Possible protective effect of the algae spirulina against nephrotoxicity induced by cyclosporine A and/or gamma radiation in rats

Cyclosporine-induced kidney damage was halted by sitagliptin and hesperidin via increasing Nrf2 and suppressing TNF-α, NF-κB, and Bax

Cyclosporine A (CsA) is employed for organ transplantation and autoimmune disorders. Nephrotoxicity is a serious side effect that hampers the therapeutic use of CsA. Hesperidin and sitagliptin were investigated for their antioxidant, anti-inflammatory, and tissue-protective properties. We aimed to investigate and compare the possible nephroprotective effects of hesperidin and sitagliptin. Male Wistar rats were utilized for induction of CsA nephrotoxicity (20 mg/kg/day, intraperitoneally for 7 days). Animals were treated with sitagliptin (10 mg/kg/day, orally for 14 days) or hesperidin (200 mg/kg/day, orally for 14 days). Blood urea, serum creatinine, albumin, cystatin-C (CYS-C), myeloperoxidase (MPO), and glucose were measured. The renal malondialdehyde (MDA), glutathione (GSH), catalase, and SOD were estimated. Renal TNF-α protein expression was evaluated. Histopathological examination and immunostaining study of Bax, Nrf-2, and NF-κB were performed. Sitagliptin or hesperidin attenuated CsA-mediated elevations of blood urea, serum creatinine, CYS-C, glucose, renal MDA, and MPO, and preserved the serum albumin, renal catalase, SOD, and GSH. They reduced the expressions of TNF-α, Bax, NF-κB, and pathological kidney damage. Nrf2 expression in the kidney was raised. Hesperidin or sitagliptin could protect the kidney against CsA through the mitigation of oxidative stress, apoptosis, and inflammation. Sitagliptin proved to be more beneficial than hesperidin.

Metabolomic and physiological changes of acid-tolerant Graesiella sp. MA1 during long-term acid stress

Algae plays a significant role for the primary production in the oligotrophic ecosystems such as the acid mine pit lakes. Graesiella sp. MA1 was a new acid-tolerant photosynthetic protist isolated from an acid mine pit lake. To understand the acid responses of Graesiella sp. MA1, its physiological changes and metabolomics were studied during long-term acid stress. Photosynthetic pigments, soluble proteins, and antioxidant systems of Graesiella sp. MA1 cells displayed two phases, the adaptation phase and the growth phase. During the adaptation phase, both photosynthetic pigments and soluble proteins were inhibited, while antioxidant activity of SOD, APX, and GSH were promoted to response to the organism's damage. Metabolomics results revealed lipids and organic acids were abundant components in Graesiella sp. MA1 cells. In response to acid stress, the levels of acid-dependent resistant amino acids, including glutamate, aspartate, arginine, proline, lysine, and histidine, accumulated continuously to maintain orderly intracellular metabolic processes. In addition, fatty acids were mainly unsaturated, which could improve the fluidity of the cell membranes under acid stress. Metabolomic and physiological changes showed that Graesiella sp. MA1 had tolerance during long-term acid stress and the potential to be used as a bioremediation strain for the acidic wastewater.

Natural Reno-Protective Agents against Cyclosporine A-Induced Nephrotoxicity: An Overview

CA (cyclosporine A) is a powerful immunosuppressing agent that is commonly utilized for treating various autoimmune illnesses and in transplantation surgery. However, its usage has been significantly restricted because of its unwanted effects, including nephrotoxicity. The pathophysiology of CA-induced kidney injury involves inflammation, apoptosis, tubular injury, oxidative stress, and vascular injury. Despite the fact that exact mechanism accountable for CA's effects is inadequately understood, ROS (reactive oxygen species) involvement has been widely proposed. At present, there are no efficient methods or drugs for treating CA-caused kidney damage. It is noteworthy that diverse natural products have been investigated both in vivo and in-vitro for their possible preventive potential in CA-produced nephrotoxicity. Various extracts and natural metabolites have been found to possess a remarkable potential for restoring CA-produced renal damage and oxidative stress alterations via their anti-apoptosis, anti-inflammatory, and antioxidative potentials. The present article reviews the reported studies that assess the protective capacity of natural products, as well as dietary regimens, in relation to CA-induced nephrotoxicity. Thus, the present study presents novel ideas for designing and developing more efficient prophylactic or remedial strategies versus CA passive influences.

