Therapeutic Efficacy of Natural Product 'C-Phycocyanin' in Alleviating Streptozotocin-Induced Diabetes via the Inhibition of Glycation Reaction in Rats

Phycocyanin attenuates skeletal muscle damage and fatigue via modulation of Nrf2 and IRS-1/AKT/mTOR pathway in exercise-induced oxidative stress in rats

Prolonged strenuous exercise induces oxidative stress, leading to oxidative damage, skeletal muscle fatigue, and reduced exercise performance. The body compensates for oxidative stress through antioxidant actions, while related enzymes alone may not overcome excessive oxidative stress during prolonged strenuous exercise. Phycocyanin is an important antioxidant supplement derived from blue-green algae, which may be helpful in this type of situation. This study determined the effects of phycocyanin on exercise performance from prolonged strenuous exercise. Forty Sprague Dawley male rats were divided into 5 groups (n = 8 /group); Control group (C), Exercise group (E), and Exercise with supplement groups receiving low dose (Phycocyanin = 100 mg/kg BW; ELP) and high dose (Phycocyanin = 200 mg/kg BW; EHP) or vitamin C (Vitamin C = 200 mg/kg BW; VC). Phycocyanin was found to decrease oxidative damage markers, muscle fatigue, and muscle atrophy through the activated AKT/mTOR pathway. This was also found to have greater increases in antioxidants via Nrf2 signaling and increases ATP synthesis, GLUT4 transporters, and insulin signaling due to increased IRS-1/AKT signaling. In conclusion, phycocyanin was found to reduce oxidative damage and muscle atrophy, including an increase in insulin signaling in skeletal muscles leading to increased exercise performance in rats.

Nutraceutical Features of the Phycobiliprotein C-Phycocyanin: Evidence from Arthrospira platensis (Spirulina)

Arthrospira platensis, commonly known as Spirulina, is a photosynthetic filamentous cyanobacterium (blue-green microalga) that has been utilized as a food source since ancient times. More recently, it has gained significant popularity as a dietary supplement due to its rich content of micro- and macro-nutrients. Of particular interest is a water soluble phycobiliprotein derived from Spirulina known as phycocyanin C (C-PC), which stands out as the most abundant protein in this cyanobacterium. C-PC is a fluorescent protein, with its chromophore represented by the tetrapyrrole molecule phycocyanobilin B (PCB-B). While C-PC is commonly employed in food for its coloring properties, it also serves as the molecular basis for numerous nutraceutical features associated with Spirulina. Indeed, the comprehensive C-PC, and to some extent, the isolated PCB-B, has been linked to various health-promoting effects. These benefits encompass conditions triggered by oxidative stress, inflammation, and other pathological conditions. The present review focuses on the bio-pharmacological properties of these molecules, positioning them as promising agents for potential new applications in the expanding nutraceutical market.

Phycocyanin alleviates alcohol-induced testicular injury in male Wistar rats

OBJECTIVE

Given the noteworthy implications of alcohol consumption and its association with male infertility, there has been a notable focus on investigating natural alternatives to mitigate its adverse effects. Thus, this study was conducted to assess the potential protective effect of phycocyanin extract derived from the blue algae Arthrospira (Spirulina) platensis against ethanol-induced oxidative stress, disturbances in testicular morphology, and alterations in sperm production.

METHODS

Male rats were divided into four groups (five rats each): the control group received a saline solution, the ethanol exposed group (EtOH) was subjected to intraperitoneal injections of 10 mL/kg of ethanol solution at a concentration of 38% (v/v), the phycocyanin alone treated group (P) received oral administration of phycocyanin at a dosage of 50 mg/kg, and the phycocyanin-cotreated group (PE) was given oral phycocyanin followed by ethanol injections. All treatments were administered over a period of 14 days.

RESULTS

Our findings demonstrated that ethanol exposure induced reproductive toxicity, characterized by reduced sperm production and viability, alterations in testicular weight and morphology, increased lipid peroxidation levels, and elevated oxidative enzyme activity. In addition, the ethanol-intoxicated group showed perturbations in serum biochemical parameters. However, the simultaneous exposure to ethanol and phycocyanin exhibited a counteractive effect against ethanol toxicity.

CONCLUSION

The results showed that supplementation of phycocyanin prevented oxidative and testicular morphological damage-induced by ethanol and maintained normal sperm production, and viability.

