Hypolipidemic activity of okra is mediated through inhibition of lipogenesis and upregulation of cholesterol degradation

An Overview of the Current Scientific Evidence on the Biological Properties of Abelmoschus esculentus (L.) Moench (Okra)

Abelmoschus esculentus (L.) Moench, commonly known as okra or lady's finger, is an annual flowering plant belonging to the Malvaceae family. Okra is a native plant in Africa as well as a traditional medicine in Africa and India for treating different diseases and conditions. Today, okra is widely consumed as a vegetable and is increasingly recognized as a superfood due to its rich nutritional profile and potential pharmacological benefits. Research indicates that okra exhibits a range of biological activities, including antidiabetic, antihyperlipidemic, antifatigue, vasoprotective, hepatoprotective, antitumor, anti-inflammatory, and antimicrobial effects. Despite its promising therapeutic potential, research on the active compounds in okra and evaluating efficacy in clinical settings remains limited. This review aims to consolidate existing scientific knowledge on the biological and pharmacological properties of okra, thereby encouraging further investigation into its health benefits. Ultimately, this could pave the way for the development of functional foods or health supplements that leverage okra as a key ingredient to prevent chronic diseases and enhance overall health outcomes.

The cardiometabolic benefits of okra-based treatment in prediabetes and diabetes: a systematic review and meta-analysis of randomized controlled trials

Background

This systematic review and meta-analysis examine the effects of okra consumption on cardiometabolic risk factors in individuals with prediabetes and diabetes. Okra is a widely consumed vegetable with potential health benefits, and understanding its impact on metabolic parameters in these populations is important.

Methods

A comprehensive search of the literature was conducted up to May 2024 in PubMed/Medline, Scopus, and Web of Science to find relevant randomized clinical trials (RCTs) by using following keyword: ("okra" OR "okras" OR "abelmoschus esculentus") AND ("intervention" OR "controlled trial" OR "randomized" OR "randomized" OR "randomly" OR "clinical trial" OR "trial" OR "randomized controlled trial" OR "randomized clinical trial" OR "RCT" OR "blinded" OR "placebo" OR "Cross-Over" OR "parallel"). The selected trials were subjected to heterogeneity tests using the I2 statistic. Random effects models were examined based on the heterogeneity tests, and the pooled data were calculated as weighted mean differences (WMD) with a 95% confidence interval (CI). In this meta-analysis, all the analyses were performed by using the STATA version 17 software.

Results

Of the 1,339 papers, nine eligible RCTs were included in the present meta-analysis. Our findings indicated that okra consumption significantly reduced total cholesterol (TC) levels (WMD: -14.40 mg/dL; (95% CI: -20.94 to -7.86); p < 0.001), low-density lipoprotein (LDL) (WMD: -7.90 mg/dL; (95% CI: -13.30 to -2.48); p = 0.004), fasting blood glucose (FBG) (WMD: -39.58 mg/dL; (95% CI: -61.60 to -17.56); p < 0.001), and hemoglobin A1C (HbA1c) (WMD: -0.46 mg/dL; (95% CI: -0.79 to -0.13); p = 0.005). Overall effect size showed that okra intake failed to change triglycerides (TG), high-density lipoprotein (HDL), Insulin, homeostatic model assessment for insulin resistance (HOMA-IR), systolic blood pressure (SBP), diastolic blood pressure (DBP), body weight, and body Mass Index (BMI) significantly.

Conclusion

Okra decreased TC, LDL, FBG, and HbA1c levels in the intervention compared to the control group. A dose ≤3,000 mg/day caused a significant decrease in TG, TC, LDL, HbA1c, and a significant increase in HDL. More study is needed to determine the optimum dose and duration of intervention.

The Effects of Okra Consumption on Glycemic Parameters and Lipid Profile in Adults: A Systematic Review and Meta-Analysis

The clinical research findings on the effects of okra consumption on blood glucose and lipids are inconsistent. In this study, we aimed to explore the impact of okra consumption on glycemic parameters and lipid profile in adults, including homeostatic model assessment for insulin resistance (HOMA-IR), glycosylated hemoglobin A1c (HbA1c), fasting blood glucose (FBG), triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C). To find relevant randomized controlled trials (RCTs), we systemically searched EMBASE, Web of Science, PubMed, Cochrane Library, and Scopus until April 2024. According to the inclusion and exclusion criteria, eight studies involving 521 participants were ultimately included in the present study. Compared to placebo, okra consumption remarkably decreased FBG (WMD: -32.56 mg/dL; 95% CI: -48.83, -16.28; p < 0.001; I 2 = 84.7%), HbA1c (WMD: -0.48%; 95% CI: -0.81, -0.16; p = 0.004; I 2 = 5.5%), TG (WMD: -13.16 mg/dL; 95% CI: -23.54, -2.77; p = 0.013; I 2 = 0.0%), and TC (WMD: -9.70 mg/dL; 95% CI: -14.95, -4.46; p < 0.001; I 2 = 38.3%) in adults. However, okra showed no notable impact on HOMA-IR, HDL-C, and LDL-C. Okra consumption has an improving effect on adult FBG, HbA1c, TG, and TC levels. More large-scale RCT studies are necessary to validate the beneficial effects of okra on adults due to the limited number of included RCTs. Trial Registration: PROSPERO: CRD42024540121.

