Recent advances and insights into bromelain processing, pharmacokinetics and therapeutic uses

Bromelain is a mixture of proteolytic enzymes that is extracted primarily from pineapples. It is present in almost all the aerial parts of the plant—the peels, leaves, stems and fruit—although only the fruit and stems contain significant amounts. The market-demand for bromelain is quickly increasing, especially in the health sector as it can be used as a drug and/or nutraceutical. Although the complete molecular mechanism has not been fully identified, bromelain possesses several properties, including anti-inflammatory, anti-oedema, antithrombotic and fibrinolytic, mucolytic, anticancer and cicatrizing effects that have been evaluated in several clinical trials. However, one of the main limitations for the clinical use of this supplement is the varying composition of extracts, which leads to heterogeneity in results and, therefore, difficulty in making evidence-based prescriptions. In fact, different geographic locations, land and modes of cultivation, as well as extraction methods, can all give extracts with different activities, depending on the plant part used. Additionally, although novel extraction techniques have been developed to improve bromelain purification and extraction and give higher yields without loss in enzymatic activity, these methods are still expensive and challenging. This review will describe the state of the art in the main conventional and unconventional extraction and purification methods of bromelain and discuss the advantages and limitations of these strategies. Pharmacokinetic and pharmacodynamic profiles and the clinical applications that have arisen from randomized controlled clinical trials are also discussed. Finally, future perspectives for bromelain extracts will be presented

Towards a metabolomic approach to investigate iron-sulfur cluster biogenesis

Iron–sulfur clusters are prosthetic groups that are assembled on their acceptor proteins through a complex machine centered on a desulfurase enzyme and a transient scaffold protein. Studies to establish the mechanism of cluster formation have so far used either in vitro or in vivo methods, which have often resulted in contrasting or non‐comparable results. We suggest, here, an alternative approach to study the enzymatic reaction, that is based on the combination of genetically engineered bacterial strains depleted of specific components, and the detection of the enzymatic kinetics in cellular extracts through metabolomics. Our data prove that this ex vivo approach closely reproduces the in vitro results while retaining the full complexity of the system. We demonstrate that co‐presence of bacterial frataxin and iron is necessary to observe an inhibitory effect of the enzymatic activity of bacterial frataxin. Our approach provides a new powerful tool for the study of iron–sulfur cluster biogenesis

On the regulation of human D‐aspartate oxidase

The human flavoenzyme D-aspartate oxidase (hDASPO) controls the level of D-aspartate in the brain, a molecule acting as an agonist of NMDA receptors and modulator of AMPA and mGlu5 receptors. hDASPO-induced D-aspartate degradation prevents age-dependent deterioration of brain functions and is related to psychiatric disorders such as schizophrenia and autism. Notwithstanding this crucial role, less is known about hDASPO regulation. Here, we report that hDASPO is nitrosylated in vitro, while no evidence of sulfhydration and phosphorylation is apparent: nitrosylation affects the activity of the human flavoenzyme to a limited extent. Furthermore, hDASPO interacts with the primate-specific protein pLG72 (a well-known negative chaperone of D-amino acid oxidase, the enzyme deputed to D-serine degradation in the human brain), yielding a similar to 114 kDa complex, with a micromolar dissociation constant, promoting the flavoenzyme inactivation. At the cellular level, pLG72 and hDASPO generate a cytosolic complex: the expression of pLG72 negatively affects the hDASPO level by reducing its half-life. We propose that pLG72 binding may represent a protective mechanism aimed at avoiding cytotoxicity due to H2O2 produced by the hDASPO enzymatic degradation of D-aspartate, especially before the final targeting to peroxisomes

Towards the abandonment of surgical castration in pigs: How is immunocastration perceived by Italian consumers?

Immunocastration of pigs represents an alternative method to surgical castration, being more respectful of animal welfare. However, this new technology may not be accepted by consumers due to their perception of possible risks tied to the use of the product, thus representing a concern for the production sector. The study aimed at verifying the attitude of Italian consumers towards immunocastration and to assess whether their perception can be affected by science-based information on advantages and disadvantages of immunocastration. A total of 969 consumers (divided in three groups representative of the Italian population) were contacted and asked to complete an online questionnaire. Only technical (neutral) information on immunocastration was provided to the first group; the second and the third group received information on the advantages (+) and disadvantages (-) of the technique, shown in reverse order (+/- and -/+, respectively). The level of information did not affect consumers\u2019 perception of immunocastration. Overall, immunocastration is perceived in a predominantly positive manner (54.5%), with a relatively low level of risk perception (34.2%), and a good willingness to pay more for meat deriving from immunocastrated pigs (+18.7%)

Non-Alcoholic Fatty Liver Disease: From Pathogenesis to Clinical Impact

Non-Alcoholic Fatty Liver Disease (NAFLD) is caused by the accumulation of fat in over 5% of hepatocytes in the absence of alcohol consumption. NAFLD is considered the hepatic manifestation of metabolic syndrome (MS). Recently, an expert consensus suggested as more appropriate the term MAFLD (metabolic-associated fatty liver disease). Insulin resistance (IR) plays a key role in the development of NAFLD, as it causes an increase in hepatic lipogenesis and an inhibition of adipose tissue lipolysis. Beyond the imbalance of adipokine levels, the increase in the mass of visceral adipose tissue also determines an increase in free fatty acid (FFA) levels. In turn, an excess of FFA is able to determine IR through the inhibition of the post-receptor insulin signal. Adipocytes secrete chemokines, which are able to enroll macrophages inside the adipose tissue, responsible, in turn, for the increased levels of TNF-. The latter, as well as resistin and other pro-inflammatory cytokines such as IL-6, enhances insulin resistance and correlates with endothelial dysfunction and an increased cardiovascular (CV) risk. In this review, the role of diet, intestinal microbiota, genetic and epigenetic factors, low-degree chronic systemic inflammation, mitochondrial dysfunction, and endoplasmic reticulum stress on NAFLD have been addressed. Finally, the clinical impact of NAFLD on cardiovascular and renal outcomes, and its direct link with type 2 diabetes have been discussed

Circulating miRNA-195-5p and -451a in Patients with Acute Hemorrhagic Stroke in Emergency Department

(1) Background: In our previous study, acute ischemic stroke (AIS) patients showed increased levels of circulating miRNAs (-195-5p and -451a) involved in vascular endothelial growth factor A (VEGF-A) regulation. Here, we evaluated, for the first time, both circulating miRNAs in acute intracerebral hemorrhagic (ICH) patients. (2) Methods: Circulating miRNAs and serum VEGF-A were assessed by real-time PCR and ELISA in 20 acute ICH, 21 AIS patients, and 21 controls. These were evaluated at hospital admission (T0) and after 96 h (T96) from admission. (3) Results: At T0, circulating miRNAs were five-times up-regulated in AIS patients, tending to decrease at T96. By contrast, in the acute ICH group, circulating miRNAs were significantly increased at both T0 and T96. Moreover, a significant decrease was observed in serum VEGF-A levels at T0 in AIS patients, tending to increase at T96. Conversely, in acute ICH patients, the levels of VEGF-A were significantly decreased at both T0 and T96. (4) Conclusions: The absence of a reduction in circulating miRNAs (195-5p and -451a), reported in acute ICH subjects after 96 h from hospital admission, together with the absence of increment of serum VEGF-A, may represent useful biomarkers indicating the severe brain damage status that characterizes acute ICH patients