Edible mushroom Morchella esculenta (L.) Pers. mycelium protects DNA and mitochondria from radiation induced damages

842-847Mushrooms have gained great attraction not only for their nutritional and medicinal values but also for diversity of their bioactive components. Morchella esculenta, commonly called Morel, is an edible and nutritious mushroom. In the present study, we evaluated the radioprotective effect of cultured mycelium of M. esculenta against radiation induced damages in mouse spleen lymphocyte DNA and rat liver mitochondria. The mitochondria were exposed to 450 Gy γ-radiation and lipid peroxidation caused by radiation was studied by LOOH assay and TBARS assay. M. esculenta extract at a concentration of 200 and 50 µg/mL significantly inhibited the formation of LOOH and TBARS formation in mitochondria. The protective effect of M. esculenta against radiation-induced damage to DNA in the spleen lymphocyte was measured using comet assay. Spleen lymphocytes were exposed to γ-radiation at a dose of 6 Gy in the presence and absence of the extract and the strand break were analyzed. The extract inhibited the strand break significantly. The study indicate that M. esculenta mycelia protect mitochondria form oxidative stress and DNA from deleterious effects induced by radiation and has potential for the development of safe and non-toxic radio protector with significant nutritional properties

Drought Impact Is Alleviated in Sugar Beets (Beta vulgaris L.) by Foliar Application of Fullerenol Nanoparticles

Over the past few years, significant efforts have been made to decrease the effects of drought stress on plant productivity and quality. We propose that fullerenol nanoparticles (FNPs, molecular formula C-60(OH)(24)) may help alleviate drought stress by serving as an additional intercellular water supply. Specifically, FNPs are able to penetrate plant leaf and root tissues, where they bind water in various cell compartments. This hydroscopic activity suggests that FNPs could be beneficial in plants. The aim of the present study was to analyse the influence of FNPs on sugar beet plants exposed to drought stress. Our results indicate that intracellular water metabolism can be modified by foliar application of FNPs in drought exposed plants. Drought stress induced a significant increase in the compatible osmolyte proline in both the leaves and roots of control plants, but not in FNP treated plants. These results indicate that FNPs could act as intracellular binders of water, creating an additional water reserve, and enabling adaptation to drought stress. Moreover, analysis of plant antioxidant enzyme activities (CAT, APx and GPx), MDA and GSH content indicate that fullerenol foliar application could have some beneficial effect on alleviating oxidative effects of drought stress, depending on the concentration of nanoparticles applied. Although further studies are necessary to elucidate the biochemical impact of FNPs on plants; the present results could directly impact agricultural practice, where available water supplies are often a limiting factor in plant bioproductivity

Methods for estimating lipid peroxidation: An analysis of merits and demerits

Among the cellular molecules, lipids that contain unsaturated fatty acids with more than one double bond are particularly susceptible to action of free radicals. The resulting reaction, known as lipid peroxidation, disrupts biological membranes and is thereby highly deleterious to their structure and function. Lipid peroxidation is being studied extensively in relation to disease, modulation by antioxidants and other contexts. A large number of by-products are formed during this process. These can be measured by different assays. The most common method used is the estimation of aldehydic products by their ability to react with thiobarbituric acid (TBA) that yield 'thiobarbituric acid reactive substances' (TBARS), which can be easily measured by spectrophotometry. Though this assay is sensitive and widely used, it is not specific and TBA reacts with a number of components present in biological samples. Hence caution should be used while employing this method. Wherever possible this assay should be combined with other assays for lipid peroxidation. Such methol are measurement of conjugated dienes, lipid hydroperoxides, individual aldehydes, exhaled gases like pentane, isoprostanes, etc. The modern methods also involve newer techniques involving HPLC, spectrofluorimetry, mass spectrometry, chemiluminescence etc. These and other modem methods are more specific and can be applied to measure lipid peroxidation. There are certain restraints, in terms of high cost and certain artifacts, and these should be considered while selecting the method for estimation. This review analyses the merits and demerits of various assays to measure lipid peroxidation

Photocleavage of plasmid DNA by the prophyrin meso-tetrakis[4-(carboxymethyleneoxy)phenyl]porphyrin

meso-Tetrakis [4-(carboxymethylenzoxy)phenyl]porphyrin (H(2)T4CPP) cleaves pBR322 plasmid DNA to single strand breaks in the presence of molecular oxygen and visible light. The above photocleavage was much more efficient in D2O buffer of sodium phosphate (pD = 7.4) than H2O buffer of sodium phosphate (pH = 7.4). In addition this photocleavage of plasmid DNA was inhibited in the presence of sodium azide, lipoic acid, tert-butanol or mannitol suggesting the involvement of O-1(2) and OH in the photocleavage of plasmid DNA. The photocleavage was observed to be more efficient in the presence of H2CPP than in the presence of H(2)T4CPP [meso-tetrakis(4-carboxy-phenyl) porphyrin]. Our spectral studies using UV-visible, fluorescence and circular dichroism techniques suggest that H(2)T4CPP binds to DNA while H(2)T4CPP does not, Thus, the difference in photocleavage may be caused by the nonbinding of H2CPP and by the binding of H(2)T4CPP to calf thymus (CT) DNA. (C) 1997 Elsevier Science S.A

Lipid peroxidation induced by meso-tetrakis[3,4-bis(carboxymethyleneoxy)phenyl]prophyrin on photosensitization in hepatic and tumor microsomes

