Elevated antioxidant potential of chlorocholine chloride-treated in vitro grown Stevia rebaudiana Bertoni

Medicinal plants contain a plethora of secondary metabolites, most of which are bioactive in nature. The role of a popular plant growth retardant CCC has been investigated to explore its impact on secondary metabolite production, particularly phenols and flavonoids from in vitro grown Stevia rebaudiana. CCC stimulated the production of total phenols and flavonoids in calli and leaves. Moreover, this elevated level of phenols and flavonoids was correlated with the antioxidant potential of the tissue extracts. Methanolic extracts from CCC-treated calli and leaves showed significant increment in antioxidant activity as determined by standard DPPH, ABTS, and hydroxyl radical scavenging assays. No significant antiproliferative effect of methanolic extracts from different tissue was noticed against THP-1 monocyte (ATCC-TIB202), Hela cell (ATCC-CCL2) lines endorses the issue of clinical safety of the extracts.     

Study on the chemical composition and antioxidant activity of extracts from shoot culture and regenerated plants of <Emphasis Type="Italic">Scutellaria altissima</Emphasis> L.

The flavonoid (baicalin, wogonoside, luteolin, luteolin-7-glucoside) and verbascoside contents of Scutellaria altissima in both shoot cultures, and the shoots and roots of micropropagated plants grown in the greenhouse for 12 weeks or in the field for 2 years were determined. The level of secondary metabolites was found to be strongly affected by the age and type of plant organ. A comparative analysis of S. altissima plants propagated in vitro and from seeds revealed no differences in the level of secondary metabolites when plants of the same age were studied. The antioxidant potential of methanolic extracts from shoot cultures, and the shoots and roots of S. altissima plants propagated in vitro, were evaluated using ABTS radical scavenging, FRAP metal reduction power and the lipid peroxidation test, in relation to the content of baicalin, wogonoside, verbascoside, total phenolic and total flavonoid compounds. Extracts from the roots of field-grown regenerated plants at the flowering stage were found to possess the strongest antioxidant activity. Correlation analysis revealed that the antioxidant activity of extracts correlated most closely with their total phenolic content estimated by the Folin-Ciocalteu method.     

In vitro propagation of Caralluma tuberculata and evaluation of antioxidant potential

Present study describes rapid in vitro propagation of Caralluma tuberculata, a traditional medicinal plant, and antioxidant potential of calli and plants extracts. The highest callus induction rate (93.3%) with maximum weight of calli 5.2 g was achieved from shoot tip explants on MS medium supplemented with 9.04 μM 2,4-D and 4.44 μM BA. The maximum shoot induction rate (71.1%) with mean number of shoots 3.66 ± 1.53 and 4.6 cm average shoot length was observed on 13.32 μM BA, 4.52 μM 2,4-D and 2.89 μM GA3 appended in MS medium. The developed shoots were best rooted in the presence of 5.07 μM IAA with 3.0 ± 0.15 roots per plantlet. The plants were successfully acclimatized under in vivo conditions. The plants and calli extracts exhibited good antioxidant activities, however, plant extract activities were more pronounced. The phenolic compounds in plant and calli extracts were 0.16% and 0.057%, respectively. While the flavonoids were 0.092% in plant and 0.039% in calli extract. Total Phenolics, flavonoids; DPPH radical scavenging activity and reducing power potential distributed among different fractions depending upon polarity of the solvent. The highest DPPH scavenging activity and reducing power was exhibited by water fractions; 4.95 mg/mL and 0.729 OD at 10 mg/mL, respectively. The micropropagation protocol can be successfully used for large-scale multiplication and conservation of germplasm of this threatened plant. Furthermore, antioxidant value describes importance of this valuable plant as food and medicine.     

