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Soil salinization is one of the abiotic stresses that inhibit plant growth and development, which seriously restricts global crop production. WRKY transcription factors play an important role in regulating plant responses to stress such as salt stress. In our previous study, two WRKY family genes from okra, AeWRKY32 and AeWRKY70, were significantly up-regulated and down-regulated, respectively, in response to salt stress. In this study, subcellular localization showed that they were localized to the nucleus. The down-regulation of AeWRKY32 and AeWRKY70 via whole plant virus-induced gene silencing (VIGS) increased and decreased plant sensitivity to salt stress, respectively. Ectopic expression of AeWRKY32 and AeWRKY70 led to promoted and reduced salt tolerance in transgenic Arabidopsis, respectively. There was no significant difference between transgenic plants and wild type (WT) without salt treatment. Salt stress significantly inhibited plant growth. The decrease of chlorophyll content and the increase of anthocyanin content in AeWRKY32-overexpressed transgenic plants were lower than those in the WT, while AeWRKY70-overexpressed plants had the opposite effect. Under salt stress, the AeWRKY70-overexpressed plants had the highest malondialdehyde (MDA) content, followed by the WT, and the lowest in AeWRKY32-overexpressed plants. The hydrogen peroxide (H2O2) content and superoxide anion (O2•−) generation rate were only slightly increased. Moreover, salt stress significantly increased plant proline content and antioxidant enzyme activities, which was highest in AeWRKY70-overexpressed plants except superoxide dismutase (SOD). Taken together, these results suggest that AeWRKY32 and AeWRKY70 play positive and negative roles in plant in response to salt stress, respectively. [ABSTRACT FROM AUTHOR]

The global prevalence of cardiovascular diseases (CVDs), including dyslipidemia and atherosclerosis, is rising. While pharmacological treatments for dyslipidemia and associated CVDs exist, not all individuals can afford them, and those who do often experience adverse side effects. Preclinical studies have indicated the potential benefits of Abelmoschus esculentus and its active phytochemicals in addressing dyslipidemia in rodent models of diabetes. However, there is limited clinical evidence on lipid parameters. Thus, this study aimed to assess the potential impact of Abelmoschus esculentus on dyslipidemia. A literature search was performed on PubMed, Scopus, and Cochrane Library for relevant trials published from inception until 11 August 2024. Data analysis was performed using Jamovi software version 2.4.8 and Review Manager (version 5.4), with effect estimates reported as standardized mean differences (SMDs) and 95% confidence intervals (CI). The evidence from eight studies with nine treatment arms showed that Abelmoschus esculentus reduces total cholesterol (TC), SMD = −0.53 (95% CI: −1.00 to −0.07), p = 0.025), compared to placebo. Additionally, triglyceride (TG) was reduced in Abelmoschus esculentus compared to placebo, SMD = −0.24 (95% CI: −0.46 to −0.02), p = 0.035. Furthermore, low-density lipoprotein (LDL) was also reduced, SMD = −0.35 (95% CI: −0.59 to −0.11), p = 0.004 in Abelmoschus esculentus versus placebo. This remedy substantially increased high-density lipoprotein (HDL), SMD = 0.34 (95% CI: 0.07 to 0.61), p = 0.014). Abelmoschus esculentus substantially improved lipid profile in prediabetes, T2D, obesity, and diabetic nephropathy. While the evidence confirms the potential benefits of Abelmoschus esculentus in reducing dyslipidemia, it is important for future clinical studies to standardize the effective dosage for more reliable results. Therefore, future trials should focus on these markers in well-designed trials with sufficient sample sizes. Furthermore, Abelmoschus esculentus can be supplemented to the diet of the relevant populations to alleviate dyslipidemia. [ABSTRACT FROM AUTHOR]

The use of medicinal plants in the management of diabetes mellitus (DM) is extensively reported. However, there is still very limited information on the role of these plants as markers of oxidative stress in DM. This current review evaluated the effect of Amaranthus spinosus, Amaranthus hybridus, and Abelmoschus esculentus on markers of oxidative stress in rodent models of DM. Current findings indicate that these plants have the potential to reduce prominent markers of oxidative stress, such as serum malondialdehyde and thiobarbituric acid-reactive substances, while increasing enzymes that act as antioxidants, such as superoxide dismutase, catalase, glutathione, and glutathione peroxidase. This may reduce reactive oxygen species and further ameliorate oxidative stress in DM. Although the potential benefits of these plants are acknowledged in rodent models, there is still a lack of evidence showing their efficacy against oxidative stress in diabetic patients. Therefore, we recommend future clinical studies in DM populations, particularly in Africa, to evaluate the potential effects of these plants. Such studies would contribute to enhancing our understanding of the significance of incorporating these plants into dietary practices for the prevention and management of DM. [ABSTRACT FROM AUTHOR]

