Protective effect of aqueous garlic extract against renal ischemia/reperfusion injury in rats

Alleviation of ischemia-reperfusion induced renal injury by chemically modified SOD2 mRNA delivered via lipid nanoparticles

Ischemia-reperfusion injury (IRI) is a major cause of acute kidney injury, which is a serious clinical condition with no effective pharmacological treatment. Mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) significantly alleviate kidney IRI; however, the underlying mechanisms and key molecules conferring renoprotection remain elusive. In this study, we characterized the protein composition of MSC-EVs using a proteomics approach and found that mitochondrial protein superoxide dismutase 2 (SOD2) was enriched in MSC-EVs. Using lipid nanoparticles (LNP), we successfully delivered chemically modified SOD2 mRNA into kidney cells and mice with kidney IRI. We demonstrated that SOD2 mRNA-LNP treatment decreased cellular reactive oxygen species (ROS) in cultured cells and ameliorated renal damage in IRI mice, as indicated by reduced levels of serum creatinine and restored tissue integrity compared with the control mRNA-LNP-injected group. Thus, the modulation of mitochondrial ROS levels through SOD2 upregulation by SOD2 mRNA-LNP delivery could be a novel therapeutic method for ischemia-reperfusion-induced acute kidney injury.

Hepatoprotective and Renoprotective Properties of Lovastatin-Loaded Ginger and Garlic Oil Nanoemulsomes: Insights into Serum Biological Parameters

Background and Objectives: Dyslipidemia is gaining much attention among healthcare professionals because of its high association with the malfunctioning of a number of normal physiological and metabolic processes in the body. Obesity is directly interconnected with dyslipidemia and is said to be a denouement of hyperlipidemia and, if left untreated, may lead to intense damage to organs that are directly involved in fat metabolism. The objective of this study was to investigate the synergistic antiobesity and anti-hyperlipidemic activities along with hepato- and renoprotective potential of nanoemulsomes (NES) of lovastatin (LTN)-loaded ginger (GR) and garlic (GL) oils. Materials and Methods: LTN nanoemulsomes co-encapsulated with GR oil and GL oil were prepared by a thin hydration technique. Eight-week-old male Wistar rats weighing 200-250 g were induced with hyperlipidemia via a high-fat diet (HFD) comprising 40% beef tallow. Body weight, serum biochemical lipid parameters, and those for liver and kidney functions, serum TC, LDL-C, vLDL-C, HDL-C, TG, atherogenic index (AI), ALT, AFT, ALP, γ-GT, total protein (TP), serum albumin and globulin ratio (A/G), serum creatinine, blood urea nitrogen (BUN) and blood urea, and histopathology of hematoxylin and eosin (H&E) stained liver and kidney sections of all aforementioned groups were examined in the treated animals. Results: Nanoemulsomes of LTN-loaded GR and GL oils provided synergistic effects with LTN, exerted better ameliorative actions in reducing serum TC, LDL-C, vLDL-C, triglycerides, and AI, and improved serum HDL-C levels. Serum ALT, AST, ALP, and γ-GT levels were in the normal range for nanoemulsome groups. H&E stained liver and kidney sections of these animals confirmed better hepatoprotective and renoprotective effects than LTN alone. Serum biochemical parameters for renal functions also claimed to be in the moderate range for nanoemulsome-treated groups. Conclusion: This study demonstrated that nanoemulsomes of LTN-loaded GR and GL oils synergistically provided better antihyperlipidemic, hepatoprotective, and renoprotective effects as compared to LTN alone.

Prophylactic Potential of Conventional and Supercritical Garlic Extracts to Alleviate Diet Related Malfunctions

OBJECTIVES

The present research was tailored to explore the prophylactic role of garlic extracts to mitigate some diet related malfunctions. The recent patents regarding antidiabetic agents (US 20140147528 A1) and garlic compositions (US 20110129580 A1) also helped in the study design.

METHODS

Bioevaluation trials were conducted on Sprague Dawley rats by feeding garlic extracts for a period of sixty days. Accordingly, three studies were carried out comprising of normal, hyperglycemic and hypercholesterolemic rats. Drink & feed intakes and weight gain were measured throughout the trial. After sixty days, collected sera from rats were analyzed for serum cholesterol, LDL, HDL & triglyceride levels and glucose & insulin concentrations. Finally, the data obtained were subjected to statistical modeling.

RESULTS

Results concerning the bioevaluation trials revealed that maximum 12.39% reduction was observed in serum cholesterol in Study III (hypercholesterolemic rats) on the provision of garlic supercritical extract (nutraceutical diet) followed by 10.24% decline in rats fed on solvent extract supplemented diet (functional diet). Regarding LDL, maximum decrease (17.02%) was recorded on the administration of diet having garlic supercritical extract to the hypercholesterolemic rats. While in Study II (hyperglycemic rats) maximum decrease of 11.03% in glucose level was recorded in rats fed on supercritical extract containing diet. In the same group maximum increase in insulin (7.95%) was recorded.

