Action of Hygrophila auriculata against streptozotocin-induced oxidative stress

Recent Advances in Using Natural Antibacterial Additives in Bioactive Wound Dressings

Wound care is a global health issue with a financial burden of up to US $96.8 billion annually in the USA alone. Chronic non-healing wounds which show delayed and incomplete healing are especially problematic. Although there are more than 3000 dressing types in the wound management market, new developments in more efficient wound dressings will require innovative approaches such as embedding antibacterial additives into wound-dressing materials. The lack of novel antibacterial agents and the misuse of current antibiotics have caused an increase in antimicrobial resistance (AMR) which is estimated to cause 10 million deaths by 2050 worldwide. These ongoing challenges clearly indicate an urgent need for developing new antibacterial additives in wound dressings targeting microbial pathogens. Natural products and their derivatives have long been a significant source of pharmaceuticals against AMR. Scrutinising the data of newly approved drugs has identified plants as one of the biggest and most important sources in the development of novel antibacterial drugs. Some of the plant-based antibacterial additives, such as essential oils and plant extracts, have been previously used in wound dressings; however, there is another source of plant-derived antibacterial additives, i.e., those produced by symbiotic endophytic fungi, that show great potential in wound dressing applications. Endophytes represent a novel, natural, and sustainable source of bioactive compounds for therapeutic applications, including as efficient antibacterial additives for chronic wound dressings. This review examines and appraises recent developments in bioactive wound dressings that incorporate natural products as antibacterial agents as well as advances in endophyte research that show great potential in treating chronic wounds.

Evaluation of a labdane diterpene forskolin isolated from Solena amplexicaulis (Lam.) Gandhi (Cucurbitaceae) revealed promising antidiabetic and antihyperlipidemic pharmacological properties

Solena amplexicaulis (Lam.) Gandhi (Family Cucurbitaceae) is one of the important plant species used by the Irula tribes of Walayar valley of southern Western Ghats, India for the management of diabetes. To confirm the antidiabetic property of S. amplexicaulis, the present study was addressed using crude methanolic leaf extract of S. amplexicaulis (MeOHSa) and its isolated compound, Forskolin against streptozotocin (STZ) induced diabetic rats. The oral glucose tolerance test (OGTT), blood glucose, lipid profile, serum liver markers, antioxidants, hemoglobin and glycogen were evaluated using standard procedure. The oral administration of Forskolin and MeOHSa (600 mg/kg b.w.) for 30 days resulted in significant restoration of all these parameters supported by histopathological observations too. The results clearly suggest that the Forskolin (diterpene) possess potent antidiabetic and antihyperlipidemic activities, which may be considered as a lead molecule for therapeutic purposes, and the source of Forskolin i.e. S. amplexicaulis can be further exploited for pharmaceutical industries.

Nutritional value, micronutrient and antioxidant capacity of some green leafy vegetables commonly used by southern coastal people of Bangladesh

Southern coastal people of Bangladesh are highly vulnerable to food insecurity and malnutrition due to coastal flooding, deforestation and increased soil salinity. A number of green leafy vegetables are found in the southern coastal belt being traditionally eaten as daily basis by local people. But they are unaware of nutritional and medicinal use of these vegetables. To contribute to their wider utilization, five common vegetables namely Hibiscus sabdariffa, Trianthema portulacastrum, Diplazium esculentum, Heliotropium indicum L. and Hygrophila auriculata were selected for analysis of nutritional proximate, micronutrients and antioxidant potential. Nutritional properties were analyzed in terms of moisture, pH, protein, lipid, ash, fibre, minerals and carbohydrate. Total flavonoid, tannin and antioxidant capacity were evaluated using established protocols. The results demonstrated that collected plants are rich in carbohydrate, fibre, proteins, moisture and ash content but low in lipid content. The mineral elements were high with remarkable amount of Na (19.9–21.5 mg/gm), K (7.9–13.5 mg/gm) and P (1.0–1.8 mg/gm). All the samples were found to have considerable amount of flavonoid (90.6–144.5 mg QE/gm) and tannin content (26.8–57.2 mg GAE/gm). The IC₅₀ value of DPPH and superoxide radical scavenging was the lowest for H. indicum (37.1 and 83.4 μg/ml, respectively) whereas T. portulacastrum possessed high reducing power (IC₅₀ 53.7 μg/ml). Among the five investigated species, T. portulacastrum and H. indicum were found to have good nutritional and antioxidant properties, thus can be promoted as a significant source of nutritional and antioxidant food supplements.

Silver Fir (Abies alba) Extracts Inhibit Enzymes Involved in Blood Glucose Management and Protect against Oxidative Stress in High Glucose Environment

The diet rich in fruits and vegetables reduces the risk of metabolic syndrome, including diabetes development by various mechanisms of action, mainly due to the presence of polyphenolic compounds. Extracts from different conifer species are known to be a rich source of various polyphenols. In the present study we elucidated the in vitro mechanism of anti-diabetic activity of silver fir (Abies alba) wood and bark extracts and compared their activity to non-coniferous sweet chestnut wood extract and standardized maritime pine bark extract. Extracts and lignans were tested for their inhibitory activity of enzymes involved in the regulation of blood glucose in vitro. The ability of extracts to protect against oxidative stress in high glucose environment was tested on mouse myoblast cell line. Silver fir wood and bark extracts were shown to be effective inhibitors of α-glucosidase, α-amylase and dipeptidyl peptidase 4, three enzymes involved in the regulation of blood glucose levels. Coniferous extracts also showed protection against oxidative stress generated in high glucose environment. Lignans, particularly pinoresinol diglucoside, isolariciresinol and secolariciresinol were shown to be important contributors of antihyperglycemic activity through inhibition of dipeptidyl peptidase 4. This corroborates previously published in vivo results on blood glucose level obtained with silver fir wood extract and supports the use of silver fir wood and bark extracts as food supplements or functional foods in borderline diabetes.