Micropropagation of Rehmannia glutinosa Libosch.: production of phenolics and flavonoids and evaluation of antioxidant activity

Rehmannia glutinosa Libosch., a valuable medicinal plant, was successfully propagated in vitro using shoot tip explants. Shoot multiplication was performed in glass tubes and in a nutrient sprinkle bioreactor. A mixture of 0.1 mg L^?1 indole-3-acetic acid (IAA) and 1.0 mg L^?1 of 6-benzylaminopurine in Murashige and Skoog (MS) agar-solidified medium proved the best combination for multiple shoot induction, yielding 8.2 shoots per explant after 4 weeks of culture in glass tubes. The number of shoots increased to 21 per explant when the same combination of growth regulators was used in a nutrient sprinkle bioreactor. The shoots rooted with a frequency of 93 % after 6 weeks of culture on MS agar medium supplemented with IAA (0.1 mg L^?1) before being acclimatized in the greenhouse. The antioxidant activities of methanolic extracts from the leaves and roots of the in vitro-regenerated plants of R. glutinosa cultivated in the greenhouse were evaluated using four in vitro assays: scavenging of free radicals (DPPH and ABTS), transition metal reduction and total antioxidant activity phosphomolybdenum test. In all cases, the methanolic extract from leaves demonstrated better antioxidant activity than those taken from roots. A strong correlation was found between total phenolic and flavonoid content, and the antioxidant capacity of the studied extracts.     

Characteristics of strawberry plants propagated by in vitro bioreactor culture and ex vitro propagation method

Reproducible protocol for regeneration of complete plantlets from ‘Bounty’ strawberry (Fragaria ananassa Duch.), using a combination of gelled medium and bioreactor system, has been standardized. Sepals, leaf discs, and petiole halves produced multiple buds and shoots when cultured on semi solid‐gelled medium containing 4 μM thidiazuron (TDZ) for 4 wk followed by transferring in liquid medium containing 2 μM TDZ in a bioreactor system and cultured for another 4 wk. TDZ induced shoot proliferation at 0.1 μM in the bioreactor system but inhibited shoot elongation. TDZ‐induced shoots were elongated and rooted in vitro on gelled medium containing 2 μM zeatin. Such bioreactor‐derived tissue culture (BC) plantlets obtained from sepal explants were grown ex vitro and compared with those propagated by tissue culture on gelled medium (GC) and by conventional runner cuttings (RC), for growth, morphology, anthocyanin content, and antioxidant activity after three growth seasons. The BC and GC plants produced more crowns, runners, leaves, and berries than the RC plants although berry weight per plant did not differ significantly. BC and GC plants produced berries with more anthocyanin contents and antioxidant activities than those produced by the RC plants. However, intersimple sequence repeat (ISSR) marker assay produced a homogenous amplification profile in the tissue culture and donor control plants confirming the clonal fidelity of micropropagated plants. In vitro culture on TDZ and zeatin‐containing nutrient media apparently induced the juvenile branching characteristics that favored enhanced vegetative growth with more crown, runners, leaf, and berry production.     

In vitro propagation of the medicinal plant Ziziphora tenuior L. and evaluation of its antioxidant activity

Ziziphora tenuior L. (Lamiaceae) is an aromatic herb used for its medicinal values against fungi, bacteria. Micropropagation can be used for large-scale multiplication of essential oil producing plants thus avoiding an overexploitation of natural resources. This work aims to develop a reliable protocol for the in vitro propagation of Z. tenuior, and to compare the antioxidant activity between in vitro propagated and wild plants.The explants were sterilized and cultured on MS medium containing different concentrations of growth regulators naphthalene acetic acid (NAA) or indole-3-butyric acid (IBA) with 0.5 mg/L of kinetin (Kin) callus formation was 70.2% after 45 days of incubation in dark on medium supplemented with 1.5 mg/L of NAA. After one month of callus culture on medium supplemented with 2 mg/L BA the shoot number was 5.12 and for the multiplication stage. The shoot number was 4.21 and length was 6.17 cm on medium supplemented with 1 mg/L Kin + 0.1 mg/L NAA.DPPH• reagent was used to test the antioxidant activity. The aqueous and methanol extracts of in vitro plants which were treated with 1.5 and 1 mg/L of kin plus 0.1 mg/L of NAA showed a strong DPPH• scavenging activity where IC₅₀ was 0.307 and 0.369 mg/ml, respectively, while the IC₅₀ of aqueous and methanol extracts of wild plants was 0.516 and 9.229 mg/ml, respectively. Our results suggested that plant growth regulators and in vitro culture conditions increased the antioxidant activity.     

