Antidiabetic drug sitagliptin blocks cyclophosphamide cerebral neurotoxicity by activating Nrf2 and suppressing redox cycle imbalance, inflammatory iNOS/NO/NF-κB response and caspase-3/Bax activation in rats

Cyclophosphamide (CYP) is a classic DNA-interacting anticancer agent with broad application in chemotherapy. However, CYP cerebral neurotoxicity is a worrisome side effect for clinicians and patients. Strategies to mitigate the underlying oxidative inflammatory cascades and neuroapoptosis induced by CYP are urgently needed. Herein, we have repurposed an antidiabetic drug, sitagliptin (STG), for a possible abrogation of CYP-induced cerebral neurotoxicity in rats. Healthy rats were administered STG (20 mg/kg body weight) for 5 days prior to neurotoxicity induced by CYP (200 mg/kg body weight, ip) on day 5 only, and rats were sacrificed after 24 h post-CYP injection. CYP caused profound increases in the cerebral levels of nitric oxide (NO), acetylcholinesterase (AChE), malondialdehyde (MDA), interleukin-1β (IL-1β), interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α), nuclear factor-kappaB (NF-κB), inducible nitric oxide synthase (iNOS), caspase-3 and Bax protein compared to the control. Furthermore, CYP markedly depressed the activities of glutathione peroxidase (GPx), catalase (CAT) and superoxide dismutase (SOD), along with levels of reduced glutathione (GSH) and nuclear factor erythroid 2-related factor2 (Nrf2) compared to the control (p < 0.05). Interestingly, STG pretreatment inhibited the CYP-induced alterations in caspase-3, Bax, pro-inflammatory cytokines, NO, iNOS, AChE, NF-κB, and restored the cerebral antioxidant apparatus, including the Nrf2 and histopathological abrasions. Therefore, these findings show that STG could be repurposed to prevent CYP-induced cerebral toxicity in the brain.

Dipeptidyl Peptidase-4 Inhibitor Sitagliptin Exhibits Antioxidant Mechanism for Abrogation of Cyclophosphamide-Induced Cardiac Damage and Oxidative Hepatorenal Toxicity in Rats

Cyclophosphamide (CYP) is a potent DNA-interactive anticancer drug; however, its clinical drawbacks are chiefly associated with induction of oxidative multi-organ toxicity. Sitagliptin (STG) is an antidiabetic dipeptidyl peptidase-4 inhibitor drug with antioxidant efficacy. Herein, we have explored whether STG could abrogate the CYP-induced oxidative stress-mediated cardiac and hepatorenal toxicities in male rats. Sitagliptin (20 mg/kg, o.p) was administered to rats for 5 consecutive days against organ toxicities induced by CYP (200 mg/kg, i.p) on day 5 only. CYP induced marked injuries in the liver, kidney and heart underscored by prominent increases in serum activities of ALT, AST, LDH, creatine kinase and levels of urea, uric acid and creatinine, while albumin level significantly decreased compared to normal control rats. Further, CYP considerably reduced the activities of SOD, CAT, GPx, and levels of GSH, whereas MDA level increased significantly in comparison to control rats. These biochemical alterations were confirmed by multiple histopathological lesions in the tissues. Interestingly, the STG pretreatment abrogated the biochemical and histopathological changes induced by CYP. These results provide first evidence that repurposing STG may protect the liver, kidney and heart from the oxidative deterioration associated with CYP chemotherapy.

Phylogenic analysis of coronavirus genome and molecular studies on potential anti-COVID-19 agents from selected FDA-approved drugs

The emergence of 2019 novel Coronavirus (COVID-19 or 2019-nCoV) has caused significant global morbidity and mortality with no consensus specific treatment. We tested the hypothesis that FDA-approved antiretrovirals, antibiotics, and antimalarials will effectively inhibit COVID-19 two major drug targets, coronavirus nucleocapsid protein (NP) and hemagglutinin-esterase (HE). To test this hypothesis, we carried out a phylogenic analysis of coronavirus genome to understand the origins of NP and HE, and also modeled the proteins before molecular docking, druglikeness, toxicity assessment, molecular dynamics simulation (MDS) and ligand-based pharmacophore modeling of the selected FDA-approved drugs. Our models for NP and HE had over 95% identity with templates 5EPW and 3CL5 respectively in the PDB database, with majority of the amino acids occupying acceptable regions. The active sites of the proteins contained conserved residues that were involved in ligand binding. Lopinavir and ritonavir possessed greater binding affinities for NP and HE relative to remdesivir, while levofloxacin and hydroxychloroquine were the most notable among the other classes of drugs. The Root Mean Square Deviation (RMSD), Root Mean Square Fluctuation (RMSF), Radius of gyration (Rg), and binding energy values obtained after 100 ns of MDS revealed good stability of these compounds in the binding sites of the proteins while important pharmacophore features were also identified. The study showed that COVID-19 likely originated from bat, owing to the over 90% genomic similarity observed, and that lopinavir, levofloxacin, and hydroxychloroquine might serve as potential anti-COVID-19 lead molecules for additional optimization and drug development for the treatment of COVID-19.Communicated by Ramaswamy H. Sarma.