Siddha Medicine in Eastern Sri Lanka Today-Continuity and Change in the Treatment of Diabetes

Diabetes is affecting the social and economic developments in developing countries like Sri Lanka. Siddha Medicine (Tamil Medicine) is mostly practiced in the Eastern and Northern Provinces of Sri Lanka. Our recent review of Sri Lankan Siddha historical documents identified 171 plant species used to prepare anti-diabetic preparations. On the other hand, there is no study of plants currently used to treat diabetes in Sri Lankan Siddha Medicine. Hence, the aim of this study is to identify and document the plant species currently used in anti-diabetic preparations in Eastern Province, also enabling a comparative analysis with historical uses. Further, assessing the level of scientific evidence (in vitro, in vivo, and clinical studies) available for recorded species. A systematically prepared questionnaire was used to conduct an ethnobotanical survey with 27 Siddha healers residing in Eastern Province to identify the currently used anti-diabetic plants. Furthermore, Web of Science electronic database was used to assess the level of scientific evidence available excluding widespread and very well studied species. On average 325 diabetic patients were seen by 27 healers per week. Interestingly, inorganic substances, and animal parts used as ingredients in historical anti-diabetic preparations are currently not used in Eastern Province. A total of 88 plant species from 46 families were reported in this study. Syzygium cumini (L.) Skeels was the most frequently recorded species and the largest number of taxa are from Fabaceae. Remarkably, one third of reported species were not stated in Sri Lankan Siddha historical documents. The highest number of plant species (59%) have been studied up to an in vivo level followed by no scientific evidence for anti-diabetic activity found (27%), clinical evidence (10%), and in vitro (2%). This is the first ethnobotanical study of plants used to treat diabetes by Siddha healers in the Eastern Province in Sri Lanka. Moreover, awareness should be created to the diabetics about the side effects of herb-drug interactions and complications caused by taking both herbal preparations and biomedical drugs.

Ethnomedicinal, phytochemical and pharmacological updates on Hygrophila auriculata (Schum.) Hiene: an overview

This article explores the most recent evidence-based information on ethnomedicinal, phytochemical and pharmacological understanding of Hygrophila auriculata for the treatment of various diseases and health conditions. Various ethnomedicinal writings suggest the use of the plant or its parts for the treatment of jaundice, oedema, gastrointestinal ailments, diarrhoea, dysentery, urinogenital disorder, gall stones, urinary calculi, kidney stone, leucorrhoea, rheumatism, tuberculosis, anaemia, body pain, constipation, skin disease, and as an aphrodisiac. The plant has been reported to contain flavonoids (apigenin, luteolin, ellagic acid, gallic acid and quercetin), alkaloids (asteracanthine and asteracanthicine), triterpenes (lupeol, lupenone, hentricontane and betulin), sterols (stigmasterol and asterol), minerals, amino acids, fatty acids, aliphatic esters and essential oils. Extracts and bioactive compounds from the plant have been found to possess antimicrobial, anthelmintic, antitermite, nephroprotective, hepatoprotective, central nervous system protective, antitumour, antidiabetic, anticataract, antioxidant, haematopoietic, diuretic, antinociceptive, anti-inflammatory, antipyretic, antimotility, aphrodisiac, neuroprotection, anti-endotoxin and anti-urolithiatic activities. For this paper, we reviewed patents, clinical studies, analytical studies and marketed formulations from the earliest found examples from 1887 to the end of 2017.

Escalation of liver malfunctioning: A step toward Herbal Awareness

ETHNOPHARMACOLOGICAL RELEVANCE

About 2-5% of the world's population is suffering from liver toxicity including Pakistan with the second highest rate of hepatitis prevalence. Liver is a vital body organ which not only performs metabolic activities but also aids in detoxification, storage and digestion of food. Now a day's malnutrition, alcohol consumption and drug addiction are major causes of liver diseases throughout the world. In fact, there is no possible outcome to compensate liver malfunction for long term, and transplantation of liver is the only option left after the irretrievable injury of hepatic function. Subsequently, natural based therapeutic approaches are in the process of scrupulous testing as strong hepatoprotective mediator. In this regard plants are well thought hepatoprotective agents having multiple active components. In this review, based on species' pharmacology and safety we have compiled some plants which show strong hepatoprotective activity, main phytoconstituents with biological activities and few commercially used herbal formulations.

MATERIALS AND METHODS

Ethnopharmacological information was gathered by an extensive literature survey like WHO monographs on selected herbal medicinal plants (Vol 1-Vol 4); Principles and Practice of Phytotherapy, Mills S and Bone K, Churchill Livingstone, London, UK; Herbal Drugs and Phytopharmaceuticals, Wichtl M Medpharm Press, Stuttgart 3rd edn; Pharmacology and Applications of Chinese Materia Medica Vols 1 and 2, Chang H-M and But P P-H World Scientific, Singapore; British Herbal Compendium Vol. 2, Bradley P British Herbal Medicine Association, Bournemouth, UK; ESCOP Monographs 2nd edn. Thieme, Stuttgart, Germany; as well as by using electronic databases such as Pubchem, Chemspider, http://www.herbal-ahp.org; http://www.ahpa.org; http://whqlibdoc.who.int/publications/2003/9241546271.pdf; http://www.escop.com, Pubmed, HubMed and Scopus.

RESULTS

Data for more about 29 plants have been accomplished for their bioactive constituent(s), biological activities and medicinal uses. Some of the plants have been identified as strong hepato-modulator. Such knowledge about traditional medicinal plants can be globally applied for safe and evidence based use in pharmacological applications.

CONCLUSION

With the rise in liver risks a meek struggle has been made to draw attention toward herbal therapy. Hepatoprotective constituents of said plants are expressed with chemical structures. However, for certain plants active constituents are not still isolated/purified but overall plant extract was found effective in providing protection against hepatic injury. As a future perspective, there is need to purify plant active constituents for ethnomedical rationale.

Evaluation of cytotoxic, analgesic, antidiarrheal and phytochemical properties of Hygrophila spinosa (T. Anders) whole plant

BACKGROUND

Synthetic drugs are going to be replaced by plant-derived traditional drugs due to their cost effectiveness, relatively less harmfulness, and efficacy against multidrug resistance organisms. Hygrophila spinosa (Acanthaceae) has been used in a wide range of ailments including flatulence, diarrhea, dysentery, gonorrhea, and menorrhagia. Therefore, we investigated the cytotoxic, antinociceptive, and antidiarrheal effects of H. spinosa ethanol extract (EExHs).

METHODS

Preliminary phytochemical screening was accomplished by established methods modified in experimental protocol. EExHs was undertaken for cytotoxic assay by Brine shrimp lethality bioassay, antinociceptive action by acetic acid induced writhing test, and antidiarrheal activity by castor oil induced antidiarrheal test. Data were analyzed by GraphPad Prism 6.0 software using Dunnett's test for multiple comparisons.

RESULTS

Reducing sugar, steroid, glycoside, tannin, alkaloid, saponins, and flavonoids were found to be present in EExHs. Lethal concentration (LC50) of EExHs for brine shrimps was 50.59 µg/mL which was relatively lower than that of the standard drug vincristine sulfate. In acetic acid induced writhing test, oral administration of EExHs at three different doses (125, 250, and 500 mg/kg) decreased writhing in dose-dependent manner while the highest dose (500 mg/kg) achieved the maximum percentages of pain inhibition (58.8%). Diclofenac sodium (25 mg/kg) was used as a reference antinociceptive drug. The antidiarrheal action of EExHs was not found to be very promising for further use; however, the pure compounds from EExHs could be analyzed to justify the effects.