Biphasic effect of copper on the ascorbate-glutathione pathway in primary leaves of Phaseolus vulgaris seedlings during the early stages of metal assimilation

Copper‐imposed oxidative stress and antioxidative defence responses were investigated in the primary leaves of Phaseolus vulgaris L. plants grown on hydroponics containing 50 μM CuSO₄. Copper mainly accumulates in roots; therefore, an increase of the copper content in the leaves was only observed 48 h after the start of the copper supply. Nevertheless, an increase of the thiobarbituric acid reactive metabolites (TBArm) content, an indication of stress, occurred immediately following copper application. Because the ascorbate‐glutathione pathway is considered as a major antioxidative defence mechanism, the evolution of the enzymes and the related metabolites involved in this pathway were studied in the primary leaves as a function of plant copper assimilation. The capacities of monodehydroascorbate reductase (EC 1.6.5.4), dehydroascorbate reductase (EC 1.8.5.1), and glutathione reductase (EC 1.6.4.2) were increased before elevated amounts of copper could be detected in the leaves. The early enhancement of glutathione reductase was only temporary. After copper accumulation in the leaves, a second increase of the glutathione reductase capacity and also an increase of the ascorbate peroxidase capacity (EC 1.11.1.11) were observed. These changes in enzymatic capacity modified the level of the metabolites involved. Increase of the ascorbate pool and maintenance in its reduced form was observed immediately after the start of the treatment. In the beginning of the experiment, the glutathione disulphide/reduced glutathione ratio was higher in the treated plants as compared to the controls. However, towards the end of the experiment, the total glutathione pool, as well as the reduced glutathione content, increased, resulting in a lower ratio value for the treated plants. In conlusion, copper‐imposed oxidative stress, as well as the antioxidative defence response in the leaves, appears to be biphasic. An indirect preventive effect on the antioxidative defence system was observed during the first phase before the leaf copper content increased. A root‐to‐shoot signalling system appears to be involved. Direct oxidation by copper of reduced cell metabolites occurred during the second phase when the leaf copper content was enhanced.     

An efficient in vitro propagation,antioxidant and antimicrobial activities of Aphyllorchis montana Rchb.f.

An in vitro plant regeneration protocol was successfully established in Aphyllorchis montana, a saprophytic achlorophyllous orchid by culturing immature seeds. Among the six basal media evaluated for seed germination, BM-1-Terrestrial Orchid medium was found to be the best followed by Knudson C medium. Half-strength BM-1-Terrestrial Orchid medium was supplemented with different growth regulators either individually or in combinations for multiplication of shoots induction. Of the five cytokinins tested, thidiazuron at 6.8 μM was found to be most effective for multiple shoot induction yielding 17.24 ± 0.27 shoots after 10 weeks of culture. Addition of low concentration of α-Naphthaleneacetic acid (1.3 μM) in MS medium supplemented with the cytokinin thidiazuron (6.8 μM) favored shoot multiplication. The addition of organic additives to the medium containing thidiazuron enhanced the number of regenerated shoots. The plantlets were acclimatized, and the survival rate was 100%. Screening of the antioxidant and antimicrobial activities and estimation of total phenolics and flavonoid content of methanolic extracts of micropropagated plants were also carried out and compared with that of the wild-grown plants. In all the tests, methanolic extract from wild-grown plants showed higher antioxidant, antimicrobial activity, total phenolics and flavonoid content than in vitro propagated plants.     