Effect of Abelmoschus esculentus L. (Okra) on Dyslipidemia: Systematic Review and Meta-Analysis of Clinical Studies

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.

Effects of dried okra extract on lipid profile, renal function and some RAGE-related inflammatory genes expression in patients with diabetic nephropathy: A randomized controlled trial

BACKGROUND

Diabetic nephropathy (DN) is a common complication of type 2 diabetes. Okra (Abelmoschus esculentus L) is reported to have anti-diabetic effects. The present study aimed to investigate the effects of dried okra extract (DOE) supplementation on lipid profile, renal function indices, and expression of inflammatory genes, as well as serum level of soluble Receptor for Advanced glycation end products (sRAGE) in patients with DN.

METHODS

In this triple-blind randomized placebo-controlled clinical trial, 64 eligible patients with DN received either 125 mg of DOE or placebo daily along with DN-related nutritional recommendations for 10 weeks. Changes in kidney indices including proteinuria and estimated glomerular filtration rate (eGFR), lipid profile, serum SRAGE, as well as the expression of RAGE, ICAM-1, and IL-1 genes were measured over 10 weeks.

RESULTS

After adjustment for the potential confounders, between-group analyses showed no significant differences in terms of lipid profile, kidney function indices, sRAGE, and RAGE-related inflammatory genes expression after 10 weeks.

CONCLUSION

Daily 125 mg DOE along with nutritional recommendations on top of usual care did not lead to significant changes in renal function indices, lipid profile, and inflammatory genes expression in patients with DN.

Structural characterization and anti-lipotoxicity effects of a pectin from okra (Abelmoschus esculentus (L.) Moench)

Okra (Abelmoschus esculentus (L.) Moench) is rich in various bioactive ingredients and used as a medicinal plant in traditional medicine. In the present study, to find the polysaccharide with anti-lipotoxicity effects from okra and clarify its structure, a pectin OP-1 was purified from okra, which had a backbone containing →4)-α-GalpA-(1 → residues, and 1,5-Ara linked the main chain through the O-3 of the residue →3,4)-α-GalpA-(1→, and the C-6 of residue 1, 4-α-GalpA replaced by methyl ester. In vitro experiments showed that OP-1 pretreatment alleviated oleic acid (OA)-induced lipid accumulation, ROS generation, apoptosis, transaminase leakage, and inflammatory cytokine secretion in HepG2 cells, resulting in reduced lipotoxicity. Further molecular results revealed that OP-1 increased Adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) phosphorylation and affected the expression of AMPK downstream targets, including inhibit SREBP1c and FAS, as well as activate CPT-1A. Impressively, AMPK inhibitor dorsomorphin (Compound C) blocked the effects of OP-1 against lipotoxicity. The effects of OP-1 on lipid metabolism were also diminished by dorsomorphin. Our results demonstrated that OP-1 possesses a potent function in preventing lipotoxicity via regulating AMPK-mediated lipid metabolism and provide a novel insight into the future utilization of okra polysaccharide.

Optimization of near-infrared reflectance models in determining flavonoid composition of okra (Abelmoschus esculentus L.) pods

Okra pods have been utilized as a functional food due to their rich active ingredient composition, especially the high content of flavonoid compounds. This study conducted near-infrared spectroscopy (NIRS) modeling optimization and external validation based on the flavonoid components of 219 pod samples. Spectral correlation analyses identified two types of spectral response patterns classified as quercetin-3-O-xylose (1-2) glucoside (QOXG) and total flavonoid content (TFC), consisting of six different spectral regions. Different modeling effects were observed for QOXG and TFC with various spectral region combination analyses, where the lower wave-number region contributed more to both flavonoids calibration models. The combination of standard normal variate / "1, 9, 3" / partial least squares was found to be the most effective for developing calibration models for both flavonoids. The resulting models had small root mean square errors of prediction for external validation and high determination coefficients, indicating their usefulness for rapid prediction of flavonoid composition in okra pods.

Investigating the in vitro mode of action of okra (Abelmoschus esculentus) as hypocholesterolemic, anti-inflammatory, and antioxidant food

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Okra leaf butanol extract and fruit extract induce the LDLR expression in human hepatoma cell line Huh7.

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Okra leaf butanol extract reduced the mRNA levels of proinflammatory cytokines IL-1β, IL-6 and TNF-α in THP1-derived macrophages.