The difficulty in obtaining commercial fertilizers by smallholder farmers in sub-Saharan Africa makes it very important to optimize the use of local organic resources. In VilanKulo, Mozambique, a study was carried out on okra (Abelmoschus esculentus) over two growing seasons. The soil was a haplic, loamy-sand textured Lixisol. As organic amendments, bat guano and biochar were used. Bat guano is a phosphorus (P)-rich and low-carbon (C)/nitrogen (N)-ratio material from natural deposits on a cave floor. Biochar is a C-rich material prepared via an artisanal process using forest residues as a feedstock. Bat guano was applied at two rates (5 and 10 t ha−1) just before sowing. It was also applied at the same rates one month before sowing. Biochar was used at two rates (5 and 10 t ha−1) applied at sowing. Biochar and guano were mixed at the rates of 1 and 4 t ha−1 and 2 and 8 t ha−1, respectively, and applied at sowing. The experiment also used a non-fertilized control. Field trials were arranged in a completely randomized design with three replicates. The treatments that received high rates of guano tended to show significantly higher fruit yields (>10 t ha−1 as the two-year average) in comparison with the control, which showed the lowest average okra fruit yield (6.21 t ha−1). In the guano treatments, the apparent recovery by okra of some important nutrients, such as N, was greater than the amount of the nutrient contained in the guano itself. This result, together with many others related to the tissue nutrient concentration, soil properties and residual fertilizing value in guano plots, indicated a strong mineralization of guano during the growing season. This was probably due to its low C/N ratio and favourable environmental conditions for the mineralization process. The result also suggests some kind of manuring effect, i.e., a fertilizing effect of guano beyond what can be explained by the nutrient supply. The use of biochar increased the total organic C in the soil and cation exchange capacity (CEC) compared with the control but did not affect the variables related to plant performance. Overall, the results showed that farmers can benefit from the use of guano in the short term because it releases nutrients, while with the use of biochar, the benefits can arise in the long term by improving the soil properties. [ABSTRACT FROM AUTHOR]

In this work, stable and spherical silver nanoparticles (AgNPs) were synthesized in situ from silver salt (silver nitrate) using the aqueous extract of the okra plant (Abelmoschus esculentus) at room temperature and ambient pH conditions. The influences of different parts of the plant (such as the leaves, stems, and pods) on the chemical-reducing effectiveness of silver nitrate to silver nanoparticles were investigated. The aqueous extract of the leaves was found to be more effective in the chemical reduction of silver nanoparticles and in stabilizing them at the same time. The silver nanoparticles produced were stable and did not precipitate even after storage for 1 month. The extract of the stem was less effective in the reduction capacity followed by the extract of the pods. The results indicate that the different amounts of phytochemicals present in the leaves, stems, and pods of the okra plant are responsible for the chemical reduction and stabilizing effect. The silver nanoparticles were characterized by UV-Vis spectroscopy, Fourier-transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), and energy-dispersive X-ray spectroscopy (EDX). The surface plasmon resonance (SPR) peak at 460 nm confirmed the formation of silver nanoparticles. The nanoparticles were spherical with an average size of 16 nm and polycrystalline with face-centered cubic (fcc) structures. The z-scan technique was used to study the nonlinear refraction and absorption coefficients of AgNPs at wavelengths of 488 and 514 nm under C.W. mode excitation. The nonlinear refraction index and nonlinear absorption coefficients were calculated in the theoretical equations in the experimental data. The antibacterial properties of the nanoparticles were evaluated against Gram-positive and Gram-negative bacteria. [ABSTRACT FROM AUTHOR]

Okra (Abelmoschus esculentus L.), a tropical annual crop, is a highly perishable vegetable. Okra pods deteriorate rapidly after harvesting. The pods undergo physical and physiological changes that diminish storability and quality. The purpose of this study was to investigate the effect of bio-stimulants on the storability and quality of okra pods stored at 4 °C and 25 °C for 12 days. Dipping okra pods for 5 min in a solution of 0.5% ascorbic acid, citric acid, or salicylic acid pre-storage significantly extended the shelf life and preserved the quality of the pods compared to the control condition at 4 °C and 25 °C. Citric acid and ascorbic acid were the most effective in preserving most traits. Citric acid reduced the loss in weight, firmness, appearance, and prevented decay at 4 °C and 25 °C. Ascorbic acid decreased the loss of moisture and the degradation of carbohydrates, vitamin C and lycopene at 4 °C and 25 °C. Salicylic acid decreased the degradation of protein at 25 °C. The low temperature was highly effective in decreasing the loss or degradation of most of the studied traits. Taken together, bio-stimulants and storing at 4 °C played a prominent role in extending the shelf life and preserving the quality of okra pods. [ABSTRACT FROM AUTHOR]