Arthrospira maxima (Spirulina) prevents endoplasmic reticulum stress in the kidney through its C-phycocyanin

Arthrospira maxima (Spirulina) is a cyanobacterium which is considered a nutraceutical because it has antioxidant, anti-inflammatory, and cytoprotective properties in different renal disease models (Rodriguez-Sánchez et al., 2012; Aziz et al., 2018; Memije-Lazaro et al., 2018). The therapeutic effects are due to the presence of metabolites with biological effects similar to those of essential fatty acids ω-3 and ω-6, vitamins A, C and E, and accessory pigments such as phycobiliproteins. One of the most abundant phycobiliproteins in A. maxima is C-phycocyanin (Mysliwa-Kurdziel and Solymosi, 2017). This molecule is responsible for nephroprotective action in a model of acute kidney injury (AKI) because it reduces oxidative stress and caspase activation (Rodriguez-Sánchez et al., 2012; Rojas-Franco et al., 2018). However, both A. maxima and its C-phycocyanin are related to the reduction of the redox environment. Thus, they probably help to maintain the adequate function of the intracellular organelles like the endoplasmic reticulum. However, this therapeutic action has not been evaluated previously.

Protective effects of Saraca indica L. leaves extract (family Fabaceae) against gamma irradiation induced injury in the kidney of female albino rats

This work was designed to estimate the protective effect of Saraca indica L. leaves ethanolic exract against γ-irradiation induced renal damage in rats. Phytochemical examinations of S. indica L. leaves extract resulted in the separation of three flavanone glycosides: Astilibin (1), Neoastilbin (2), and Eriodictyol-7-O-α-l-rhamnopyranoside (3); two flavonols: Quercetin (4) and Quercetin-3-O-α-l-arabinopyranosyl-(1'''-6'')-O-β-D-galactopyranoside (5) in addition of Gallic acid (6) and methyl gallate (7). Their structures elucidated by chemical evidences and spectroscopic analysis (1 and 2D-NMR, -ESI-MS, UV). Female rats were used and classified into: control, Ext (200 mg/kg body wt/day orally for 7 days), IRR (8Gy), Ext + IRR, and Sily+IRR groups (received silymarin 50 mg/kg b.wt orally as reference drug). Results showed that S. indica L. leaves extract ameliorated the kidney function tests, hs-CRP, IL-1β, ACE, TNF-α, GSH, and MDA as well as, decreased the histopathological changes of kidney. In conclusion, S. indica L. leaves extract had a renoprotective activity against irradiation induced renal injury due to its flavononid contents.

The radioprotective effect of N-acetylcysteine against x-radiation-induced renal injury in rats

The purpose of this study was therefore to investigate the effects of radiotherapy on the kidney and the potential use of agents such as N-acetylcysteine (NAC) in developing a future therapeutic protocol for radiation-induced nephrotoxicity at the histopathological and biochemical levels. Our study consisted of three groups: control (oral saline solution only; group 1), irradiation (IR; group 2), and NAC + IR (group 3). The irradiation groups received a single dose of whole-body 6-Gy x-irradiation. The NAC group received 300 mg/kg by the oral route for 7 days, from 5 days before irradiation to 2 days after. All subjects were sacrificed under anesthesia 2 days after irradiation. IR increased tubular necrosis scores (TNS), MDA, and caspase-3 expression, while reducing renal tissue GSH levels. We also observed dilation in renal corpuscles and tubules. Capillary congestion was present in the intertubular spaces. NAC reduced the levels of TNS, MDA, and caspase-3 expression, but increased the levels of renal tissue GSH. ROS-scavenging antioxidants may represent a promising means of preventing renal injury in patients undergoing radiotherapy.

Phycobiliproteins and phycocyanin of Arthrospira maxima (Spirulina) reduce apoptosis promoters and glomerular dysfunction in mercury-related acute kidney injury

Arthrospira maxima ( Spirulina) is considered a nutraceutical or functional food because it provides health benefits and it is used as nephroprotector because it contains nucleophilic compounds as phycobiliproteins and phycocyanin that prevent oxidative stress and cellular damage process. Also, it is known that inorganic mercury is bioaccumulated and exerted kidney toxicity. Despite the nephroprotective effect of Spirulina and its components, there is not enough information about the effect of them on renal function as well as the apoptosis process inhibition. This work aimed to investigate whether phycobiliproteins and phycocyanin of Spirulina can improve HgCl2-related glomerular and tubular renal dysfunction as well as the Bax, Bcl2, and effectors caspases alterations. Male mice were administrated with Spirulina, phycobiliproteins or phycocyanin 30 min before 5 mg/Kg HgCl2 administration. The nutraceuticals were administrated for the next 5 days. Then, the mice were euthanized. The renal function, caspases 3 and 9 activities, as well as Bax and Bcl2 expression were evaluated. Spirulina and its components prevent HgCl2-related apoptosis induction and glomerular dysfunction. We concluded that phycobiliproteins and phycocyanin of Spirulina reduce glomerular damage but not the tubular dysfunction in a mercury-related acute kidney injury.