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Okra fruit extract showed a sequestering ability of cholic acid providing an additional mechanism of hypocholesterolemic activity.

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Leaf ethyl acetate extract exerted significant antioxidant activity with IC₅₀ comparable to ascorbic acid.

Okra (Abelmoschus esculentus) have been introduced as food relatively recently in Europe. It is native to India and one of the most important vegetables in Nigeria. The leaves can be consumed but also the fruit is rich in nutrients and bioactive compounds (i.e., dietary fiber, vitamins, oils, polysaccharides, polyphenols) and several health promoting actions have been ascribed, including a lipid-lowering properties. In this work the effects of fruit and leaf extracts on expression of key mediators of cholesterol metabolism, i.e., the low-density lipoprotein receptor (LDLR) and proprotein convertase subtilisin/kexin type 9 (PCSK9), were investigated in human hepatoma cell line Huh7. Furthermore, effects on proinflammatory cytokines (IL-1β, IL-6 and TNF-α) expressed by THP1-derived macrophages were studied to assess potential anti-inflammatory actions.

Okra fruit extract significantly induced the mRNA and protein levels of the LDLR by 1.4 ± 0.3 and 4.8 ± 1.5-fold, respectively without any significant modification of PCSK9 expression. In addition, fruit extract showed a significant sequestering ability of cholic acid. Leaf butanol extract exerted similar action by inducing the expression of both the LDLR (+3.1 ± 1.6-fold vs control) and PCSK9 (+1.3 ± 0.4-fold vs control). The evaluation of the potential anti-inflammatory effect revealed a significant action of leaf butanol extract with reduced mRNA levels of IL-1β (−28 ± 8 % vs control), IL-6 (−11 ± 1 % vs control) and TNF-α (−43 ± 8 % vs control), while fruit extract did not show any anti-inflammatory activity. Finally, leaf ethyl acetate extract showed a significant antioxidant capacity comparable to ascorbic acid. Taken together, we provided evidence that leaf butanol extract and, more effectively, fruit extract induced the LDLR expression, effect that may explain the previously reported hypocholesterolemic action of okra. In addition, okra’s extracts reduced the expression of pro-inflammatory cytokines from THP1-derived macrophages, an effect that may suggest a vascular protective action of okra.

The effect of Abelmoschus esculentus L. (Okra) extract supplementation on dietary intake, appetite, anthropometric measures, and body composition in patients with diabetic nephropathy

Background: Diabetes is a risk factor for chronic kidney disease because it induces nephropathy. Okra is a rich source of antioxidants, vitamins, minerals, and fibers, of which favorable effects in diabetes have been reported in many animal studies. The present trial aimed to investigate the effect of dried okra extract (DOE) supplementation on anthropometric measures, body composition, appetite, and dietary intake in diabetic nephropathy (DN) patients. Methods: In this triple-blind placebo-controlled randomized clinical trial, 64 DN patients were randomly allocated to receive a 125-mg capsule of DOE (n=32) or placebo (n=32) for 10 weeks. At baseline and endpoint of the trial, anthropometric variables, body composition indices, dietary intake, and appetite scores were evaluated. Results: The results showed that energy (P=0.047, CI: -425.87, -3.25, ES: 0.539) and carbohydrate (P=0.038, CI: -85.64, -2.53, ES: 0.555) intake as well as desire to eat salty food (P=0.023) were reduced in DOE group at the endpoint, compared to the baseline values. However, anthropometric measures, body composition, and appetite score were not significantly different between the two study groups. Conclusion: In conclusion, the present clinical trial showed that DOE could significantly decrease energy intake and carbohydrate consumption in the DN patients. Further clinical trials are needed to determine the effects of this supplement.

Efficacy and safety of Abelmoschus manihot in treating chronic kidney diseases: A multicentre, open-label and single-arm clinical trial

RATIONALE AND OBJECTIVE

The efficacy of Abelmoschus manihot (AM) in treating of chronic kidney disease (CKD) has been confirmed by prior trials. AM is also commonly combined to other medicines among CKD patients in clinic. This trial aimed at evaluating the safety of AM combination application, and further verifying the efficacy of AM in treating various types of CKD.

STUDY DESIGN

A multicentre, prospective, open-label, single-arm trial SETTING AND PARTICIPANTS: Approximately 2000 CKD patients with proteinuria (≥ 150 mg/d), from 105 centres across China INTERVENTIONS: AM was administered to patients three times per day for 24 weeks: the daily dose was based on age (> 12 years old: 2.5 g tid; 6∼12 years old: 1.5 g tid; 2∼6 years old: 1 g tid) OUTCOMES: The efficacy outcomes were the change in 24-hour proteinuria and estimated glomerular filtration rate (eGFR) from baseline to week 24. Safety outcomes included adverse events and laboratory tests.

