Enhanced antitumor activity of doxorubicin by naringenin and metformin in breast carcinoma: an experimental study.

Breast cancer is the most common malignancy in women worldwide. Strategies for cancer chemotherapy commonly require the use of combination therapy for better outcomes of results. The present work is aimed to evaluate the potential of naringenin and metformin concomitant addition with doxorubicin chemotherapy against experimental breast carcinoma. The antitumor potential of drugs under the study was evaluated against methylnitrosourea (MNU)-induced breast cancer in rats and 4T1 cells-induced orthotopic breast cancer mouse model. Parameters like tumor growth, body weight, survival rate, blood glucose, hematology, and histology were determined. There was a marked reduction in tumor weight and an observed decrease in tumor multiplicity by naringenin and metformin concomitant addition with doxorubicin against MNU-induced breast carcinoma. Likewise, naringenin and metformin with doxorubicin showed a significant reduction of tumor volume and tumor weight (p < 0.01) in 4T1-induced orthotopic mouse model as compared to the same dose of doxorubicin alone, suggesting combination treatment enhanced antitumor activity in vivo. Furthermore, histology of tumor biopsies presented the improved antitumor activity of doxorubicin via increasing tumor necrosis. Hematological parameters, body weight, and survival data presented remarkable safety of combination treatment without compromising efficacy using 50% lower dose of doxorubicin as compared to the large dose of doxorubicin alone. These results demonstrate that naringenin and metformin enhanced the antitumor effect of doxorubicin in animal models of breast carcinoma, and therefore can be useful as an adjunct treatment with doxorubicin to increase its effectiveness at the lower dose level for the treatment of cancer.

Combining naringenin and metformin with doxorubicin enhances anticancer activity against triple-negative breast cancer in vitro and in vivo.

Triple-negative breast cancer (TNBC) grows fast and represents poor prognosis and management. This work is aimed to determine the effect of concomitant use of naringenin and metformin with doxorubicin chemotherapy using in vitro and in vivo breast carcinoma models. Cell viability and xenograft study were performed using TNBC cell lines. The use of naringenin and metformin together with doxorubicin, have shown a significant increase in cytotoxicity when compared with the same concentration of doxorubicin alone in MDA-MB-231 cells and 4T1 cells in vitro. In the xenograft mouse model, a significant reduction of tumor volume and tumor weight was observed in contrast to a similar dose of doxorubicin alone; suggesting combining treatment enhanced antitumor activity in vivo. Besides, H&E and Ki-67 staining of tumor biopsies showed enhancement of the antitumor activity via increasing necrosis and inhibiting cell proliferation respectively. Additionally, there was no marked change observed in the organ weights, blood glucose, cardiac histology and cardiac Troponin I levels under the study treatment groups. The beneficial effects of using both the naringenin and metformin along with the lower dose of doxorubicin were evident from the reduced dose-related body weight loss and increase in cytokines (TNF-α and IL-1ß) compared to a large dose of doxorubicin alone. Thus, naringenin and metformin combination with doxorubicin found useful as an adjunct therapy to improve the effectiveness of doxorubicin at the lower dose against the breast carcinoma.

Antidiabetic activity of Cassia angustifolia Vahl. and Raphanus sativus Linn. leaf extracts.

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Investigation of the effects of vanilloids in chronic fatigue syndrome.

AIM OF THE STUDY: To assess the effectiveness of TRPV1 modulators in animal model of Chronic fatigue syndrome (CFS). To assess central and peripheral behavioral activity of TRPV1 modulators. MATERIAL AND METHODS: CFS was induced by forcing the rats to swim for 10min for 21 consecutive days. The rats were treated with capsaicin (TRPV1 agonist, 2.5mg/kg) and n-tert-butylcyclohexanol (TRPV1 antagonist, 10mg/kg) for 21days 30min before the exposure to stress procedure. The behavioral consequence of CFS was measured in terms of immobility time, grip strength, locomotor activity, and anxiety level using Rota rod, Actophotometer, and Elevated plus maze model respectively. The other parameters include Plasma corticosterone, adrenal gland and spleen weight, complete blood count, blood urea niterogen (BUN), Lactate dehydrogenase (LDH), Lipid peroxidation, catalase and reduced glutathione (GSH). RESULTS AND DISCUSSION: TRPV1 modulators reversed (p<0.05) the increase in immobility period, anxiety, spleen weight, BUN and LDH levels, and MDA levels along with decrease in grip strength, locomotor activity, plasma corticosterone, adrenal gland weight, catalase, and GSH. There was also significant increase in total WBC count when compared with the disease control group. The reversal was attributed to modulation of HPA axis, oxidative stress, anaerobic respiration product, muscle degradation product. CONCLUSION: The present study reveals the effectiveness of n-tert-butylcyclohexanol and capsaicin against chronic fatigue syndrome. The mechanism of action can be attributed to inhibition of TRPV1 channel and thereby modulating pain perception, neuroendocrine function, oxidative stress and immune function.