CONCLUSIONS

This research demonstrates that the secondary metabolites guided cytotoxic and analgesic effects could be extensively studied in multiple models to confirm the effects.

Rosemary (Rosmarinus officinalis) as a potential therapeutic plant in metabolic syndrome: a review

Metabolic syndrome is defined by a constellation of complex coexisting cardiometabolic risk factors such as hyperglycemia, dyslipidemia, inflammation, abdominal obesity, coagulopathies, and hypertension that raise the risk of diabetes mellitus and cardiovascular disease. Recently, there has been an increasing interest in the use of herbs and natural compounds in prevention and treatment of diseases and a large number of published articles have focused on this issue. Rosmarinus officinalis L. or rosemary (Lamiaceae) is a rich source of phenolic phytochemicals having significant anti-oxidant, anti-inflammatory, hypoglycemic, hypolipidemic, hypotensive, anti-atherosclerotic, anti-thrombotic, hepatoprotective, and hypocholesterolemic effects. The purpose of this review is to highlight the interesting pharmacological effects of rosemary, and its active compounds, and the related mechanisms in the management of metabolic syndrome that are documented in in vitro and in vivo studies.

Screening of Bioactivities and Toxicity of Cnidoscolus quercifolius Pohl

The caatinga, an exclusively Brazilian biome, is one of the most endangered vegetation systems in the planet. To be exploited rationally, its potential needs to be scientifically demonstrated. Among these is the faveleira, used in northeastern Brazil. It stands out for its extraordinary drought resistance and medicinal properties. The objective of this study was to assess the therapeutic potential of compounds extracted from Cnidoscolus quercifolius Pohl in preventing disease and its rational use as a herbal therapeutic tool. The methodology began with the collection and herborization of the plant material, to obtain the chemical compounds, preliminary phytochemical analysis, and extraction of the constituents of the active extracts. To determine the biological activities the authors conducted investigation of antioxidant and antimicrobial activities, inhibition capacity of the acetylcholinesterase enzyme, and initial assessment of toxicity of the extracts. The results demonstrated great potential as an antimicrobial agent, an important antioxidant capacity, and acetylcholinesterase inhibition response with no significant difference compared with the reference drug. The authors expect to develop a new herbal product, resulting in lower production costs and that, consequently, could be commercialized in more accessible form to the population, highlighting the risk reduction of contraindication of this category of medications.

Pharmacodynamic interaction of fenugreek, insulin and glimepiride on sero-biochemical parameters in diabetic Sprague-Dawley rats

AIM

This study was undertaken to assess the pharmacodynamic interaction of fenugreek, insulin and glimepiride on sero-biochemical parameters in streptozotocin-induced diabetic rats.

MATERIALS AND METHODS

A total of 56 male Sprague-Dawley rats, randomly divided into seven Groups. Group 1: Non-diabetic control; Group 2: Streptozotocin induced diabetic control; Groups 3, 4 and 5 were treated with insulin, glimepiride and fenugreek seed powder, respectively; Groups 6 and 7: Insulin + fenugreek seed powder treatment and glimepiride + fenugreek seed powder treatment respectively, in diabetic rats. Body weights, blood glucose, lipids total cholesterol (TC), high-density lipoprotein (HDL), low-density lipoprotein (LDL), triglycerides (TG) and proteins (total protein, albumin, globulin, A/G ratios) were studied at different time intervals. Rats were sacrified at the end of 8 weeks, pancreas and aorta collected for histopathological study.

RESULTS

The results of Group 2 showed significantly (p<0.05) higher concentration of glucose, TC, TG, LDL, globulin, A/G ratios and significantly (p<0.05) lower concentration of albumin, total protein, HDL and body weights when compared to Group 1 at the end of 4(th) and 8(th) weeks intervals with marked alteration in histopathology of pancreas and aorta. All the treatment Groups 3-7 showed significantly (p<0.05) improvement in the all the parameters and the Groups 6 and 7 showed highest decrease in the concentration blood glucose, TC, TG, LDL and increase in the albumin, total protein and body weights during 6(th) and 8(th) week, respectively.

CONCLUSION

The treatment with fenugreek, insulin and glimepiride countered the alteration in the sero biochemical parameters in diabetic rats, and their combination was found a positive interaction in improving the sero biochemical status of diabetic rats.

Evaluating the toxic and beneficial effects of lichen extracts in normal and diabetic rats

Lichens can be used as a novel bioresource for natural antioxidants. However, there is need for further investigations to validate the lichens used in medicinal remedies. In this study, the effects of Cetraria islandica and Pseudevernia furfuracae lichen species in streptozotocin (STZ)-induced diabetes were evaluated. Diabetic rats were treated with aqueous lichen extracts (250 and 500 mg/kg/day) for 2 weeks starting at 72 h after STZ injection. On the 14th day, animals were anesthetized, and then metabolic and biochemical parameters were evaluated between control and treatment groups. Pancreatic histology and β-cell mass were examined by hematoxylin and eosin and insulin immunohistochemistry stainings. Our findings revealed that these lichen species could be used safely in this dose range. In addition, C. islandica extracts showed prominent results compared to the doses of P. furfuracae extract for antioxidant capacity. However, the protectivity of C. islandica extract was inadequate against diabetes-induced pancreatic damages via forming oxidative stress. In conclusion, the usage of C. islandica might serve for early intervening in the risk reduction of type 1 diabetes.

Pyrroloquinoline quinone ameliorates oxidative stress and lipid peroxidation in the brain of streptozotocin-induced diabetic mice

Diabetes, characterized by hyperglycemia, leads to several complications through the generation of reactive oxygen species and initiates tissue damage. Pyrroloquinoline quinone (PQQ) is believed to be a strong antioxidant, as it protects cells from oxidative damage. In this study, we elucidated the hitherto unknown potential of PQQ to ameliorate the brain damage caused by diabetes mellitus and the associated hyperglycemia-induced oxidative damage. Administration of a single dose of streptozotocin (STZ), i.e., 150 mg·(kg body mass)−1significantly enhanced the brain tissue levels of lipid peroxidation and hydroperoxidation and decreased the levels of antioxidants. It also increased the serum levels of glucose, cholesterol, and triglycerides. However, when STZ-treated animals received PQQ (20 mg·(kg body mass)−1·d−1, for 15 days), this significantly decreased the serum levels of glucose and lipid peroxidation products, and increased the activities of antioxidants in the diabetic mouse brain. These findings suggest that PQQ has the potential to ameliorate STZ-induced oxidative damage in the brain, as well as the STZ-induced diabetes.

