oxidative stress

This study explored the effect of bark of Holarrhena antidysenterica Linn in management of diabetic neuropathy in experimental animals. Adult Wistar rats (either sex; 250-275 g) were injected with streptozotocin (50 mg/kg; i.p.) to induce diabetes. Methanol extract of bark of Holarrhena antidysenterica was administered in 3 doses (200, 400 and 600 mg/kg; p.o.) to rats for 28 successive days daily after 4 weeks of STZ administration. After 8 weeks, the neuropathic activity was evaluated using Open field test, Tail Flick test, Cold Allodynia and Formalin test. Afterwards, sciatic nerve was used for TBARS, GSH, Nitrite, Catalase and protein estimations. STZ induced diabetic neuropathy caused decrease in tail-flick latency time in radiant heat test and decreased allodynic response in tail-immersion (cold water) test. STZ caused increase in blood glucose, Glycosylated Haemoglobin and blood Cholesterol levels. Furthermore, activity of endogenous antioxidants like GSH and catalase significantly decreased; however, TBARS and nitrite levels were increased. Administration of MEHA for 28 days prevented the development of diabetic neuropathy as evident from reversed (p< 0.05) cold allodynia and tail flick latency (p< 0.05) as compared to diabetic control group. Glycosylated haemoglobin and cholesterol levels were significantly decreased (p< 0.05) in rats as compared to diabetic control group. MEHA treated rats showed significant decreased TBARS and nitrite levels and increased GSH and Catalase level. Thus, Holarrhena antidysenterica not only improved the diabetic condition but also reversed neuropathic pain through modulation of oxidative–nitrosative stress.

Green beans contain high concentration of polyphenols, carotenoids, ascorbic acids, tocopherol and flavonoids which fight against oxidative damage. Free radicals have been implicated in the pathogenesis of most diseases. Thus, the consumption of dietary antioxidants from vegetables and fruits is beneficial in preventing these diseases. The present study was undertaken to evaluate antioxidant potential of ethanolic extracts of four different species of green beans. Ethanolic extract of Phaseolus vulgaris (french bean), Vicia faba (broad bean), Cyamopsis tetragonoloba (cluster bean) and Vigna unguiculata (cowpea) were studied for antioxidant properties by 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay, H2O2 decomposition, reducing power ability assay. Total phenolic content was measured by Folin Coilteau reaction and flavonoid contents were determined by AlCl3 assay. Efforts were made to study the iron chelation. Total phenol content ranged from 17.00 ± 0.004 to 53± 0.007 µg GAE/mg while total flavonoid ranged 22 ± 0.003 to 36 ± 0.006 µg QE/ mg. All the extracts scavenged DPPH radical, decomposed H2O2 and had significant reducing potential. The IC50 for DPPH scavenging activity was highest for Vigna unguiculata as 2.27 ± 0.19 mg/ml while lowest for Vicia faba as 0.18± 0.02 mg/ml. All the extracts chelated Fe2+ form of iron but not Fe3+. A positive and strong correlation (r2 = 0.9) between total phenolic content & antioxidant activity suggests that green beans have enormous potential to enhance antioxidant capacity of our daily food supply and may provide health benefits in oxidative stress as neutraceuticals.

Alzheimer disease (AD) is a progressive dementia affecting a large proportion of the aging population, which is characterized by memory impairment, cognitive dysfunction, behavioral disturbances, and deficits in activities of daily living. Multiple lines of evidence demonstrate that oxidative stress is an early event in Alzheimer’s disease (AD), occurring prior to cytopathology, and therefore may play a key pathogenic role in AD. Cure of cognitive disorders such as amnesia, attention deficit and Alzheimer’s disease is still a nightmare in the field of medicine and several nootropic agents are being used to improve memory, mood and behavior, but the resulting side effects associated with these agents have made their use limited. Indian system of medicine emphasizes use of herbs, nutraceuticals and life style changes for age related neurodegenerative disorders like Alzheimer’s disease. In Ayurveda, Medhya herbs such as Centella asiatica, Bacopa monnieri, Acorus calamus and several others are beneficial in cognitive disorders including Alzheimer’s disease and if their scientific evidences and proofs are taken into consideration they make themselves a reasonably good target in finding a cure for memory and intellectual disorders.  Current review sums up the plants that have shown the beneficial and encouraging results in treating ailments like Alzheimer’s disease having antioxidant properties which play an important role in pathogenesis of Alzheimer’s disease.

