Myocardial protection by propolis during prolonged hypothermic preservation

Hypothermic and cryogenic preservation of cardiac tissue-engineered constructs

Cardiac tissue engineering (cTE) has already advanced towards the first clinical trials, investigating safety and feasibility of cTE construct transplantation in failing hearts. However, the lack of well-established preservation methods poses a hindrance to further scalability, commercialization, and transportation, thereby reducing their clinical implementation. In this study, hypothermic preservation (4 °C) and two methods for cryopreservation (i.e., a slow and fast cooling approach to -196 °C and -150 °C, respectively) were investigated as potential solutions to extend the cTE construct implantation window. The cTE model used consisted of human induced pluripotent stem cell-derived cardiomyocytes and human cardiac fibroblasts embedded in a natural-derived hydrogel and supported by a polymeric melt electrowritten hexagonal scaffold. Constructs, composed of cardiomyocytes of different maturity, were preserved for three days, using several commercially available preservation protocols and solutions. Cardiomyocyte viability, function (beat rate and calcium handling), and metabolic activity were investigated after rewarming. Our observations show that cardiomyocytes' age did not influence post-rewarming viability, however, it influenced construct function. Hypothermic preservation with HypoThermosol® ensured cardiomyocyte viability and function. Furthermore, fast freezing outperformed slow freezing, but both viability and function were severely reduced after rewarming. In conclusion, whereas long-term preservation remains a challenge, hypothermic preservation with HypoThermosol® represents a promising solution for cTE construct short-term preservation and potential transportation, aiding in off-the-shelf availability, ultimately increasing their clinical applicability.

Mini-encyclopedia of mitochondria-relevant nutraceuticals protecting health in primary and secondary care-clinically relevant 3PM innovation

Despite their subordination in humans, to a great extent, mitochondria maintain their independent status but tightly cooperate with the "host" on protecting the joint life quality and minimizing health risks. Under oxidative stress conditions, healthy mitochondria promptly increase mitophagy level to remove damaged "fellows" rejuvenating the mitochondrial population and sending fragments of mtDNA as SOS signals to all systems in the human body. As long as metabolic pathways are under systemic control and well-concerted together, adaptive mechanisms become triggered increasing systemic protection, activating antioxidant defense and repair machinery. Contextually, all attributes of mitochondrial patho-/physiology are instrumental for predictive medical approach and cost-effective treatments tailored to individualized patient profiles in primary (to protect vulnerable individuals again the health-to-disease transition) and secondary (to protect affected individuals again disease progression) care. Nutraceuticals are naturally occurring bioactive compounds demonstrating health-promoting, illness-preventing, and other health-related benefits. Keeping in mind health-promoting properties of nutraceuticals along with their great therapeutic potential and safety profile, there is a permanently growing demand on the application of mitochondria-relevant nutraceuticals. Application of nutraceuticals is beneficial only if meeting needs at individual level. Therefore, health risk assessment and creation of individualized patient profiles are of pivotal importance followed by adapted nutraceutical sets meeting individual needs. Based on the scientific evidence available for mitochondria-relevant nutraceuticals, this article presents examples of frequent medical conditions, which require protective measures targeted on mitochondria as a holistic approach following advanced concepts of predictive, preventive, and personalized medicine (PPPM/3PM) in primary and secondary care.

Insights into the physico-chemical and biological characterization of sodium lignosulfonate - silver nanosystems designed for wound management

Chronic wounds represent one of the complications that might occur from the disruption of wound healing process. Recently, there has been a rise in interest in employing nanotechnology to develop novel strategies for accelerating wound healing. The aim of the present study was to use a green synthesis method to obtain AgNPs/NaLS systems useful for wounds management and perform an in-depth investigation of their behavior during and post-synthesis as well as of their biological properties. The colloids obtained from silver nanoparticles (AgNPs) and commercial sodium lignosulfonate (NaLS) in a single-pot aqueous procedure have been fully characterized by UV-Vis, FT-IR, DLS, TEM, XRD, and XPS to evaluate the synthesis efficiency and to provide new insights in the process of AgNPs formation and NaLS behavior in aqueous solutions. The effects of various concentrations of NaLS (0-16 mg/mL) and AgNO3 (0-20 mM) and of two different temperatures on AgNPs formation have been analyzed. Although the room temperature is feasible for AgNPs synthesis, the short mixing at 70 °C significantly increases the speed of nanoparticle formation and storage stability. In all experimental conditions AgNPs of 20-40 nm in size have been obtained. The antimicrobial activity assessed quantitatively on clinical and reference bacterial strains, both in suspension and biofilm growth state, revealed a broad antimicrobial spectrum, the most intensive inhibitory effect being noticed against Pseudomonas aeruginosa and Escherichia coli strains. The AgNP/NaLS enhanced the NO extracellular release, potentially contributing to the microbicidal and anti-adherence activity by protein oxidation. Both AgNP/NaLS and NaLS were non-hemolytic (hemolytic index<5%, 2.26 ± 0.13% hemolysis) and biocompatible (102.17 ± 3.43 % HaCaT cells viability). The presence of AgNPs increased the antioxidative activity and induced a significant cytotoxicity on non-melanoma skin cancer cells (62.86 ± 8.27% Cal-27 cells viability). Taken together, all these features suggest the multivalent potential of these colloids for the development of novel strategies for wound management, acting by preventing infection-associated complications and supporting the tissue regeneration.