Antidiabetic activity of Pterospermum acerifolium flowers and glucose uptake potential of bioactive fraction in L6 muscle cell lines with its HPLC fingerprint

The present study was designed to estimate the detailed antidiabetic activity of Pterospermum acerifolium (L.) Willd flowers. In vitro alpha amylase inhibition study was carried out on 50% ethanol extract of flowers (PAFEE) and its various fractions. The active ethyl acetate fraction (PAFEF) was subfractionated into three subfractions (PAFE1, PAFE2, and PAFE3) and subjected to acute toxicity studies followed by antidiabetic screening in vivo by streptozotocin-nicotinamide induced type II diabetes. Diabetic animals treated with PAFE2 (30 mg/kg) reduced the levels of fasting blood glucose, significantly (P < 0.001) compared to that of diabetic control animals. Histological studies on drug treated groups did not show remarkable positive changes in β-cells. PAFE2 showed 32.6 ± 1.93% glucose uptake over control and, in the presence of PI3K inhibitor wortmannin, declined to 13.7 ± 2.51%. HPLC analysis of PAFE2 reveals the presence of quercetin and apigenin as major constituents and both are inhibiting the glycogen phosphorylase enzyme in molecular modelling studies. The study evidenced strongly that the probable glucose lowering mechanism of action of active subfraction PAFE2 is by increasing the glucose uptake in peripheral tissues and by inhibition of gluconeogenesis.

Chemical and pharmacological investigation of micropropagated Hygrophila pogonocalyx produced from leaf explants

BACKGROUND

An optimized method for indirect shoot organogenesis from the leaf explants of Hygrophila pogonocalyx, a rare and endemic species in Taiwan, was developed to supply enough quantity of plant materials for the first chemical and pharmacological investigation.

RESULTS

Incubation of the young leaves on Murashige and Skoog (MS) medium supplemented with 6-benzylaminopurine (0.5 mg/l) and indole-3-acetic acid (0.1 mg/l) resulted in the best multiplication rate for organogenesis. The average number of adventitious buds per leaf was 22.8 ± 1.9 after 8-week culture. The adventitious buds rooted and developed into plantlets when cultured simply on MS medium. Using this protocol, up to 37,600 plants were produced from a single leaf explant in one year. From the ethanol extract of the leaves of this micropropagated plant, 13 compounds were isolated and identified, including two flavones (1, 11), four flavonols (9, 10, 12, and 13), three phenylethanoid glycosides (6-8), two alkylated glycosides (2-3), and two steroids (4-5). Of these, acteoside (7) exhibited anti-tyrosinase activity in human epidermal melanocytes and luteolin 7-O-β-D-glucopyranoside (11) exhibited the greatest neurocytoprotective activity.

CONCLUSIONS

The method, indirect shoot organogenesis from leaf explants of H. pogonocalyx, could be developed to supply enough quantity of plant materials for the chemical and pharmacological investigation. In the present study, the isolated active compounds may develop for whitening agents or treating neurodegenerative diseases in the future.

The biochemical and histological effects of lichens in normal and diabetic rats

Oxidative stress plays an important role in causing diabetes; however, no studies have thoroughly reported on the toxic and beneficial effects of lichen extracts in patients with diabetes mellitus (DM). This study covers a previously unrecognized effect of two well-known lichen species Cetraria islandica and Pseudevernia furfuracae in streptozotocin (STZ)-induced diabetes. In experimental design, control or diabetic rats were either untreated or treated with aqueous lichen extracts (250–500 mg/kg /day) for 2 weeks starting at 72 h after STZ injection. On day 14, animals were anaesthetized, and metabolic and biochemical parameters were appreciated between control and treatment groups. The histopathology of liver was examined using three different staining methods: hematoxylin–eosin (H&E), periodic acid Schiff (PAS), and reticulin and Sudan Black B. Our experimental data showed that increasing doses of C. islandica and P. furfuracae alone did not have any detrimental effects on studied parameters and the malondialdehyde level of liver. C. islandica extract showed positive results for antioxidant capacity compared to doses of P. furfuracae extract. However, the protective effect of C. islandica extract on diabetes-induced disorders and hepatic damages is still unclear. Moreover, unfortunately, animals subjected to DM therapy did not benefit from the usage of increasing lichen doses due to their unchanged antioxidant activity in tissues. The results obtained in present study suggested that C. islandica and P. furfuracae is safe but the power of these is limited because of intensive oxidative stress in liver of type 1 diabetic rats. It is also implied that C. islandica extract is especially suitable for different administration routes in DM animals.

The effects of Cetraria islandica and Pseudevernia furfuracea extracts in normal and diabetic rats

Lichens are symbiotic organisms composed of a fungus joined to a photosynthesizing partner that can be either an alga or a cyanobacterium. They can be used as a novel bioresource for natural antioxidants. However, there is also a need for further studies to validate the lichens used in medicinal remedies. This study covers a previously unrecognized effects of Cetraria islandica (CIAE) and Pseudevernia furfuracea (PFAE) in streptozotocin (STZ)-induced diabetes. In experimental design, control or diabetic rats were either untreated or treated with aqueous lichen extracts (250–500 mg/kg/day) for 2 weeks starting at 72 h after STZ injection. On day 14, animals were anesthetized, metabolic and biochemical parameters were appreciated between control and treatment groups. The histopathology of kidney was examined using four different staining methods: hematoxylin–eosin (H&E), periodic acid-Schiff (PAS), Masson trichrome and Congo red. Our experimental data showed that increasing doses of CIAE and PFAE did not have any detrimental effects on the studied parameters and the malondialdehyde level of kidney. CIAE extract showed prominent results compared to doses of PFAE extract for antioxidant capacity. However, the protective effect of CIAE extract was inadequate on diabetes-induced disorders and kidney damages. Moreover, animals subjected to diabetes mellitus (DM) therapy did not benefit unfortunately from the usage of increasing lichen doses due to their unchanged antioxidant activity to tissue. The results obtained in present study suggested that CIAE and PFAE are safe but the power of these is limited because of the intensive oxidative stress in kidney of type 1 diabetic rats. It is also implied that CIAE extract is especially suitable for different administration routes in DM.

