also inhibit skin tumor apparition and promotion, proved by histological results and VEGF (vascular endothelial growth factor) expression correlated to non-invasive measurements. Betulin is active in nanoemulsion formulation as a potential inhibitory on the angiogenic process in CAM assay. BetNE can develop a potent anti-inflammatory and anti-carcinogenic activity with a low toxicity at skin level. It can also influence the penetration of carcinogens and reduce damage in main organs (e.g., liver).

Betulinic acid (BA), a natural compound with a lupan skeleton, has been highly investigated in the past decade for a plethora of beneficial properties, including anti-cancer, anti-inflammatory, anti-angiogenic, immune-modulatory, and anti-HIV effects. In particular, BA has been reported to be effective in vitro against tumor cell lines of different origins, and also in vivo, in animal models of cancer. The best characterized mechanism of its antitumor effect consists of triggering apoptosis via the mitochondrial pathway. BA has also an anti-metastatic effect via the prevention of the epithelial-to-mesencymal transition in highly aggressive melanoma cells. Furthermore, in the same model, BA is able to counteract the pro-invasive potential of the pro-tumoral protein neutrophil gelatinaseassociated lipocalin. The present review addresses the current state of knowledge regarding the anti-tumor effects of betulinic acid, a potent chemotherapeutic agent.

It is widely recognized that mitochondrial dysfunction is a key component of the multifactorial process of ageing. The effects of age on individual components of mitochondrial function vary across species and strains. In this study we investigated the oxygen consumption, the mitochondrial membrane potential (Δψ), the sensitivity of mitochondrial permeability transition pore (mPTP) to calcium overload, and the production of reactive oxygen species (ROS) in heart mitochondria isolated from old compared with adult healthy Sprague-Dawley rats. Respirometry studies and Δψ measurements were performed with an Oxygraph-2k equipped with a tetraphenylphosphonium electrode. ROS production and calcium retention capacity were measured spectrofluorimetrically. Our results show an important decline for all bioenergetic parameters for both complex I and complex II supported-respiration, a decreased Δψ in mitochondria energized with complex I substrates, and an increased mitochondrial ROS production in the old compared with the adult group. Mitochondrial sensitivity to Ca²⁺-induced mPTP opening was also increased in the old compared with the adult animals. Moreover, the protective effect of cyclosporine A on mPTP opening was significantly reduced in the old group. We conclude that healthy ageing is associated with a decrease in heart mitochondria function in Sprague-Dawley rats.

Betulinic acid (BA) exhibits antitumoral activity by blocking proliferation, invasion, and angiogenesis. However, the impact of BA on epithelial-to-mesenchymal transition (EMT), a hallmark of cancer metastasis induced among others by neutrophil gelatinase-associated lipocalin (NGAL), remains unknown. The present study aimed at determining the effect of BA on NGAL-induced EMT. In A375 melanoma cells, BA downregulated mesenchymal markers, increased epithelial markers, and inhibited cytoskeletal reorganization. In addition, BA limited endogenous NGAL production and further suppressed EMT induced by exogenously added NGAL and the corresponding invasive cellular phenotype. In conclusion, BA interferes with EMT-associated changes, a mechanism to antagonize invasive melanoma cells.

BackgroundThe compatibility study of active substances with excipients finds an important role in the domain of pharmaceutical research, being known the fact that final formulation is the one administered to the patient. In order to evaluate the compatibility between active substance and excipients, different analytical techniques can be used, based on their accuracy, reproducibility and fastness.ResultsCompatibility study of two well-known active substances, procaine and benzocaine, with four commonly used excipients, was carried out employing thermal analysis (TG/DTG/HF) and Fourier Transform Infrared Spectroscopy (UATR-FT-IR). The selected excipients were microcrystalline cellulose, lactose monohydrate, magnesium stearate and talc. Equal proportion of active substance and excipients (w/w) was utilized in the interaction study. The absolute value of the difference between the melting point peak of active substances and the one corresponding for the active substances in the analysed mixture, as well the absolute value of the difference between the enthalpy of the pure active ingredient melting peak and that of its melting peak in the different analysed mixtures were chosen as indexes of the drug-excipient interaction degree. All the results obtained through thermal analysis were also sustained by FT-IR spectroscopy.ConclusionsThe corroboration of data obtained by thermal analysis with the ones from FT-IR spectroscopy indicated that no interaction occurs between procaine and benzocaine, with microcrystalline cellulose and talc, as well for the benzocaine-lactose mixture. Interactions were confirmed between procaine and benzocaine respectively and magnesium stearate, and for procaine and lactose.