Metabolomic profiling and antioxidant activity of some Acacia species

Metabolomic profiling of different parts (leaves, flowers and pods) of Acacia species (Acacia nilotica, Acacia seyal and Acacia laeta) was evaluated. The multivariate data analyses such as principal component analysis (PCA) and partial least square-discriminant analysis (PLS-DA) were used to differentiate the distribution of plant metabolites among different species or different organs of the same species. A.nilotica was characterized with a high content of saponins and A.seyal was characterized with high contents of proteins, phenolics, flavonoids and anthocyanins. A.laeta had a higher content of carbohydrates than A. nilotica and A. seyal. On the basis of these results, total antioxidant capacity, DPPH free radical scavenging activity and reducing power of the methanolic extracts of studied parts were evaluated. A.nilotica and A.seyal extracts showed less inhibitory concentration 50 (IC₅₀) compared to A.laeta extracts which means that these two species have the strongest radical scavenging activity whereas A. laeta extracts have the lowest radical scavenging activity. A positive correlation between saponins and flavonoids with total antioxidant capacity and DPPH radical scavenging activity was observed. Based on these results, the potentiality of these plants as antioxidants was discussed.     

Phytochemical analysis,antioxidant and antimicrobial activity of wild and in vitro derived plants of Ceropegia thwaitesii Hook – An endemic species from Western Ghats,India

Ceropegia thwaitesii Hook (Asclepiadaceae), an endemic plant species, due to habitat destruction and over exploitation has a very restricted distribution in the Western Ghats of Tamil Nadu, India. The present wrok aimed to determine the chemical composition, the total phenolic (TPC), flavonoid (TFC) and tannin content (TEC), and to assess the antioxidant properties of various extracts of in vivo plants (IVP) and in vitro regenerated plants (IRP) of C. thwaitesii. Some phenolic compounds like gallic acid, cathechol, vanillin and salicylic acid were identified and quantified by HPLC. All the extracts possessed relevant radical scavenging activity on DPPH, Superoxide radical scavenging activity, and Nitric oxide radicals as well as total antioxidant ability. DPPH assay of in vitro methanol stems extracts and ethanol leaves extracts revealed the best antioxidant properties with important IC₅₀ values of 0.248?±?0.45?µg/mL and 0.397?±?0.67?µg/mL, respectively, whereas in vivo chloroform stems extracts showed a lower antioxidant activity (IC₅₀ of 10.99?±?0.24?µg/mL). The IRP methanol extracts of stem and leaves had good inhibitory activity against all tested microorganisms in a dose-dependent manner. These results suggested that in vitro raised plants of C. thwaitesii are an excellent source of antioxidant compounds to be exploited on an industrial level as food additive.     

Correction to: Performance of cowpea as influenced by native strain of rhizobia,lime and phosphorus in Samaru,Nigeria

Garden thyme (Thymus vulgaris L., Lamiaceae) is an important aromatic herb used for its medicinal values including antioxidant and antimicrobial properties. The present study was performed to analyze the changes in natural antioxidants after inoculation of in vitro propagated garden thyme plants with arbuscular mycorrhizal fungi (AMF). An efficient and low-cost protocol for large-scale multiplication of this aromatic plant was developed. The explants were cultured on full and half strength Murashige and Skoog (MS) medium containing indole-3-butyric acid (IBA). The maximum number of shoots and roots was obtained on ½ MS medium supplemented with 0.1 mg L^?1 IBA after 4 weeks of culture. The successfully adapted in vitro plants (survival rate 95%) were inoculated with arbuscular mycorrhizal fungi (Claroideoglomus claroideum, ref. EEZ 54). Plants were then transferred into field conditions. Mycorrhizal fungi enhanced the activity of some soil enzymes, acid and alkaline phosphatase, urease as well as the levels of extractable glomalin-related proteins in plant rhizosphere. Arbuscular mycorrhizal associations with higher plants promote the accumulation of antioxidant metabolites such as phenols and flavonoids and increase the activity of antioxidant enzymes. The results from the present study suggest enhanced antioxidant capacity of the inoculated T. vulgaris plants which was due mainly to increased accumulation of phenolic compounds (total phenols and flavonoids) together with stimulation of the activity of superoxide dismutase (SOD) and guaiacol peroxidase (GPO).     

