<Emphasis Type="Italic">Nigella sativa</Emphasis> and Derived Thymoquinone Prevents Hippocampal Neurodegeneration After Chronic Toluene Exposure in Rats

The aim of this study was designed to investigate the possible beneficial effects of Nigella sativa (NS) and derived thymoquinone (TQ) on neurodegeneration in hippocampus after chronic toluene exposure in rats. The rats were randomly allotted into one of four experimental groups: A (control), B (toluene treated), C (toluene treated with NS) and D (toluene treated with TQ); each group contain 10 animals. Toluene treatment was performed by inhalation of 3,000 ppm toluene, in a 8 h/day and 6 day/week order for 12 weeks. Control group received 1 ml serum physiologic and the rats in NS and TQ treated groups (C and D) were given NS (in a dose of 400 mg/kg body weight) and TQ (50 mg/kg body weight) once a day orally by using intra gastric intubation for 12 weeks starting just after toluene exposure respectively. Tissue samples were obtained for histopathological investigation. To date, no histopathological changes of neurodegeneration in hippocampus after chronic toluene exposure in rats by NS and TQ treatment have been reported. In this study, chronic toluene exposure caused severe degenerative changes, shrunken cytoplasma, slightly dilated cisternae of endoplasmic reticulum, markedly swollen mitochondria with degenerated cristae and nuclear membrane breakdown with chromatin disorganization in neurons of the hippocampus. The distorted nerve cells were mainly absent in the TQ and NS-treated rats. We conclude that TQ and especially NS therapy causes morphologic improvement on neurodegeneration in hippocampus after chronic toluene exposure in rats. We believe that further preclinical research into the utility of NS and TQ may indicate its usefulness as a potential treatment on neurodegeneration after chronic toluene exposure in rats.     

Terpene Conjugates of the Nigella sativa Seed‐Oil Constituent Thymoquinone with Enhanced Efficacy in Cancer Cells

Thymoquinone (TQ; 1 ) is a weak anticancer constituent of black seed oil. Derivatives bearing terpene‐terminated 6‐alkyl residues were tested in cells of human HL‐60 leukemia, 518A2 melanoma, multidrug‐resistant KB‐V1/Vbl cervix, and MCF‐7/Topo breast carcinomas, as well as in non‐malignant human foreskin fibroblasts. Derivatives with a short four‐atom spacer between quinone and cyclic monoterpene moieties were more antiproliferative than analogues with longer spacers. 6‐(Menthoxybutyryl)thymoquinone ( 3a ) exhibited single‐digit micromolar IC₅₀ (72 h) values in all four cell lines. It was seven times more active than TQ ( 1 ) in 518A2 melanoma cells and four times in KB‐V1/Vbl cervix carcinoma cells, while only half as toxic in the fibroblasts. Compound 3a was also not a substrate for the P‐gp and BCRP drug transporters of the resistant cancer cells. The caryophyllyl and germacryl conjugates 3e and 3f specifically inhibited the growth of the resistant MCF‐7 breast carcinoma cells. Conjugation of TQ with the triterpene betulinic acid via the OH group as in 3g led to a loss in activity, while conjugation via the carboxylic acid afforded compound 4 with nanomolar IC₅₀ (72 h) activity against HL‐60 cells. All anticancer‐active derivatives of TQ ( 1 ) induced apoptosis associated with DNA laddering, a decrease in mitochondrial membrane potential and a slight increase in reactive oxygen species.     

Protective Effects of Nigella sativa on the Neuronal Injury in Frontal Cortex and Brain Stem After Chronic Toluene Exposure

