Protective effects of ethanolic neem leaf extract on DMBA-induced genotoxicity and oxidative stress in mice

We evaluated the effects of pretreatment with ethanolic neem leaf extract on 7,12-dimethylbenz[a]anthracene (DMBA)-induced genotoxicity and oxidative stress in male Swiss albino mice. The frequency of bone marrow micronuclei, the extent of hepatic lipid peroxidation and the status of antioxidants-reduced glutathione (GSH), glutathione peroxidase (GPx) and glutathione-S-transferase (GST) were used as intermediate biomarkers of chemoprotection. In DMBA-treated mice, the increases in micronuclei and lipid peroxides were accompanied by compromised antioxidant defenses. Pretreatment with ethanolic neem leaf extract (200 mg/kg body weight) significantly reduced DMBA-induced micronuclei and lipid peroxides and enhanced GSH-dependent antioxidant activities. The results of the present study suggest that ethanolic neem leaf extract exerts protective effects against DMBA-induced genotoxicity and oxidative stress by enhancing the antioxidant status.     

Protective effects of ethanolic neem leaf extract on N-methyl-N'-nitro-N-nitrosoguanidine-induced genotoxicity and oxidative stress in mice

We evaluated the effects of pretreatment with ethanolic neem leaf extract on N-methyl-N'-nitro-N-nitrosoguanidine (MNNG)-induced genotoxicity and oxidative stress in male Swiss albino mice. The frequency of micronuclei (MN), concentrations of lipid peroxides and the status of the antioxidants, reduced glutathione (GSH), glutathione peroxidase (GPx) and glutathione-S-transferase (GST) were used as intermediate biomarkers of chemoprotection. Animals were divided into four groups of five animals each. Animals in group 1 were given MNNG (40 mg/kg body weight) by intragastric intubation. Animals in group 2 received intragastric administration of ethanolic neem leaf extract at a concentration of 200 mg/kg body weight for 5 days followed by MNNG 1.5 h after the final feeding. Group 3 animals received ethanolic neem leaf extract alone for five days. Group 4 received the same volume of normal saline and served as control. The animals were sacrificed by cervical dislocation 27 h after the carcinogen exposure. In MNNG-treated mice, enhanced lipid peroxidation with compromised antioxidant defences in the stomach, liver and erythrocytes was accompanied by increase in bone marrow micronuclei. Pretreatment with ethanolic neem leaf extract significantly reduced MNNG-induced micronuclei and lipid peroxides and enhanced GSH-dependent antioxidant activities. The results of the present study demonstrate that ethanolic neem leaf extract exerts protective effects against MNNG-induced genotoxicity and oxidative stress by augmenting host antioxidant defence mechanisms.     

Modulatory effects of Aloe vera leaf gel extract on oxidative stress in rats treated with streptozotocin

Oxidative stress is currently suggested as a mechanism underlying diabetes and diabetic-related complications. Oxidative stress results from an imbalance between radical-generating and radical-scavenging systems. Many secondary plant metabolites have been reported to possess antioxidant activity. This study was designed to evaluate the potential antioxidative activity of the ethanolic extract from Aloe vera leaf gel in the plasma and pancreas of streptozotocin (STZ)-induced diabetic rats. Glibenclamide was used as a standard reference drug. Oral administration of ethanolic extract at a concentration of 300 mg kg(-1) body weight for 21 days resulted in a significant reduction in fasting blood glucose, thiobarbituric acid reactive substances, hydroperoxides and alpha-tocopherol and significant improvement in ascorbic acid, reduced glutathione and insulin in the plasma of diabetic rats. Similarly, the treatment also resulted in a significant reduction in thiobarbituric acid reactive substances, hydroperoxides, superoxide dismutase, catalase and glutathione peroxidase and significant improvement in reduced glutathione in the pancreas of STZ-induced diabetic rats when compared with untreated diabetic rats. The ethanolic extract appeared to be more effective than glibenclamide in controlling oxidative stress. Thus, this study confirms the ethnopharmacological use of Aloe vera in ameliorating the oxidative stress found in diabetes.     