In vitro propagation,clonal fidelity and phytochemical analysis of <Emphasis Type="Italic">Rhodiola imbricata</Emphasis> Edgew: a rare trans-Himalayan medicinal plant

The present study focuses on development of a micropropagation protocol for true to type plants of Rhodiola imbricata, an endangered medicinal plant found in trans-Himalayan Leh-Ladakh region of India. It also aims at analyzing the pharmaceutically important secondary metabolites and antioxidant potential of in vitro and in vivo plants. Various cytokinins and auxins were tested for shoot proliferation and in vitro rooting of the microshoots, respectively. Random primers were used for checking genetic uniformity at different stages of micropropagation. Pharmaceutically important secondary metabolites of R. imbricata such as Rosavin, total polyphenols and free radical scavenging activity were analyzed by HPLC. Among different cytokinins used, BAP (5 µM) and TDZ (1 µM) were found to perform better in terms of shoot proliferation, shoot length and number of leaves as compared to other concentrations. For rooting of microshoots, a lower concentration of NAA (0.5 µM) yielded more efficient rooting of micro shoots (17.33 roots per micro shoot). In vitro rooted microshoots were hardened and showed 60% survival rate. The content of gallic acid, chlorogenic acid and 4-hydroxybenzoic acid was higher in the in vivo plant. The amount of ferulic acid was higher in the in vitro raised plant when compared to field grown plant. Furthermore, caffeic acid and p-coumaric acid were higher in the in vitro raised plants as compared to field grown plants. This work will facilitate in conservation of this endangered herb and provide necessary plant materials for various biotechnological and pharmaceutical applications.     

Changes of phenylethanoid and iridoid glycoside distribution in various tissues of shoot cultures and regenerated plants of Harpagophytum procumbens (Burch.) DC. ex Meisn

Harpagophytum procumbens is a medicinal plant containing several compounds with pharmaceutical activity. Previously, we established shoot culture and in vitro regenerated plants of H. procumbens. In this study, HPLC and LC-ESI-MS were used to identify harpagoside, harpagide, verbascoside and isoverbascoside in various tissues (stems, leaves and callus) of shoots multiplied on Schenk and Hildebrandt (SH) solid medium supplemented with 0.57 μM indole-3-acetic acid (IAA) and 8 μM 6-benzylaminopurine (BAP), as well as in stems, leaves and root tubers of in vitro propagated plants grown in the greenhouse for 3, 6 and 12 months. The content of the compounds was also determined by HPLC. For comparison, control H. procumbens plants initiated from seeds were analyzed. H. procumbens shoots grown under in vitro conditions accumulated lower amounts of iridoids and phenylethanoids than the plants derived from them. The levels of analyzed compounds were higher in the organs of 3- or 6-month-old plants than in those of 12-month-old plants. Differences in the distribution of secondary metabolites were also observed between organs. The aerial parts (stems, leaves) of 3-month-old in vitro regenerated plants were characterized by the highest amounts of phenylethanoids, which significantly exceeded those detected in control plants. Total iridoid content, calculated as the sum of harpagoside and harpagide, was highest in the root tubers of 6-month-old plants. In these organs the level of harpagoside was comparable to that in root tubers of 6-month-old seed-propagated plants, but the level of harpagide was much lower.     