Improved cardioprotective effect of 3-nitro-N-methyl salicylamide solution after a prolonged preservation time of rat heart

Ischemic reperfusion injury, caused by oxidative stress during reperfusion, is an inevitable outcome of organ transplantation, especially when the organ preservation time is prolonged. Prolonged ischaemic preservation is a valuable technique for improving the success of organ transplantation, but numerous challenges remain. 3-nitro-N-methyl salicylamide (3-NNMS), an inhibitor of mitochondrial electron transport chain complex III, can be used to reduce reactive oxygen species production during blood reperfusion by slowing the electron flow rate of the respiratory chain. Based on this property, a novel preservation solution was developed for the preservation of isolated rat heart and its cardioprotective effect was investigated during an 8-h cold ischaemia preservation time for the first time. For comparison, 3-NNMS was also included in the histidine-tryptophan-ketoglutarate (HTK) solution. Compared to HTK, HTK supplemented with 3-NNMS significantly improved the heart rate of isolated rat hearts after 8 h of cold storage. Both 3-NNMS solution and HTK supplemented with 3-NNMS solution decreased cardiac troponin T and lactate dehydrogenase levels in perfusion fluid and reduced reactive oxygen species and malondialdehyde levels in the myocardium. The 3-NNMS also maintained the membrane potential of myocardial mitochondria and significantly increased superoxide dismutase levels. These results showed that the new 3-NNMS solution can protect mitochondrial and cardiomyocyte function by increasing antioxidant capacity and reducing oxidative stress in cryopreserved rat hearts during a prolonged preservation time, resulting in less myocardial injury and better heart rate.

Ameliorative effects of propolis upon reproductive toxicity in males

Propolis is a sticky natural product produced by honeybees. Research studies have discussed the effectiveness of propolis, directly or indirectly, for ameliorating reproductive toxicity in males; however, this research has not yet been reviewed. The current paper presents an integrative summary of all research studies in Scopus and PubMed that investigated the effects of propolis on semen quality, and hence on male fertility, in conditions of reproductive toxicity. The consensus indicates that propolis ameliorates reproductive toxicity and enhances semen quality in vivo in test animals. These effects may be attributable to the ability of propolis to reduce testicular oxidative damage, enhance testicular antioxidant defense mechanisms, increase nitric oxide production, reduce testicular apoptotic injury, and boost testosterone production. However, to generalize these effects in humans would require further research.

Enhancement of the Antioxidant Capacity of Thyme and Chestnut Honey by Addition of Bee Products

Honey consumption and imports have increased in recent years, and it is considered by consumers to be a healthy alternative to more commonly used sweeteners. Honey contains a mixture of polyphenols and antioxidant compounds, and the botanical origin and geographical area of collection play an important role on its chemical composition. The present study investigated the physicochemical properties, total phenolic content and antioxidant capacity of Spanish thyme honey and chestnut honey, and their mixtures with royal jelly (2% and 10%) and propolis (2% and 10%). The analysis of the physicochemical parameters of both honey samples showed values within the established limits. Propolis showed the highest value of total phenolic content (17.21–266.83 mg GAE/100 g) and antioxidant capacity (DPPH, ORAC and ABTS assays; 0.63–24.10 µg eq. Tx/g, 1.61–40.82 µg eq. Tx/g and 1.89–68.54 µg eq. Tx/g, respectively), and significantly reduced ROS production in human hepatoma cells. In addition, mixtures of honey with 10% of propolis improved the results obtained with natural honey, increasing the value of total phenolic content and antioxidant capacity. A significant positive correlation was observed between total phenolic compounds and antioxidant capacity. Therefore, the antioxidant capacity could be attributed to the phenolic compounds present in the samples, at least partially. In conclusion, our results indicated that thyme and chestnut honey supplemented with propolis can be an excellent natural source of antioxidants and could be incorporated as a potential food ingredient with biological properties of technological interest, added as a preservative. Moreover, these mixtures could be used as natural sweeteners enriched in antioxidants and other bioactive compounds.