Escueltin is a coumarin derivative with wide range of biological activity. In the present study we investigated the protective effects of esculetin against cyclophosphamide induced oxidative stress and DNA damage. Following parameters were evaluated: (a) chromosomal aberration and mitotic index; (b) micronuclei formation and polychromatic erythrocyte frequency, and (c) malondialdehyde, glutathione and superoxide dismutase levels in liver homogenates. CP (50 mg/kg intraperitopeanlly) treatment significantly increased the different types of aberrant cells and micronuclei formation in bone marrow cells of mice. It also increase the lipid peroxidation and decreased glutathione and superoxide dismutase activity in liver. Whereas, pretreatment with esculetin (50, 75 and 100 mg/kg, per orally) alleviated aberrations in chromosome and lessened micronuclei formation. Esculetin pretreatment also shielded the liver of mice against cyclophosphamide induced oxidative stress as the levels of oxidative stress markers where near normal levels. Protective effect of esculetin correlated well with its genoprotective activity. It can be concluded that esculetin offsets cyclophosphamide induced oxidative stress and resulting DNA damage and can be useful as a chemopreventive agent against cyclophosphamide induced toxicity.

The most important problem that humanity is facing in this century is environmental pollution. Polycyclic aromatic hydrocarbons (PAHs) are abundant pollutants and many of them are carcinogenic. The most important PAH is Benzo(a)pyrene [B(a)P] which is formed by the incomplete combustion of organic substances, cigarette smoke, charcoal and grilling of food. Benzo(a)pyrene [B(a)P]  has been shown to cause mutagenic, carcinogenic and cytotoxic effects in various species and tissues. The present study was aimed to divulge the cytotoxic effect of B(a)P induced oxidative damage in liver of male Swiss albino mice. Animals were divided into 3 groups of which Group I served as control and were given corn oil, Group II animals were administered with B(a)P (100 mg/kg body weight) dissolved in corn oil orally thrice a week for three successive weeks for an induction period of 6 weeks, Group III animals were  administered with B(a)P (100 mg/kg body weight) dissolved in corn oil orally thrice a week for three successive weeks for an induction period of  12 weeks. At the end of the experimental period, the extracted liver tissue was investigated biochemically for cytotoxic markers, oxidative stress markers, lipid peroxidation and antioxidant enzymes .The evaluation of these enzymes and their activities reflect the severity of damage caused to the membrane or to the organ itself.  The data suggests that the difference in morphology and cellular changes in liver on exposure to B(a)P is time dependent. Key words: PAH, B(a)P, toxicity, swiss albino mice,  liver, oxidative stress

  Oxidative stress caused by free radicals is associated to various diseases. Modern research is directed towards finding naturally-occurring antioxidants of plant origin. The aim of the present study was to evaluate the in vitro antioxidant activities of punica granatum rind extracts of ganesh variety. The present investigation was to examine the free radical scavenging activity of various extracts of punica granatum rind by different in-vitro methods. The antioxidant activity was evaluated by DPPH assay, FRAP assay, Hydrogen peroxide radical scavenging activity, Nitric oxide radical scavenging activity. The methanolic extract of punica granatum rind was found to more effective in the radical scavenging activity. All the above invitro studies clearly indicate that the methanolic extract of punica granatum rind has a significant antioxidant activity. These invitro assays indicate that this rind extracts is a better source of natural antioxidant, which might be helpful in preventing the progress of various oxidative stresses and also support the ethnomedical use of this rind to promote good health for humans.