CONCLUSIONS

From the current investigations, it can be concluded that garlic based designer foods possess the prophylactic perspectives to alleviate the risk of metabolic ailments. Thus, it can be used in the diet based therapeutic interventions as an adjuvant to pharmaceuticals.

Flavonoids in Kidney Health and Disease

This review summarizes the latest advances in knowledge on the effects of flavonoids on renal function in health and disease. Flavonoids have antihypertensive, antidiabetic, and antiinflammatory effects, among other therapeutic activities. Many of them also exert renoprotective actions that may be of interest in diseases such as glomerulonephritis, diabetic nephropathy, and chemically-induced kidney insufficiency. They affect several renal factors that promote diuresis and natriuresis, which may contribute to their well-known antihypertensive effect. Flavonoids prevent or attenuate the renal injury associated with arterial hypertension, both by decreasing blood pressure and by acting directly on the renal parenchyma. These outcomes derive from their interference with multiple signaling pathways known to produce renal injury and are independent of their blood pressure-lowering effects. Oral administration of flavonoids prevents or ameliorates adverse effects on the kidney of elevated fructose consumption, high fat diet, and types I and 2 diabetes. These compounds attenuate the hyperglycemia-disrupted renal endothelial barrier function, urinary microalbumin excretion, and glomerular hyperfiltration that results from a reduction of podocyte injury, a determinant factor for albuminuria in diabetic nephropathy. Several flavonoids have shown renal protective effects against many nephrotoxic agents that frequently cause acute kidney injury (AKI) or chronic kidney disease (CKD), such as LPS, gentamycin, alcohol, nicotine, lead or cadmium. Flavonoids also improve cisplatin- or methotrexate-induced renal damage, demonstrating important actions in chemotherapy, anticancer and renoprotective effects. A beneficial prophylactic effect of flavonoids has been also observed against AKI induced by surgical procedures such as ischemia/reperfusion (I/R) or cardiopulmonary bypass. In several murine models of CKD, impaired kidney function was significantly improved by the administration of flavonoids from different sources, alone or in combination with stem cells. In humans, cocoa flavanols were found to have vasculoprotective effects in patients on hemodialysis. Moreover, flavonoids develop antitumor activity against renal carcinoma cells with no toxic effects on normal cells, suggesting a potential therapeutic role in patients with renal carcinoma.

Hydrogen Sulfide Protects Renal Grafts Against Prolonged Cold Ischemia-Reperfusion Injury via Specific Mitochondrial Actions

Ischemia-reperfusion injury is unavoidably caused by loss and subsequent restoration of blood flow during organ procurement, and prolonged ischemia-reperfusion injury IRI results in increased rates of delayed graft function and early graft loss. The endogenously produced gasotransmitter, hydrogen sulfide (H₂ S), is a novel molecule that mitigates hypoxic tissue injury. The current study investigates the protective mitochondrial effects of H₂ S during in vivo cold storage and subsequent renal transplantation (RTx) and in vitro cold hypoxic renal injury. Donor allografts from Brown Norway rats treated with University of Wisconsin (UW) solution + H₂ S (150 μM NaSH) during prolonged (24-h) cold (4°C) storage exhibited significantly (p < 0.05) decreased acute necrotic/apoptotic injury and significantly (p < 0.05) improved function and recipient Lewis rat survival compared to UW solution alone. Treatment of rat kidney epithelial cells (NRK-52E) with the mitochondrial-targeted H₂ S donor, AP39, during in vitro cold hypoxic injury improved the protective capacity of H₂ S >1000-fold compared to similar levels of the nonspecific H₂ S donor, GYY4137 and also improved syngraft function and survival following prolonged cold storage compared to UW solution. H₂ S treatment mitigates cold IRI-associated renal injury via mitochondrial actions and could represent a novel therapeutic strategy to minimize the detrimental clinical outcomes of prolonged cold IRI during RTx.

Inflammasomes and Natural Ingredients towards New Anti-Inflammatory Agents

Inflammasomes are a family of proteins in charge of the initiation of inflammatory process during innate immune response. They are now considered major actors in many chronic inflammatory diseases. However, no major drug focusing on this target is currently on the market. Among the various approaches aiming to control this major metabolic pathway, compounds aiming to modify the intracellular antioxidant profile appear to be promising. This can be obtained by “light” antioxidants able to induce natural antioxidant response of the cell itself. This review will give an overview of the current available information on this promising pharmacology approach.

