Oral administration of Nigella sativa oil attenuates arsenic-induced redox imbalance, DNA damage, metabolic distress, and histopathological alterations in rat intestine

BACKGROUND

Exposure to arsenic, a widespread environmental toxin, produces multiple organ toxicity, including gastrointestinal toxicity. Nigella sativa (NS) has long been revered for its numerous health benefits under normal and pathological states. In view of this, the present study attempts to evaluate the protective efficacy of orally administered Nigella sativa oil (NSO) against arsenic-induced cytotoxic and genotoxic alterations in rat intestine and elucidate the underlying mechanism of its action.

METHODS

Rats were categorized into the control, NaAs, NSO, and NaAs+NSO groups. After pre-treatment of rats in the NaAs+NSO and NSO groups daily with NSO (2 ml/kg bwt, orally) for 14 days, NSO treatment was further continued for 30 days, with and without NaAs treatment (5 mg/kg bwt, orally), respectively. Various biochemical parameters, such as enzymatic and non-enzymatic antioxidants, carbohydrate metabolic and brush border membrane marker enzyme activities were evaluated in the mucosal homogenates of all the groups. Intestinal brush border membrane vesicles (BBMV) were isolated, and the activities of membrane marker enzyme viz. ALP, GGTase, LAP, and sucrase were determined. Further, the effect on kinetic parameters viz K_M (Michaelis-Menten constant) and V_max of these enzymes was assessed. Integrity of enterocyte DNA was examined using the comet assay. Histopathology of the intestines was performed to evaluate the histoarchitectural alterations induced by chronic arsenic exposure and/or NSO supplementation. Arsenic accumulation in the intestine was studied by inductively coupled plasma-mass spectroscopy (ICP-MS).

RESULTS

NaAs treatment caused substantial changes in the activities of brush border membrane (BBM), carbohydrate metabolism, and antioxidant defense enzymes in the intestinal mucosal homogenates. The isolated BBM vesicles (BBMV) also showed marked suppression in the marker enzyme activities. Severe DNA damage and mucosal arsenic accumulation were observed in rats treated with NaAs alone. In contrast, oral NSO supplementation significantly alleviated all the adverse alterations induced by NaAs treatment. Histopathological examination supported the biochemical findings.

CONCLUSION

NSO, by improving the antioxidant status and energy metabolism, could significantly alter the ability of the intestine to protect against free radical-mediated arsenic toxicity in intestine. Thus, NSO may have an excellent scope in managing gastrointestinal distress in arsenic intoxication.

Thymoquinone supplementation mitigates arsenic-induced cytotoxic and genotoxic alterations in rat liver

Arsenic, a widespread environmental toxin, produces multiple organ toxicity, including hepatotoxicity. Thymoquinone (TQ) is known to restore liver functions in several hepatic injury models. This study aims to assess the mitigative potential of TQ against sodium arsenate (NaAs)-induced cytotoxic and genotoxic alterations in the liver. Rats were randomly distributed to control, NaAs, TQ, and NaAs+TQ groups. NaAs+TQ and TQ group of rats were pre-treated with TQ (1.5 mg/kg bwt, orally) for 14 days, and the treatment was further continued for 30 days, with and without NaAs treatment (5 mg/kg bwt, orally), respectively. The deleterious histological alterations in the liver of arsenic intoxicated animals were accompanied by an upsurge in the activities of serum ALT and AST, the diagnostic indicators of liver injury. NaAs caused pronounced alterations in the activities of membrane marker and carbohydrate metabolic enzymes and the enzymatic and non-enzymatic components of hepatic antioxidant defense. Significant hepatocyte DNA damage and hepatic arsenic accumulation were also observed in arsenic-exposed rats. TQ supplementation alleviated these adverse alterations and improved the overall hepatic metabolic and antioxidant status in NaAs-administered rats. Prevention of oxidative injury could be the key mechanism of TQ-elicited protective effects. TQ may have an excellent scope as a dietary supplement in the management of arsenic-induced hepatic pathophysiology.