Salinity is one of the most devastating abiotic stresses that limit plant growth and yield, especially in arid and semi-arid regions. The objective of this study was to evaluate the effect of foliar application of salicylic acid in mitigating the effects of salt stress on okra cultivation in a hydroponic system. The study was conducted in a greenhouse, consisting of two experiments. A completely randomized design was adopted in a split-plot scheme, with four levels of electrical conductivity of the nutrient solution—EC (2.1; 3.6; 5.1, and 6.6 dS m−1) considered the plots and four salicylic acid concentrations—SA (0, 1.2; 2.4, and 3.6 mM), the subplots, with four replications. The second experiment differed from the first only by the increase in the EC levels (3.0, 5.0, 7.0, and 9.0 dS m−1). An increase in the electrical conductivity of the nutrient solution negatively affected the physiology and production components of okra. However, foliar application of salicylic acid at concentrations between 1.2 and 2.3 mM reduced the harmful effects of salt stress. The salinity threshold for hydroponic cultivation of okra was 2.54 dS m−1, with a reduction of 7.98% per unit increment in EC above this level. [ABSTRACT FROM AUTHOR]

Beneficial soil microorganisms influence nutrient recycling, soil fertility, plant growth, and productivity and reduce chemical fertilizer application. This study aimed to isolate bacteria from non-agricultural soils in the Al-Ahsa region and characterize the bacteria with the best biostimulating characteristics at the physiological, biochemical, and molecular level. DPM17, a bacterial isolate, promotes plant growth through phosphate solubilization, nitrogen fixation, and ammonia production. DPM17 also produces the phytohormones, indole acetic acid (IAA; 4.516 μg mL−1) and gibberellin (1.33 µg mL−1), and ammonia (0.06 µg mL−1). Additionally, DPM17 grows in the presence of up to 10% NaCl, indicating its halophilic nature. DPM17 was identified as Bacillus baekryungensis based on comparative sequence analysis of the 16S rRNA gene, and neighbor-joining phylogenetic analyses indicated that DPM17 was 96.51% identified to Bacillus sp. DPM17 inoculation substantially improved Abelmoschus esculentus (okra) root length, lateral root count, and dry weight from 7.03 to 9.41 (p = 0.03), 3.2 to 7.2, and 6 to 13 mg (p = 0.032), respectively. The results suggest that DPM17 enhances plant growth and can be exploited to develop efficient formulations for sustainable agriculture and food security in Saudi Arabia. [ABSTRACT FROM AUTHOR]

Okra is a kind of flavonoid-rich food which was reported to have a variety of health functions. Flavonoids are the major polyphenolic compounds in okra and are thought to play a role in reducing the risk of disease. The aim of this study was to isolate and identify the flavonoids composition in okra pods and explore the activity of the main flavonoids components identified on inhibiting tumor cell proliferation in vitro. Six individual flavonoids were identified by HPLC-MS/MS: quercetin-3-gentiobioside (Q3G), quercetin-3-sambubioside (Q3S), rutin, quercetin-7-glucoside (Q7G), isoquercitrin (ISO) and quercetin-3-malonylglucoside (Q3M), which were all separated well within 30 min. The analytical method was validated by the recovery of spiked samples and so on. Moreover, four main flavonoids components, namely Q3G, Q3S, ISO and Q3M, exhibited significant (p < 0.05) inhibition of NCI-N87, A375, A549 cells proliferation (25−100 μmol/L) and of HFLS-RA (200−300 μmol/L) in different levels, according to MTT method, respectively. It is demonstrated that the flavonoids components of okra exhibited a noteworthy development prospect as a possible nutraceutical dietary supplement. [ABSTRACT FROM AUTHOR]