The goal of this study was designed to evaluate the possible protective effects of Nigella sativa (NS) on the neuronal injury in the frontal cortex and brain stem after chronic toluene exposure in rats. The rats were randomly alotted into one of three experimental groups: A (control), B (toluene treated) and C (toluene treated with NS); each group contain 10 animals. Control group received 1 ml serum physiologic and toluene treatment was performed by inhalation of 3,000 ppm toluene, in a 8 h/day and 6 day/week order for 12 weeks. The rats in NS treated group was given NS (in a dose of 400 mg/kg body weight) once a day orally by using intra gastric intubation for 12 weeks starting just after toluene exposure. Tissue samples were obtained for histopathological investigation. To date, no histopathological changes of neurodegeneration in the frontal cortex and brain stem after chronic toluene exposure in rats by NS treatment have been reported. In this study, chronic toluene exposure caused severe degenerative changes, shrunken cytoplasma, severely dilated cisternae of endoplasmic reticulum, markedly swollen mitochondria with degenerated cristae and nuclear membrane breakdown with chromatin disorganization in neurons of the frontal cortex and brain stem. The nerve cells showing the pathologic changes were almost absent in the NS-treated rats. We conclude that NS therapy causes morphologic improvement on neurodegeneration in frontal cortex and brain stem after chronic toluene exposure in rats. We believe that further preclinical research into the utility of NS may indicate its usefulness as a potential treatment on neurodegeneration after chronic toluene exposure in rats.     

Effect of black cumin (Nigella sativa) on cadmium-induced oxidative stress in the blood of rats

The protective effect of black cumin (Nigella sativa=NS) on cadmium-induced oxidative stress was studied in rats. The rats were randomly divided into three experimental groups: A (conrol), B (Cd treated), and C (Cd+NS treated), each containing 10 animals. The Cd-treated and Cd+NS-treated groups were injected subcutaneously daily with CdCl₂ dissolved in isotonic NaCl in the amount of 2 mL/kg for 30 d, resulting in a dosage of 0.49 mg Cd/kg/d. The control group was injected with only isotonic NaCl (2 mL/kg/d) throughout the experiment (for 30 d). Three days prior to induction of CdCl₂, the Cd+NS-treated group received a daily intraperitoneal injection of 0.2 mL/kg NS until the end of the study. Cd treatment increased significantly the malondialdehyde levels in plasma and erythrocyte (p<0.01 and p<0.05, respectively) and also increased significantly the antioxidant levels (superoxide dismutase, glutathione peroxidase, and catalase) (p<0.05) compared to the control group. Cd+NS treatment decreased significantly the elevated malondialdehyde levels in plasma and erythrocyte (p<0.01 and p<0.05, respectively) and also reduced significantly the enhanced antioxidant levels (p<0.05). Cd treatment increased significantly the activity of iron levels (p<0.05) in the plasma compared to the control group. Cd+NS treatment decreased the activity of iron levels (p<0.05) in the plasma compared to the Cd-treated group. In the control group with no treatment, histology of erythrocytes was normal. In the Cd-treated group, there were remarkable membrane destruction and hemolytic changes in erythrocytes. In the Cd+NS treated group, these changes were less than in the Cd-treated group. Our results show that N. sativa exerts a protective effect against cadmium toxicity.     

Effects of Nigella sativa L. and Urtica dioica L. on selected mineral status and hematological values in CCl4-treated rats

This study was designed to investigate the effects of Nigella sativa L. (NS), known as black seed, or/and Urtica dioica L. (UD), known as stinging nettle root, treatments on serum Na, K, Cl, and Ca levels and some hematological values of CCl₄-treated rats. Sixty healthy male Sprague-Dawley rats, weighing 250–300 g, were randomly allotted into 1 of 4 experimental groups: A (CCl₄-only treated), B (CCl₄+UD treated), C (CCl₄+NS treated), and D (CCl₄+UD+NS treated), each containing 15 animals. All groups received CCl₄ (0.8 mL/kg of body weight, subcutaneously, twice a week for 90 d starting d 1). In addition, B, C, and D groups also received the daily ip injection of 0.2 mL/kg NS and/or 2 mL/kg UD oils for 45 d starting d 46. Group A, on the other hand, received only 2 mL/kg normal saline solution for 45 d starting d 46. Blood samples for the biochemical analysis were taken by cardiac puncture from five randomly chosen rats in each treatment group at the beginning, d 45, and d 90 of the experiment. The CCl₄ treatment for 45 d significantly (p<0.05) increased the serum K and Ca and decreased (p<0.05) the red blood cell count (RBC), white blood cell count (WBC), packed cell volume (PCV), and Hb levels without changing (p>0.05) the serum Na and Cl levels. NS or UD treatments (alone or combination) for 45 d starting d 46 significantly (p<0.05) decreased the elevated serum K and Ca levels and also increased (p<0.05) the reduced RBC, WBC, PCV, and Hb levels. It is concluded that NS and/or UD treatments might ameliorate the CCl₄-induced disturbances of anemia, some minerals, and body’s defense mechanism in CCl₄-treated rats.     