N-methyl-N'-nitro-N-nitrosoguanidine (MNNG)-induced in vivo clastogenicity: protective effects of aqueous neem leaf extract

We evaluated the modifying effects of aqueous neem leaf extract on the in vivo clastogenicity of N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), a potent gastric carcinogen by quantitation of micronuclei and chromosomal aberrations in metaphase cells from the bone marrow of male Wistar rats. Intraperitoneal injection of MNNG (40 mg/kg body weight) induced a significant increase in the frequency of micronuclei and chromosomal aberrations. Pretreatment with aqueous neem leaf extract (100 mg/kg body weight) significantly reduced MNNG-induced increase in micronuclei and chromosomal aberrations. These results reveal the chemoprotective potential of aqueous neem leaf extract against the clastogenic effects of MNNG.     

Antibody response against neem leaf preparation recognizes carcinoembryonic antigen

An immune serum generated in Swiss mice against an aqueous preparation from neem leaf was reactive with carcinoembryonic antigen (CEA) and a peptide sequence derived from it. Using ELISA, we have demonstrated that CEA reactive antibody titer (chiefly IgG2a) was significantly decreased after absorption of the immune sera with CEA. Neem leaf preparation (NLP) generated immune sera was also reactive with CEA in immunoblotting and CEA reactive component in the NLP sera can be immunoprecipitated. Identical recognition of CEA expressed on human colorectal cancer specimens, by anti-CEA monoclonal antibody and NLP sera was documented by immunohistochemistry. NLP generated sera could also react with NLP in ELISA and this reactivity was decreased after absorption of the NLP with anti-CEA antibody. Estimation of protein in NLP revealed the presence of it, at least 10% of the total dry weight. In addition, existence of flavone and quercetin was also evidenced from LC-MS analysis. Further studies are needed to identify the antigenic component may have some homology with CEA molecule. This unique property of neem may be utilized for the immunotherapy of CEA positive tumors.     

Protective effects of Sesamum indicum extract against oxidative stress induced by vanadium on isolated rat hepatocytes

Vanadium toxicity is a challenging problem to human and animal health with no entirely understanding cytotoxic mechanisms. Previous studies in vanadium toxicity showed involvement of oxidative stress in isolated liver hepatocytes and mitochondria via increasing of ROS formation, release of cytochrome c and ATP depletion after incubation with different concentrations (25–200 µM). Therefore, we aimed to investigate the protective effects of Sesamum indicum seed extract (100–300 μg/mL) against oxidative stress induced by vanadium on isolated rat hepatocytes. Our results showed that quite similar to Alpha‐tocopherol (100 µM), different concentrations of extract (100–300 μg/mL) protected the isolated hepatocyte against all oxidative stress/cytotoxicity markers induced by vanadium in including cell lysis, ROS generation, mitochondrial membrane potential decrease and lysosomal membrane damage. Besides, vanadium induced mitochondrial/lysosomal toxic interaction and vanadium reductive activation mediated by glutathione in vanadium toxicity was significantly (P < 0.05) ameliorated by Sesamum indicum extracts. These findings suggested a hepato‐protective role for extracts against liver injury resulted from vanadium toxicity. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 979–985, 2016.     

Protective effects of Forsythia suspensa extract against oxidative stress induced by diquat in rats

Forsythia suspensa extract has been proved as a potential antioxidant in the recent years. The present study was undertaken to obtain the optimal antioxidant fraction in vitro and examine its antioxidative potential against diquat-induced oxidative stress in male Sprague Dawley rats in vivo. In vitro, 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging experiment indicated that the CH₂Cl₂ fraction of F. suspensa (FSC) exerted the strongest scavenging activities; forsythoside A, forythialan A and phillygenin from it might be the major antioxidant constituents. In vivo, pretreatment of rats with different doses of FSC (25, 50 and 100 mg/kg bw) and vitamin C (100 mg/kg bw, positive control) for 15 days significantly lowered the tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6) in plasma compared to the negative control group. Also, FSC significantly increased the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and the levels of glutathione (GSH) in plasma, liver and kidney whereas it decreased the levels of malondialdehyde (MDA) in plasma and kidney. Moreover, the protective effect of FSC (100 mg/kg bw) was better than vitamin C. These results revealed that FSC exerted a protective effect against diquat-induced oxidative stress and is worthy of becoming a potential dietary antioxidant.     