Oral Nigella sativa oil administration alleviates arsenic-induced redox imbalance, DNA damage, and metabolic and histological alterations in rat liver

Arsenic, an omnipresent environmental contaminant, is regarded as a potent hepatotoxin. Nigella sativa oil (NSO) consumption has been shown to improve hepatic functions in various in vivo models of acute hepatic injury. The present study evaluates the protective efficacy of NSO against sodium arsenate (As)-induced deleterious alterations in the liver. Male Wistar rats were divided into four groups, namely, control, As, NSO, and AsNSO. After pre-treating rats in AsNSO and NSO groups with NSO (2 mL/kg bwt, orally) for 14 days, NSO treatment was further extended for 30 days, with and without As treatment (5 mg/kg bwt, orally), respectively. As induced an upsurge in serum ALT and AST activities indicating liver injury, as also confirmed by the histopathological findings. As caused significant alterations in the activities of membrane marker enzymes and carbohydrate metabolic enzymes, and in the vital components of antioxidant defense system. Marked DNA damage and hepatic arsenic accumulation were also observed in As-treated rats. Oral NSO administration ameliorated these deleterious alterations and improved overall hepatic antioxidant and metabolic status in As-treated rats. Prevention of oxidative damage could be the underlying mechanism of NSO-mediated protective effects. The results suggest that NSO could be a useful dietary supplement in the management of arsenic hepatotoxicity.

Thymoquinone supplementation ameliorates cisplatin-induced hepatic pathophysiology

Hepatotoxicity is a major dose-limiting side effect of CP chemotherapy besides nephrotoxicity and gastrointestinal dysfunction. TQ, a principal Nigella sativa seed oil constituent, has been shown to improve hepatic functions in various in vivo models of acute hepatic injury. In view of this, the present study aimed to evaluate the effect of TQ against CP-induced hepatotoxicity. Rats were divided into four experimental groups; control, CP, CP+TQ and TQ. Animals in CP+TQ and TQ groups were administered TQ (1.5 mg/kg bwt, orally), with or without a single hepatotoxic dose of CP (6 mg/kg bwt, i.p.) respectively, for 14 days before and four days following the CP treatment. CP induced an upsurge in serum ALT and AST activities, indicating liver injury, as also confirmed by the histopathological findings. CP caused significant alterations in the activities of membrane marker enzymes, carbohydrate metabolic enzymes, and the enzymatic and nonenzymatic components of the antioxidant defense system. TQ supplementation ameliorated all these adverse biochemical and histological changes in CP-treated rats. Thus, TQ may have excellent scope for clinical applications in combating CP-induced hepatic pathophysiology.

Molecular and culture based assessment of bacterial pathogens in subjects with diabetic foot ulcer

INTRODUCTION

Expeditious and precise discerning of bacterial pathogens is a fundamental grail, of clinical diagnostic microbiology. Genotypic detection is a budding substitute to recognize phenotypic culture based processes in bacterial identification.

AIMS

We report a comparative evaluation of biochemical and genomic-based assays for exploring the commonest bacterial flora of infected diabetic foot ulcers along with clinical variables of subjects enrolled.

METHODS

The pathogens selected (i) Staphylococcus aureus ii) Pseudomonas aeruginosa, iii) Escherichia coli and iv) Klebsiella pneumonia, stood for the most frequent isolates of diabetic foot infection in previous studies from Northern India. Identification of these pathogens were done by conventional assays and polymerase chain reaction.

RESULTS

Of 50 specimens obtained from infected DFUs, 74% of cases were affirmative by bacteriological assays and 90% showed positivity via polymerase chain reaction (PCR). Among processed samples 44 isolates were detectable through phenotypic analysis and 65 bacteria by species-specific PCR. Thirteen samples and 21 isolates could not be scrutinized by phenotypic identification systems. The most prevalent pathogens identifiable were Klebsiella pneumonia, followed by Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli.

CONCLUSIONS

We have shown that PCR-based diagnostic methods improved the identification compared to conventional methods and highlight the incorporation of PCR due to shorten turnaround time translating into improved clinical outcomes.

Oral administration of thymoquinone mitigates the effect of cisplatin on brush border membrane enzymes, energy metabolism and antioxidant system in rat intestine

Cisplatin (CP) is a widely used chemotherapeutic agent that elicits severe gastrointestinal toxicity. Nigella sativa, a member of family Ranunculaceae, is one of the most revered medicinal plant known for its numerous health benefits. Thymoquinone (TQ), a major bioactive component derived from the volatile oil of Nigella sativa seeds, has been shown to improve gastrointestinal functions in animal models of acute gastric/intestinal injury. In view of this, the aim of the present study was to investigate the protective effect of TQ on CP induced toxicity in rat intestine and to elucidate the mechanism underlying these effects. Rats were divided into four groups viz. control, CP, TQ and CP+TQ. Animals in CP+TQ and TQ groups were orally administered TQ (1.5mg/kg bwt) with and without a single intraperitoneal dose of CP (6mg/kg bwt) respectively. The effect of TQ was determined on CP induced alterations in the activities of brush border membrane (BBM), carbohydrate metabolism, and antioxidant defense enzymes in rat intestine. TQ administration significantly mitigated CP induced decline in the specific activities of BBM marker enzymes, both in the mucosal homogenates and in the BBM vesicles (BBMV) prepared from intestinal mucosa. Furthermore, TQ administration restored the redox and metabolic status of intestinal mucosal tissue in CP treated rats. The biochemical results were supported by histopathological findings that showed extensive damage to intestine in CP treated rats and markedly preserved intestinal histoarchitecture in CP and TQ co-treated group. The biochemical and histological data suggest a protective effect of TQ against CP-induced gastrointestinal damage. Thus, TQ may have a potential for clinical application to counteract the accompanying gastrointestinal toxicity in CP chemotherapy.