Phytochemical and Biological Activities in Limonium Species Collected in Different Biotopes of Tunisia

A particular interest is nowadays given to natural antioxidants occurring in foods which can reduce the risk of several diseases through their protective effect. The genus Limonium is widely distributed in different salt regions of Tunisia and known in traditional medicine for the presence of highly effective viral and bacterial replication inhibitors. Limonium leaves have possible beneficial effects on human health for their antioxidant activities and free radical scavenging abilities. To exploit the potential of plants from extreme environments as new sources of natural antioxidants, we studied the extracts from leaves of eight Limonium species growing in extreme environments in Tunisia. Antioxidant molecules (polyphenols, flavonoids, flavonols, ascorbate, tocopherols), in vitro (DPPH, ORAC) and ex vivo antioxidant potential on human erythrocytes, antioxidant enzymes activities (superoxide dismutase, peroxidases, glutathione reductase) were evaluated to identify the species with the best antioxidant capacity. The results showed variability among the species considered in function of the environmental conditions of their natural biotopes, as for the antioxidants measured. In particular, L. vulgare from Oued Rane biotope, characterized by dryness and high temperatures, was the species with the highest enzymatic activity and antioxidant capacity, making it interesting as possible edible halophyte plant or as food complement.     

Variation in antioxidant properties and phenolics concentration in different organs of wild growing and greenhouse cultivated Castilleja tenuiflora Benth.

The content of total phenolic compounds and flavonoids was determined in methanol extracts of root, stem, leaves, and inflorescences from wild growing and greenhouse cultivated plants of Castilleja tenuiflora. The antioxidant activity in each extract was evaluated using three in vitro models: scavenging of free radicals with 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS), and reducing power by the phosphomolybdenum assay. Both, antioxidant activity and phytochemicals content were influenced significantly (P < 0.05) by the source of the plant material and the organ. Cultivated plants had the highest content of phenolic compounds (37.95 mg gallic acid equiv. g^?1 dry weight, P < 0.05) and the strongest antioxidant activity. Total phenolic compounds content correlated significantly with the antioxidant activity for all studied plant material and organs (P < 0.05). TLC profile using DPPH as a detection reagent indicated that the phenylethanoids verbascoside and isoverbascoside are the main contributors to the free-radical scavenging of C. tenuiflora. Cultivated plants of C. tenuiflora are an alternative source of natural antioxidants to wild growing plants. The antioxidant properties of C. tenuiflora may be associated with its traditional use to treat conditions consistent with radical-related diseases (e.g. inflammation, tumors).     

Antioxidative responses in Vitis vinifera infected by grapevine fanleaf virus

The antioxidative response of grapevine leaves (Vitis vinifera cv. Trebbiano) affected by the presence of grapevine fanleaf virus was studied during the summer of 2010 at three different harvest times (July 1st and 26th, and August 30th). At the first and second harvest, infected leaves showed increases in the concentration of superoxide radical and hydrogen peroxide, the latter increasing for enhanced activity of superoxide dismutase. In contrast, at the last harvest time, increases in the ascorbate pool and ascorbate peroxidase activity maintained hydrogen peroxide to control levels. The glutathione pool was negatively affected as summer progressed, showing a decrease in its total and reduced form amounts. At the same time, increases in the ascorbate pool were observed, making antioxidant defenses of grapevine effective also at the last harvest time. Increases in phenolic acids, and in particular in p-hydroxybenzoic acid, at the first and second harvest might have enhanced the efficiency of the antioxidant system through an interrelation between a peroxidase/phenol/ascorbate system and the NADPH/glutathione/ascorbate cycle. The lack of increase in p-hydroxybenzoic acid at the third harvest could be due instead to the enhanced utilization of this acid for hydrogen peroxide detoxification. With time, grapevine plants lost their capacity to contrast the spread of grapevine fanleaf virus, but acquired a greater ability to counteract pathogen-induced oxidative stress, being endowed with more reduced antioxidant pools.     