ROS-Mediated NLRP3 Inflammasome Activation in Brain, Heart, Kidney, and Testis Ischemia/Reperfusion Injury

Ischemia and reperfusion (I/R) causes a reduction in arterial blood supply to tissues, followed by the restoration of perfusion and consequent reoxygenation. The reestablishment of blood flow triggers further damage to the ischemic tissue through reactive oxygen species (ROS) accumulation, interference with cellular ion homeostasis, and inflammatory responses to cell death. In normal conditions, ROS mediate important beneficial responses. When their production is prolonged or elevated, harmful events are observed with peculiar cellular changes. In particular, during I/R, ROS stimulate tissue inflammation and induce NLRP3 inflammasome activation. The mechanisms underlying the activation of NLRP3 are several and not completely elucidated. It was recently shown that NLRP3 might sense directly the presence of ROS produced by normal or malfunctioning mitochondria or indirectly by other activators of NLRP3. Aim of the present review is to describe the current knowledge on the role of NLRP3 in some organs (brain, heart, kidney, and testis) after I/R injury, with particular regard to the role played by ROS in its activation. Furthermore, as no specific therapy for the prevention or treatment of the high mortality and morbidity associated with I/R is available, the state of the art of the development of novel therapeutic approaches is illustrated.

Renal ischemia/reperfusion injury; from pathophysiology to treatment

Ischemia/reperfusion injury (IRI) is caused by a sudden temporary impairment of the blood flow to the particular organ. IRI usually is associated with a robust inflammatory and oxidative stress response to hypoxia and reperfusion which disturbs the organ function. Renal IR induced acute kidney injury (AKI) contributes to high morbidity and mortality rate in a wide range of injuries. Although the pathophysiology of IRI is not completely understood, several important mechanisms resulting in kidney failure have been mentioned. In ischemic kidney and subsequent of re-oxygenation, generation of reactive oxygen species (ROS) at reperfusion phase initiates a cascade of deleterious cellular responses leading to inflammation, cell death, and acute kidney failure. Better understanding of the cellular pathophysiological mechanisms underlying kidney injury will hopefully result in the design of more targeted therapies to prevent and treatment the injury. In this review, we summarize some important potential mechanisms and therapeutic approaches in renal IRI.

Renoprotective effect of aged garlic extract in streptozotocin-induced diabetic rats

OBJECTIVE

Aged garlic extract (AGE) has been proven to exhibit antioxidant, hypolipidemic, hypoglycemic and antidiabetic properties. However, its effect on diabetic nephropathy was unexplored. Therefore, the present study was designed to investigate the renoprotective effect of AGE in streptozotocin-induced diabetic rats.

MATERIALS AND METHODS

Albino Wistar rats were induced with diabetes by a single intraperitoneal injection of 45 mg/kg b.w. of streptozotocin. Commercially available AGE was supplemented orally at a dose of 500 mg/kg body weight/day. Aminoguanidine, which has been proven to be an anti-glycation agent was used as positive control and was supplemented at a dose of 1 g/L in drinking water. The serum and urinary biochemical parameters were analyzed in all the groups and at the end of 12 weeks follow up, the renal histological examination were performed using H & E and PAS staining.

RESULTS

The diabetic rats showed a significant change in the urine (P < 0.001) and serum (P < 0.01) constituents such as albumin, creatinine, urea nitrogen and glycated hemoglobin. In addition, the serum lipid profile of the diabetic rats were altered significantly (P < 0.05) compared to that of the control rats. However, the diabetic rats supplemented with aged garlic extract restored all these biochemical changes. The efficacy of the extract was substantiated by the histopathological changes in the kidney.

CONCLUSION

From our results, we conclude that aged garlic extract has the ability to ameliorate kidney damage in diabetic rats and the renoprotective effect of AGE may be attributed to its anti-glycation and hypolipidemic activities.

Neuroprotective effects of diallyl sulfide against transient focal cerebral ischemia via anti-apoptosis in rats

OBJECTIVES

Diallyl sulfide (DAS) is the main organosulfur component of garlic and it is known for multiple pharmacological actions. Recent studies have demonstrated that DAS has neuroprotective effects against ischemia/reperfusion injury. While some of the possible mechanisms behind this protection have been explored, its ability to inhibit apoptosis has yet to be fully explained. In the present study, the effects of DAS on focal cerebral ischemia in rats were tested and its anti-apoptotic action was explored.

METHODS

To examine the protective effects of DAS, focal cerebral ischemia/reperfusion was induced in rats by transient middle cerebral artery occlusion for 2 hours followed by reperfusion for 24 hours. The animals received DAS in quantities of 100, 150, and 200 mg/kg (intraperitoneal; every day), for 7 days before transient middle cerebral artery occlusion. The neurological score and infarct volume were measured at 24 hours after the end of reperfusion. Apoptotic cells were counted by terminal dUTP nick end labeling staining and apoptotic mechanisms were studied by fluorescence immunohistochemistry staining and western blot analysis.

RESULTS

For animals with induced ischemia/reperfusion, those pretreated with 200 mg/kg DAS showed an infarct volume (22.36 ± 0.67%) significantly lower than that of the non-treated ischemia/reperfusion group (38.23 ± 0.72%), and the percentage of terminal dUTP nick-end labeling-positive cells (23.46 ± 1.02%) of the DAS-pretreated group was also significantly decreased compared to non-treated (36.41 ± 1.58%). Fluorescence immunohistochemistry staining and western blot analysis indicated that DAS reduced caspase-3 expression and increased Bcl-2 expression.