Oral administration of Nigella sativa oil ameliorates the effect of cisplatin on brush border membrane enzymes, carbohydrate metabolism and antioxidant system in rat intestine

Cisplatin (CP) is an effective chemotherapeutic agent that induces gastrointestinal toxicity. Nigella sativa oil (NSO) has been shown to be beneficial in a wide range of gastrointestinal disorders. The present study investigates the possible protective effect of NSO on CP-induced gastrointestinal toxicity. NSO administration (2ml/kg bwt, orally), prior to and following, a single dose CP treatment (6mg/kg bwt. ip), significantly attenuated the CP-induced decrease in brush border membrane (BBM) enzyme activities in intestinal homogenates and BBM vesicles (BBMV). NSO administration also mitigated CP induced alterations in the activities of carbohydrate metabolism enzymes and in the enzymatic and non-enzymatic antioxidant parameters in the intestine. The results suggest that NSO by empowering the endogenous antioxidant system improves intestinal redox and metabolic status and restores BBM integrity in CP treated rats. Histopathological studies supported the biochemical findings. Thus, NSO may help prevent the accompanying gastrointestinal dysfunction in CP chemotherapy.

Culture-Based Screening of Aerobic Microbiome in Diabetic Foot Subjects and Developing Non-healing Ulcers

The study was carried on diabetic foot patients to deduce clinical attributes, the occurrence of the range of aerobic microbial flora and to assess their comparative in vitro susceptibility to the customarily used antimicrobials. We also studied the potential risk factors involved in the development of non-healing ulcers. A total of 87 organisms were isolated from 70 specimens, including Escherichia coli (19.5%) among the Gram-negative and Staphylococcus aureus (18.4%) among the Gram-positive as the predominant aerobes explored. Pseudomonas aeruginosa and E. coli were predominant isolates of non-healing ulcers. The antimicrobial sensitivity pattern revealed that vancomycin (100%) and amikacin (90.4%) exhibited highest sensitivity to Gram-positive cocci, while all strains of P. aeruginosa were sensitive toward imipenem (100%). The prevalent uncontrolled glycemic status, altered lipid spectra, the existence of neuropathy, and peripheral vascular disease, suggested predisposition toward the development of non-healing lesions. The study has underlined the need for continuous surveillance of bacteria and their antimicrobial sensitivity blueprints to provide the basis for empirical therapy and to minimize the risk of complications. Further, stringent clinical evaluation, and medical history will help in revealing the risk of developing non-healing status in diabetic foot ulcers.

Correlation of serum chromium, zinc, magnesium and SOD levels with HbA1c in type 2 diabetes: A cross sectional analysis

The loss of dynamic integrity between homoeostasis of free radicals and antioxidants causes the development of complications like retinopathy, nephropathy, neuropathy, atherosclerosis and cardiovascular diseases in T2DM.

AIMS AND OBJECTIVES

To assess the concentrations of serum chromium, zinc, magnesium and SOD in subjects of T2DM and control and to investigate the effect of these variables versus HbA1c.

RESULTS

Insignificant difference (P=0.493) was reported in age (50±4.7 year compared with 50±7.2 year), while body mass Index (23±2kg/m(2) compared with 26±4.5kg/m(2)) between the T2DM subjects and control subject showed significant difference (<0.0001). Inverse Pearson correlation coefficient, r (-0.376), (-0.689), (-0.05), (-0.05), (-0.40), (-0.14), (-0.342) and (-0.548) were established when HbA1c of control and T2DM patients were compared with control and T2DM patients of serum Cr, Zn, Mg and SOD variables in that order. The overall "p"-value demonstrated highly significant result at p<0.0001 between the T2DM subjects and controls.

CONCLUSION

Strong association between serum chromium and SOD in relation to HbA1c in this study gives a strong point that these variables could be used as markers of cell injury with the intention in further part of life en route to progressive complications in T2DM.