Inhibition of Protein Kinase C Restores Na+, K+-ATPase Activity in Sciatic Nerve of Diabetic Mice

We have tested if inhibition of protein kinase C is able to prevent and/or to restore the decrease of Na+,K(+)-ATPase activity in the sciatic nerve of alloxan-induced diabetic mice. Mice were made diabetic by subcutaneous injection of 200 mg of alloxan/kg of body weight. The activity of Na+,K(+)-ATPase decreased rapidly (43% after 3 days) and slightly thereafter (58% at 11 days). We show that intraperitoneal injection of 1-(5-isoquinolinylsulfonyl)-2-methylpiperazine (H7), an inhibitor of protein kinase C, prevents completely the loss of Na+,K(+)-ATPase activity produced by alloxan. Also, H7 injected into diabetic mice, 4-9 days after the injection of alloxan, restores the activity of the enzyme. The amount of activity recovered depends on the dose of H7 administered; complete recovery was reached with injection of 15 mg of H7/kg of body weight. The effect of H7 is transient, with a half-life of approximately 1 h.     

Alterations in mRNA Expression of Myelin Proteins in the Sciatic Nerves and Brains of Streptozotocin-induced Diabetic Rats

Diabetic neuropathy is the most common complication of diabetes. We examined the levels and the mRNA expression of myelin proteins in the sciatic nerves and the brains of streptozotocin-induced diabetic rats. The diabetic rats exhibited a decrease in body weight, elevation of the blood glucose level and a decrease in motor nerve conduction velocity at 2 weeks after streptozotocin injection. In the sciatic nerves of diabetic rats, the level of P0 protein and its mRNA expression were markedly reduced at 20 weeks after the injection. In the brains, the levels of proteolipid protein and myelin-associated glycoprotein and their mRNA expression were selectively decreased at 20 weeks after the injection. This affected expression of myelin proteins was found even when no histological abnormalities were detectable. Considering the functional significance of myelin proteins, this impairment of protein expression is possibly involved in the pathogenesis of diabetic neuropathy, including that in brain disorders.     

Investigations on the Incorporation of a Tritiated Ganglioside, GM1, in the Injured and Intact Sciatic Nerves of the Rat

Following injury of their left sciatic nerves by means of a standardized procedure, male rats received intravenous injections of a tritiated ganglioside. GM1, on different days during the process of regeneration. The rats were killed at two different times after the injection and the concentrations of the total radioactivity, nonvolatile radioactivity, and labelled GM1 were estimated in six segments of the crushed and intact sciatic nerves. The segments of the damaged nerves showed higher concentrations of radioactivity and a higher content of GM1 than the corresponding segments of the contralateral nerves. Within the immediate area of the lesion the highest levels were found on the 3rd and 6th days after the injury; the segments distal from the lesion showed the highest levels of activity on days 9 and 12. The nerve segments proximal to the site of the injury showed a low rate of radioactivity incorporation. The higher concentrations of [3H]GM1 in damaged nerves as well as the rate of incorporation as a function of time indicate that exogenous gangliosides may be involved in the processes of regeneration and have a bearing on the latter.     

Phorbol Ester-Mediated Stimulation of Phospholipase D Activity in Sciatic Nerve from Normal and Diabetic Rats

Evidence for the presence of phospholipase D activity in sciatic nerve was obtained by incubation of 32P-prelabeled nerve segments in the presence of ethanol and measurement of [32P]phosphatidylethanol (PEth) formation expressed as a fraction of total phospholipid radioactivity. PEth synthesis was enhanced with increasing concentrations of ethanol (100 mM-2 M). 4-beta-Phorbol dibutyrate (100 nM-1 microM) stimulated PEth formation up to twofold in a time- and dose-dependent manner. The stimulatory effect evoked by 100 nM phorbol ester was completely abolished by Ro 31-8220 (compound 3), a selective protein kinase C inhibitor. Efforts to identify the phospholipid precursor of PEth were unsuccessful, suggesting this product arises from a small discrete precursor pool. On subcellular fractionation of nerve, the ratio of basal and 4-beta-phorbol dibutyrate-stimulated phospholipase D activity recovered in a myelin-enriched fraction, compared with a nonmyelin fraction, was 0.5 when results are expressed as a percentage of total phospholipid radioactivity. This ratio rises to 1.2 if the results are calculated assuming only phosphatidylcholine and phosphatidylethanolamine are potential precursors. The results suggest that myelin is a major locus of phospholipase D activity. Nerve from streptozotocin-induced diabetic and control animals displayed the same basal phospholipase D activity, but the enzyme in diabetic nerve was stimulated to a greater extent by a suboptimal concentration of 4-beta-phorbol dibutyrate. These results support the conclusion that protein kinase C modulates phospholipase D activity in nerve and suggest that in diabetic nerve the enzyme activation mechanism may possess increased sensitivity.     