CONCLUSION

These results suggest that the mechanism by which DAS protects the brain from ischemia/reperfusion injury is related to its anti-apoptotic effects in part.

Garlic extract ameliorates renal and cardiopulmonary injury in the rats with chronic renal failure

Chronic renal failure (CRF) is associated with oxidative stress that promotes production of reactive oxygen species and cytokine release. We aimed to investigate the possible protective and antioxidant effects of aqueous garlic extract (AGE) in a rat model of CRF. Male Sprague-Dawley rats were randomly assigned as either CRF group with 5/6 reduction in the renal mass or sham-operated control group. CRF group received either saline or AGE (250 mg/kg/day/1 mL) orally for 3 weeks. At the end of the 3 weeks, rats were decapitated and trunk blood was collected. Creatinine, blood urea nitrogen (BUN) and lactate dehydrogenase (LDH) activity, and TNF-α and IL-1β levels were measured in the serum samples, while malondialdehyde (MDA), glutathione (GSH) levels, and myeloperoxidase (MPO) activity were determined in the kidney, lung, and heart samples. CRF caused significant decreases in tissue GSH, which were accompanied with significant increases in MDA levels and MPO activities, while the circulating levels of the LDH activity, creatinine, BUN, TNF-α, and IL-1β were elevated. AGE treatment alleviated CRF-induced oxidative changes in the injured tissues, while CRF-induced elevations in the blood levels of the pro-inflammatory cytokines and LDH were reduced. In conclusion, CRF-induced oxidative tissue injury occurs via the activation of pro-inflammatory mediators and by neutrophil infiltration into tissues and that the protective effects of garlic on CRF-induced injury can be attributed to its ability to inhibit neutrophil infiltration and pro-inflammatory mediators. These findings suggest that garlic, as a supplementary to diet, may have a potential therapeutic use in delimitating the systemic oxidant effects of CRF on remote organs.

Effect of garlic oil on neutrophil infiltration in the small intestine of endotoxin-injected rats and its association with levels of soluble and cellular adhesion molecules

Garlic ( Allium sativum ) possesses anti-inflammatory effects. This study investigated the effects of garlic oil on endotoxin-induced neutrophil infiltration in the small intestine. Wistar rats received by gavage 10, 50, or 100 mg/kg body wt garlic oil (GO) or the vehicle (corn oil; 2 mL/kg body wt) every other day for 2 weeks before being injected with endotoxin (ip, 5 mg/kg body wt). Control rats were administered corn oil and injected with sterile saline. Blood samples for the measurement of soluble adhesion molecules were collected at various time points after injection, and all other samples were collected 18 h after injection. The 10 and 50 mg/kg doses suppressed endotoxin-induced neutrophilia, serum levels of sL-selectin and sICAM-1, cellular CD11b on neutrophils, intestinal ICAM-1 content, and neutrophil infiltration (P < 0.05). The 100 mg/kg dose significantly lowered local ICAM-1 and cellular CD11b on neutrophils (P < 0.05) but did not have a beneficial effect on neutrophil infiltration. In addition, 100 mg/kg of GO worsened the elevation of the local TNF-α level and neutrophilia. Appropriate doses of garlic oil have a preventive effect on endotoxin-induced neutrophil infiltration and damage to the small intestine.

The antioxidant role of oral administration of garlic oil on renal ischemia-reperfusion injury

AIM

In this study we examined the effect of oral application of garlic form [garlic oil (GO)] on rats after renal ischemia-reperfusion (I/R) injury.

MATERIALS AND METHODS

Forty male Wistar albino rats were divided into four groups: control, sham-operated, I/R, and I/R+GO. GO was diluted in water and administered by oral intubation three times each week for 6 weeks. All rats except sham-operated underwent 45 min of bilateral renal ischemia followed by 6 hr of reperfusion. Blood samples and kidney tissues were harvested from the rats, and then rats were killed. Serum urea, creatinine, and cystatin C levels were determined. Total antioxidant capacity (TAC), catalase (CAT), total oxidant status (TOS), oxidative stress index (OSI), myeloperoxidase (MPO), nitrite oxide (NO), and protein carbonyl (PC) levels in kidney tissue and blood were measured. In addition, kidney tissue histopathology was evaluated.

RESULTS

The serum urea, creatinine, and cystatin C levels were significantly higher in I/R group compared to I/R+GO group (p<0.01). The serum and tissue antioxidant markers (TAC, CAT) were significantly lower in I/R group than I/R+GO group (p<0.01). The serum oxidant markers (TOS, MPO, NO, and PC) were significantly higher in I/R group than I/R+GO group (p<0.01). Also oral application of GO was effective in decreasing of tubular necrosis score.

CONCLUSION

Based on the present data, we conclude that increased antioxidants and decreased oxidants modulated by oral application of GO attenuated the renal I/R injury.