Effect of chromium picolinate and melatonin either in single or in a combination in high carbohydrate diet-fed male Wistar rats

This study is designed to know the effects of chromium picolinate (CrPic) and melatonin (Mel) each alone and in a combination on high carbohydrate diet-fed (HCD-fed) male Wistar rats that exhibit insulin resistance (IR), hyperglycemia, and oxidative stress. Wistar rats have been categorized into five groups. Each group consisted of six male Wistar rats, control rats (group I), HCD (group II), HCD + CrPic (group III), HCD + Mel (group IV), and HCD + CrPic + Mel (group V). Insignificant differences were observed in serum levels of superoxide dismutase, nitric oxide, and zinc in group III, group IV, and group V when each group was compared with group II rats respectively. Significant differences were observed in group III, group IV, and group V when each group was compared with group II in homeostasis model assessment-estimated IR (P < 0.05, <0.0.05, <0.05), and in the levels of blood glucose (P < 0.05, <0.0.05, <0.05), total cholesterol (P < 0.05, <0.001, <0.001), triacylglycerols (<0.05, <0.001, <0.001), high density lipoprotein cholesterol (P < 0.05, <0.001, <0.001), malondialdehyde (P < 0.05, <0.05, <0.001), catalase (P <0.05, <0.05, <0.05), glutathione (P < 0.05, <0.05, <0.05), Mel (P < 0.05, <0.05, <0.001), and copper (P < 0.05, <0.05, < 0.001). In view of these results, HCD-fed male Wistar rats that are destined to attain IR and T2DM through diet can be prevented by giving CrPic and Mel administration in alone or in a combination.

Effect of 5-year enalapril therapy on progression of microalbuminuria and glomerular structural changes in type 1 diabetic subjects

A 5-year randomized, double blind, placebo-controlled study was carried out to determine the effect of the angiotensin-converting enzyme (ACE) inhibitor enalapril (E) on the progress of renal function and histology in subjects with type 1 diabetes and microalbuminuria. Seventy three type 1 diabetic patients with BP <140/90 and with persistent albuminuria (AER 20-200 microg/min) and normal renal function were randomly assigned to receive E (n=37) or placebo (n=36). A percutaneous renal biopsy was successfully performed in 69 patients and repeated in 59 patients after 5 years. The mean glomerular volume (MGV), mesangial volume (Vv mes) and glomerular basement membrane thickness (GBMT) were measured histomorphometrically. Before treatment, both groups had similar clinical characteristics, blood pressure, HbA(1c), albumin excretion rate (AER), glomerular filtration rate (GFR), serum creatinine and renal structural damage. Blood pressure was well controlled in both groups. In the patients treated with E, albuminuria decreased significantly (P<0.05) and only 8.1% (3/37) of subjects progressed to clinical albuminuria (AER >300 mg/24 h) compared with 30.5% (11/36) in the placebo group. The E treatment resulted in absolute risk reduction of 22.4 percentage points for the development of clinical albuminuria over a 5-year period (P<0.01). After 5 years of treatment, GBM thickness showed a consistent, though statistically insignificant, increase in the placebo group, whereas it remained stable in the E group. A significant increase in MGV and Vv mes was also observed in the placebo group on completion of the study. The present study indicates that long term therapy with E may decrease or delay the progression of structural glomerular damage in microalbuminuric diabetic subjects without marked hypertension (BP <140/90).

Effects of stress and food deprivation on catfish, Heteropneustes fossilis (Bloch)

No significant changes in plasma cortisol and plasma osmolarity (the indicators of primary and secondary response respectively) were observed when the blood samples were obtained from unanaesthetized, anaesthetized and stressed catfish, H. fossilis. The results suggest that the catfish is fairly hardy and not easily susceptible to stress by routine laboratory handling. The sustained plasma glucose levels and decreased liver and muscle glycogen concentrations during cessation of feeding of the catfish suggest that during period of food deprivation, it draws its energy through glycogenolysis. Hence, in any study dealing with carbohydrate metabolism, the catfish needs to be fed during acclimation and experimental periods.

Analysis of VNTR loci in fish genomes using synthetic oligodeoxyribonucleotide probes

