Tuberculostatic activity of henna (Lawsonia inermis Linn.)

The tuberculostatic activity of the herb henna (Lawsonia inermis Linn.) was tested in vitro and in vivo. On Lowenstein Jensen medium, the growth of tubercle bacilli from sputum and of Mycobacterium tuberculosis H37Rv was inhibited by 6 micrograms/ml of the herb. In vivo studies on guinea pigs and mice showed that the herb at a dose of 5 mg/kg body weight led to significant resolution of experimental tuberculosis following infection with M. tuberculosis H37Rv.     

Pain-relieving effects of Lawsonia inermis on neuropathic pain induced by chronic constriction injury

The aim of this study was to determine the role of Lawsonia inermis (L. inermis) extract in the chronic constriction injury (CCI)-induced neuropathic pain. Following CCI surgery, L. inermis extract (250 mg/kg and 500 mg/kg) and gabapentin (100 mg/kg) were administered intraperitoneally for 14 consecutive days. Heat hyperalgesia and allodynia were assessed by radiant heat, aceton drop, and von frey filament tests, respectively. Rat pain behaviors were evaluated on -1sh, 3rd, 5th, 7th, 10th and 14th days post CCI surgery. At the end of the study, the spinal levels of malondialdehyde (MDA), total thiol, IL1-β, and TNF-α were estimated. Treatment of L. inermis extract reversed the decreased level of thiol and the elevation of MDA level in the spinal cord of CCI rats. Besides, L. inermis extract treatment decreased the elevation of inflammatory markers including IL1-β, and TNF-α in the spinal cord of CCI rats. These results indicated that L. inermis has potential neuroprotective effects against CCI induced neuropathic pain due to its anti-oxidant, and anti-inflammatory effects.

     

Free radical scavenging potential of Lagenaria siceraria (Molina) Standl fruits extract

ObjectiveTo elucidate free radical scavenging activity of ethanolic extract Lagenaria siceraria (L. siceraria) (Molina) fruit.MethodsThe free radical scavenging activity of the L. siceraria (Molina) fruit extract was assayed by using α,α-diphenyl-β-picrylhydrazyl (DPPH), 2,20-azinobis 3-ethyl benzothiazoline-6-sulfonate (ABTS), FRAP, reducing power, chelating ability and β-carotene bleaching assay.ResultsThe IC₅₀ values of DPPH and ABTS radical-scavenging activity was found to be 1.95 mg/mL and 19 mg/mL, respectively. In ferrous chelation assay, the percentage of inhibition was found to be 89.21%. The reducing power of ethanolic extract of L. siceraria (Molina) fruit was 0.068 at 1 mg/mL and increased to 0.192 at 5 mg/mL. The β-carotene linoleate bleaching assay was 46.7% at 5 mg/mL and antioxidant activity using FRAP at 0.305 for 1 mg/mL to 0.969 for 5 mg/mL.ConclusionsThe results indicate that L. siceraria (Molina) fruit could be an important sources of natural radical scavengers.     

Free radical scavenging systems and the effect of peroxide damage in aged human skin fibroblasts

One prominent theory of aging postulates an accumulation of cell damage resulting from nonenzymatic chemical reactions between important cellular components and free radicals. Fibroblast lines derived from skin biopsies of psychiatric patients ranging in age from 22 to 70 were evaluated soon after adaptation to culture. No significant correlation was found between donor age and the detoxification enzyme activities of superoxide dismutase (SOD) or aryl hydrocarbon hydroxylase (AHH) or susceptibility to damage by oxygen metabolites as measured by cell viability or lactate dehydrogenase (LDH) leakage.     

Free radical scavenging property and antiproliferative activity of Rhodiola imbricata Edgew extracts in HT-29 human colon cancer cells

ObjectiveTo investigate the in vitro antioxidant and antiproliferative activity of rhizome extracts of Rhodiola imbricata (R. imbricata) in HT-29 human colon cancer cell line.MethodsThe successively extracted rhizome of R. imbricata using various solvents was analyzed for their total phenolics, tannins and flavonoid contents. In vitro antioxidant activity was evaluated by employing different assays, including DPPH, ABTS radical scavenging assays, FRAP, phosphomolybdenum reduction assay, superoxide anion, hydroxyl radical scavenging activities and metal chelating ability.ResultsAcetone and methanol extracts recorded higher phenolic content and showed comparable antioxidant activity with standard reference. Additionally, they also inhibited the proliferation of HT-29 cells upon treatment at higher concentration (200 μg/mL) (acetone and methanol, 84% and 84%, respectively). On examination acetone extract exhibited antiproliferative activity in a concentration dependent manner whereas, methanol extract showed both dose dependent and time dependent inhibitory activity.ConclusionsThe results obtained justify the traditional usage of R. imbricata from their promising antioxidant activity.     