Protective effects of Phyllanthus amarus aqueous extract against renal oxidative stress in Streptozotocin -induced diabetic rats

Aim and Objectives:

In the present study, we have evaluated the antihyperglycemic, hypolipidemic and antioxidant activities of aqueous extract of Phyllanthus amarus (PAAEt) in streptozotocin (STZ)-induced diabetic rats.

Materials and Methods:

PAAEt was administered at 200 mg/kg body weight/day to normal treated (NT-group) and STZ-induced diabetic treated rats (DT-group) by gavage for eight weeks. During the experimental period, blood was collected from fasted rats at 10 days intervals and plasma glucose level was estimated. The plasma lipid profile was estimated at the end of experimental period. After the treatment, period kidney lipid peroxidation (LPO), protein oxidation and reduced glutathione (GSH) were estimated and antioxidant enzymes viz., glutathione reductase (GR), glutathione peroxidase (GPx) and glutathione-S-transferase (GST), catalase (CAT) and superoxide dismutase (SOD) were also assayed.

Results:

The significant decrease in the body weight, hyperglycemia and hyperlipidemia observed in STZ-induced diabetic rats (D-group) were rectified with PAAEt treatment in diabetic treated group (DT-group). D-group rats showed increased renal oxidative stress with increased LPO and protein oxidation. DT-group showed a significant decrease in renal LPO, protein oxidation and a significant increase in GSH content and GR, GPx and GST activities when compared with D-group. The activities of SOD and CAT decreased significantly in D-group, but were normalized in DT-group. Normal rats treated with PAAEt (NT-rats) showed a significant decrease in lipid profile, renal LPO and protein oxidation, with significant increase in renal GSH and activities of antioxidant enzymes compared to normal rats (N-group).

Conclusion:

Our results demonstrated that PAAEt with its antidiabetic, hypolipidemic and antioxidant properties could be a potential herbal medicine in treating diabetes and renal problems.     

In vivo antimalarial activity of ethanolic leaf extract of Stachytarpheta cayennensis

Objective:

To evaluate the in vivo antiplasmodial activity of the ethanol leaf extract of Stachytarpheta cayennensis in the treatment of various ailment in Niger Delta region of Nigeria, in Plasmodium berghei infected mice.

Materials and Methods:

The ethanolic leaf extract of Stachytarpheta cayennensis (90-270 mg/kg/day) was screened for blood schizonticidal activity against chloroquine sensitive Plasmodium berghei berghei in mice. The schizonticidal effect during early and established infections was investigated.

Result:

Stachytarpheta cayennensis (90-270 mg/kg/day) exhibited significant (P< 0.05) blood schizonticidal activity both in 4-day early infection test and in established infection with a considerable mean survival time comparable to that of the standard drug, chloroquine, 5 mg/kg/day.

Conclusion:

The leaf extract possesses significant (P< 0.05) antiplasmodial activity which confirms it''s use in folkloric medicine in the treatment of malaria.     

Protective effect of aqueous Curry leaf (Murraya koenigii) extract against cadmium-induced oxidative stress in rat heart

Treatment of rats with a low dose of cadmium chloride caused a significant damage in the rat cardiac tissue indicated by the increase in the level of serum glutamate oxaloacetate transaminase and lactate dehydrogenase1 activities. Histological studies confirmed the damage due to cadmium. That cadmium-induced tissue damage was caused due to oxidative stress was evident from the changes observed in the levels of lipid peroxidation and reduced glutathione, the protein carbonyl content, and the alterations in the activities of cardiac antioxidant and pro-oxidant enzymes. Treatment of rats with cadmium also caused alterations in the activities of mitochondrial Kreb’s cycle as well as respiratory chain enzymes. All these changes were ameliorated when the rats were pre-treated with an aqueous extract of Curry leaf (Murraya koenigii). The studies indicated that the aqueous extract of Curry leaf protects the rat cardiac tissue against cadmium-induced oxidative stress possibly through its antioxidant activity. As curry leaf is consumed by people as part of their diet in India and South-East Asian and some European countries as well, and, as it has no reported side-effects, the results seem to have relevance at places where humans are exposed to cadmium environmentally or occupationally.     