RESULTS

2054 CKD patients from 105 centres were enrolled in this trial, with 1843 (89.7%) completing the 24-week follow-up. The participants' median age was 44 years old and 44.6% were female. Compared to baseline, 24-hour proteinuria decreased 471 mg (95% confident interval, 367 to 575, p < 0.001) at week 24. eGFR did not change significantly relative to baseline with the mean increase as 1.7 ml/min/1.73 m2 (95% confident interval, -0.3 to 3.7, p = 0.09). 902 (43.9%) participants combined medication to AM during follow-up. The total incidence of adverse events was 12.9%; and the most common adverse events were hyperlipidaemia (4.1%), abnormal liver function (2.3%), upper respiratory infection (1.8%), and hyperglycaemia (1.1%). Combined medications did not change the risk for hyperlipidaemia and upper respiratory infection. The combination application with antiplatelet reagents increased the risk of abnormal liver function, and with calcium channel blockers increased the risk of hyperglycaemia.

LIMITATIONS

Single-arm clinical trial and short observation time CONCLUSION: We have provided safety information of AM on various types of CKD in a large trial, especially when combination to medications most commonly prescribed to CKD patients. AM also showed to decrease proteinuria with stable kidney function during follow up. AM is a promising treatment for CKD patients.

Abelmoschus esculentus subfractions ameliorate hepatic lipogenesis and lipid uptake via regulating dipeptidyl peptidase-4—With improving insulin resistance

Nonalcoholic fatty liver disease (NAFLD) is recognized as the liver component of metabolic syndrome. The regulation of hepatic lipid should be emphasized to prevent accompanying illness. As AMP-activated protein kinase (AMPK) and sterol regulatory element binding protein (SREBP) regulate lipid metabolism, CD36 and fatty acid synthase (FAS) promote lipid uptake and lipogenesis respectively, while acetyl-CoA carboxylase (ACC) is an indicator of negative feedback. The increase of IRS-1 phosphorylation at the residue ser307 (p-ser307-IRS-1) and decrease of p-ser473-Akt (p-Akt) are viewed as the insulin resistance markers, and our previous reports suggested dipeptidyl peptidase-4 (DPP-4) mediates insulin resistance, the crucial factor of metabolic syndrome. Abelmoschus esculentus (AE) fruit is well-known for its antidiabetic utility. We had isolated several AE subfractions by successive steps, and found that F1 and F2 were especially valid in suppressing DPP-4 signaling. Since little is known if AE works on NAFLD, now we first attempt to investigate whether AE is useful to attenuate hepatic lipogenesis and lipid uptake in liver cells, along with improving the metabolic targets. We demonstrated that AE subfractions attenuated the hepatic lipid accumulation induced by free fatty acids. Treatment of AE alleviated FAS and returned the level of p-ser79-ACC (p-ACC). Although F1 was more effective on AMPK, F2 seemed more stable to attenuate SREBP-1. Moreover, as fatty acids stimulated the expression of CD36, F2 showed a superior effect to down-regulate the lipid uptake. Both AE subfractions reduced the generation of ROS, decreased the level of p-ser307-IRS-1, and restored the expression of p-Akt. Moreover, treatment of DPP-4 inhibitor linagliptin revealed that, AE could prevent the hepatic lipogenesis, oxidative burden, and the related insulin resistance via downregulating DPP-4. In conclusion, the present investigation revealed that AE, especially F2, is potential to be developed as adjuvant to prevent NAFLD.

Biological activity and development of functional foods fortified with okra (Abelmoschus esculentus)

The Abelmoschus esculentus plant, better known as okra, is an interesting crop from a nutritional standpoint. The okra plant is native to the African region but can now be found throughout tropical and subtropical areas of the world. This plant, known for its healing abilities, has been used as a traditional medicine to treat several diseases and external ailments, such as wounds or boils. This article reviews the potential health benefits from okra consumption, as well as the bioactive compounds that are suggested to be responsible. Furthermore, the okra plant and its derivatives have been evaluated in the formulation and manufacture of new functional food products. The latest advances in this direction, which includes characterizing the technical properties of functional foods fortified with okra are also presented in this review. A series of bioactive compounds such as flavonoids and catechins have been found in the okra plant, which were associated with numerous biological properties observed in research studies that reported potential anti-diabetic, anti-cancer, anti-hypertensive, and antimicrobial effects, among others, as a result of their consumption. These potential health benefits contribute to the development of new and useful functional foods, with okra (or its derivatives) being used as the highlighted ingredient.

Okra (Abelmoschus esculentus L. Moench) prevents obesity by reducing lipid accumulation and increasing white adipose browning in high-fat diet-fed mice

Anti-obesity effects of OKC in HFD-fed obese mice. Treatment with OKC reduced lipid accumulation and promoted energy expenditure through browning. This was associated with improvements in the hyperglycemia, dyslipidemia, and hepatic steatosis.