Beneficial effect of aspirin against interferon-α-2b-induced depressive behavior in Sprague Dawley rats.

Accumulating data advocates that inflammatory mediators may contribute to depression in experimental models as well as in humans. Nonetheless, whether anti-inflammatory treatments can prevent depression still remains controversial. To substantiate our hypothesis, we used an interferon-α-2b model of depression using Sprague Dawley rats. Interferon-α-2b is a cytokine which activates immune response and also produces depression. The animals were treated for 21 days with aspirin (10 mg/kg, per oral (p.o.)) dexamethasone (1 mg/kg p.o.) and amitriptyline (10 mg/kg p.o.). Amitriptyline was used as reference standard, and given concurrently with aspirin and dexamethasone to examine any synergy. Interferon-α-2b (6000 IU/kg, intraperitoneal (i.p.)) was administered in all the above groups daily, except normal control. Tests performed included sucrose preference test, behavioural tests like forced swim test, elevated plus maze, light dark box and locomotor activity along with biochemical estimations like serum cortisol and brain neurotransmitters. The rats in the group treated with Interferon-α-2b produced depressive behaviour in rats. We found that animals treated with aspirin decreased immobility time in forced swim test, increased sucrose preference, decreased serum cortisol and increased brain serotonin levels signifying antidepressant action. In contrast, there was no effect in groups treated with dexamethasone. Our results suggest that aspirin can serve as a potential antidepressant both individually and as adjuvant agent in the treatment of depression. Inhibition of the cyclo-oxygenase-2 levels and prostaglandins concentration or any other potential physiological and biochemical mechanisms may be involved in antidepressant effect.

Role of Aspirin and Dexamethasone against Experimentally Induced Depression in Rats.

A large number of current studies indicate that inflammatory mediators may contribute to depression in experimental models as well as in human beings. Nevertheless, the subject, whether anti-inflammatory treatments can prevent depression still remains controversial. In the present study, a chronic mild stress (CMS) model of male Sprague Dawley rats was used to investigate the role of anti-inflammatory drugs in the treatment of depression. All the animals in different groups, except the normal control group, were exposed to CMS procedure for 28 days and concurrently treated with aspirin (10 mg/kg, p.o.), dexamethasone (1 mg/kg p.o.) and amitriptyline (10 mg/kg p.o., reference standard), respectively. Amitriptyline was also used in combination with aspirin and dexamethasone to inspect any synergistic effects. Tests performed towards the end of the study included sucrose preference test, behavioural tests like forced swim test, elevated plus-maze, light/dark box, locomotor activity and biochemical estimations like serum cortisol and brain neurotransmitters. Disease control group (CMS-treated) produced significant depressive behaviour in rats. The animals treated with aspirin showed increased sucrose preference, decreased immobility time in forced swim test, decreased serum cortisol and increased brain serotonin levels signifying antidepressant action. In contrast, there was aggravation of depressive behaviour in rats treated with dexamethasone. Together, these findings suggest that aspirin can serve as a potential antidepressant both individually and as adjunctive agent in the treatment of depression. Inhibition of the inflammatory mediators during stress procedures or any other potential physiological and biochemical mechanisms may be involved in its antidepressant effect.

Evaluation of adverse effects of lisinopril and rosuvastatin on hematological and biochemical analytes in wistar rats.