Protective effects of Semiaquilegia adoxoides n-butanol extract against hydrogen peroxide-induced oxidative stress in human lens epithelial cells

Context Hydrogen peroxide (H₂O₂)-induced damage in the lens epithelium leads to cell death and cataract. Semiaquilegia adoxoides (DC.) Makino (Ranunculaceae), a folk medicine of Hmong (an ethnic group of China), has been traditionally used to treat cataract; however, the underlying molecular mechanism is yet to be uncovered.

Objective This study aimed to investigate whether the n-butanol extract of S. adoxoides (nSA) is effective against the H₂O₂-induced oxidative stress in human lens epithelial (HLE) cells.

Materials and methods Human lens epithelial (SRA 01/04) cells were stimulated by H₂O₂ (250?μM) in the presence or absence of nSA. The antioxidant effects of nSA were determined in terms of cell viability (MTT assay), apoptosis (AnnexinV/PI staining), radical scavenging capability (various enzymatic assays), loss of mitochondrial membrane potential (Rhodamine 123 staining), expression of apoptotic markers including caspase-3 and caspase-9 and the change of Bcl-2/Bax ratio (western blot) in the HLE cells.

Results The results showed that pretreatment of nSA (250, 500 and 1000?μg/mL) markedly reduced H₂O₂-induced cellular apoptosis and malondialdehyde accumulation, but elevated the activities of total superoxide dismutase, catalase, glutathione peroxidase. Thus, the total antioxidative capability was enhanced upon the nSA treatment meanwhile the loss of mitochondrial membrane potential was prevented. Moreover, nSA at concentrations of 250, 500 and 1000?μg/mL also significantly suppressed the activation of caspase-3 and -9, and increased the Bcl-2/Bax ratio in the HLE cells.

Discussion and conclusion Our findings suggested that nSA is a potential prophylactic agent in the prevention of cataractogeneis.     

Protective effects of grape seed procyanidin extract against nickel sulfate-induced apoptosis and oxidative stress in rat testes

This study determined whether nickel sulfate (Ni)-induced reproductive damage occurs via apoptosis and oxidative stress and to examine the expression of Bax and c-kit and their effects on Ni exposure. The study also explored the protective effects of grape seed proanthocyanidin extract (GSPE) against Ni toxicity in the testes. Wistar rats were treated with normal saline, Ni alone (1.25, 2.5, and 5?mg/kg/day), and Ni (2.5?mg/kg/day) plus GSPE (50 and 100?mg/kg/day). After 30 days, Ni significantly decreased sperm motility and the percentage of S-phase cells and enhanced testicular apoptosis in the 2.5 and 5?mg groups. The levels of malondialdehyde (MDA), hydrogen peroxide (H₂O₂), and nitric oxide (NO) significantly increased. The decreased activity of glutathione peroxidase and catalase in the Ni groups showed that Ni could increase oxidative stress, especially at 2.5 and 5?mg. Western blot analysis showed that the expression of Bax protein and c-kit increased in 2.5 and 5?mg Ni groups compared with controls. Conversely, these changes were partially attenuated in rats simultaneously administered GSPE, especially in the 100?mg group. These results demonstrate the following: (1) Ni exhibits reproductive toxicity in rats by decreasing sperm at concentrations of 2.5 and 5?mg; (2) intratesticular apoptosis, oxidative stress, and c-kit overexpression play pivotal roles in reproductive damage induced by Ni; and (3) GSPE enhances sperm motility by down-regulating c-kit expression and offsetting the apoptosis and oxidative stress induced by Ni by directly decreasing MDA and NO, scavenging H₂O₂, and down-regulating Bax expression.     