Can a Short-term Daily Oral Administration of Propolis Improve Muscle Fatigue and Recovery?

This study investigated the effect of 1-week oral administration of propolis on muscle fatigue and recovery after performing a fatigue task (total 100 maximal voluntary concentric knee extension repetitions). In this placebo-controlled, double-blind study, 18 young men consumed a formulation with high Brazilian green propolis dose (H-BGP), a formulation with low Brazilian green propolis dose, or a placebo, for 1 week before performing the fatigue task (an interval between each intervention: 1-2 weeks). Maximal voluntary contraction torque, central fatigue (voluntary activation and root mean square values of the surface electromyography amplitude), and peripheral fatigue (potentiated triplet torque) were assessed before, immediately after, and 2 minutes after the fatigue task. Maximal voluntary contraction torque decreased immediately after the fatigue task in all conditions (P<0.001); however, it recovered from immediately after to 2 minutes after the fatigue task only in the H-BGP condition (P<0.001). Furthermore, there was a significant decrease in voluntary activation (P<0.001) and root mean square values of the surface electromyography amplitude (P≤0.035) only in the placebo condition. No significant difference was observed in the time-course change in potentiated triplet torque between the conditions. These results suggest that oral administration of propolis promotes muscle fatigue recovery by reducing central fatigue.

The effect of propolis on 5-fluorouracil-induced cardiac toxicity in rats

5-Fluorouracil (5-FU) is one of the most common chemotherapeutic agents used in treating solid tumors, and the 5-FU-induced cardiotoxicity is the second cause of cardiotoxicity induced by chemotherapeutic drugs. Propolis (Pro) has vigorous anti-inflammatory activity. Its cardio-protective characteristic against doxorubicin-induced cardiotoxicity was previously proven. The current study aimed to appraise the effect of Pro on 5-FU-induced cardiotoxicity in rats. Twenty-four male Wistar rats were divided into four groups: Control, 5-FU, 5-FU + Pro 250 mg/kg, and 5-FU + Colchicine (CLC) 5 mg/kg. Different hematological, serological, biochemical, histopathological, and molecular assays were performed to assess the study’s aim. Moreover, a rat myocardium (H9C2(2–1)) cell line was also used to assess this protective effect in-vitro. 5-FU resulted in significant cardiotoxicity represented by an increase in malondialdehyde (MDA) levels, cyclooxygenase-2 (COX-2) and tumor necrosis factor-α (TNF-α) expression, cardiac enzyme levels, and histopathological degenerations. 5-FU treatment also decreased bodyweight, total anti-oxidant capacity (TAC), catalase (CAT) levels, blood cell counts, and hemoglobin (Hb) levels. In addition, 5-FU disrupted ECG parameters, including increased elevation in the ST-segment and increased QRS complex and QTc duration. Treating with Pro reduced oxidative stress, cardiac enzymes, histopathological degenerations, and COX-2 expression in cardiac tissue alleviated ECG disturbances and increased the number of blood cells and TAC levels. Moreover, 5-FU-induced bodyweight loss was ameliorated after treatment with Pro. Our results demonstrated that treatment with Pro significantly improved cardiotoxicity induced by 5-FU in rats.

Tanshinone IIA attenuates renal injury during hypothermic preservation via the MEK/ERK1/2/GSK-3β pathway

Background

Oxidative stress-induced injury during hypothermic preservation is a universal problem that delays graft function and decrease the success of organ transplantation. Tanshinone IIA (Tan IIA) was reported to exhibit a variety of biochemical activities, including protection against oxidative stress. Therefore, the specific molecular pathway by which Tan IIA protects renal tissues during preservation was investigated in this study.

Methods

In vivo study, Sprague-Dawley (SD) rats were divided into twelve groups and the kidneys were isolated and preserved in different solutions for 0, 24 or 48 h, respectively: control group (Celsior solution) and Tan II groups (Celsior solution containing 10, 50,100 μM). In vitro study, primary renal cell from SD rats was cultured which was treated H₂O₂ (800 μM) for 6 h to mimic oxidative stress injury. Four groups were finally divided: control group; H₂O₂ group; H₂O₂ + Tan IIA group; H₂O₂ + Tan IIA + G15 group.