The ability of a novel porphyrin, meso-tetrakis[3,4-bis(carboxymethyleneoxy)phenyl]porphyrin (T3,4-CPP), to induce photodamage in subcellular membranes, in the form of rat hepatic and tumor microsomes, was evaluated with a view to locating suitable porphyrin derivative for possible use in photodynamic therapy. This water-soluble porphyrin, on exposure to visible light, induced a significant extent of membrane lipid peroxidation as assessed by the formation of thiobarbituric acid reactive substances, lipid hydroperoxides and conjugated dienes. The peroxidation induced in hepatic microsomes is both time-and concentration-dependent. Using inhibitors of reactive oxygen species and comparing products of peroxidation, it is shown that the damage induced is mainly due to singlet oxygen and partly due to other species like free radicals. T3,4-CPP also caused the generation of singlet oxygen as a function of illumination time. Since membrane damage induced by a sensitizer on photoexcitation has been considered to be an important mechanism by which photodynamic cell killing of tumor occurs, the studies on this novel porphyrin indicate the possible potential of this compound in photodynamic therapy. (C) 1997 Elsevier Science Ireland Ltd

Photocleavage of plasmid pBR322 DNA by some anionic porphyrins

The;water-soluble porphyrins meso-tetrakis[4-(carboxymethyleneoxy)phenyl]porphyrin (H(2)T4CPP), meso-tetrakis[3-(carboxymethyleneoxy)phenyl]porphyrin (H(2)T3CPP) and meso-tetrakis[3,4-bis(carboxymethyleneoxy)phenyl]porphyrin (H(2)T3,4BCPP) cleave plasmid pBR322 DNA to single-strand breaks (SSBs) in the presence of molecular oxygen and visible light. These porphyrins induced SSBs in DNA as a function of irradiation time as well as porphyrin concentration. Under similar conditions (10 mu M or more), H2T3CPP showed more SSBs in DNA than the porphyrins H(2)T4CPP and H(2)T3,4BCPP. The DNA cleavage was more in D2O-based buffer than in H2O buffer. in addition, this DNA cleavage was inhibited by the presence of sodium azide and lipoic acid, which are potent quenchers of singlet oxygen (O-1(2)). These observations suggest the involvement of O-1(2) in photocleavage of DNA. Further, the DNA cleavage, to a limited extent, was also inhibited by tert-butanol and mannitol, both quenchers of hydroxyl radical ((OH)-O-.), suggesting the involvement of (OH)-O-. in photocleavage of DNA. Thus both O-1(2) and (OH)-O-. are involved in photocleavage of plasmid DNA by these porphyrins. (C) 1998 , Ltd

Lipid peroxidation induced by a novel porphyrin plus light in isolated mitochondria: Possible implications in photodynamic therapy

With a view to locate porphyrins for use in photodynamic therapy (PDT), the new modality of cancer treatment we have evaluated the ability of a novel water soluble porphyrin meso-tetrakis[4-(carboxymethyleneoxy)phenyl]porphyrin (T4CPP) to induce damage to mitochondria during photosensitization. T4CPP, when exposed to visible light, induced lipid peroxidation in rat liver mitochondria as assessed by the formation of thiobarbituric acid reactive substances (TBARS), conjugated dienes (CD) and lipid hydroperoxides (LOOH). The effect on mitochondrial function was assessed by estimating the activity of succinate dehydrogenase (SDH). The peroxidation induced was observed to be time- and concentration- dependent. Analysis of product formation and selective inhibition by scavengers of reactive oxygen species showed that the oxidative damage observed was mainly due to singlet oxygen (O-1(2)) and partly due to other reactive species. T4CPP plus light also caused significant lipid peroxidation in Sarcoma 180 ascites tumour mitochondria. Our studies indicate that T4CPP has the potential to photoinduce damage in hepatic and ascites mitochondria, a crucial site of damage in PDT

Oxidative damage induced by a novel porphyrin on rat brain mitochondria and its possible implications in therapy

Free radical-induced oxidative damage is involved in several pathological disorders. On the other hand, selective induction of peroxidation in diseased tissue is a promising approach to the treatment of cancer by photodynamic therapy. In this study we have used rat brain mitochondria as a model to evaluate the ability of a new water soluble porphyrin, 5,10,15,20-tetrakis[4-(carboxymethyleneoxy)phenyl]porphyrin (T4CPP), to induce peroxidative damage during photosensitization. Peroxidation in mitochondria, one of the crucial targets of the photodynamic effect, was assessed from the formation of thiobarbituric acid reactive substances and lipid hydroperoxides. The effect on mitochondrial function was estimated from the loss of a mitochondrial marker enzyme, succinate dehydrogenase (SDH). The photodamage was observed to be time-and concentration-dependent of T4CPP. Inhibition studies suggested involvement of singlet oxygen (O-1(2)) and, to a lesser extent, of hydroxyl ((OH)-O-.), peroxyl (ROO.-) and superoxide radicals (O-2(.-)) in the photodamage. The addition of gamma-linolenic acid (a promoter of lipid peroxidation) to the system led to an enhancement of the T4CPP-induced peroxidative damage. Thus, our study indicated that the combination of gamma-linolenic acid and T4CPP could enhance the photodynamic effect and has potential applications in photodynamic therapy