Okra (Abelmoschus Esculentus) as a Potential Dietary Medicine with Nutraceutical Importance for Sustainable Health Applications

Recently, there has been a paradigm shift from conventional therapies to relatively safer phytotherapies. This divergence is crucial for the management of various chronic diseases. Okra (Abelmoschus esculentus L.) is a popular vegetable crop with good nutritional significance, along with certain therapeutic values, which makes it a potential candidate in the use of a variety of nutraceuticals. Different parts of the okra fruit (mucilage, seed, and pods) contain certain important bioactive components, which confer its medicinal properties. The phytochemicals of okra have been studied for their potential therapeutic activities on various chronic diseases, such as type-2 diabetes, cardiovascular, and digestive diseases, as well as the antifatigue effect, liver detoxification, antibacterial, and chemo-preventive activities. Moreover, okra mucilage has been widely used in medicinal applications such as a plasma replacement or blood volume expanders. Overall, okra is considered to be an easily available, low-cost vegetable crop with various nutritional values and potential health benefits. Despite several reports about its therapeutic benefits and potential nutraceutical significance, there is a dearth of research on the pharmacokinetics and bioavailability of okra, which has hampered its widespread use in the nutraceutical industry. This review summarizes the available literature on the bioactive composition of okra and its potential nutraceutical significance. It will also provide a platform for further research on the pharmacokinetics and bioavailability of okra for its possible commercial production as a therapeutic agent against various chronic diseases.

Structural Properties, Bioactivities, and Applications of Polysaccharides from Okra [Abelmoschus esculentus (L.) Moench]: A Review

Okra [Abelmoschus esculentus (L.) Moench], as a kind of nutritive vegetable, is rich in flavonoids, polyphenols, polysaccharides, amino acids, and other bioactive substances and has various biological activities. As one of main bioactive components, okra polysaccharides (OPs), mainly comprising pectic polysaccharides, have various biological activities. OPs have been extensively investigated in recent years. Many studies characterized structures of OPs obtained by different extraction methods, which were confirmed to be rhamnogalacturonan-I-type polysaccharides in most cases. OPs have a thick and slimy texture, suggesting that they can be a promising source of texture modifiers for complex food matrices. They have various biological activities, such as antioxidant activity, immunomodulatory activity, hypoglycaemic activity, and improving intestinal function. Therefore, OPs may potentially serve as novel immunomodulators or an adjuvant for diabetic nephropathy. Up to now, there is no specific summary on the research progress of OPs. In this paper, the latest research progress on the extraction, purification, characterization, rheological properties, biological activities, and applications of OPs is reviewed, to provide the reference for the processing and comprehensive utilization of OPs in the future.

Highland Barley Whole Grain (Hordeum vulgare L.) Ameliorates Hyperlipidemia by Modulating Cecal Microbiota, miRNAs, and AMPK Pathways in Leptin Receptor-Deficient db/db Mice

The mechanisms of highland barley whole grain (BWG) with rich phenolics on obese db/db mice were investigated in this study. Oral consumption of BWG reduced food intake, body weight, organ/body weight indexes of liver and fat, levels of serum and hepatic lipids, liver injury, and oxidative stress. Furthermore, BWG recovered the disorder of cecal microbiota by augmenting the Bacteroidetes/Firmicutes ratio and Alistipes abundance and decreasing the abundances of Bacteroides and Desulfovibrionaceae to modulate lipid metabolism-related genes. BWG inhibited fatty acid biosynthesis via upregulating the phosphorylation of AMP-activated protein kinase α, while downregulating sterol regulatory element binding protein-1c, fatty acid synthase (FAS), and stearoyl-CoA desaturase 1 levels. BWG also significantly downregulated miRNA-122, miRNA-33, miRNA-34a, and miRNA-206 levels. Accordingly, BWG exhibited hypolipidemic potential through modulating cecal microbiota, AMPK/SREBP-1c/FAS pathway, and related miRNAs, triggering the alleviation of dyslipidemia. These findings suggested BWG as an effective candidate to ameliorate the symptoms of hyperlipidemia.

Effect of Abelmoschus esculentus (okra) on metabolic syndrome: A review

Metabolic syndrome is a disorder characterized by dyslipidemia, insulin resistance, abdominal fat, high blood pressure, hypertriglyceridemia, and diminished high density lipoprotein cholesterol. Okra (Abelmoschus esculentus L.), routinely called lady's finger, has belonged to the Malvaceae family. Okra is considered as a valuable crop due to the multiple functions of its leaves, buds, flowers, pods, stems, and seeds in traditional and modern medicines. Several bioactive components are presented in different parts of okra including polyphenolic compounds especially oligomeric catechins and flavonol derivatives such as quercetin. The antioxidant, anti-inflammatory, anticancer, immunomodulatory, gastroprotective, neuroprotective, lipid lowering, and antidiabetic effects of okra have been established. Although different in vivo and in vitro studies revealed that okra has an ability to overcome metabolic syndrome symptoms, the lack of clinical studies is notable. So, further clinical trials should be accomplished to confirm the role of okra in metabolic syndrome. The aims of this review are to gather different studies regarding the potential efficacy of okra in metabolic syndrome.