Effects of<Emphasis Type="Italic">Nigella sativa</Emphasis> and human parathyroid hormone on bone mass and strength in diabetic rats

Osteoporosis is a major complication in patients with diabetes mellitus (DM), particularly in those with insulin dependency. Recently, many therapeutic effects ofNigella sativa L. (NS) extracts have been exhibited such as anti-inflammatory, antitumor, and antidiabetic with clinical and experimental studies. Mechanical strength in the femur and vertebrae increases with human parathyroid hormone (hPTH) treatment. The aim of the present study was to test the hypothesis that combined treatment with NS and hPTH is more effective than treatment with NS or hPTH alone in improving bone mass, connectivity, and biomechanical behavior using the finite element method (FEM) in insulin-dependent diabetic rats. In the mechanical analysis, five rat bones (control, diabetic diabetic NS treated, diabetic hPTH treated, and diabetic NS + hPTH treated) have been studied for bending analysis using the finite element analysis program ANSYS. Combined treatment of NS and hPTH was more effective on bone histomorphometry and mechanical strength than treatment with NS or hPTH alone for streptozotocin-induced diabetic osteopenia, which notably decreased bone volume.     

Serum trace elements status of rabbits supplemented with Nigella sativa,vitamins C and E,and selenium against damage by N-methyl-N'-nitro-N-nitrosoguanidine

In this study, we investigated the effects of Nigella sativa, vitamins C and E, and selenium on the levels of trace elements in the serum of N-methyl-N′-nitro-N-nitrosoguanidine (MNNG)-injected rabbits. The rabbits were separated into one control and three experimental groups, each consisting of eight rabbits. MNNG was administered to all rabbits at a dose of 20 mg/kg. Group A received a suspension of N. sativa, group B received a combination of vitamins C and E and selenium, and group C received MNNG without any additional treatment. Group D did not receive any treatment and acted as control. The concentrations of serum zinc, copper, and iron were determined for groups A, B, C, and D. The zinc levels were 155.3±25.8, 304.7±14.22, 117.2±27.9, and 87.0±8 μ/dL for groups A-D, respectively; copper was measured at 234.8±31.9, 214.3±14.2, 196.5±19.3, and 359.2±19.9 μ/dL and iron levels were 276.3±10.71, 260.8±7.15, 211.2±13.47, and 223.4±9.5 μ/dL, in the stated group order. There were statistically significant differences between groups (p<0.05). The results obtained in this work may be of use for monitoring and preventing the nocive effects of N-methyl-N′-nitro-N-nitrosoguanidine and similar carcinogens.     

The oldest evidence of Nigella damascena L. (Ranunculaceae) and its possible introduction to central Europe

After the beginning of metal processing at the transition from the Neolithic to the Bronze Age, further knowledge of ore mining and smelting had spread from the Near East to central Europe. In the copper ore deposits of Schwaz, in the central part of the Alps, the oldest traces of copper mining derive from the early to middle Bronze Ages. Investigation of a middle to late Bronze Age (1410–920 cal B.C.) slag-washing site in the area revealed a carbonised seed of Nigella damascena (Ranunculaceae) (love-in-a-mist) together with individual other food plants. The plant remains had become incorporated into the slag sediments by chance and had been preserved in an excellent state due to toxic copper salts contained in the soil. Nigella damascena, like N. sativa (black cumin), is traditionally used as a condiment and healing herb in southern Europe and the Near East, but has never grown in the wild in central Europe. Until now, there has been no evidence of prehistoric large-scale cultivation of N. damascena in central Europe. This leads to two possible conclusions: the find may either originate from an exchange of goods with the cultures in the Mediterranean during the Bronze Age, or indicate an introduction of the plant by an immigrant population from that area. Implicating the latter alternative together with the archaeological context of the ore processing site suggests that Nigella damascena had been introduced to the Alps by foreign miners in the course of ore exploitation during the middle to late Bronze Age.     