Evaluation of protective action of fenugreek, insulin and glimepiride and their combination in diabetic Sprague Dawley rats

The present study was conducted to assess the effect of fenugreek, insulin and glimepiride alone and their combination in diabetic rat liver. Fifty six male Sprague dawley rats of uniform age were randomly divided into seven groups. Group 1: Non-diabetic control; Group 2: Streptozotocin (40 mg/Kg i/p single dose)-induced diabetic control; Group 3: Insulin (4 U/kg once daily for 8 weeks) treatment in diabetic rats; Group 4: Glimepiride (4 mg/Kg orally once daily for 8 weeks) treatment in diabetic rats; Group 5: Fenugreek seed powder treatment (1 g/kg orally once daily for 8 weeks) in diabetic rats; Group 6: Insulin + Fenugreek seed powder treatment (once daily for 8 weeks) in diabetic rats; Group 7: Glimepiride + Fenugreek seed powder treatment (once daily for 8 weeks) in diabetic rats. Livers were collected at the end of experiment for histopathology and estimation of reduced glutathione (GSH), thiobarbituric acid reacting substances (TBARS), protein carbonyls, glutathione S-transferase (GST), glucose-6-phosphate dehydrogenase (G6PD), Na(+)/K(+) ATPase and Mg(2)+ ATPase, cytochrome P450 (CYP) and glycogen. There was an increase in the concentration of TBARS and protein carbonyls, and decrease in the concentration of GSH and glycogen, and the activity of GST, G6PD, Na(+)/K(+) ATPase and Mg(2)+ ATPase in diabetic livers, while treatment groups showed significant (P < 0.05) increase in the above parameters. The histology of liver revealed marked changes in diabetic rats and mild changes in combination treatment groups. The treatment with fenugreek, insulin and glimepiride improved the liver parameters in diabetic rats and their combination showed a beneficial effect on liver.

Carvacrol partially reverses symptoms of diabetes in STZ-induced diabetic rats

Little is known about the protective effects of carvacrol on the symptoms of streptozotocin induced diabetes in rats. Hence, this present study was designed to evaluate the protective effect of the strong antioxidant, carvacrol, on the symptoms of streptozotocin induced diabetes in rats. Carvacrol at the doses of 25 and 50 mg/kg body weight were orally administered to diabetic rats for a period of 7 days after the onset of diabetes. Food-water intake and body weight changes were daily recorded. Biochemical parameters such as serum glucose, insulin, total cholesterol, alanine aminotransferase, aspartate aminotransferase and lactate dehydrogenase were measured. Although treatment of diabetic rats with oral administration of carvacrol resulted in a slight reduction in serum glucose level and significant reduction in serum total cholesterol, alanine aminotransferase, aspartate aminotransferase and lactate dehydrogenase in comparison with diabetic control rats, there were no significant differences in serum insulin levels, food-water intake values and body weight changes. Despite the inadequacy of carvacrol on diabetes treatments, it was determined to have at least a partially protective role on liver enzymes.

Exploring antiurolithic effects of gokshuradi polyherbal ayurvedic formulation in ethylene-glycol-induced urolithic rats

Gokshuradi Yog (GY) is a polyherbal ayurvedic formulation used traditionally for several decades in India for the treatment of urolithiasis. The aim of the present study was to determine the underlying mechanism of GY action in the management of calcium oxalate urolithiasis. The effect of Gokshuradi polyherbal aqueous extracts (GPAEs) was studied on various biochemical parameters involved in calcium oxalate formation by employing in vitro and in vivo methods. GPAE exhibited significant antioxidant activity against 1, 1-diphenyl-2-picrylhydrazyl free radical and inhibited lipid peroxidation in the in vitro experiments. The rat model of urolithiasis induced by 0.75% ethylene glycol (EG) and 1% ammonium chloride (AC) in water caused polyuria, weight loss, impairment of renal function, and oxidative stress and decreased antioxidant enzyme activities in untreated control groups. However, GPAE- (25, 50, and 100 mg/kg) treated groups caused diuresis accompanied by a saluretic effect and revealed significant increase in antioxidant enzyme activities along with decreased oxalate synthesizing biochemical parameters at higher doses. This study revealed the antiurolithic effect of GPAE mediated possibly through inhibiting biochemical parameters involved in calcium oxalate formation, along with its diuretic and antioxidant effects, hence supporting its use in the treatment of calcium oxalate urolithiasis.

Neuroprotective and antioxidant potential of terpenoid fraction from Hygrophila auriculata against transient global cerebral ischemia in rats

CONTEXT

The plant Hygrophila auriculata (K. Schum) Heine. (Acanthaceae) is widely used in the Indian System of Medicine as "Rasayana" for treating brain and liver diseases.

OBJECTIVES

The present study evaluated the in vivo antioxidant and neuroprotective effect of aterpenoid rich fraction (TF) from Hygrophila auriculata in a rat model of transient global cerebral ischemia (tGCI).

MATERIALS AND METHODS

Male Wistar rats were grouped as sham control, tGCI control, vitamin E (500 mg/kg) and TF (100 & 200 mg/kg) treated groups. Following 7 days of drug administration, animals were subjected to tGCI by permanent occlusion of both vertebral and transient occlusion of carotid arteries for 10 min followed by reperfusion. The neuroprotective effect was assessed by tGCI induced neurological, sensory motor deficit in rats. Brain antioxidants such as superoxide dismutase (SOD), catalase (CAT) and malondialdehyde (MDA) were investigated. Further, a histopathological examination was done in CA1 hippocampus.

RESULTS

tGCI induction resulted in an increase in beam balance score (5.1), number of entries in open field (131) and a decrease in time spent in rotorod (47 s). In contrast, TF treatment resulted in a significant decrease in (p < 0.01) beam balance score (2.9), number of entries (67) and increased time spent in rotorod (63.25 s). There was also a significant (p < 0.001) decrease in brain SOD and GSH with an increase in MDA. TF treatment resulted in restoration of antioxidants and protection of hippocampal CA1 neurons against tGCI insult.

CONCLUSION

It is concluded that TF from Hygrophila auriculata shows neuroprotective potential against tGCI induced oxidative stress.

Effects of lichen extracts on haematological parameters of rats with experimental insulin-dependent diabetes mellitus

The prevalence of diabetes mellitus in the world is steadily increasing. Oxidative stress contributes to the development of diabetic complications, including diabetic haematological changes. Lichens are used as food supplements and are also used as possible natural antioxidant, antimicrobial and anticancer agents. We hypothesized that antioxidant activity of lichens may decrease hyperglycaemia-induced oxidative stress and prevent the development of diabetic complications, including abnormality in haematological condition. Therefore, the effects of Cetraria islandica water extract (CIWE) and Pseudevernia furfuracea water extract (PFWE) on the haematological parameters of rats with type 1 DM were investigated for the first time in the present study. Control Sprague-Dawley or streptozotocin (STZ)-induced diabetic rats were either untreated or treated with water lichen extracts (5–500 mg/kg body weight (bw)/day) for 2 weeks, starting at 72 h after STZ injection. On day 14, animals were anaesthetized and haematological and metabolic parameters were determined between control and experimental groups. In addition, the total oxidative stress (TOS), a specific indicator of oxidative stress, and the total antioxidant capacity (TAC) were measured by biochemical studies. In diabetic rats, CIWE of 250–500 mg/kg bw dose showed more prominent results when compared with doses of PFWE for TAC. The results obtained in the present study suggested that the antioxidant activities of lichens might be the possible reason behind the observed antihaematological status. However, the protective effect of lichen extracts were inadequate on diabetes-induced microcytic hypochromic anaemia. In addition, the extracts have no effect on metabolic complications. Our experimental data showed that high doses of CIWE and PFWE alone have no detrimental effect on blood cells and TOS status of plasma. Hence, they are safe and suitable for different administration routes.