In vitro free radical scavenging capacity of thyroid hormones and structural analogues.

It was reported that thyroid hormones decreased Cu(2+)-induced low-density lipoprotein (LDL) oxidation in vitro. Here, we investigated free radical scavenging capacities of thyroid hormones (3,5,3'-tri-iodo-L-thyronine (T(3)), thyroxine (T(4)) and 3,3',5'-tri-iodo-L-thyronine (rT(3))) and structural analogues (L-thyronine (T(0)), 3,5,3'tri-iodothyroacetic acid (TA(3)) and 3,5,3',5'-tetra-iodothyroacetic acid (TA(4))), using three different models of free radical generation. T(0), T(3) and TA(3) slowed down production of conjugated diene and thiobarbituric acid-reactive substances during LDL oxidation by 2,2'-azobis-[2-amidinopropane] (water-soluble), whereas rT(3), T(4) and TA(4) had practically no effect. In this system, T(0) was the more active compound. Using a 1,1-diphenyl-2-picrylhydrazyl (lipid-soluble) test, all compounds also revealed free radical scavenging capacities, but rT(3), T(4) and TA(4) were more active than T(0), T(3) and TA(3). T(3) was able to scavenge superoxide anion and hydroxyl radicals generated in an aqueous phase by a xanthine-xanthine oxidase system, as measured by electron paramagnetic resonance spectroscopy. It may be concluded that: (1) thyroid hormones and analogues with a 4'-hydroxy diphenylether structure have free radical scavenging capacities, (2) this property is influenced by the number of iodines on the phenolic ring, and (3) thyroid hormone scavenging capacity should not be the only mechanism explaining their protective effect on Cu(2+)-induced LDL oxidation. The physiological significance of the findings is discussed.     

Antioxidant activity and free radical scavenging activities of Streptomyces sp.strain MJM 10778

Objective:To investigate the antioxidant activity of soil-borne aetinobacteria.Methods:The total phenolic contents,the level of antioxidant potential by DPPH radical scavenging activity,MO scavenging activity,and ABTS radical scavenging activity in ethyl acelale extract were determined.Results:The 16 S rDNA sequencing analysis revealed that Streptomyces sp.strain MJM 10778.which was isolated from Hambak Mountain.Korea,has 99.9% similarity to Streptomyces misionensis(S.misionenis) NBRC 13063.The physiological and the morphological test revealed that the strain MJM 10778 has different characteristics from the strain NBRC.13063.The entire antioxidant assay with the ethyl acelale extract displayed good radical scavenging activity.The IC_(50) values of the strain MJM 10778 extract on DPPH,.NO.and ABTS radicals were identified to he 92.8 μg/mL,0.02 μg/ml,and 134.9 μg/mL,respectively.The ethyl acetate extract of the strain MJM 10778 showed an 81.500% of cell viability at 100 μg/mL in Raw264.7cell viability assay.Conclusions:The results obtained suggesl that the ethyl acetate extract of Streptomyces sp.strain MJM 10778 could be considered as a potential source of drug for the diseases that is caused by free radicals with its anti-oxidant activities and low cytotoxicity.     

Phytopharmacological approach of free radical scavenging and anti-oxidative potential of eugenol and Ocimum gratissimum Linn.

ObjectiveTo evaluate phytopharmacologically eugenol and two extract products of Ocimum gratissimum Linn. (O. gratissimum) (Labiaceae) on free radical scavenging and antioxidant activity.MethodsAqueous and methanol extract of fresh aerial part of O. gratissimum were prepared and eugenol (1-allyl-4-hydroxy-3-methoxybenzene) was isolated from fresh leaves and characterized by high performance liquid chromatography, fourier transform infrared spectroscopy, 1 h nuclear magnetic resonance. To establish the antioxidant potentiality of aqueous extract, methanol extract and eugenol, 1, 1-diphenyl-2-picrylhydrazyl radical, hydroxyl radical, nitric oxide scavenging activity, antioxidant activity by ferric thiocyanate and reducing power were measured in chemical system in vitro.ResultsSignificant (P<0.05) concentration-dependent free radical scavenging activity, antioxidant activity, and reducing power was observed by O. gratissimum products. Moreover, eugenol is more potent than the two extract products of O. gratissimum, but lower than potent antioxidant ascorbic acid.ConclusionsHence, O. gratissimum presents a potentially valuable source of natural antioxidant and bioactive material.     