The central bacterial community in Pericarpium Citri Reticulatae 'Chachiensis'

The dried and aged pericarps of Citri Reticulatae are condiments and medicinal products in southeast and eastern Asia for hundreds of years, among which Pericarpium Citri Reticulatae 'Chachiensis' (PCR-C) is the premium one with obvious health benefits. In order to explore the microbiota in PCR-C and their relationship with the chemical components during aging, culture-independent methods were applied to investigate PCR-C microbiota for the first time. Here in different PCR-C samples, 16S rRNA gene amplicon sequencing revealed common central bacterial community, which were absent or only accounted for small proportion in fresh pericarps or jute bag controls. Bacillus and Lactococcus were the top two dominant genera in PCR-C with acidic pH (4.06-4.51) and low moisture (11.48%-19.13%). Several OTUs were found to closely relate with specific compositions in essential oils and phenolics, such as d-limonene and nobiletin, which contributed to PCR-C flavor and quality. As the first study to reveal the central bacterial communities in PCR-C, it provides new insights to improve the quality and aging process of traditional Pericarpium Citri Reticulatae, and lays foundation for functional characterization of the microbes within.

Double-Blind, Randomized, Three-Armed, Placebo-Controlled, Clinical Investigation to Evaluate the Benefit and Tolerability of Two Dosages of IQP-AE-103 in Reducing Body Weight in Overweight and Moderately Obese Subjects

Objective

This study was performed to determine the efficacy and tolerability/safety of IQP-AE-103 on body weight reduction in overweight to moderately obese adults.

Methods

A double-blind, randomized, placebo-controlled trial involved one hundred and eight subjects (BMI between 25 and 35 kg/m2) that were randomly assigned to either the low-dose or the high-dose IQP-AE-103 group, or the placebo group. Following a 2-week run-in period, subjects received two capsules of investigational product after three daily main meals for 12 weeks. Subjects were instructed to maintain a nutritionally balanced hypocaloric diet according to the individual's energy requirement. Body weight, body fat, and waist and hip circumference were measured at baseline, and after 2, 4, 8, and 12 weeks. Subjects also rated their feelings of hunger and fullness using visual analogue scales, and food craving on a 5-point scale at the same time intervals. Blood samplings for safety laboratory parameters were taken before and at the end of the study.

Results

After 12 weeks of intake, the high-dose IQP-AE-103 group had a significantly greater weight loss compared with the placebo (5.03 ± 2.50 kg vs. 0.98 ± 2.06 kg, respectively; p < 0.001) and the low-dose group (3.01 ± 2.19 kg; p=0.001). The high-dose group experienced a decrease in body fat of 3.15 ± 2.41 kg compared with a decrease of 0.23 ± 2.74 kg for the placebo group (p < 0.001). High-dose IQP-AE-103 also decreased the feeling of hunger in 66% subjects. A beneficial effect of IQP-AE-103 on the lipid metabolism was also demonstrated in the subgroup of subjects with baseline total cholesterol levels above 6.2 mmol/L. No side effects related to the intake of IQP-AE-103 were reported.

Conclusions

These findings indicate that IQP-AE-103 could be an effective and safe weight loss intervention. This trial is registered with NCT03058367.

Antidepressant activity of an aqueous extract from okra seeds

Faced with the increasing incidence of major depression disorder (MDD) and the unsatisfactory effect of current drugs, there has been growing attention on the relation between dietary supplements and MDD prevention. In this research, the antidepressant activity of okra seed extract (OSE) was evaluated with behavioral tests including an open field test, tail suspension test (TST), forced-swimming test (FST) and novelty suppressed feeding test (NSFT) for sub-chronic treatment and chronic sleep-interruption (CSI) animal models. The chemical constituents of OSE were identified by using UPLC-DAD/Q-TOF MS. To investigate the mechanism, the prefrontal cortex and hippocampus were collected to determine neurotransmitters, total antioxidant capacity (T-AOC), superoxide dismutase (SOD) and malondialdehyde (MDA). Blood serum was prepared for the determination of corticosterone (CORT) and adrenocorticotropic hormone (ACTH). Results demonstrated that OSE possessed an antidepressant effect in both sub-chronic treatment and CSI animal models through suppressing the hyperactivation of the hypothalamic-pituitary-adrenal (HPA) axis, alleviating oxidative stress and regulating neurotransmitter levels in the hippocampus and frontal cortex. Besides, chemical analysis based on the UPLC-DAD/ESI-Q-TOF MS approach showed that OSE mainly contained catechin and quercetin derivatives. The present study provided a scientific basis for developing okra seeds to be a dietary supplement for MDD prevention.