Therapeutic potential of some plant extracts used in Turkish traditional medicine on streptozocin-induced type 1 diabetes mellitus in rats

Diabetes mellitus (DM) is known to impair many physiological functions. Some reports claim that medicinal plants can reduce these alterations caused by DM. The aim of this study was to investigate the therapeutic potential of aqueous-methanol extracts of Urtica dioica, Thymus vulgaris (TV), Myrtus communis (MC), Scolymus hispanicus (SH) and Cinnamomun zeylanicum (CZ) on streptozotocin (STZ)-induced type 1 DM in rats. Diabetes was induced via a single i.p. injection of STZ (65 mg/kg body weight). After 1 week to allow for development of diabetes, each plant extract was administered to diabetic rats separately at a dose of 100 mg/kg body weight daily for 28 days. The results showed that only SH extract significantly (P < 0.05) amended fasting blood glucose level. The lipid profile was ameliorated especially by supplementations of TV, MC and CZ extracts. Almost all plant extract treatments markedly (P < 0.05) increased reduced glutathione content and decreased lipid peroxidation levels of erythrocyte, plasma, retina and lens tissues. They also significantly (P < 0.05) amended erythrocyte catalase activity, levels of marker serum enzymes (except amylase), urea and blood urea nitrogen when compared to diabetic rats treated with nothing. Furthermore, none of the plant extracts counteracted body weight loss of diabetic rats. Our data revealed that the aforementioned plant extracts have remarkable potential to counteract DM-caused alterations, probably through their antioxidant and free radical-defusing effects.

Hygrophila spinosa: A comprehensive review

Hygrophila spinosa T Ander, belonging to the family Acanthaceae, is a promising medicinal plant with great economic potential. The medicinal value of H. spinosa has been appreciated in the ancient medical literature. The plant contains terpenoids, alkaloids, flavonoids, and is traditionally known as an aphrodisiac, renal tonic, and for its health-promoting properties. The plant is cultivated throughout India. However, systematic information on the different aspects of this species is not available. In this review, an attempt has been made to present this information.

Treatment with aqueous extract from Croton cajucara Benth reduces hepatic oxidative stress in streptozotocin-diabetic rats

Croton cajucara Benth is a plant found in Amazonia, Brazil and the bark and leaf infusion of this plant have been popularly used to treat diabetes and hepatic disorders. The present study was designed to evaluate the oxidative stress as well as the therapeutic effect of Croton cajucara Benth (1.5 mL of the C. cajucara extract i.g.) in rats with streptozotocin-induced diabetes. Croton cajucara Benth was tested as an aqueous extract for its phytochemical composition, and its antioxidant activity in vitro was also evaluated. Lipid peroxidation and superoxide dismutase, catalase, and glutathione reductase activities were measured in the hepatic tissue, as well as the presence activation of p65 (NF-κB), through western blot. Phytochemical screening of Croton cajucara Benth detected the presence of flavonoids, coumarins and alkaloids. The extract exhibited a significant antioxidant activity in the DPPH-scavenging and the hypoxanthine/xanthine oxidase assays. Liver lipid peroxidation increased in diabetic animals followed by a reduction in the Croton-cajucara-Benth-treated group. There was activation of p65 nuclear expression in the diabetic animals, which was attenuated in the animals receiving the Croton cajucara Benth aqueous extract. The liver tissue in diabetic rats showed oxidative alterations related to the streptozotocin treatment. In conclusion the Croton cajucara Benth aqueus extract treatment effectively reduced the oxidative stress and contributed to tissue recovery.

Antidiabetic activity of alcoholic leaves extract of Alangium lamarckii Thwaites on streptozotocin-nicotinamide induced type 2 diabetic rats

OBJECTIVE

To investigate antidiabetic potential of alcoholic leaves extract of Alangium lamarckii (A. lamarckii) on streptozotocin-nicotinamide induced type 2 diabetic rats.

METHODS

Oral glucose tolerance test was done by inducing hyperglycemic state via administration of glucose in water (2g/kg). Single dose of alcoholic leaves extract of A. lamarckii (250 and 500 mg/kg, p.o.) were administered to normoglycemic, hyperglycemic rats. Type 2 diabetes was induced by single intraperitoneal injection of nicotinamide (110 mg/kg) followed by streptozotocin (65mg/kg). The study also included estimations of blood plasma glucose, lipid profile, liver glycogen, body weight and antioxidant status in normal and diabetic rats.

RESULTS

Admistration of alcoholic extract of A. lamarckii at two dosage 250 and 500 mg/kg, p.o. did not showed any significant change in blood glucose level of normoglycemic rats (P>0.05), whereas, oral glucose tolerance test depicted reduction in blood glucose level (P<0.05). The streptozotocin-nicotinamide induced diabetic rats, significantly decreased the blood plasma glucose level (P<0.001) comparable to glibenclamide (10 mg/kg), restored the lipid profile and showed improvement in liver glycogen, body weight and antioxidant status in diabetic rats.

CONCLUSIONS

Present finding demonstrated the significant antidiabetic activity of alcoholic leaves extract of A. lamarckii.

A pharmacological appraisal of medicinal plants with antidiabetic potential

Diabetes mellitus is a complicated metabolic disorder that has gravely troubled the human health and quality of life. Conventional agents are being used to control diabetes along with lifestyle management. However, they are not entirely effective and no one has ever been reported to have fully recovered from diabetes. Numerous medicinal plants have been used for the management of diabetes mellitus in various traditional systems of medicine worldwide as they are a great source of biological constituents and many of them are known to be effective against diabetes. Medicinal plants with antihyperglycemic activities are being more desired, owing to lesser side-effects and low cost. This review focuses on the various plants that have been reported to be effective in diabetes. A record of various medicinal plants with their established antidiabetic and other health benefits has been reported. These include Allium sativa, Eugenia jambolana, Panax ginseng, Gymnema sylvestre, Momrodica charantia, Ocimum sanctum, Phyllanthus amarus, Pterocarpus marsupium, Trigonella foenum graecum and Tinospora cordifolia. All of them have shown a certain degree of antidiabetic activity by different mechanisms of action.