OBJECTIVE: Combination therapy of lisinopril and rosuvastatin may be an important concept in developing more effective strategies to treat and prevent atherosclerosis, coronary heart disease, and co-morbid metabolic disorders. The present study was designed to evaluate toxic effects of lisinopril and rosuvastatin alone or its combination therapy on hematological and biochemical analytes in Wistar rats. MATERIALS AND METHODS: Forty-two rats were divided into seven groups, with each group comprising six rats. Rats were administered with lisinopril, rosuvastatin alone, or in-combination at two different doses. The blood samples were collected from rats after 21 days of oral administration of the drug/s and analyzed for various hematological and biochemical analytes. RESULTS: Lisinopril alone and its combination treatment with rosuvastatin at high doses decreased hemoglobin and hematocrit. Rosuvastatin alone at high dose and its concomitant administration with lisinopril at two different doses showed increase in total white blood cells and absolute lymphocyte count and neutrophil count. Serum levels of aspartate aminotransferase (AST), alkaline phosphatase (ALP), and total bilirubin were significantly increased in rosuvastatin alone and its combination with lisinopril at both the doses. Besides this, lisinopril treatment decreased serum levels of sodium and increased the levels of potassium. Serum creatine kinase (CK) levels were increased in the animals treated with rosuvastatin at both the doses. However, increased serum CK level because of rosuvastatin became normal with co-administration of lisinopril at low doses. CONCLUSION: Our results indicate that administration of lisinopril with rosuvastatin does not ameliorate hepatotoxicity caused by rosuvastatin. However, combination treatment reduces serum CK levels elevated due to rosuvastatin, implicating protective effect of combination treatment on myopathy at low doses.

Reversal of experimentally induced seizure activity in mice by glibenclamide.

BACKGROUND: ATP sensitive potassium channels are widely distributed in central nervous system (CNS) and these channels could be the target in CNS disorders by their modulators. PURPOSE: The present study was designed to investigate the anticonvulsant potential of glibenclamide on MES induced seizure and pentylenetetrazole induced seizure in mice. METHODS: Seizures were induced in 7 months albino mice with a single 12 mA intensity of 50 Hz stimulus for 0.2 s using electroconvulsiometer. Tonic flexion, tonic extension, clonic convulsion and mortality protection were recorded, 60 minutes after the oral administration of the vehicle (3% Tween 80), Standard (diazepam 3 mg/kg i.p.) and glibenclamide (5 mg/kg). In second model, seizures were induced with a single convulsive dose (80 mg/kg i.p) of pentylentetrazole (PTZ). Seizures were assessed in terms of onset of seizure, number of jerks, onset of tonic convulsion and clonic convulsions and mortality protection. The study was performed at antidiabetic dose of glibenclamide 5 mg/kg per oral. RESULTS: Glibenclamide (5 mg/kg p.o.) showed significant (p<0.05) protective activity in MES induced seizures and attenuated pentylenetetrazole-induced seizure activity in mice. The anticonvulsant action of glibenclamide was noticeable in this study. However, further studies are required to elucidate its full anticonvulsant potential. CONCLUSIONS: Glibenclamide is able to exert protective effects in MES induced seizures and attenuates pentylenetetrazole induced seizure activity in mice.

Evaluation of antiulcer potential of Mimusops hexandra in experimental gastro duodenal ulcers.

The study was aimed to investigate antiulcer effects of acetone extract and its different fractions Mimusops hexandra against experimental gastro-duodenal ulcers. 80% acetone extract of stem bark of Mimusops hexandra (Extract A, p.o.) and its different fractions namely diethyl ether (Extract A1, p.o.), ethyl acetate (Extract A2, p.o.) and aqueous (Extract A3, p.o.) were tested for the presence of preliminary phytoconstituents and were screened for their antiulcer potential in experimental animals using ethanol-HCl and aspirin-induced gastric damage at the dose of 500 mg kg-1p.o. Extract A2 being the most active fraction amongst all the fractions tested was also studied at different doses to find its ED50. Further, to establish the mechanism of action, Extract A2 was also tested for its effects in acetic acid-induced gastric ulcer models and cysteamine-induced duodenal ulcer. The effect was compared with cimetidine. Flavonoids (quercetin), procyanidins, saponins and triterpenoids were found to be present in bark. Oral administration of Extract A2 inhibited formation of gastric lesions induced by aspirin in a dose dependent manner. Elevated level of lipid peroxidation due to ethanol-HCl and aspirin induced gastric damage was significantly (p<0.05) reduced by the treatment with Extract A2. Further, Extract A2 at the dose of 100 mg kg-1 (p.o.) reduced extent of acetic acid induced gastric ulcer in experimental animals. Moreover, protection afforded by Extract A2 against cysteamine-induced duodenal lesions was evident from dose dependent decrease in ulcer index (p<0.05), score for intensity (p<0.05) and total lesion area (p<0.05), when compared with the control group. The antiulcer activity shown by Extract A2 in experimental gastro-duodenal ulcer could be attributed to decrease in gastric acid secretory activity along with strengthening of mucosal defensive mechanisms.