Anti-Glycation Properties of Zinc-Enriched Arthrospira platensis (Spirulina) Contribute to Prevention of Metaflammation in a Diet-Induced Obese Mouse Model

Advanced glycation end products (AGEs) exert a key pathogenic role in the development of obesity and insulin resistance. Thanks to its abundance in bioactive compounds, the microalga Arthrospira platensis (spirulina, SP) is proposed as a nutritional supplement. Here, we investigated the potential anti-glycating properties of SP enriched with zinc (Zn-SP) and the following impact on diet-induced metabolic derangements. Thirty male C57Bl6 mice were fed a standard diet (SD) or a high-fat high-sugar diet (HFHS) for 12 weeks, and a subgroup of HFHS mice received 350 mg/kg Zn-SP three times a week. A HFHS diet induced obesity and glucose intolerance and increased plasma levels of pro-inflammatory cytokines and transaminases. Zn-SP administration restored glucose homeostasis and reduced hepatic dysfunction and systemic inflammation. In the liver of HFHS mice, a robust accumulation of AGEs was detected, paralleled by increased expression of the main AGE receptor (RAGE) and depletion of glyoxalase-1, whereas Zn-SP administration efficiently prevented these alterations reducing local pro-inflammatory responses. 16S rRNA gene profiling of feces and ileum content revealed altered bacterial community structure in HFHS mice compared to both SD and HFHS + Zn-SP groups. Overall, our study demonstrates relevant anti-glycation properties of Zn-SP which contribute to preventing AGE production and/or stimulate AGE detoxification, leading to the improvement of diet-related dysbiosis and metabolic derangements.

Generation of autoantibodies against glycated fibrinogen: Role in diabetic nephropathy and retinopathy

The process of glycation, characterized by the non-enzymatic reaction between sugars and free amino groups on biomolecules, is a key contributor to the development and progression of both microvascular and macrovascular complications associated with diabetes, particularly due to persistent hyperglycemia. This glycation process gives rise to advanced glycation end products (AGEs), which play a central role in the pathophysiology of diabetes complications, including nephropathy. The d-ribose-mediated glycation of fibrinogen plays a central role in the pathogenesis of diabetes nephropathy (DN) and retinopathy (DR) by the generation and accumulation of advanced glycation end products (AGEs). Glycated fibrinogen with d-ribose (Rb-gly-Fb) induces structural changes that trigger an autoimmune response by generating and exposing neoepitopes on fibrinogen molecules. The present research is designed to investigate the prevalence of autoantibodies against Rb-gly-Fb in individuals with type 2 diabetes mellitus (T2DM), DN & DR. Direct binding ELISA was used to test the binding affinity of autoantibodies from patients' sera against Rb-gly-Fb and competitive ELISA was used to confirm the direct binding findings by checking the bindings of isolated IgG against Rb-gly-Fb and its native conformer. In comparison to healthy subjects, 32% of T2DM, 67% of DN and 57.85% of DR patients' samples demonstrated a strong binding affinity towards Rb-gly-Fb. Both native and Rb-gly-Fb binding by healthy subjects (HS) sera were non-significant (p > 0.05). Furthermore, the early, intermediate, and end products of glycation have been assessed through biochemical and physicochemical analysis. The biochemical markers in the patient groups were also significant (p < 0.05) in comparison to the HS group. This study not only establishes the prevalence of autoantibodies against d-ribose glycated fibrinogen in DN but also highlights the potential of glycated fibrinogen as a biomarker for the detection of DN and/or DR. These insights may open new avenues for research into novel therapeutic strategies and the prevention of diabetes-related nephropathy and retinopathy.

Communal interaction of glycation and gut microbes in diabetes mellitus, Alzheimer's disease, and Parkinson's disease pathogenesis

Diabetes and its complications, Alzheimer's disease (AD), and Parkinson's disease (PD) are increasing gradually, reflecting a global threat vis-à-vis expressing the essentiality of a substantial paradigm shift in research and remedial actions. Protein glycation is influenced by several factors, like time, temperature, pH, metal ions, and the half-life of the protein. Surprisingly, most proteins associated with metabolic and neurodegenerative disorders are generally long-lived and hence susceptible to glycation. Remarkably, proteins linked with diabetes, AD, and PD share this characteristic. This modulates protein's structure, aggregation tendency, and toxicity, highlighting renovated attention. Gut microbes and microbial metabolites marked their importance in human health and diseases. Though many scientific shreds of evidence are proposed for possible change and dysbiosis in gut flora in these diseases, very little is known about the mechanisms. Screening and unfolding their functionality in metabolic and neurodegenerative disorders is essential in hunting the gut treasure. Therefore, it is imperative to evaluate the role of glycation as a common link in diabetes and neurodegenerative diseases, which helps to clarify if modulation of nonenzymatic glycation may act as a beneficial therapeutic strategy and gut microbes/metabolites may answer some of the crucial questions. This review briefly emphasizes the common functional attributes of glycation and gut microbes, the possible linkages, and discusses current treatment options and therapeutic challenges.