Prevention of selenite-induced cataractogenesis in Wistar albino rats by aqueous extract of garlic

PURPOSE

The main aim of this study was to evaluate the inhibitory impacts of the aqueous extract of garlic (Ga) on the formation of cataract induced by sodium selenite (Se).

METHODS

Thirty-two Wistar albino rat pups (4 equal groups: G1, G2, G3, and G4) were treated as follows: G1, subcutaneous (s.c.) and intraperitoneal (i.p.) injection of normal saline (0.3 mL) on postpartum (day 10); G2, i.p. injection of aqueous extract of garlic (1 mL/kg body weight) and s.c. injection of normal saline (0.3 mL) on postpartum (day 10); G3, s.c. injection of sodium selenite (20 nmol/g body weight) and i.p. injection of normal saline (0.3 mL) on postpartum (day 10); and G4, s.c. injection of sodium selenite (20 nmol/g body weight) and i.p. injection of aqueous extract of garlic (1 mL/kg body weight) on postpartum (day 10). Daily i.p. injections of aqueous extract of garlic (in G2 and G4) and normal saline (in G1 and G3) were continued for 14 days. The development of cataract was assessed over a period of 2 weeks after injection of sodium selenite. For further examination, the rats' lenses were removed and analyzed for glutathione (GSH), malondialdehyde (MDA) levels, and superoxide dismutase (SOD), glutathione peroxidase (GPX) activities.

RESULTS

In G3 (Se-treated group), all rats developed grade 3 cataract in both eyes. However, in G1 (untreated control group), G2 (Ga-treated group), and G4 (Ga-Se-treated group), the lenses in both eyes of all rats remained clear (P < 0.0001). This clinical finding was associated with higher GSH level and GPX, SOD activities and lower level of MDA in the Se- and Ga-treated group (G4) compared with SS-treated group (G3) rat lenses (P < 0.003).

CONCLUSIONS

Intraperitoneal injection of the Ga in rat model appeared to effectively prevent Se-induced cataract, thus such herbal remedy may be considered for treatment of cataract.

Nutraceutical use of garlic sulfur-containing compounds

Garlic is one of the world's oldest medicines that has been employed not only for flavouring but also as a medical herb for its prophylactic and therapeutic actions. Most garlics' beneficial effects are due to the presence of the organosulphate molecule allicin. Allicin is a highly unstable molecule and, during processing, is rapidly transformed into a variety of organosulfur components. The enzyme alliinase, which is responsible for the conversion of alliin to allicin, is irreversibly destroyed at the acidic environment of stomach. This is the reason why most garlic supplements contain garlic powder or granules, but do not contain allicin itself. Garlic alliinase could be encapsulated and coated with materials which would protect it in the harsh conditions of the stomach. The objective of this chapter is to summarize the most important garlic health benefits and to discuss promising encapsulation/stabilization approaches.

Pollution dilemma in Asian population: CNG and wound healing

Automobile exhaust constituents contribute significantly to air pollution in urban areas and compressed natural gas (CNG) is considered one of the most promising fuel alternatives for the future. CNG-powered four-stroke engine auto-rickshaws are ubiquitous in South Asian cities as taxi and for commercial transportation. Automotive exhaust contains several toxins, which are overwhelmingly toxic to the processes of wound healing. By utilizing the in vivo mouse model of wound healing, this report analyzes the effects of CNG-powered four-stroke auto-rickshaws smoke solution (4SARSS) on different events of wound healing; dermal matrix regeneration, re-epithelialization and neovascularization. A total of 72 adult mice, divided in eight groups were exposed to 4SARSS for 12 days. A highly significant reduction (P<0.001) in wound closure was observed among all 4SARSS treated groups, at each time point of the experiment. An immature development in both the neoepidermis and the neodermis was observed among all 4SARSS treated wounds with defective re-epithelialization, dermal matrix regeneration and maturation of collagen bundles. Abbott curve, angular spectrum, 3D surface topographies, and histological investigations of wounds explicated highly significant activation (P<0.001) of delayed-neovascularization among 4SARSS treated wounds. All these annotations advocate excessive toxicity of emission from CNG-powered auto-rickshaws to the process of wound healing and people occupationally exposed to this toxic emissions may suffer varying degree of delayed wound healing.

Effect of aged garlic extract on wound healing: a new frontier in wound management