A set of synthetic oligodeoxyribonucleotide (oligo) probes, OAT18, OMS1 and OAT24 carrying the (TGG)6, (GGAT)4 and (GACA)6 repeat motifs, respectively, was used to analyze the variable number tandem repeat (VNTR) loci in the genomes of Oncorhyncus mykiss (rainbow trout; family Salmonidae), Oreochromis mossambicus and Oreochromis niloticus (both tilapia belonging to family Cichlidae). Of all the oligos and enzymes (AluI, MboI, HaeIII and HinfI) used, the OAT18/HaeIII combination was found to be most informative for detecting DNA fingerprinting in rainbow trout, while the OMS1/MboI combination gave the most informative pattern for the Or. niloticus genome. In the rainbow trout genome, all three repeat loci were hypervariable, revealing varying degrees of polymorphism as compared to tilapia genomes. Startlingly, the OAT24 probe did not cross-hybridize with Or. mossambicus and lamprey salmon (Lampertra japonica) although GACA repeats have been reported to be evolutionarily conserved in all eukaryotes studied thus far. Cluster analysis with respect to GGAT repeat loci revealed that Or. niloticus diverged from Or. mossambicus before the separation of On. mykiss, suggesting the relatively recent evolution of these loci in rainbow trout, compared to the tilapia genomes. These highly informative probes will find application in various genetic studies of fishes.

Osmoregulation in the stenohaline freshwater catfish, Heteropneustes fossilis (Bloch) in deionized water

Transfer of the stenohaline catfish, Heteropneustes fossilis from tap water (TW) to deionized water (DW) resulted in an increase in the glomerular filtration rate, urine volume and osmolar and free water clearance. In a closed system, where the DW was renewed only once a day, no change in the plasma osmolality was evident for up to 14 days. When DW was renewed four times a day for 25 days, a significant reduction in the plasma osmolality was observed within 24h. When the fish were transferred back to TW, plasma osmolality increased to normal freshwater level within 24h. These observations suggest the existence of highly efficient branchial mechanisms for active uptake of salts from an exceedingly dilute ambient medium. The fact that prolactin-secreting cells as well as corticotrophs in the pituitary of the fish in DW were highly stimulated suggests the involvement of the hormones in the adaptive responses of the catfish to DW.

Relevance of empirical optimization for cross-linking DNA by using an ordinary ultraviolet-light source

For cross-linking DNA onto nitrocellulose or nylon membranes by using ordinary ultraviolet (UV) light, empirical optimization with respect to exposure time is crucial for obtaining complete hybridization signals. Longer than optimal UV exposure reduces the signal intensity particularly in the larger DNA fragments, whereas shorter exposure due to insufficient immobilization produces incomplete signals. Relevance of using ordinary source of UV light with respect to fixing DNA on a large number of circular filters during library screening is discussed.

Effects of prolactin, adrenocorticotrophin, neurohypophysial peptides, cortisol, and androgens on some osmoregulatory parameters of the hypophysectomized catfish, Heteropneustes fossilis (bloch)

Daily injections of ovine prolactin (PRL), cortisol acetate (FA), arginine vasotocin (AVT), and adrenocorticotrophic hormone (ACTH), at doses ranging from 0.1 to 500 mU/g, 0.2 to 25 micrograms/g, 0.01 to 0.02 micrograms/g, and 5 to 10 mU/g respectively, for 5 days elevated plasma osmolarity and plasma sodium levels in the 3-day hypophysectomized catfish, Heteropneustes fossilis maintained in tap water. PRL enhanced urine production and decreased urine osmolarity and sodium concentration. Administration of FA and AVT increased urine output as well as urine osmolarity and sodium concentration, thereby resulting in severe natriuresis. Simultaneous administration of PRL and FA to hypophysectomized catfish restored plasma osmolarity and sodium concentration to normal levels even in the presence of increased urinary salt loss. However, if the fishes were maintained in deionized water, administration of PRL and FA had no effect on plasma osmolarity or plasma sodium levels suggesting that these hormones increase plasma osmotic pressure by stimulating active uptake of salts from the external medium. Neither PRL nor AVT evoked any increase in plasma cortisol level indicating that their effects on catfish osmoregulation are not mediated through cortisol production. Isotocin, testosterone, and delta 4-androstenedione had no effect on any of the plasmatic or urinary parameters. It is concluded that prolactin, cortisol, and AVT are the principal hormones for osmoionic homeostasis in this catfish and that they act through independent mechanisms.

Effects of hypophysectomy on some osmoregulatory parameters of the catfish, Heteropneustes fossilis (Bloch)

The catfish, H. fossilis, survives for long periods after hypophysectomy, although with impaired osmoregulatory mechanisms. Plasma osmolarity and cortisol levels decline significantly within 2 hr after hypophysectomy and attain the lowest values by about 27 hr. Hypophysectomy also results in a marked decrease in urine flow rate principally due to reduced glomerular filtration. The reduction in the ability of the kidney of hypophysectomized catfish to eliminate water results in hyperhydration of blood and muscle. Urine osmolarity and sodium concentration increase due to reduced tubular reabsorption of sodium. There is, however, no net change in the total urinary sodium loss. The catfish survives in fresh water after hypophysectomy presumably because its tissues can tolerate significant dilution of the body fluids.