The antiplasmodial and radical scavenging activities of flavonoids of Erythrina burttii

The acetone extract of the root bark of Erythrina burttii showed in vitro antiplasmodial activity against the chloroquine-sensitive (D6) and chloroquine-resistant (W2) strains of Plasmodium falciparum with IC(50) values of 0.97 ± 0.2 and 1.73 ± 0.5 μg/ml respectively. The extract also had radical scavenging activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical with an EC(50) value of 12.0 μg/ml. The isoflav-3-enes burttinol-A and burttinol-C, and the 2-arylbenzofuran derivative burttinol-D were identified as the most active antiplasmodial (IC(50)<10 μM) and free radical scavenging (EC(50)ca. 10 μM) principles. The acetone extract of E. burttii at 800 mg/kg/day, in a 4-day Plasmodium berghei ANKA suppressive test, showed in vivo antimalarial activity with 52% chemosuppression. In the same in vivo test, marginal activities were also observed for the extracts of the root and stem bark of Erythrina abyssinica and the root bark of Erythrina sacleuxii.     

Free radical scavengers and diaphragm injury following inspiratory resistive loading.

Three groups of NZW rabbits were studied to examine the role of free radical scavengers in preventing diaphragm injury produced by inspiratory resistive load (IRL): control, IRL, and scavenger groups. An IRL (Pao: 45-55 cm H2O) was applied to the IRL and the scavenger groups on Day 1. Free radical scavengers (polyethylene glycol superoxide dismutase, N-acetylcysteine, and mannitol) were given (intravenously) to the scavenger group both before and after the IRL. All rabbits were killed on Day 3 to collect diaphragms. Point counting H&E-stained diaphragm x-sections indicated that abnormal diaphragm muscle in the IRL group was significantly greater than control (p < 0.01). However, it was significantly lower in the scavenger group than the IRL group (p < 0.05) and it did not differ from control. In vitro diaphragm physiological studies found that the twitch tension (p < 0.05) and maximal tension (p < 0.01) in the IRL group were significantly lower than control. The maximal tensions (p < 0.05) in the scavenger group were lower than control. After the fatigue protocol, diaphragmatic contractility in the scavenger group was similar to control and was better maintained compared with the IRL group. We conclude that free radical scavengers can prevent the development of diaphragm injury as evidenced by histology but the protection of diaphragm function is limited.     

Free radical scavenger activity of rutosides

BACKGROUND: The O-(beta-hydroxyethyl)-rutosides (HRs) are a standard mixture of flavonoid-derivatives that have a clinico-pharmacological activity on peripheral circulation, particularly on the endothelial cells of veins and lymphatics. Flavonoids are believed to prevent the oxidative damage derived from radical oxidative species (ROS), like hydroxyl radicals (HO.) and hypochlorite (-OCl). The aim of the study was to investigate the stability and capability of HRs in toto and of their single components (7-mo-nohydroxy ethyl rutoside; 7,4'-dihydroxyethyl rutoside; 7,3',4'-trihydroxyethyl rutoside and the 7,5,3',4'-tetrahydroxyethyl rutoside) of scavenging ROS and other radicals generated by different oxidative systems, and also their anti-lipoperoxidative activity at mM concentrations (1.0-10.0 mM). METHODS: The following oxidative systems have been employed: Fenton reaction for the hydro-xylation of l-tyrosine to l-DOPA and the peroxidation of arachidonic acid; photo-Fenton type reaction for the oxidation of toluene in the aqueous UV irradiated TiO2 system; the azocompound 2.2'-azobis(2, 4-dimethylvaleronitrile (AMVN) to produce peroxy radicals and the daily autoxidation of arachidonic acid. Analyses were performed by HPLC, HPLC-MS, GC-MS, and spectrophotometry. RESULTS: At 5.0 mM concentration, HRs produced the following inhibitions: 63+/-5% of the overall formation of cresols, benzaldehyde, benzyl alcohol, and biphenyl induced by photo-Fenton reaction; 91.6+/-5% and 59+/-8% of the synthesis of l-DOPA induced by HO. generated by Fenton reaction; 45+/-7% and 52+/-6% of the oxidation of arachidonic acid induced by Fenton reaction and AMVN; 60+/-4% of the autoxidation of arachidonic acid. These effects were strictly concentration dependent. CONCLUSIONS: At mM concentrations, HRs display a significant antilipoperoxidative activity due to their notable scanvenging activity against HO.; moreover these actions are concentration-dependent.     