Structure and Antidiabetic Activity of a Glycoprotein from Porphyra haitanensis

A novel antidiabetic glycoprotein (PG) was isolated and purified from Porphyra haitanensis, and its structure and inhibiting activity on α-amylase and α-glucosidase were analyzed. The purity of the PG was 95.29 ± 0.21%, and its molecular weight was 163.024 ± 5.55 kDa. The PG had a tetramer structure with α- and β-subunits, and it contained 54.12 ± 0.86% protein (with highly hydrophobic amino acids) and 41.19% ± 0.64% carbohydrate (composed of galactose). The PG was linked via an O-glycosidic bond, exhibiting an α-helical structure and high stability. In addition, the PG inhibited the activities of α-amylase and α-glucosidase, by changing the enzyme's structure toward the PG's structure in a noncompetitive inhibition mode. Molecular docking results showed that the PG inhibited α-amylase activity by hydrophobic interaction, whereas it inhibited α-glucosidase activity by hydrogen bonds and hydrophobic interaction. Overall, the PG was linked to polysaccharides via O-glycosidic bonds, showing an α-helical configuration and a hydrophobic effect, which altered the configuration of α-amylase and α-glucosidase and exerted hypoglycemic activity. This study provides insights into analyzing the structure and antidiabetic activity of glycoproteins.

Phycocyanin as a nature-inspired antidiabetic agent: A systematic review

BACKGROUND

Nutraceuticals have been important for more than two decades for their safety, efficacy, and outstanding effects. Diabetes is a major metabolic syndrome, which may be improved using nutritional pharmaceuticals. Some microalgae species, such as spirulina, stand out by providing biomass with exceptional nutritional properties. Spirulina has a wide range of pharmacological effects, mostly related to phycocyanin. Phycocyanin is a protein compound with antidiabetic properties, known as a nutraceutical.

OBJECTIVE

This review delves into phycocyanin applications in diabetes and its complications and ascertains the mechanisms involved.

METHODS

Scopus, PubMed, Cochrane Library, Web of Science, and ProQuest databases were systematically reviewed (up to April 30, 2023), in which only animal and cellular studies were found.

RESULTS

According to animal studies, the administration of phycocyanin affected biochemical parameters (primary outcome) related to diabetes. These results showed an increase in fasting insulin serum and a decrease in fasting blood glucose, glycosylated serum protein, and glycosylated hemoglobin. In cellular studies, though, phycocyanin prevented methylglyoxal and human islet amyloid polypeptide-induced dysfunction in β-cells and induced apoptosis through different molecular pathways (secondary outcome), including activation of Nrf2, PI3K/Akt, and suppression of JNK and p38. Also, phycocyanin exerted its antidiabetic effect by affecting the pathways regulating hepatic glucose metabolism.

CONCLUSIONS

Thus, based on the available information and literature, targeting these pathways by phycocyanin may unleash an array of benefits, including positive outcomes of the antidiabetic effects of phycocyanin as a nutraceutical.

OTHER

This systematic review was registered in the International Prospective Register of Systematic Reviews (PROSPERO) at the National Institute of Health. The registration number is CRD42022307522.

Exploring the Benefits of Phycocyanin: From Spirulina Cultivation to Its Widespread Applications

Large-scale production of microalgae and their bioactive compounds has steadily increased in response to global demand for natural compounds. Spirulina, in particular, has been used due to its high nutritional value, especially its high protein content. Promising biological functions have been associated with Spirulina extracts, mainly related to its high value added blue pigment, phycocyanin. Phycocyanin is used in several industries such as food, cosmetics, and pharmaceuticals, which increases its market value. Due to the worldwide interest and the need to replace synthetic compounds with natural ones, efforts have been made to optimize large-scale production processes and maintain phycocyanin stability, which is a highly unstable protein. The aim of this review is to update the scientific knowledge on phycocyanin applications and to describe the reported production, extraction, and purification methods, including the main physical and chemical parameters that may affect the purity, recovery, and stability of phycocyanin. By implementing different techniques such as complete cell disruption, extraction at temperatures below 45 °C and a pH of 5.5-6.0, purification through ammonium sulfate, and filtration and chromatography, both the purity and stability of phycocyanin have been significantly improved. Moreover, the use of saccharides, crosslinkers, or natural polymers as preservatives has contributed to the increased market value of phycocyanin.