Protective effects of grape seed procyanidin extract against nickel sulfate-induced apoptosis and oxidative stress in rat testes

This study determined whether nickel sulfate (Ni)-induced reproductive damage occurs via apoptosis and oxidative stress and to examine the expression of Bax and c-kit and their effects on Ni exposure. The study also explored the protective effects of grape seed proanthocyanidin extract (GSPE) against Ni toxicity in the testes. Wistar rats were treated with normal saline, Ni alone (1.25, 2.5, and 5?mg/kg/day), and Ni (2.5?mg/kg/day) plus GSPE (50 and 100 mg/kg/day). After 30 days, Ni significantly decreased sperm motility and the percentage of S-phase cells and enhanced testicular apoptosis in the 2.5 and 5?mg groups. The levels of malondialdehyde (MDA), hydrogen peroxide (H?O?), and nitric oxide (NO) significantly increased. The decreased activity of glutathione peroxidase and catalase in the Ni groups showed that Ni could increase oxidative stress, especially at 2.5 and 5 mg. Western blot analysis showed that the expression of Bax protein and c-kit increased in 2.5 and 5?mg Ni groups compared with controls. Conversely, these changes were partially attenuated in rats simultaneously administered GSPE, especially in the 100?mg group. These results demonstrate the following: (1) Ni exhibits reproductive toxicity in rats by decreasing sperm at concentrations of 2.5 and 5 mg; (2) intratesticular apoptosis, oxidative stress, and c-kit overexpression play pivotal roles in reproductive damage induced by Ni; and (3) GSPE enhances sperm motility by down-regulating c-kit expression and offsetting the apoptosis and oxidative stress induced by Ni by directly decreasing MDA and NO, scavenging H?O?, and down-regulating Bax expression.     

Protective effect of aqueous garlic extract against naphthalene-induced oxidative stress in mice

The aim of this study was to investigate the possible protective effects of aqueous garlic extract (AGE) against naphthalene-induced oxidative changes in liver, kidney, lung and brain of mice. Balb/c mice (25-30 g) of either sex were divided into five groups each comprising 10 animals. Mice received for 30 days: 0.9% NaCl, i.p. (control); corn oil, i.p; AGE in a dose of 125 mg kg-1, i.p.; naphthalene in a dose of 100 mg kg-1, i.p. (dissolved in corn oil); and AGE (in a dose of 125 mg kg-1, i.p.) plus naphthalene (in a dose of 100 mg kg-1, i.p.). After decapitation, liver, kidney, lung and brain tissues were excised. Malondialdehyde (MDA) and glutathione (GSH) levels and myeloperoxidase activity (MPO) were determined in the tissues, while oxidant-induced tissue fibrosis was determined by collagen content. Tissues were also examined microscopically. Serum aspartate aminotransferase, alanine aminotransferase levels and blood urea nitrogen and creatinine concentrations were measured for the evaluation of hepatic and renal function, respectively. MDA and GSH levels were also assayed in serum samples. In the naphthalene-treated group, GSH levels decreased significantly, while MDA levels, MPO activity and collagen content increased in the tissues (P<0.01-0.001), suggesting oxidative organ damage, which was also verified histologically. In the AGE-treated naphthalene group, all of these oxidant responses were reversed significantly (P<0.05-0.01). Hepatic and renal function test parameters, which increased significantly (P<0.001) following naphthalene administration, decreased (P<0.05-0.001) after AGE treatment. The results demonstrate the role of oxidative mechanisms in naphthalene-induced tissue damage. The antioxidant properties of AGE ameliorated oxidative organ injury due to naphthalene toxicity.     

Croton cajucara Benth. leaf extract scavenges the stable free radical DPPH and protects against oxidative stress induced by paraquat

Antioxidant effects of extracts from Croton cajucara BENTH. leaves was investigated in different in vitro and in vivo models. Extracts showed inhibitory radical scavenging activity against the stable radical 2,2-diphenyl-1-picrylhydrazyl (DPPH) (75%, 43% and 25% of the standard trolox at 1, 10 and 100 mg/ml, respectively; IC50 218 mg/ml). Percentage survival of Saccharomyces cerevisiae cells treated with 10 mM paraquat increased by 21% and 55%, when 1 mg/ml and 10 mg/ml concentrations of the extract, respectively, were added. The cytosolic concentration of TBARS increased in animals treated with paraquat (+283%), while values did not significantly differ from the controls in rats additionally receiving the leaf extract. Paraquat administration also induced a significant increase in hydroperoxide-initiated chemiluminiscence (+76%), that was partially prevented by the leaf extract (+31%). Liver SOD activity was a 158% higher in animals receiving paraquat as compared to the controls. This effect was abolished by administration of the leaf extract. Paraquat administration did not significantly modify the activity of GPx or catalase. Croton cajucara extract increased GPx and catalase activities in paraquat treated-animals by 342% and 70%, respectively. Our results confirm that Croton cajucara leaf extract present radical scavenging activity and reduce oxidative stress induced by paraquat, suggesting the beneficial use as a potential source of antioxidant agents of natural origin.     