Successful wound healing depends upon angiogenesis, and impaired angiogenesis is a hallmark of the chronic wounds encountered with diabetes and venous or arterial insufficiency. To intervene and improve wound closure, it is essential to investigate the effects of different natural remedies in wound healing. The chicken dorsum skin excisional wound assay was used to investigate the influence of different concentrations of aged garlic solution (AGS) on wound healing. Gross, histopathology, scanning electron microscopy (SEM) and computer-based three-dimensional (3D) image-probing techniques were utilized to determine the effects of AGS on wound closure, re-epithelialization, dermal matrix regeneration, and angiogenesis. Ninety chicks, aged 1 week and divided in 6 groups, were topically exposed to different concentrations of AGS for 6 days: control (group A), 1% (group B), 5% (group C), 10% (group D), 15% (group E), and skin lotion (group F). Different patterns, ranging from incomplete to almost complete wound closure, were observed among different groups with highly significant results (P < 0.001) in group E. Histological investigations revealed a positive augment in the re-epithelialization of all AGS exposed wounds. An increase in the number of new loosely packed collagen and maturation of collagen bundles was observed in all treated wounds at days 4 and 6 post-wounding, respectively. Similar results were achieved through SEM of treated wounds. Histological investigations revealed the profuse dose-dependent neovascularization among AGS-treated wounds. Abbott curve, angular spectrum, and different parameters of 3D surface roughness of wounds were also measured for the precise quantification of angiogenesis. A very highly significant (P < 0.001) increase in angiogenesis was observed among all treated groups. No significant change was observed among control and skin lotion-treated groups. These observations substantiate the beneficial use of AGS in the treatment of wounds. Additional studies are needed to study the specific wound-healing mechanisms of chemical, or group of chemicals, present in AGS.

Garlic: nature's protection against physiological threats

Currently reliance on natural products is gaining popularity to combat various physiological threats including oxidative stress, cardiovascular complexities, cancer insurgence, and immune dysfunction. The use of traditional remedies may encounter more frequently due to an array of scientific evidence in their favor. Garlic (Allium sativum) holds a unique position in history and was recognized for its therapeutic potential. Recent advancements in the field of immunonutrition, physiology, and pharmacology further explored its importance as a functional food against various pathologies. Extensive research work has been carried out on the health promoting properties of garlic, often referred to its sulfur containing metabolites i.e. allicin and its derivatives. Garlic in its preparations are effective against health risks and even used as dietary supplements such as age garlic extract (AGE) and garlic oil etc. Its components/formulations can scavenge free radicals and protect membranes from damage and maintains cell integrity. It also provides cardiovascular protection mediated by lowering of cholesterol, blood pressure, anti-platelet activities, and thromboxane formation thus providing protection against atherosclerosis and associated disorders. Besides this, it possesses antimutagenic and antiproliferative properties that are interesting in chemopreventive interventions. Several mechanisms have been reviewed in this context like activation of detoxification phase-I and II enzymes, reactive oxygen species (ROS) generation, and reducing DNA damage etc. Garlic could be useful in preventing the suppression of immune response associated with increased risk of malignancy as it stimulates the proliferation of lymphocytes, macrophage phagocytosis, stimulates the release of interleukin-2, tumor necrosis factor-alpha and interferon-gamma, and enhances natural killer cells. In this paper much emphasis has been placed on garlic's ability to ameliorate oxidative stress, core role in cardiovascular cure, chemopreventive strategies, and indeed its prospective as immune booster.

Toxicological evaluation of the effects of 2-stroke auto-rickshaw smoke solutions on wound healing

Vehicle exhaust from traffic is a widespread air pollutant. The use of 3-wheel auto-rickshaws powered by a 2-stroke engine is widespread in south Asia; exhaust from these vehicles may cause different types of toxicities resulting in different pathologies. The aim of this study was to explore the association between exposure to 2-stroke auto-rickshaw smoke solution (2SARSS) and wound healing. The in vivo model of wound healing was customized to evaluate different stages of wound healing: dermal matrix regeneration, re-epithelialization, and neovascularization. A total of 72 adult mice were divided into 8 groups and exposed to 2SARSS for 12 days. A highly significant reduction (p<0.001) in wound closure was observed among all 2SARSS-treated groups at day 8 post-wounding. Histological examination revealed a significant delay in the outcome of re-epithelialization, dermal matrix regeneration, and maturation of collagen bundles among all 2SARSS-exposed wounds. Delayed activation of neovascularization was seen in the 2SARSS-treated groups at day 12 post-wounding. The Abbot curve, angular spectrum, and several other 3D surface parameters of reverse wound topographies revealed a highly significant reduction (p<0.001) in angiogenesis. These results demonstrate that application of 2SARSS causes a substantial delay in the progression of angiogenesis, resulting in delayed onset of wound healing. These observations validate the damaging effects of 2SARSS on wound healing. Thus, people who are directly or indirectly exposed to this toxic exhaust are expected to have delayed wound healing, which could result in chronic wounds.

Allicin, a major component of garlic, inhibits apoptosis in vital organs in rats with trauma/hemorrhagic shock

OBJECTIVE

Allicin is believed to be the main component responsible for the biological activity of garlic. The regulation of cell apoptosis may have therapeutic potential for trauma/hemorrhagic shock, and previous studies have demonstrated that allicin exerts protective effects against tissue ischemia-reperfusion injury. Therefore, this study examined the effects of allicin on apoptosis-related organ damage, induced by trauma/hemorrhagic shock.

METHODS

Studies were performed on an in vivo model of spontaneously breathing rats with induced trauma/hemorrhagic shock; the left lower lobe of the lungs, left kidney, and intestine were resected, and the rats were subjected to femur fracture, ischemia for 30 mins, and reperfusion for 20 mins. Allicin (30 microg/kg) was administered during reperfusion.