心脑肾康对自由基清除作用的实验研究

目的研究心脑肾康对自由基的清除作用。方法连续给大鼠灌胃心脑肾康7d后，以线栓法建立大脑中动脉梗死（MCAO）缺血再灌注模型，缺血1．5h再灌注24h后断头取脑，检测大脑皮层丙二醛（MDA）、超氧化物歧化酶（SOD）、一氧化氮（NO）、活性氧（ROS）、谷胱甘肽（GSH）含量。结果与模型组相比，商、中、低3个剂量心脑肾康用药后均能显著降低缺血后脑组织匀浆中MDA、NO、ROS含量，增加SOD、GSH活性（P〈0．05）并呈剂量依赖性。其中，高剂量效果最好，优于阳性对照药（P〈0．05）。结论心脑肾康具有良好的自由基清除作用。     

Free radical scavenging and antioxidant activity of D-pinitol against 7, 12 dimethylbenz (a) anthracene induced breast cancer in sprague dawley rats

ObjectiveTo investigate whether D-pinitol efficiently scavenge free radicals using various in vitro models [1, 1-diphenyl-2-picrylhydrazyl (DPPH), nitric oxide, superoxide anion and total antioxidant activity] and in vivo models.MethodsFemale Sprague-Dawley rats (150-160 g) were divided into four groups and each group consisting of six animals. Group I and group IV were vector and drug control. The group II and group III animals were treated with 7, 12-dimethylbenz(a)anthracene (DMBA) 20 mg/kg body weight to induce mammary carcinoma. Rats received cancer bearing Group III animals were treated with D-pinitol at the concentration of 200 mg/kg bodyweight for 45 d orally. Five different concentrations of D-pinitol (100 to 500 μg/mL) were used in in vitro studies.ResutlsThe results revealed that D-pinitol efficiently scavenges DPPH radicals and the IC₅₀ was found to be 290 μg/mL and it also exhibited a dose dependent antioxidant activity at different concentrations. In addition, the superoxide and nitricoxide radicals were also significantly inhibited by D-pinitol at the concentrations of 360 and 390 μg/mL respectively. On the other hand, D-pinitol has significantly increased antioxidant enzymes during DMBA induced mammary carcinoma.ConclusionsIt can be concluded from the investigation that D-pinitol has an excellent antioxidant activity which could be due to the scavenging capacities on the stable DPPH radicals, superoxide, nitric oxide and DMBA induced free radicals thereby it exhibits remarkable total antioxidant activity.     

Brief myocardial ischemia affects free radical generating and scavenging systems in dogs

Summary This study examined whether brief repeated myocardial ischemia altered free radical generating and scavenging activity in a dog model. In dogs preconditioned with four 5-min left anterior descending coronary artery (LAD) occlusions and reperfusions, we examined transcardiac changes in both the function of neutrophils, cells which are major free radical generators, and in myocardial antioxidant enzyme activity, as an indication of free radical scavenging. Neutrophil function was assessed by determining luminol-enhanced whole blood chemiluminescence (CL) induced by zymosan. Blood was taken simultaneously from the carotid artery and the cardiac vein running along the occluded LAD. Preconditioning with sublethal ischemia significantly reduced whole blood CL in the cardiac vein compared with the carotid artery after the first and fourth 5-min reperfusions, while there was no difference in neutrophil count between these sampling sites. Immediately after brief repeated ischemia and reperfusion, manganese-superoxide dismutase (SOD) activity was significantly enhanced, and glutathione reductase activity was markedly reduced in the ischemic, compared with the non-ischemic, myocardium. There were no differences in the myocardial activities of copper, zinc-SOD, glutathione peroxidase, and glutathione S-transferase between the ischemic and non-ischemic regions. Also, no difference was observed between the reduced myocardial glutathione levels in these regions, although the oxidized glutathione level was significantly higher in the ischemic regions of the subepicardial and subendocardial areas. We demonstrated that brief repeated ischemia affects free radical generating and scavenging systems in the ischemic myocardium.This study was supported, in part, by research grants from the Ministries of Education, Science, and Culture of Japan.     