银杏叶提取物对糖尿病肾病抗氧化应激及血液流变作用的影响

目的：观察银杏叶提取物对糖尿病肾病（DN）患者血清氧化应激及血液流变学指标的影响。方法：将DN患者按自愿原则分为银杏叶提取物（美怡欣注射液）治疗组和对照组。观察两组治疗前后血清超氧化物歧化酶（SOD）、谷光甘肽过氧化酶（GSH—Px）、丙二醛（MDA）及血液流变学指标的变化。结果：治疗前两组SOD、GSH—Px、MDA和血液流变学指标无明显差异。银杏叶提取物治疗后SOD、GSH—Px较对照组明显升高,MDA明显降低（P〈0．01）;尿蛋白定量较对照组明显下降（P〈0．01）;低切全血黏度、红细胞压积、红细胞聚集指数和血小板聚集率较对照组和同组治疗前显著下降（P〈0．01）,而高切全血黏度和血浆黏度下降不明显;红细胞变形性显著增高（P〈0．01）。结论：DN患者细胞抗氧化能力明显降低;银杏叶提取物通过提高抗氧化应激能力及改善血液流变性,减少蛋白尿对肾脏起保护作用。     

Gingko biloba leaf extract induces oxidative stress in carcinoma HSC-2 cells

The antiproliferative effects of a Gingko biloba leaf extract to cells from tissues of the human oral cavity were studied. Toxicity to carcinoma HSC-2 cells was correlated with the prooxidative nature of the extract. G. biloba leaf extract generated reactive oxygen species (ROS) in cell culture medium and, albeit to a lesser extent, in buffer, with higher levels detected at alkaline pH. Lowered levels of ROS were detected in culture medium coamended with the extract and with either catalase or superoxide dismutase, indicating the generation of hydrogen peroxide and superoxide anion, respectively. Biological activity of the extract was through oxidative stress. Toxicity to the HSC-2 cells was lessened by the ROS scavengers, divalent cobalt and pyruvate, by catalase, and by the antioxidant, N-acetyl-l-cysteine, and was potentiated by the glutathione depleters, dl-buthionine-[S,R]-sulfoximine, 1-chloro-2,4-dinitrobenzene, and bis(2-chloroethyl)-N-nitrosourea. G. biloba reacted directly with authentic glutathione and lowered the intracellular glutathione content in HSC-2 cells. Induction of apoptosis upon exposure of HSC-2 cells to G. biloba extract was noted by apoptotic cell morphologies, by TUNEL staining, and by PARP cleavage. The data strongly suggest that the prooxidative nature of the G. biloba extract was the cause of apoptotic cell death.     

Effect of neem leaf extract and neem oil on Penicillium growth, sporulation, morphology and ochratoxin A production

In vitro trials were conducted to evaluate the effect of Azadirachtaindica (neem) extracts on mycelial growth, sporulation, morphology and ochratoxin A production by P. verrucosum and P. brevicompactum. The effect of neem oil extract from seeds and leaf was evaluated at 0.125; 0.25 and 0.5% and 6.25 and 12.5 mg/mL, respectively, in Yeast Extract Sucrose (YES) medium. Ochratoxin A production was evaluated by a thin-layer chromatography technique. Oil extracts exhibited significant (p ≤ 0.05) reduction of growth and sporulation of the fungi. No inhibition of ochratoxin A production was observed. Given its accessibility and low cost, neem oil could be implemented as part of a sustainable integrated pest management strategy for plant disease, as it has been shown to be fungitoxic by inhibition of growth and sporulation.