Renal toxicity of lisinopril and rosuvastatin, alone and in combination, in Wistar rats.

The aim of study was to evaluate the effect of commonly used lisinopril, rosuvastatin and their combined action on site-specific nephrotoxicity in rats using clusterin and microalbumin nephrotoxic biomarkers and other related parameters using oral gavage. Rosuvastatin at 2 different doses showed increase in urinary microalbumin levels whereas lisinopril and its combination with rosuvastatin at 2 different doses did not show urinary microalbumin excretion indicating beneficial effects of lisinopril in terms of reducing microalbumin. Urinary clusterin levels significantly increased in high-dose treated animals of lisinopril and rosuvastatin. The use of lisinopril plus rosuvastatin at low dose also led to worsened renal function by raising urinary clusterin levels (217 ± 4.6 ng/ml) when compared with the control (143 ± 3.3 ng/ml). Renal histopathology showed multifocal regeneration of tubules indicating proximal tubule damaged. These results indicate that lisinopril (50 mg/kg), rosuvastatin (100 mg/kg), lisinopril+rosuvastatin (20+40 mg/kg) and lisinopril+rosuvastatin (50+100 mg/kg) showed toxicity only on proximal tubules.

A novel use of methylene blue as a pharmacological tool.

INTRODUCTION: A new use of methylene blue as an ulcerogenic agent and the mechanisms involved were identified with an objective to exploit methylene blue as a pharmacological tool to study investigational antiulcer agents. METHODS: Ulcerogenic potential was assessed using electron microscopy and measurement of an ulcer index after administering methylene blue (5-125 mg kg(-1), p.o.) or absolute ethanol (99%v/v, 2 ml, p.o.) to fasted rats. Estimation of thiobarbituric acid reactive substances, superoxide dismutase, reduced glutathione and catalase was used to assess oxidative stress. H(+)/K(+) ATPase activity, gastric mucosal blood flow and gastric acid secretion were measured to study the mechanism of methylene induced gastric ulcer. RESULTS: Methylene blue (100 mg kg(-1), p.o.) produced marked ulceration of the gastric mucosa due to increased levels of thiobarbituric acid reactive substances, activities of the H(+)/K(+) ATPase and superoxide dismutase, and decreased blood flow to the gastric mucosa, activity of catalase combined with reduced glutathione levels. DISCUSSION: It may be concluded that methylene blue activates the H(+)/K(+) ATPase to increase gastric acid secretion and reduces blood supply to gastric mucosa to produce oxidative stress that subsequently causes ulceration of gastric mucosa. Methylene blue can be used as an ulcerogenic agent to study mechanisms of investigational antiulcer agents.

Study of Mimusops elengi bark in experimental gastric ulcers.