Okra (Abelmoscus esculentus) Improved Islets Structure, and Down-Regulated PPARs Gene Expression in Pancreas of High-Fat Diet and Streptozotocin-Induced Diabetic Rats

Objective

Okra (Abelmoschus esculentus) is a tropical vegetable that is rich in carbohydrates, fibers, proteins and natural antioxidants. The aim of the present study was to evaluate the effects of Okra powder on pancreatic islets and its action on the expression of PPAR-γ and PPAR-α genes in pancreas of high-fat diet (HFD) and streptozotocin- induced diabetic rats.

Materials and Methods

In this experimental study, diabetes was induced by feeding HFD (60% fat) for 30 days followed by an injection of streptozotocin (STZ, 35 mg/kg). Okra powder (200 mg/kg) was given orally for 30 days after diabetes induction. At the end of the experiment, pancreas tissues were removed and stained by haematoxylin and Eozine and aldehyde fuchsin for determination of the number of β-cells in pancreatic islets. Fasting blood sugar (FBS), Triglycerides (TG), cholesterol, high density lipoprotein (HDL), low density lipoprotein (LDL), and insulin levels were measured in serum. Moreover, PPAR-γ and PPAR-α mRNAs expression were measured in pancreas using real time polymerase chain reaction (PCR) analysis.

Results

Okra supplementation significantly decreased the elevated levels of FBS, total cholesterol, and TG and attenuated homeostasis model assessment of basal insulin resistance (HOMA-IR) index in diabetic rats. The expression levels of PPAR-γ and PPAR-α genes that were elevated in diabetic rats, attenuated in okra-treated rats (P<0.05). Furthermore, okra improved the histological damages of pancreas including vacuolization and decreased β-cells mass, in diabetic rats.

Conclusion

Our findings confirmed the potential anti-hyperglycemic and hypolipidemic effects of Okra. These changes were associated with reduced pancreatic tissue damage. Down-regulation of PPARs genes in the pancreas of diabetic rats after treatment with okra, demonstrates that okra may improve glucose homeostasis and β-cells impairment in diabetes through a PPAR-dependent mechanism.

Averrhoa carambolafree phenolic extract ameliorates nonalcoholic hepatic steatosis by modulating mircoRNA-34a, mircoRNA-33 and AMPK pathways in leptin receptor-deficient db/db mice

Averrhoa carambolafree phenolic extract ameliorates hepatic steatosis by modulating mircoRNA-34a, mircoRNA-33 and AMPK signaling.

Antioxidant and Anti-Fatigue Constituents of Okra

Okra (Abelmoschus esculentus (L.) Moench), a healthy vegetable, is widely spread in tropical and subtropical areas. Previous studies have proven that okra pods possess anti-fatigue activity, and the aim of this research is to clarify the anti-fatigue constituents. To achieve this, we divided okra pods (OPD) into seeds (OSD) and skins (OSK), and compared the contents of total polysaccharides, total polyphenols, total flavonoids, isoquercitrin, and quercetin-3-O-gentiobiose and the antioxidant activity in vitro and anti-fatigue activity in vivo between OSD and OSK. The contents of total polyphenols and total polysaccharides were 29.5% and 14.8% in OSD and 1.25% and 43.1% in OSK, respectively. Total flavonoids, isoquercitrin and quercetin-3-O-gentiobiose (5.35%, 2.067% and 2.741%, respectively) were only detected in OSD. Antioxidant assays, including 1-diphenyl-2-picrylhydrazyl (DPPH) scavenging, ferric reducing antioxidant power (FRAP) and reducing power test, and weight-loaded swimming test showed OSD possessed significant antioxidant and anti-fatigue effects. Moreover, biochemical determination revealed that that anti-fatigue activity of OSD is caused by reducing the levels of blood lactic acid (BLA) and urea nitrogen (BUN), enhancing hepatic glycogen storage and promoting antioxidant ability by lowering malondialdehyde (MDA) level and increasing superoxide dismutase (SOD) and glutathione peroxidase (GSH-PX) levels. These results proved okra seeds were the anti-fatigue part of okra pods and polyphenols and flavonoids were active constituents.