Rice Seed Priming with Picomolar Rutin Enhances Rhizospheric Bacillus subtilis CIM Colonization and Plant Growth

The effect of rutin, a bioflavonoid on the growth and biofilm formation of Bacillus subtilis strain CIM was investigated. In addition to swimming, swarming, and twitching potentials of B. subtilis CIM (BS), one picomolar (1 pM) of rutin was also observed to boost the biofilm forming ability of the bacterium. Bio-priming of rice seeds with BS and rutin not only augmented root and shoot lengths but also the photosynthetic pigments like chlorophyll and carotenoid. Similarly, high accumulation of phenolic and flavonoid contents was observed in the leaves. Fluorescent microscopic images revealed that BS plus rutin enhanced callose deposition in the leaves. It was also established that the least formation of reactive oxygen species in BS plus rutin treated rice plants was due to higher free radicals scavenging activity and total antioxidant potential. The results highlight chemo attractant nature of BS towards rutin, which by enhancing biofilm formation and root colonization indirectly strengthened the plants’ defensive state.     

Metabolite profiling of Neptunia oleracea and correlation with antioxidant and α-glucosidase inhibitory activities using 1H NMR-based metabolomics

Neptunia oleracea is a plant consumed as vegetable and used as a traditional herb to treat several ailments. This study evaluated metabolite variations among N. oleracea leaf and stem subjected to air drying (AD), freeze drying (FD) and oven drying (OD) using proton nuclear magnetic resonance (¹H NMR) based metabolomics. The correlation was also studied for the metabolite content with total phenolic content (TPC), DPPH free radical scavenging and α-glucosidase inhibitory activities. A total of 18 metabolites were identified from N. oleracea extracts, including 10 primary metabolites, 5 flavonoids and 3 phenolic acids using NMR. Ultra-high performance liquid chromatography tandem mass spectrometry analysis (UHPLC-MS/MS) confirmed the presence of the secondary metabolites and revealed the flavonoid derivatives present. All the identified phenolics are first reported from this plant. Multivariate data analysis (MVDA) showed strong correlation between the metabolites with the antioxidant and α-glucosidase inhibitory activities of FD N. oleracea leaves. The compounds suggested to be responsible for the high activity of FD leaves include vitexin-2-O-rhamnoside, catechin, caffeic acid, gallic acid and derivatives of quercetin, kaempferol and myricetin. This study demonstrates that FD N. oleracea leaves are a potential natural source for antioxidant and α-glucosidase inhibitors.     

Improvement of element uptake and antioxidative defense in Brassica napus under lead stress by application of hydrogen sulfide

Heavy metal pollution is one of the major constraints in oilseed rape (Brassica napus L.) production. In this study, protective role of hydrogen sulfide (H₂S) on plant growth under lead (Pb) stress was studied in B. napus. Plants were grown hydroponically in greenhouse conditions under three levels (0, 100, and 400 μM) of Pb and three levels (0, 100 and 200 μM) of H₂S donor sodium hydrosulfide. Outcomes demonstrated that Pb stress significantly reduced the plant biomass, leaf chlorophyll contents, nutrients uptake in the leaves and roots of B. napus plants. Exogenous application of H₂S significantly improved the plant biomass, chlorophyll contents and concentration of macro- and micronutrients in the leaves and roots of B. napus plants under Pb-toxicity conditions. The data indicated that application of Pb alone significantly increased the reactive oxygen species (ROS) as well as malondialdehyde (MDA) in the leaves and roots of plants. Meanwhile, application of H₂S decreased the production of MDA and ROS in the leaves and roots by increasing antioxidant activities under Pb stress. Moreover, this study also revealed that plants treated with H₂S at different concentrations enhanced the contents of total glutathione and glutathione reduced/glutathione oxidized ratio in leaves and roots under different levels of Pb. The results depicted that H₂S improved the plant biomass, uptake of nutrients in the leaves and roots of B. napus plants and enhanced the performance of antioxidant defense system due to its ameliorative potential under Pb stress conditions.