Relationship of ATP Turnover, Polyphosphoinositide Metabolism, and Protein Phosphorylation in Sciatic Nerve and Derived Peripheral Myelin Subfractions from Normal and Streptozotocin Diabetic Rats

Sciatic nerve from streptozotocin-induced diabetic rats has previously been shown to incorporate more 32P into phosphatidylinositol-4,5-bisphosphate (PIP2) and the principal myelin proteins than normal nerve. In the present study, labeling of ATP and PIP2 was compared. Using nerve segments, [gamma-32P]ATP specific activity reached a plateau after incubation for 4 h with [32P]orthophosphate, whereas the specific activity of [32P]PIP2 rose much more slowly and was still increasing after 8 h. The rate of disappearance of radioactivity from prelabeled ATP was biphasic, with 75% being lost within 30 min and the remainder declining much more slowly for several hours thereafter. In contrast, no decrease in prelabeled PIP2 radioactivity could be detected for up to 4 h. The kinetics of ATP metabolism were not appreciably different for normal and diabetic nerve. However, after incubation with [32P]orthophosphate for 2 h, the specific activity of PIP2 was 50-120% higher in diabetic nerve. This phenomenon, therefore, cannot be ascribed to altered specific activity of the ATP precursor pool. Greater labeling of PIP2 in 32P-labeled diabetic nerve was present in purified myelin isolated using a simple discontinuous sucrose density gradient, but not in a "nonmyelin" fraction. When nerve homogenate was fractionated on a more complex gradient, three myelin-enriched subfractions were obtained which were heterogeneous as judged by morphological appearance, protein profile, and lipid metabolic activity. The proportion of total lipid radioactivity accounted for by PIP2 was elevated in all the subfractions relative to the homogenate. As compared to myelin subfractions from normal nerve, an increased percentage of 32P in PIP2 was obtained only in the major myelin subfraction from diabetic nerve. The phosphorylation of P0 relative to the other myelin proteins was also enhanced in this subfraction in nerve from diabetic animals.     

Effects of Nigella sativa oil on ovarian volume,oxidant systems,XIAP and NF-kB expression in an experimental model of diabetes

ABSTRACT

We investigated the effects of Nigella sativa oil on ovary volume, nuclear factor-kappaB (NF-κB), X-linked inhibitor of apoptosis protein (XIAP) expression, and serum malondialdehyde (MDA), superoxide dismutase (SOD), total antioxidant status (TAS) and total oxidant status (TOS) levels in diabetic rats. We divided 21 adult female rats into three groups: controls, diabetics and diabetics + N. sativa oil. The diabetics + N. sativa oil group was given 0.2 mg/kg/day N. sativa oil 6 days/week for 4 weeks. NF-κB and XIAP expression was assessed in ovarian sections using immunohistochemistry. The right and left ovary volumes were calculated using stereology. We also measured serum MDA, SOD, TAS and TOS levels. We found that N. sativa oil reduced hyperglycemia, but not to control levels. N. sativa oil also exhibited antioxidant properties as demonstrated by reduced serum TOS and MDA levels, and increased SOD and TAS levels compared to controls. We found no significant difference in total ovarian volume, XIAP or NF-κB expression among the groups, which may be due to the short study period. Our findings suggest that N. sativa oil may be useful for reducing blood glucose levels and elevated oxidant activity in diabetic patients.     