Ginger juice prevents cisplatin-induced oxidative stress, endocrine imbalance and NO/iNOS/NF-κB signalling via modulating testicular redox-inflammatory mechanism in rats

The off-target testicular toxicity of the anticancer drug, cisplatin, is a current clinical concern and worrisome to male cancer patients. Growing evidence has implicated oxidative stress and inflammation in cisplatin toxicity. We have explored whether fresh ginger juice could mitigate testicular toxicity induced by anticancer drug cisplatin in rats. Rats were subjected to oral administration of fresh ginger juice (5 ml/kg body weight/day) for 5 days against testicular damage induced by single ip injection of cisplatin (CIS) (10 mg/kg body weight) on day 2 only. Testicular activities of antioxidant enzymes, malondialdehyde (MDA), reduced glutathione (GSH), nitric oxide (NO), inflammatory cytokines, inducible nitric oxide synthase (iNOS) and nuclear factor-ĸB (NF-ĸB) and serum hormone levels were estimated. CIS-induced prominent decreases in antioxidant enzyme activities, GSH and serum hormone levels, whereas levels of MDA, cytokines, NO, iNOS and NF-ĸB increased remarkably (p < .05) compared to control. Interestingly, the CIS-induced testicular alterations were considerably mitigated by the fresh ginger juice via abrogation of oxidative stress and anti-inflammatory mechanism. The study suggests, for the first time, antioxidant and anti-inflammatory effects of ginger juice against CIS testicular damage. Fresh ginger juice may have beneficial health impact on testicular side effect of CIS chemotherapy.

Nephroprotective Effect of Moringa Oleifera Seed Oil on Gentamicin-Induced Nephrotoxicity in Rats: Biochemical Evaluation of Antioxidant, Anti-inflammatory, and Antiapoptotic Pathways

Objective: Gentamicin is an efficacious aminoglycoside antibiotic widely used to treat life-threatening Gram-negative bacteria infections. However, its specific non-targeted induction of nephrotoxicity is a worrying clinical challenge. The study explored the nephroprotective effect of Moringa oleifera seed oil (MOO) against gentamicin-induced oxidative nephrotoxicity, pro-inflammation, and apoptosis in male Wistar rats.Method: Twenty-four rats divided into 4 groups (n = 6) were administered MOO (5 ml/kg) for 16 days and/or gentamicin (100 mg/kg bw/d, ip) injected from day 11 to day 16. The renal antioxidant enzyme activities reduced glutathione, lipid peroxidation, and serum renal markers. Urea and creatinine levels were estimated. The renal expression of interleukin-1β (IL-1β), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and nitric oxide (NO) were determined. Renal levels of inducible nitric oxide synthase (iNOS), nuclear factor-ĸB (NF-ĸB), and caspase-3 were determined to detect possible mechanism of inflammation and apoptosis with histology.Results: MOO prominently reduced serum creatinine and urea levels with amelioration of histopathological abrasions induced by gentamicin (GM). It significantly depressed oxidative stress through lowering of renal malondialdehyde (MDA) and elevation of renal superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) activities, and reduced glutathione (GSH) level. MOO restored renal content of IL-1β, IL-6, TNF-α, and NO, coupled with the mechanistic downregulation of NF-ĸB, iNOS, and caspase-3 activities. The histopathological alterations were ameliorated by MOO.Conclusions: MOO possesses marked nephroprotective effect against GM-induced renal damage via modulating oxidative stress, inflammation, and apoptosis in Wistar rats.

Effects of manufactured nano-copper on copper uptake, bioaccumulation and enzyme activities in cowpea grown on soil substrate

Increased use of nanoparticles-based products in agriculture portends important implications for agriculture. Therefore, the impact of nano-copper particles (<25 nm and 60-80 nm) on Cu uptake, bioaccumulation (roots, leaves and seeds), activity of ascorbate peroxidase (APX), catalase (CAT), superoxide dismutase (SOD), glutathione reductase (GR), and lipid peroxidation in leaves and roots of Vigna unguiculata (cowpea) was studied. Plants were exposed to four levels (0, 125, 500 and 1000 mg/kg) of 25 nm or 60-80 nm nano-Cu for 65 days. Results indicated significant (P<.05) uptake of Cu at all nano-Cu levels compared to control, and bioaccumulation increased in seeds by at least 250%. Response of antioxidant enzymes to both nano-Cu types was concentration-dependent. Activity of APX and GR was enhanced in leaves and roots in response to both nano-Cu treatments in similar patterns compared to control. Both nano-Cu increased CAT activity in roots while SOD activity reduced in both leaves and roots. This shows that response of antioxidant enzymes to nano-Cu toxicity was organ-specific in cowpea. Malondialdehyde, a measure of lipid peroxidation, increased at 500 -1000 mg/kg of 25 nm nano-Cu in leaves by average of 8.4%, and 60-80 nm nano-Cu in root by 52.8%, showing particle-size and organ-dependent toxicity of nano-Cu. In conclusion, exposure of cowpea to nano-Cu treatments increased both the uptake and bioaccumulation of Cu, and also promoted the activity of APX and GR in root and leaf tissues of cowpea. Therefore, APX- and GR-activity level could be a useful predictive biomarker of nano-Cu toxicity in cowpea.