The present study was designed to investigate the effect of Mimusops elengi (Sapotaceae) against experimental gastric ulcers. The 50% alcoholic extract of Mimusops elengi (Ext E) and its different fractions namely ethyl acetate (Ext E1), n-butanol (Ext E2), methanol (Ext E3) and aqueous (Ext E4) were studied (p.o.) against ethanol-induced gastric damage. Ext E1 was also studied in ethanol-induced, pylorus-ligated and water-immersion plus stress-induced gastric ulcer models. Ranitidine HCl (80 mg kg(-1)) was used as a reference standard. In ethanol-induced gastric ulcer model, pantoprazole (20 mg kg(-1)) was also used as a reference standard. Ext E1 tested in mice up to the dose of 5000 mg kg(-1) (p.o.) did not produce any sign of toxicity. Ext E at the doses of 50, 100, 300 and 500 mg kg(-1) and its different fractions (100 mg kg(-1)) showed reduction in gastric ulceration (P < 0.05). Ext E1 at the doses of 10, 50 and 100 mg kg(-1) showed dose-dependent inhibition of gastric lesions against ethanol-induced gastric damage. In 19 h pylorus-ligated animals, Ext E1 at 50 and 100 mg kg(-1) doses showed significant reduction in ulcer index (P < 0.05). Significant reduction was also observed in total acidity, volume of gastric acid secretion, total acid output and pepsin activity (P < 0.05) when compared with the control group. Besides, Ext E1 showed increase in the mucosal glycoproteins that was evident from significant rise in total carbohydrates to protein ratio (TC:PR ratio) (P < 0.05), which is an indication of mucin activity. Ext E1 also showed protection against water-immersion plus stress-induced gastric lesions that was evident from dose-dependent decrease in ulcer index (P < 0.05), score for intensity (P < 0.05) and total lesion area (P < 0.05) when compared with the control group. It can be concluded from our study that Ext E1 possesses anti-ulcer activity against experimental gastric ulcers. The mechanism of anti-ulcer activity can be attributed to decrease in gastric acid secretory activity along with strengthening of mucosal defensive mechanisms.

Gastroprotective effect of beta3 adrenoreceptor agonists ZD 7114 and CGP 12177A in rats.

The effects of beta(3) adrenergic receptor agonists, (S)-4-[2-hydroxy-3-phenoxy-propylamino-ethoxy]-N-(2-methoxyethyl)-phenoxyacetamide (ZD 7114) and (+/-)-4-(3-t-butylamino-2-hydroxypropoxy)benzimidazol-2-one (CGP 12177A), were studied on aspirin plus pylorus ligation-induced gastric ulcers, gastric mucosal blood flow and gastric motility in rats. Pretreatment with ZD 7114 (3 mg kg(-1), p.o.) and CGP 12177A (3.5 mg kg(-1), p.o.) resulted in significant reduction in the incidences of gastric ulceration in aspirin plus pylorus ligated rats and results were comparable with the cimetidine treated group. Ulcer index was significantly reduced by ZD 7114 (0.71+/-0.05, P<0.05) and CGP 12177A (1.15+/-0.27, P<0.05) when compared with the control group (4.47+/-0.38). Further, significant increase in total carbohydrates to protein content ratio (mucin activity) was also observed. However, they did not alter the acid secretory parameters such as total acidity, total acid output and pepsin activity. Effects of ZD 7114 and CGP 12177A on gastric mucosal blood flow were studied using neutral red clearance method. Both the treatments showed significant increase in gastric mucosal blood flow (GV/Bt) as compared to control group. Effect on gastric motility was evaluated by estimation of phenol red concentration in rat stomach. Significantly higher concentrations of phenol red in the stomach were observed in ZD 7114 and CGP 12177A treated rats. Both ZD 7114 and CGP 12177A showed significant gastroprotective effect in the present study. The mechanism of this effect may be attributed to enhancement of gastric mucosal blood flow, reduction in gastric motility and strengthening of gastric mucosal barrier.

Effect of SR 58611A, a beta-3 receptor agonist, against experimental gastro-duodenal ulcers.

The present study was designed to study the effect of SR 58611A, a selective beta 3-adrenoceptor agonist against gastric ulcers: pylorus ligation, water immersion plus restraint stress (WIRS), ethanol, aspirin-induced and on cysteamine-induced duodenal ulcers, in rats. SR 58611A (10 mg/kg, p.o.) was found to be effective in attenuating gastric ulceration and the results were comparable with those from standard cimetidine-treated group. Apart from reducing ulcer index, SR 58611A significantly decreased total acidity and thereby exhibited antisecretory activity in pylorus ligation model. SR 58611A showed significant reduction in ulcer index alongwith significant rise in the gastric wall mucus content in WIRS model. Further it showed significant cytoprotective activity against ethanol insult, that was evident from significant reduction in ulcer index. It showed significant reduction in gastric ulceration in aspirin-treated rats. The drug was found to be ineffective in inhibiting the cysteamine-induced duodenal ulcers as evident from the ulcer index and total lesion area parameters. It is concluded that SR 586111A possesses significant gastroprotective activity. This activity could be attributed to the inhibition of gastric acidity, increase in gastric wall mucus content and the reversal of gastric microvascular injury resulting into protection of the vascular integrity.