RESULTS

Allicin administered during reperfusion markedly attenuated injury and apoptosis of the lungs, kidneys, and intestine and decreased the concentrations of lactic acid and creatinine, the number of in situ TdT-mediated dUTP nick-end labeling-positive cells, and the activity and expression of caspase-3 and -9 (as determined by Western blot). Furthermore, immunohistochemistry and Western blot performed 24 hrs after reperfusion revealed increases in the levels of nuclear factor kappaB, phosphorylated p38, and extracellular signal-regulated kinase 1 mitogen-activated protein kinase in the allicin-untreated group when compared with the sham rats. Allicin treatment downregulated the levels of nuclear factor kappaB and phosphorylated p38 mitogen-activated protein kinase but did not modify those of phosphorylated extracellular signal-regulated kinase 1 mitogen-activated protein kinase.

CONCLUSION

Allicin attenuates tissue injury and inhibits trauma/hemorrhagic shock- and reperfusion-induced apoptosis in several important organs via the p38 mitogen-activated protein kinase signal transduction pathway that functions to stimulate the activation of nuclear factor-kappaB, caspase-3 and -9, but not of extracellular signal-regulated kinase 1 mitogen-activated protein kinase.

Role of garlic in the prevention of ischemia-reperfusion injury

Garlic in different forms has antioxidant properties. These properties are shown to be due to the existence of compounds such as water soluble organosulfur compounds, S-allylcysteine and lipid soluble compounds like diallyl sulfide. The in vivo and in vitro ischemia reperfusion studies showed that prophylactic administration of aqueous garlic prior to ischemia reperfusion inhibit lipid peroxidation and prevent depletion in glutathione through its compounds that led to functional recovery. Its ability to inhibit neutrophil migration could suppress fibrosis formation. These preventive effects are seen in models that studied organs such as kidney and liver with functional recovery. Organ system specific activity such as angiotensin converting enzyme-inhibiting activity contributes to a cardioprotective and blood pressure lowering effect. Future studies should focus on post ischemia reperfusion administration of garlic to explore its rescue potential rather than prophylactic impact. Bench research findings should be translated into clinical use through human studies.

Novel pharmacological approaches to the treatment of renal ischemia-reperfusion injury: a comprehensive review

Renal ischemia-reperfusion (I-R) contributes to the development of ischemic acute renal failure (ARF). Multi-factorial processes are involved in the development and progression of renal I-R injury with the generation of reactive oxygen species, nitric oxide and peroxynitrite, and the decline of antioxidant protection playing major roles, leading to dysfunction, injury, and death of the cells of the kidney. Renal inflammation, involving cytokine/adhesion molecule cascades with recruitment, activation, and diapedesis of circulating leukocytes is also implicated. Clinically, renal I-R occurs in a variety of medical and surgical settings and is responsible for the development of acute tubular necrosis (a characteristic feature of ischemic ARF), e.g., in renal transplantation where I-R of the kidney directly influences graft and patient survival. The cellular mechanisms involved in the development of renal I-R injury have been targeted by several pharmacological interventions. However, although showing promise in experimental models of renal I-R injury and ischemic ARF, they have not proved successful in the clinical setting (e.g., atrial natriuretic peptide, low-dose dopamine). This review highlights recent pharmacological developments, which have shown particular promise against experimental renal I-R injury and ischemic ARF, including novel antioxidants and antioxidant enzyme mimetics, nitric oxide and nitric oxide synthase inhibitors, erythropoietin, peroxisome-proliferator-activated receptor agonists, inhibitors of poly(ADP-ribose) polymerase, carbon monoxide-releasing molecules, statins, and adenosine. Novel approaches such as recent research involving combination therapies and the potential of non-pharmacological strategies are also considered.

The bioactivity of processed garlic (Allium sativum L.) as shown in vitro and in vivo studies on rats

Garlic (Allium sativum L.) is widely used as an obligatory part in many cooked dishes loosing during this process a certain part of its bioactivity. Antioxidant capacity measured by the ferric-reducing/antioxidant power (FRAP) method and by the 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical assay was the highest in raw and in a short time processed garlic samples by cooking. 70 Wistar rats were randomly divided into 10 diet groups, each of seven. They were named Control, NPG, PG1, PG2, PG3, Chol, Chol/NPG, Chol/PG1, Chol/PG2 and Chol/PG3. The rats of the Control group were fed basal diet (BD), which included wheat starch, casein, soybean oil, cellulose, mineral and vitamin mixtures. To the BD of the nine other groups were added 25mg of lyophilized non processed garlic equivalent of 500 mg non processed garlic/kg body weight (NPG), the same quantity of processed garlic for 20, 40 and 60 min for PG1, PG2 and PG3, respectively, 1% of cholesterol (Chol), 1% of cholesterol and 25mg/kg body weight of lyophilized non processed garlic (Chol/NPG), 1% of cholesterol and the same quantity of processed garlic for 20, 40 and 60 min for Chol/PG1, Chol/PG2 and Chol/PG3, respectively. The dose of 500 mg (25mg of lyophilized garlic/kg body weight) was chosen as the most effective (Banerjee, S.K., Maulik, M., Mancahanda, S.C., Dinda, A.K., Gupta, S.K., Maulik, S.K., 2002. Dose-dependent induction of endogenous antioxidants in rat heart by chronic administration of garlic. Life Sciences 70, pp. 1509-1518). Plasma lipid profile and the total antioxidant capacity in rats significantly differed in diet groups with addition of garlic samples cooked for a long time. In summary, garlic cooked for a short time preserves a high bioactivity of non processed garlic. The diet supplemented with these samples and cholesterol improved lipid indices, decreased fibrinogen and increased antioxidant activity in plasma of rats. Therefore, for preservation of garlic bioactivity optimal regime has to be used.