In vitro and in vivo hepatoprotective effects of the total alkaloid fraction of Hygrophila auriculata leaves

OBJECTIVE

To investigate the total alkaloid fraction of the methanol extract of leaves of Hygrophila auriculata for its hepatoprotective activity against CCl4-induced toxicity in freshly isolated rat hepatocytes, HepG2 cells, and animal models.

MATERIALS AND METHODS

Mature leaves of H. auriculata were collected, authenticated, and subjected to methanolic extraction followed by isolation of total alkaloid fraction. Freshly isolated rat hepatocytes were exposed to CCl4 (1%) along with/without various concentrations of the total alkaloid fraction (80-40 microg/ml). Protection of human liver-derived HepG2 cells against CCl4-induced damage was determined by the MTT assay. Twenty-four healthy Wistar albino rats (150-200 g) of either sex were used for the in vivo investigations. Liver damage was induced by administration of 30% CCl4 suspended in olive oil (1 ml/kg body weight, i.p).

RESULTS

The antihepatotoxic effect of the total alkaloid fraction was observed in freshly isolated rat hepatocytes at very low concentrations (80-40 microg/ml). A dose-dependent increase in the percentage viability was observed when CCl4-exposed HepG2 cells were treated with different concentrations of the total alkaloid fraction. Its in vivo hepatoprotective effect at 80 mg/kg body weight was comparable with that of the standard Silymarin at 250 mg/kg body weight.

CONCLUSION

The total alkaloid fraction was able to normalize the biochemical levels which were altered due to CCl4 intoxication.

Cytotoxic effects of bangladeshi medicinal plant extracts

To investigate the cytotoxic effect of some Bangladeshi medicinal plant extracts, 16 Bangladeshi medicinal plants were successively extracted with n-hexane, dichloromethane, methanol and water. The methanolic and aqueous extracts were screened for cytotoxic activity against healthy mouse fibroblasts (NIH3T3) and three human cancer-cell lines (gastric: AGS; colon: HT-29; and breast: MDA-MB-435S) using the MTT assay. Two methanolic extracts (Hygrophila auriculata and Hibiscus tiliaceous) and one aqueous extract (Limnophila indica) showed no toxicity against healthy mouse fibroblasts, but selective cytotoxicity against breast cancer cells (IC₅₀ 1.1–1.6 mg mL⁻¹). Seven methanolic extracts from L. indica, Clerodendron inerme, Cynometra ramiflora, Xylocarpus moluccensis, Argemone mexicana, Ammannia baccifera and Acrostichum aureum and four aqueous extracts from Hygrophila auriculata, Bruguiera gymnorrhiza, X. moluccensis and Aegiceras corniculatum showed low toxicity (IC₅₀ > 2.5 mg mL⁻¹) against mouse fibroblasts but selective cytotoxicity (IC₅₀ 0.2–2.3 mg mL⁻¹) against different cancer cell lines. The methanolic extract of Blumea lacera showed the highest cytotoxicity (IC₅₀ 0.01–0.08 mg mL⁻¹) against all tested cell lines among all extracts tested in this study. For some of the plants their traditional use as anticancer treatments correlates with the cytotoxic results, whereas for others so far unknown cytotoxic activities were identified.

Antioxidant and pancreas-protective effect of red mold fermented products on streptozotocin-induced diabetic rats

BACKGROUND

Red mold fermented products contain various antioxidants, and were mentioned in an ancient Chinese pharmacopoeia of medicinal food and herbs. They were considered useful for the treatment of diabetes. The objective of this study was to determine the antioxidant and pancreas-protective function of red mold fermented products on streptozotocin (STZ)-induced diabetic rats.

RESULTS

Throughout the experimental period (8 weeks), significantly (P < 0.05) lowered plasma glucose, amylase, triglyceride and cholesterol levels were observed in groups treated with red mold fermented products. Diabetic rats showed higher reactive oxygen species (P < 0.05) and lower activities of glutathione disulfide reductase, glutathione reductase and catalase (P < 0.05) in pancreas as compared to normal rats and those treated with red mold fermented products. There were some necrotic cells observed in the pancreas of diabetic rats and pancreatic tissue damaged by STZ in the red mold fermented products supplemented groups was ameliorated.

CONCLUSION

These results indicate that red mold fermented products not only regulate hyperglycemia but also provide prevention against the effects of STZ-induced pancreatic damage.

Attenuation of oxidative stress in streptozotocin-induced diabetic rats by Eucalyptus globulus

In traditional medicine, Eucalyptus globulus (eucalyptus) was used for the treatment of diabetes mellitus. Hyperglycemia in diabetes has been associated with increased formation of reactive oxygen species (ROS) and oxidative damage to tissue compounds. The aim of this study was to evaluate the effects of eucalyptus in the diet (20 g/Kg) and drinking water (2.5 g/L) on lipid peroxidation, protein oxidation and antioxidant power in plasma and liver homogenate, as well as glycated-Hb (HbA(1C)) of blood in streptozotocin-induced diabetic rats for a period of 4 weeks. Diabetes induced in rats by a single intraperitoneal injection of streptozotocin (STZ, 65 mg/Kg). At the end of the treatment period, the level of plasma glucose, plasma and liver malondialdehyde (MDA, the main product of lipid peroxidation), protein carbonyl (PC, one of the protein oxidation products) and HbA(1C) increased and ferric reducing antioxidant power (FRAP) decreased in diabetic rats compared to normal rats. Eucalyptus administration for 4 weeks caused a significant decrease in the plasma glucose levels, plasma and liver MDA, PC and HbA(1C), also a concomitant increase in the levels of FRAP in diabetic treated rats. In conclusion, the present study showed that eucalyptus posses antioxidant activities. Eucalyptus probably restores antioxidant power, due to the improved hyperglycemia in streptozotocin-induced diabetic rats.

Antioxidant effect of Ajuga iva aqueous extract in streptozotocin-induced diabetic rats

The purpose of this study was to investigate the possible antioxidant effect of an aqueous extract of Ajuga iva (Ai) in streptozotocin (STZ)-induced diabetic rats. Twelve diabetic rats were divided into two groups fed a casein diet supplemented or not with Ai (0.5%), for 4 weeks. In vitro, the Ai extract possessed a very high antioxidant effect (1 mg/ml was similar to those of trolox 300 mmol/l). The results indicated that plasma thiobarbituric acid reactive substances (TBARS) values were reduced by 41% in Ai-treated compared with untreated diabetic rats. TBARS concentrations were lower 1.5-fold in liver, 1.8-fold in heart, 1.9-fold in muscle and 2.1-fold in brain in Ai-treated than untreated group. In erythrocytes, Ai treatment increased significantly the activities of glutathione peroxidase (GSH-Px) (+25%) and glutathione reductase (GSSH-Red) (+22%). Superoxide dismutase activity was increased in muscle (+22%), while GSH-Px activity was significantly higher in liver (+28%), heart (+40%) and kidney (+45%) in Ai-treated compared with untreated group. Liver and muscle GSSH-Red activity was, respectively, 1.6- and 1.5-fold higher in Ai-treated than untreated diabetic group. Catalase activity was significantly increased in heart (+36%) and brain (+32%) in Ai-treated than untreated group. Ai treatment decreased plasma nitric oxide (-33%), carbonyls (-44%) and carotenoids (-68%) concentrations. In conclusion, this study indicates that Ajuga iva aqueous extract improves the antioxidant status by reducing lipid peroxidation and enhancing the antioxidant enzymes activities in plasma, erythrocytes and tissues of diabetic rats.