Changes in oxygen radical scavenging by human blood cell lysates concurrent with viral infections.

The higher superoxide dismutase (SOD) levels found in human blood cells when Nitro Blue Tetrazolium (NBT) rather than Cytochrome C was used as the colorimetric detector of superoxide (O-2) was investigated. the NBT was found to react with oxygen radicals other than O-2, thus providing measurement of total oxygen radical scavenging ability. Also investigated was the biomodal distribution of SOD activity in lymphocytes and granulocytes from a randomly selected human populace. Human lymphocytes rapidly increased their SOD activity by two- to four-fold during respiratory viral distress. The response to certain infections was probably responsible for the bimodal distribution of SOD activity in the general populace. It was concluded that the chemical events that prepare lymphocytes and granulocytes for their role in defense against infections begin long before these cells are sequestered from circulation by the infections.     

Receptor-independent intracellular radical scavenging activity of an angiotensin II receptor blocker

OBJECTIVES: Angiotensin II plays a crucial role in the induction of oxidative stress and the pathogenesis of cardiovascular and renal diseases, and the beneficial mechanisms of angiotensin II receptor 1 blockers (ARBs) are multifactorial. We investigated the receptor-independent protective role of an ARB using primary-cultured mesangial cells from angiotensin II receptor 1 knockout or wild-type mice and a highly lipophilic ARB, telmisartan. METHODS AND RESULTS: Intracellular reactive oxygen species were estimated using a fluorogenic probe, CM-H2DCFDA. Non-angiotensin II-induced reactive oxygen species production was generated by exposing cells to hydrogen peroxide alone or after treatment with telmisartan. Flow cytometry analysis showed that angiotensin II induced an increase in oxidant production in a dose-dependent manner in wild-type cells, but not in knockout cells. In contrast, hydrogen peroxide induced oxidative stress in both wild-type and knockout cells. Interestingly, telmisartan attenuated the oxidative stress induced by hydrogen peroxide in both cells, suggesting that it acted via a receptor-independent antioxidant effect. Intracellular concentrations of telmisartan were confirmed by high-performance liquid chromatography analysis. Expression of plasminogen activator inhibitor 1, which is stimulated by oxidative stress, was also attenuated by telmisartan in a receptor-independent as well as receptor-dependent manner. Telmisartan did not change expression levels of antioxidative enzymes such as catalase or glutathione peroxidase. Furthermore, the amelioration of oxidative stress by telmisartan did not involve the peroxisome proliferator-activated receptor-gamma pathway. CONCLUSIONS: Telmisartan inhibits intracellular oxidative stress, at least in part, in a receptor-independent manner, possibly owing to its lipophilic and antioxidant structure.     

Free radical theory of ageing: Applications

Ageing is the accumulation of changes that increase the risk of death. Ageing changes can be attributed to development, genetic defects, the environment, disease, and the inborn ageing process. The major contributors of ageing changes after age 28 in the developed countries are endogenous chemical reactions, which, collectively, exponentially increase the chance of disease and death with advancing age. These reactions constitute the “inborn ageing process”. This process is the major risk factor for disease and death of the 98–99% of cohorts still alive at age 28 in the developed countries, where living conditions are near optimum. In these countries average life expectancies at birth (ALE-B) range from 76–79 years, 6–9 years less than the limit of about 85 years imposed by ageing. The Free Radical Theory of Ageing (FRTA) postulates that ageing changes are caused by free radical reactions. This theory suggests the possibility that measures to decrease the rate of initiation and /or the chain length of free radical reactions may, at least in some cases, decrease the rate of reactions which produce ageing changes without significantly depressing those involved in maintenance and function. Many studies support this possibility. Applications of the FRTA have been fruitful. For example, it is a useful guide to the efforts to increase the life span, and it provides plausible explanations for ageing phenomena, (for example, the association of disease with age as well as insight into pathogenesis, the gender gap, the association between events in early life and late onset disease, and the shortening of telomeres with cell division). Further, it is reasonable to expect on the basis of animal and epidemiological studies, that the increasing population-wide use of antioxidant supplements and ingestion of foods high in antioxidant capacity over the past 40 years have helped to increase the functional life span in the U.S.A. by contributing significantly to the decline in “free radical diseases”, to increases in the fraction of elderly in the population, and to the decline in chronic disability in this group.