Preliminary probiotic and technological characterization of Pediococcus pentosaceus strain KID7 and in vivo assessment of its cholesterol-lowering activity

The study was aimed to characterize the probiotic properties of a Pediococcus pentosaceus strain, KID7, by in vitro and in vivo studies. The strain possessed tolerance to oro-gastrointestinal transit, adherence to the Caco-2 cell line, and antimicrobial activity. KID7 exhibited bile salt hydrolase activity and cholesterol-lowering activity, in vitro. In vivo cholesterol-lowering activity of KID7 was studied using atherogenic diet-fed hypercholesterolemic mice. The experimental animals (C57BL/6J mice) were divided into 4 groups viz., normal diet-fed group (NCD), atherogenic diet-fed group (HCD), atherogenic diet- and KID7-fed group (HCD-KID7), and atherogenic diet- and Lactobacillus acidophilus ATCC 43121-fed group (HCD-L.ac) as positive control. Serum total cholesterol (T-CHO) level was significantly decreased by 19.8% in the HCD-KID7 group (P < 0.05), but not in the HCD-L.ac group compared with the HCD group. LDL cholesterol levels in both HCD-KID7 and HCD-L.ac groups were decreased by 35.5 and 38.7%, respectively, compared with HCD group (both, P < 0.05). Glutamyl pyruvic transaminase (GPT) level was significantly lower in the HCD-KID7 and HCD-L.ac groups compared to HCD group and was equivalent to that of the NCD group. Liver T-CHO levels in the HCD-KID7 group were reduced significantly compared with the HCD group (P < 0.05) but not in the HCD-L.ac group. Analysis of expression of genes associated with lipid metabolism in liver showed that low-density lipoprotein receptor (LDLR), cholesterol-7α-hydroxylase (CYP7A1) and apolipoprotein E (APOE) mRNA expression was significantly increase in the HCD-KID7 group compared to the HCD group. Furthermore, KID7 exhibited desired viability under freeze-drying and subsequent storage conditions with a combination of skim milk and galactomannan. P. pentosaceus KID7 could be a potential probiotic strain, which can be used to develop cholesterol-lowering functional food after appropriate human clinical trials.

Long-term supplementation of umbelliferone and 4-methylumbelliferone alleviates high-fat diet induced hypertriglyceridemia and hyperglycemia in mice

This study was conducted to evaluate the effects of umbelliferone (UF) and 4-methylumbelliferone (mUF) on high-fat diet-induced hypertriglyceridemia and hyperglycemia in mice. The mice were assigned to normal control, high-fat control, and high-fat with UF or mUF groups. For UF or mUF groups, the high-fat diet was supplemented with UF or mUF at 0.02% (wt/wt) for 12weeks. Both UF and mUF significantly decreased plasma triglyceride, free fatty acid and glucose levels, adipocyte size, white adipose tissue weights, and hepatic phosphatidate phosphohydrolase activity and significantly increased plasma adiponectin levels and hepatic fatty acid β-oxidation activity compared with the high-fat control group. UF and mUF improved glucose intolerance and hepatic steatosis in the high-fat fed mice. Long-term high-fat diet intake induced an increase in hepatic CYP2E1 activity and lipid peroxide and cytosolic hydrogen peroxide contents and suppressed superoxide dismutase and glutathione peroxidase activities, which were reversed by UF and mUF supplementation. These results indicate that UF and mUF similarly ameliorate hypertriglyceridemia and hyperglycemia partly by modulating hepatic lipid metabolism and the antioxidant defense system along with increasing adiponectin levels.

Anti-hyperlipidemic activity of Rhynchosia nulubilis seeds pickled with brown rice vinegar in mice fed a high-fat diet

The abnormal content of blood lipids often results in metabolic diseases, such as hyperlipidemia and obesity. Many agents, including natural sources from traditional food, have been developed to regulate the blood lipid contents. In this study, we examined the anti-hyperlipidemic activity of Rhynchosia nulubilis seeds pickled with brown rice vinegar (RNSpBRV), a Korean traditional pickled soybean food. Since RNSpBRV is made of R. nulubilis seeds (RNS) soaked in brown rice vinegar (BRV), we compared the anti-adipogenic activity between RNS, BRV and solid fraction of RNSpBRV (SF-RNSpBRV), liquid fraction of RNSpBRV (LF-RNSpBRV). For this, the inhibitory effect of lipid accumulation in 3T3-L1 adipocyte was checked by adding methanol extracts of mixed RNS and BRV, LF-RNSpBRV, and SF-RNSpBRV. The addition of each methanol extract up to 1 mg/ml showed no cytotoxicity on 3T3-L1 adipocyte, and approximately 20% of the lipid droplet formation was suppressed with the methanol extract of BRL or SF-RNSpBRV. The highest suppression (42.1%) was achieved with LF-RNSpBRV. In addition, mice fed a high fat diet (HFD) supplemented with 5% RNSpBRV powder led to increased high density lipoprotein (HDL) cholesterol and lower blood glucose, triglyceride, and total cholesterol compared to mice fed with a HFD diet only. Interestingly, the size of the epididymis cells gradually decreased in HFD + 1% RNSpBRV- and HFD + 5% RNSpBRV-fed mice if compared those of HFD-fed mice. Taken together, these results provide evidence that RNSpBRV has a regulatory role in lipid metabolism that is related to hyperlipidemia.