In vivo assessment of antidiabetic and antioxidant activities of rosemary (Rosmarinus officinalis) in alloxan-diabetic rabbits

Rosemary (Rosmarinus officinalis), used in traditional Turkish folk medicine for the treatment of hyperglycaemia, is widely accepted as one of the medicinal herb with the highest antioxidant activity. Accordingly, the present study was designed to investigate the possible actions of ethanolic extract of the leaves of Rosmarinus officinalis on glucose homeostasis and antioxidant defense in rabbits. In the first set of experiments, hypoglycaemic effects of oral administration of various doses (50, 100 and 200 mg/kg) of the extract were examined in normoglycaemic and glucose-hyperglycaemic rabbits. Optimal effect was observed in both of the animal groups with a dose of 200 mg/kg of the extract and this activity was independent from the effects of insulin. In another part of experiments, acute effect of various doses of the Rosmarinus officinalis extract on blood glucose and serum insulin levels was studied in alloxan-induced diabetic rabbits. Of the three doses of extract, the highest dose (200 mg/kg) significantly lowered blood glucose level and increased serum insulin concentration in alloxan-diabetic rabbits. The last set of experiments designed to investigate the subacute effect of the Rosmarinus officinalis extract on repeated administration in alloxan-diabetic rabbits. At the doses of 100 and 200 mg/kg, antihyperglycaemic effect of extract was accompanied by a significant increase in serum insulin levels in diabetic rabbits. Furthermore, during 1 week of treatment of diabetic rabbits with a dose of 200 mg/kg of the extract showed that the extract possessed a capability to inhibit the lipid peroxidation and activate the antioxidant enzymes. It was concluded that probably, due to its potent antioxidant properties, the Rosmarinus officinalis extract exerts remarkable antidiabetogenic effect.

Attenuation of plasma dyslipidemia and oxidative damage by dietary caloric restriction in streptozotocin-induced diabetic rats

Oxidative stress has been proposed as the pathogenic mechanism linking insulin resistance with endothelial dysfunction during diabetes. The present study investigated the attenuation of plasma dyslipidemia and oxidative damage by caloric restriction in experimental diabetes. Forty male Wistar rats were divided into ad libitum and calorie-restricted groups. The calorie-restricted group was subjected to 30% caloric restriction for 63 days before induction of diabetes to 50% of both groups. Caloric restriction significantly (p<0.01) reduced the body weights, reactive oxygen species (ROS), catalase, total cholesterol levels and non-significantly reduced SOD activities in non-diabetic and diabetic rats. Caloric restriction was also found to improve blood glucose levels, glycated hemoglobin, malondialdehyde, triglyceride, oxidized glutathione and reduced glutathione levels and significantly (p<0.05) increased GPx and GR activities in the experimental animals. The non-diabetic rats fed ad libitum had the most significant increases in body weight which could be due to dyslipidemia. These results indicate that dietary caloric restriction attenuates the oxidative damage and dyslipidemia exacerbated during diabetes as evidenced by the significant reduction in their body weights, ROS, total cholesterol levels and the increases in GPx activity and redox status.

Beneficial effects of Murraya koenigii leaves on antioxidant defense system and ultra structural changes of pancreatic β-cells in experimental diabetes in rats

Oxidative stress and oxidative damage to tissues are common end points of chronic diseases such as atherosclerosis, diabetes, and rheumatoid arthritis. Oxidative stress in diabetes coexists with a reduction in the antioxidant status, which can further increase the deleterious effects of free radicals. The aim of the present study was to evaluate the possible protective effects of Murraya koenigii leaves extract against beta-cell damage and antioxidant defense systems of plasma and pancreas in streptozotocin induced diabetes in rats. The levels of glucose and glycosylated hemoglobin in blood and insulin, Vitamin C, Vitamin E, ceruloplasmin, reduced glutathione and TBARS were estimated in plasma of control and experimental groups of rats. To assess the changes in the cellular antioxidant defense system such as the level of reduced glutathione and activities of superoxide dismutase, catalase and glutathione peroxidase were assayed in pancreatic tissue homogenate. The levels of glucose, glycosylated hemoglobin, insulin, TBARS, enzymatic and non-enzymatic antioxidants were altered in diabetic rats. These alterations were reverted back to near control levels after the treatment of M. koenigii leaves extract. Transmission electron microscopic studies also revealed the protective nature of M. koenigii leaves on pancreatic beta-cells. These findings suggest that M. koenigii treatment exerts a therapeutic protective nature in diabetes by decreasing oxidative stress and pancreatic beta-cell damage. The antioxidant effect of the M. koenigii extract was compared with glibenclamide, a well-known hypoglycemic drug.

Dietary caloric restriction improves the redox status at the onset of diabetes in hepatocytes of streptozotocin-induced diabetic rats

Enhanced production of free radicals and oxidative stress induced by hyperglycemia play a central role in the pathogenesis of diabetes and its complications. This study assessed the attenuation by dietary caloric restriction on the oxidative and lipid peroxidative effects of diabetes in the liver through reduction in body and organ weights and concomitant metabolic changes. Three-month-old male Wistar rats were subjected to ad libitum feeding and 30% caloric restriction for 9 weeks before induction of diabetes by intraperitoneal injection of 35 mg/kg body weight streptozotocin. The animals were sacrificed 2 weeks after streptozotocin treatment depicting the onset of diabetes. Caloric restriction significantly reduced the organ weights (p<0.01), malondialdehyde (p<0.01) and catalase activity (p<0.01), but significantly increased glutathione reductase activity (p<0.01), and GSH/GSSG ratios (p<0.05). Caloric restriction also non-significantly reduced reactive oxygen species, superoxide dismutase and oxidized glutathione but increased glutathione peroxidase activity and reduced glutathione levels in the diabetic rats. Our data indicate a decrease in lipid peroxidation, improvement in the antioxidant defense systems and restoration of the redox status in the liver by caloric restriction. Therefore, this could provide a non-invasive antioxidant therapy early in diabetes to prevent the development of the complications associated with the disease.