Major flavonoids in uninoculated and inoculated roots of Vicia sativa subsp. nigra are four conjugates of the nodulation gene-inhibitor kaempferol

Inoculation of Vicia sativa subsp. nigra (V. sativa) roots with Rhizobium leguminosarum biovar. viciae (R.l. viciae) bacteria substantially increases the ability of V. sativa to induce rhizobial nodulation (nod) genes. This increase is caused by the additional release of flavanones and chalcones which all induce the nod genes of R.l. viciae (K. Recourt et al., Plant Mol Biol 16: 841–852). In this paper, we describe the analyses of the flavonoids present in roots of V. sativa. Independent of inoculation with R.l. viciae, these roots contain four 3-O-glycosides of the flavonol kaempferol. These flavonoids appeared not capable of inducing the nod genes of R.l. viciae but instead are moderately active in inhibiting the activated state of those nod genes. Roots of 7-day-old V. sativa seedlings did not show any kaempferol-glycosidase activity consistent with the observation that kaempferol is not released upon inoculation with R.l. viciae. It is therefore most likely that inoculation with infective (nodulating) R.l. viciae bacteria results in de novo flavonoid biosynthesis and not in liberation of flavonoids from a pre-existing pool.     

Infrequent transposition of Ac in lettuce,Lactuca sativa

The maize transposable element Activator (Ac) is being used to develop a transposon mutagenesis system in lettuce, Lactuca sativa. Two constructs containing the complete Ac from the waxy-m7 locus of maize were introduced into lettuce and monitored for activity using Southern analysis and PCR amplification of the excision site. No transposition of Ac was detected in over 32 transgenic R₁ plants, although these constructs were known to provide frequent transposition in other species. Also, no transposition was observed in later generations. In subsequent experiments, transposition was detected in lettuce calli using constructs that allowed selection for excision events. In these constructs, the neomycin phosphotransferase II gene was interrupted by either Ac or Ds. Excision was detected as the ability of callus to grow on kanamycin. Synthesis of the transposase from the cDNA of Ac expressed from the T-DNA 2 promoter resulted in more frequent excision of Ds than was observed with the wild-type Ac. No excision was observed with Ds in the absence of the transposase. The excision events were confirmed by amplification of the excision site by PCR followed by DNA sequencing. Excision and reintegration were also confirmed by Southern analysis. Ac/Ds is therefore capable of transposition in at least calli of lettuce.     

α, βI, βII, δ, and ε Protein Kinase C Isoforms and Compound Activity in the Sciatic Nerve of Normal and Diabetic Rats

Abstract: Defective protein kinase C (PKC) has been implicated in impaired Na⁺,K⁺-ATPase activity in the sciatic nerve of streptozotocin-induced diabetic rats. In the present study, α, βI, βII, γ, δ, and ε isoform-specific antibodies were used in parallel to the measurement of compound PKC activity for the characterization of PKC distribution and isoform expression in sciatic nerves of normal and diabetic rats. To distinguish isoform expression between the axonal and glial compartments, PKC isoforms were evaluated in nerves subjected to Wallerian degeneration and in a pure primary Schwann cell culture. α, βI, βII, δ, and ε but no γ isoforms were detected in sciatic nerve. Similar immunoreactivity was observed in degenerated nerves 3–4 days after transection except for diminished βI and ε species; in Schwann cell cultures, only α, βII, δ, and ε were detected. In normal nerves, two-thirds of PKC compound activity was found in the cytosol and 50% of total enzyme activity translocated to the Na⁺,K⁺-ATPase-enriched membrane fraction with phorbol myristate acetate. Similar redistribution patterns were observed for the immunoreactivity of all isoforms with the exception of δ, which did not translocate to the membrane with phorbol myristate acetate. No abnormality in compound PKC activity, in the immunoreactive intensity, or in the distribution of PKC isoforms could be detected in rat sciatic nerve after 6–12 weeks of diabetes. Thus, defective activation rather than decreased intrinsic PKC activity may occur in diabetic neuropathy.     

Effects of elevated CO2 on growth,photosynthesis and respiration of sweet chestnut (Castanea sativa Mill.)

Two year old sweet chestnut seedlings (Castanea sativa Mill) were grown in pots at ambient (350 µmol·mol^–1) and double (700 µmol·mol^–1) atmospheric CO₂ concentration in constantly ventilated greenhouses during entire growing seasons. CO₂ enrichment caused either no significant change or a decrease in shoot response, depending on yearly weather conditions. Similarly, leaf area was either reduced or unchanged under elevated CO₂. However, when grown under controlled conditions in a growth chamber, leaf area was enlarged with elevated CO₂.The CO₂ exchanges of whole plants were measured during the growing season. In elevated CO₂, net photosynthetic rate was maximum in May and then decreased, reaching the level of the control at the end of the season. End of night dark respiration of enriched plants was significantly lower than that of control plants; this difference decreased with time and became negligible in the fall. The original CO₂ level acted instantaneously on the respiration rate: a double concentration in CO₂ decreased the respiration of control plants and a reduced concentration enhanced the respiration of enriched plants. The carbon balance of a chestnut seedling may then be modified in elevated CO₂ by increased carbon inputs and decreased carbon outputs.     