In this study total twenty seven gram negative NaCl tolerant rhizobacterial strains were isolated from disturbed soils of Lucknow districts. The 3 selected sampling sites were Bijnor, Pasi Quila and Babasaheb Bhimrao Ambedkar University Campus, Lucknow, India. The isolates have been investigated for different plant growth promoting and biochemical activities. Based on morphological and biochemical tests the total eight (8) rhizobacterial strains were designated as Pseudomonas spp. Among PGP traits, all 8 Pseudomonas strains were examined for Indole-3-Acetic Acid (IAA) production activity. The bacterialisolate IAA4 produces maximum 21.16±3.24 μg mL-1 of IAA at 100 μg mL-1 tryptophan concentration among Pseudomonas strains. This strain show excellent P solubilization and N fixatation in qualitative assay. The higher amount of NaCl salt in soils positively reduces paddy plant physiology and growth parameters. The IAA4 inoculation in okra seeds significantly (P<0.001) improved plant growth parameters, green pigments and modulate antioxidant activities under pot experimental study. [ABSTRACT FROM AUTHOR]

Polysaccharide containing extracts from immature fruits of okra (Abelmoschus esculentus) are known to exhibit antiadhesive effects against bacterial adhesion of Helicobacter pylori (H. pylori) to stomach tissue. The present study investigates structural and functional features of polymers responsible for this inhibition of bacterial attachment to host cells. Ammonium sulfate precipitation of an aqueous extract yielded two fractions at 60% and 90% saturation with significant antiadhesive effects against H. pylori, strain J99, (FE60% 68% ± 15%; FE90% 75% ± 11% inhibition rates) after preincubation of the bacteria at 1 mg/mL. Sequential extraction of okra fruits yielded hot buffer soluble solids (HBSS) with dose dependent antiadhesive effects against strain J99 and three clinical isolates. Preincubation of H. pylori with HBSS (1 mg/mL) led to reduced binding to 3'-sialyl lactose, sialylated Lea and Lex. A reduction of bacterial binding to ligands complementary to BabA and SabA was observed when bacteria were pretreated with FE90%. Structural analysis of the antiadhesive polysaccharides (molecular weight, monomer composition, linkage analysis, stereochemistry, and acetylation) indicated the presence of acetylated rhamnogalacturonan-I polymers, decorated with short galactose side chains. Deacetylation of HBSS and FE90% resulted in loss of the antiadhesive activity, indicating esterification being a prerequisite for antiadhesive activity. [ABSTRACT FROM AUTHOR]

Known for its high nutritional and medicinal value, okra (Abelmoschus esculentus) is commonly used for replacing plasma and expanding blood volume in humans. It is a major economic crop cultivated in tropical and subtropical regions worldwide. The present study aimed to investigate and evaluate the nutritional properties and prospective applications of the consumable parts of okra. The total ash content (mineral content), carbohydrate, crude fiber, fat, protein, and moisture fractions of okra pod aqueous extract were determined. The results show that okra aqueous extract contained 84.670–87.650% moisture, 1.514–1.197% ash, 7.857–8.261% carbohydrate, 2.367–3.410% crude protein, and 6.781–8.314% crude fiber. Okra was determined to have high nutritional value, with γ-tocopherol and α-tocopherol contents about 2.67 mg/100 g and 1.62 mg/100 g, respectively. High-performance liquid chromatography (HPLC) was performed to determine the sugars present in okra aqueous extract. The water-soluble polysaccharide content was 10.22–16.45 g/100 g. The tested aqueous extract was a rich source of total phenolic compounds in gallic acid equivalents (288.2–3426.2 mg/100 g), chlorophyll a (3.53 mg/100), chlorophyll b (2.43 mg/100), and carotenoids (1.3 mg/100 g). The detected minerals were Ca, Mg, Cu, Zn, Fe, K, Na, and Mn. Atomic absorption spectrometry analysis of these ashed minerals was performed. In addition to the nutritional benefits, okra pods exhibited antimicrobial, anticancer, and antioxidant properties. The aqueous extract was found to be potentially active against bacterial strains of Staphylococcus aureus (MIC value = 21.8 mg/mL), Escherichia coli (MIC value = 18.7 mg/mL), Bacillus cereus (MIC value = 20.7 mg/mL), and Klebsiella pneumoniae (MIC value = 20.2 mg/mL). Okra aqueous extract exhibited inhibitory activity against α-amylase (IC50 = 120 µg/mL) and α-glucosidase (IC50 = 115 µg/mL). The okra extract exhibited high anticancer activity, concentration-dependent and with an IC50 value of about 158.3 mg/mL. The results indicated that okra pods have nutritional and medicinal properties and, hence, can be used as a functional food and broad-spectrum nutraceutical supplement. [ABSTRACT FROM AUTHOR]