Results

In present study, we demonstrate data indicating that a significant increase in the superoxide dismutase (SOD) activity and a decrease in the reactive oxygen species (ROS) content were observed in the kidneys and renal cells preserved with Tan IIA compared with those preserved with the Celsior solution alone after 24 h and 48 h of hypothermic preservation (P < 0.01). The expression of phosphorylated mitogen-activated protein kinase kinase (MEK), phosphorylated extracellular signal-regulated protein kinases 1/2 (ERK1/2), phosphorylated glycogen synthase kinase-3β (GSK-3β) and cleaved caspase-3 was lower in the kidneys and renal cells preserved with Tan IIA than in those preserved with the Celsior solution alone after 24 h and 48 h of hypothermic preservation (P < 0.01). The mitochondrial morphology was rescued and adenosine triphophate (ATP) production and mitochondrial membrane potential were increased in the Tan IIA groups. Finally, Tan IIA also decreased cell apoptosis.

Conclusion

It suggests that the supplementation of the standard Celsior solution with Tan IIA may significantly improve long-term kidney preservation. Tan IIA attenuated oxidative stress injury and decreased apoptosis levels via activation of the MEK/ERK1/2/GSK-3β signaling pathway during kidney hypothermic preservation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12906-021-03427-7.

A Roadmap to Cardiac Tissue-Engineered Construct Preservation: Insights from Cells, Tissues, and Organs

Worldwide, over 26 million patients suffer from heart failure (HF). One strategy aspiring to prevent or even to reverse HF is based on the transplantation of cardiac tissue-engineered (cTE) constructs. These patient-specific constructs aim to closely resemble the native myocardium and, upon implantation on the diseased tissue, support and restore cardiac function, thereby preventing the development of HF. However, cTE constructs off-the-shelf availability in the clinical arena critically depends on the development of efficient preservation methodologies. Short- and long-term preservation of cTE constructs would enable transportation and direct availability. Herein, currently available methods, from normothermic- to hypothermic- to cryopreservation, for the preservation of cardiomyocytes, whole-heart, and regenerative materials are reviewed. A theoretical foundation and recommendations for future research on developing cTE construct specific preservation methods are provided. Current research suggests that vitrification can be a promising procedure to ensure long-term cryopreservation of cTE constructs, despite the need of high doses of cytotoxic cryoprotective agents. Instead, short-term cTE construct preservation can be achieved at normothermic or hypothermic temperatures by administration of protective additives. With further tuning of these promising methods, it is anticipated that cTE construct therapy can be brought one step closer to the patient.

Chemical and biological characteristics of propolis from Apis mellifera caucasica from the Ardahan and Erzurum provinces of Turkey: a comparative study

The aim of this study was to compare the biological activities of ethanolic propolis extracts of Apis mellifera caucasica obtained from Ardahan and Erzurum provinces of Turkey. Samples were tested for antioxidant, anticytotoxic, anticarcinogenic, antibacterial, and antifungal potentials using different techniques. Propolis samples from the two provinces had different mineral and organic compositions related to their geographical origin. The ferric reducing antioxidant power (FRAP) test showed superiority of Ardahan propolis over the Erzurum. Regardless of origin and the presence of mitomycin C in the culture medium, propolis enhanced human peripheral lymphocyte viability, which depended on the duration and propolis concentration. Antiperoxidative activity on MCF-7 breast cancer cells was concentration-dependent. Erzurum propolis showed the highest anticarcinogenic activity at the concentrations of 62.5 μg/mL and 125 μg/ mL, which dropped at higher concentrations. All propolis samples also showed antibacterial activity against the tested human pathogens similar to ampicillin and penicillin controls, except for Pseudomonas aeruginosa. However, they did not exert any antifungal activity against Candida albicans and Yarrowia lipolytica. In conclusion, propolis samples from both provinces showed promising biological activities, but further research should focus on finding the right concentrations for optimal effect and include the cell necrosis pathway to get a better idea of the anticarcinogenic effects.

Remedying the Mitochondria to Cure Human Diseases by Natural Products

Mitochondria are the ‘engine' of cells. Mitochondrial dysfunction is an important mechanism in many human diseases. Many natural products could remedy the mitochondria to alleviate mitochondria-involved diseases. In this review, we summarized the current knowledge of the relationship between the mitochondria and human diseases and the regulation of natural products to the mitochondria. We proposed that the development of mitochondrial regulators/nutrients from natural products to remedy mitochondrial dysfunction represents an attractive strategy for a mitochondria-involved disorder therapy. Moreover, investigating the mitochondrial regulation of natural products can potentiate the in-depth comprehension of the mechanism of action of natural products.