Cytoprotective and antioxidant role of diallyl tetrasulfide on cadmium induced renal injury: An in vivo and in vitro study

Cadmium (Cd) is an environmental and industrial pollutant that affects various organs in humans and animals. A body of evidence has accumulated implicating the free radical generation with subsequent oxidative stress in the biochemical and molecular mechanisms of Cd toxicity. Since kidney is the critical target of Cd toxicity, we carried out this study to investigate the effects of diallyl tetrasulfide (DTS), an organosulfur compound derived from garlic on Cd induced toxicity in the kidney of rats and also in the kidney cell line (vero cells). In experimental rats, subcutaneous administration of Cd (3 mg/kg bw/day) for 3 weeks induced renal damage, which was evident from significantly increased levels of serum urea and creatinine with significant decrease in creatinine clearance. A markedly increased levels of lipid peroxidation markers (thiobarbituric acid reactive substances and lipid hydroperoxides) and protein carbonyl contents with significant decrease in nonenzymic antioxidants (total sulphydryl groups, reduced glutathione, vitamin C and vitamin E) and enzymic antioxidants (superoxide dismutase, catalase, glutathione peroxidase and glutathione-S-transferase) as well as glutathione metabolizing enzymes (glutathione reductase, and glucose-6-phosphate dehydrogenase) were also observed in Cd intoxicated rats. Coadministration of DTS (40 mg/kg bw/day) and Cd resulted in the reversal of the kidney function accompanied by a significant decrease in lipid peroxidation and increase in the antioxidant defense system. In vitro studies with vero cells showed that incubation of DTS (5-50 microg/ml) with Cd (10 microM) significantly reduced the cell death induced by Cd. DTS at 40 microg/ml effectively blocked the cell death and lipid peroxidation induced by Cd (10 microM) indicating its cytoprotective property. Further, the flow cytometric assessment on the level of intracellular reactive oxygen species using a fluorescent probe 2', 7'-dichlorofluorescein diacetate (DCF-DA) confirmed the Cd induced intracellular oxidative stress in vero cells, which was significantly suppressed by DTS (40 microg/ml). The histopathological studies in the kidney of rats also showed that DTS (40 mg/kg bw/day) markedly reduced the toxicity of Cd and preserved the architecture of renal tissue. The present study suggests that the cytoprotective potential of DTS in Cd toxicity might be due to its antioxidant and metal chelating properties, which could be useful for achieving optimum effects in Cd induced renal damage.

Behavioral and Histologic Neuroprotection of Aqueous Garlic Extract After Reversible Focal Cerebral Ischemia

The objective of the present study was to investigate the effects of aqueous garlic extract (AGE) on neurobehavioral activities, malondialdehyde (MDA) and reduced glutathione (GSH) levels, glutathione peroxidase (GPx), glutathione reductase (GR), glutathione S-transferase (GST), superoxide dismutase (SOD), catalase (CAT), and sodium-potassium ATPase (Na(+),K(+)-ATPase) activities, and glutamate and aspartate content in a middle cerebral artery (MCA) occlusion (MCAO) model of acute cerebral ischemia in rats. The right MCA of male Wistar rats was occluded for 2 hours using intraluminal 4-0 monofilament, and reperfusion was allowed for 22 hours. MCAO caused significant depletion in GSH and its dependent enzymes (GPx, GR, and GST) and significant elevation of MDA, glutamate, and aspartate. The activities of Na(+),K(+)- ATPase, SOD, and CAT were decreased significantly by MCAO. The neurobehavioral activities (grip strength, spontaneous motor activity, and motor coordination) were also decreased significantly in the MCAO group. All of the alterations induced by ischemia were significantly attenuated by pretreatment with AGE (500 mg/mL/kg of body weight, i.p.) 30 minutes before the induction of MCAO and correlated well with histopathology by decreasing the neuronal cell death following MCAO and reperfusion. These findings suggest that AGE effectively modulates neurobehavioral and neurochemical changes in focal ischemia, most probably by virtue of its antioxidant properties.