As climate changes increase, drought stress is becoming a problem for all major horticultural crops; among them is okra (Abelmoschus esculentus). Despite its superior resilience to heat stress and high nutritional content, it is still underutilized in contrast to other vegetable crops. Moreover, the drought-resistant and drought-sensitive genotypes of okra are also not well known and require further exploration to improve their productivity. To investigate this in more detail, we performed comparative physiological and large-scale chloroplast proteomics on drought-stressed genotypes of okra. We evaluated four major genotypes of okra, viz., NS7774, NS7772, Green Gold, and OH3312 for drought resilient rootstock. The physiological modulations demonstrated a significant change by 50–76% in biomass, net-photosynthetic machinery, water transport, and absorption both in early and late stages of drought stress compared to well-watered crops in all genotypes. Maximum oxidative damage due to drought stress was observed for the genotypes NS7772, Green Gold and OH3312 as depicted by H2O2 and O2− determination. Greater oxidative stress was correlated to lesser antioxidant activity and expression of antioxidant enzymes, such as catalase and ascorbate peroxidase under stress in okra genotypes. The overall photosynthetic pigments, such as total chlorophyll, and total carotenoid content, were also decreased, and stomatal guard cells were disrupted and appeared closed compared to the control for the above three mentioned genotypes, except NS7774. A subsequent tissue-specific proteome analysis of chloroplasts and thylakoids analyzed by BN-PAGE (blue native polyacrylamide gel electrophoresis) revealed either over or under expression of specific proteins, such as ATPase, PSI, PSII core dimer, PSII monomer and ATP synthase. The expression of multiprotein complex proteins, including PSII-core dimer and PSII-core monomer, was slightly higher for the genotype NS7774 when compared to three other genotypes for both 5 and 10 days of drought stress. Further identification of specific proteins obtained in second dimension BN-PAGE provided descriptive detail of seven proteins involved in drought resistance across all genotypes. The identified proteins are majorly involved in photosynthesis under drought stress, suggesting NS7774 as a drought tolerant genotype. Further, the proteomic results were confirmed using Immunoblot by selecting specific protein such as PsaA. Overall, from our physiological modulations and chloroplast proteomics in all genotypes, we summarized NS7774 as a resilient rootstock and the other three genotypes (NS7772, OH3312, and Green Gold) as sensitive ones. [ABSTRACT FROM AUTHOR]

Abelmoschus esculentus has fruit popularly known as okra and belongs to the Malvaceae family. It is commonly used in cooking but also in traditional medicine in the treatment of worms, dysentery, inflammation, and also irritation of the stomach, intestines, and kidneys, as it is a potential functional food. Its mucilage is a highly viscous polysaccharide that is mostly composed of monosaccharides D-galactose, L-rhamnose, and galacturonic acid, as well as proteins and minerals. The functional properties of okra mucilage have been widely studied, mainly for its potential antidiabetic activity; thus, its use as adjuvant or nutraceutical therapy for diabetes is very promising. Due to its rheological properties, it is a potential resource for pharmaceutical and food applications. Okra mucilage can be extracted by several methods, which can directly influence its physicochemical characteristics and biological activity. Features such as low cost, non-toxicity, biocompatibility, and high availability in nature arouse the interest of researchers for the study of okra mucilage. The survey of research on the applications of okra mucilage highlights the importance of using this promising source of bioactive compounds with interesting technological properties. The potential of okra as a functional food, the properties of okra mucilage, and its technological applications are discussed in this review. [ABSTRACT FROM AUTHOR]

Abelmoschus esculentus L. Moench (okra) is a commonly consumed vegetable that consists of the seeds and peel component which are rich in polyphenolic compounds. The aim of this study is to utilize pressurized hot water extraction (PHWE) for the extraction of bioactive phytochemicals from different parts of okra. A single step PHWE was performed at various temperatures (60 °C, 80 °C, 100 °C and 120 °C) to determine which extraction temperature exhibits the optimum phytochemical profile, antioxidant and antidiabetic activities. The optimum temperature for PHWE extraction was determined at 80 °C and the biological activities of the different parts of okra (Inner Skin, Outer Skin and Seeds) were characterized using antioxidant (DPPH and ABTS), α-glucosidase and vasoprotective assays. Using PHWE, the different parts of okra displayed distinct phytochemical profiles, which consist of primarily polyphenolic compounds. The okra Seeds were shown to have the most antioxidant capacity and antidiabetic effects compared to other okra parts, likely to be attributed to their higher levels of polyphenolic compounds. Similarly, okra Seeds also reduced vascular inflammation by downregulating TNFα-stimulated VCAM-1 and SELE expression. Furthermore, metabolite profiling by LC/MS also provided evidence of the cytoprotective effect of okra Seeds in endothelial cells. Therefore, the use of PHWE may be an alternative approach for the environmentally friendly extraction and evaluation of plant extracts for functional food applications. [ABSTRACT FROM AUTHOR]