Effect of thymoquinone and Nigella sativa seeds oil on lipid peroxidation level during global cerebral ischemia-reperfusion injury in rat hippocampus

It has been previously reported that Nigella sativa oil (NSO) and thymoquinone (TQ), active constituent of N. sativa seeds oil, may prevent oxidative injury in various models. Therefore, we considered the possible effect of TQ and NSO on lipid peroxidation level following cerebral ischemia-reperfusion injury (IRI) in rat hippocampus. Male NMRI rats were divided into nine groups, namely, sham, control, ischemia and ischemia treated with NSO or TQ. TQ (2.5, 5 and 10 mg/kg), NSO (0.048, 0.192 and 0.384 mg/kg), phenytoin (50 mg/kg, as positive control) and saline (10 ml/kg, as negative control) were injected intraperitoneally immediately after reperfusion and the administration was continued every 24h for 72 h after induction of ischemia. The transient global cerebral ischemia was induced using four-vessel-occlusion method for 20 min. Lipid peroxidation level in hippocampus portion was measured as malondialdehyde (MDA) based on its reaction with thiobarbituric acid (TBA) following ischemic insult. The transient global cerebral ischemia induced a significant increase in TBA reactive substances (TBARS) level (p<0.001), in comparison with sham-operated animal. Pretreatment with TQ and NSO were resulted a significant decrease in MDA level as compared with ischemic group (66.9+/-1.5 vs. 297+/-2.5 nmol/g tissue for TQ, 10 mg/kg; p<0.001 and 153.5+/-1.3 nmol/g tissue for NSO, 0.384 mg/kg; p<0.001). Using a reversed-phase HPLC system, the amount of TQ in NSO was also quantified and was 0.58% w/w. These results suggest that TQ and NSO may have protective effects on lipid peroxidation process during IRI in rat hippocampus.     

Reduced Na+/K+ ATPase transport activity,resting membrane potential,and bradykinin-stimulated phosphatidylinositol synthesis by polyol accumulation in cultured neuroblastoma cells

In these studies we examined the effect of polyol accumulation on neural cellmyo-inositol metabolism and properties. Neuroblastoma cells were cultured for two weeks in media containing 30 mM glucose, fructose, galactose or mannose with or without 0.4 mM sorbinil or 250 Mmyo-inositol. Chronic exposure of neuroblastoma cells to media containing 30 mM glucose, galactose, or mannose caused a decrease inmyo- inositol content and myo-[2-³H]inositol accumulation and incorporation into phosphoinositides compared to cells cultured in unsupplemented medium or medium containing 30 mM fructose as an osmotic control. These monosaccharides each caused an increase in intracellular polyol levels with galactitol > sorbitol = mannitol accumulation. Chronic exposure of neuroblastoma cells to media containing 30 mM glucose, galactose, or mannose caused a significant decrease in Na⁺/K⁺ ATPase transport activity, resting membrane potential, and bradykinin-stimulated³²P incorporation into phosphatidylinositol compared to cells cultured in medium containing 30 mM fructose. In contrast, basal incorporation of³²P into phosphatidylinositol or basal and bradykinin-stimulated³²P incorporation into phosphatidylinositol 4,5-bisphosphate were not effected. Each of these cellular functions as well asmyo-inositol metabolism and content and polyol levels remained near control values when 0.4 mM sorbinil, an aldose reductase inhibitor, was added to the glucose, galactose, or mannose supplemented media.myo-Inositol metabolism and content and bradykinin-stimulated phosphatidylinositol synthesis were also maintained when media containing 30 mM glucose, galactose, or mannose was supplemented with 250 Mmyo-inositol. The results suggest that polyol accumulation induces defects in neural cellmyo-inositol metabolism and certain cell functions which could, if they occurred in vivo, contribute to the pathological defects observed in diabetic neuropathy.