A Randomized, Double-Blind, Placebo Controlled Trial to Determine the Effectiveness a Polyphenolic Extract (Hibiscus sabdariffa and Lippia citriodora) in the Reduction of Body Fat Mass in Healthy Subjects

Roselle Extract Ameliorates Abnormal Glucolipid Metabolism and Gut Microbiota in Obese Mice Fed With High-Fat Diet

Roselle extract (RE) is rich in anthocyanins and chlorogenic acids. This study investigated the health-promoting effects of RE on lipid metabolism, oxidative stress, glycometabolism, and gut microbiota in obese mice fed a high-fat diet (HFD). The obesity model was induced by feeding mice a HFD, with RE supplementation added to their drinking water at concentrations of 2 and 4 mg/mL for 12 weeks. RE significantly reduced body weight gain and fat accumulation compared to the control group, alleviated hepatic steatosis, and improved insulin sensitivity. Additionally, RE restored antioxidative enzyme activities such as SOD and GSH-PX while reducing MDA levels. Transcriptomic analysis of the liver was performed to evaluate gene expression related to lipid metabolism, particularly in the PPAR signaling pathway. Gut microbiota analysis showed that RE increased beneficial bacteria and reduced the Firmicutes-to-Bacteroidetes ratio, suggesting an improvement in gut dysbiosis caused by the HFD. RE enhanced lipid metabolism, reduced oxidative stress, and improved insulin sensitivity in obese mice, potentially through modulation of the PPAR signaling pathway and gut microbiota, suggesting its potential as a therapeutic candidate for obesity-related metabolic disorders.

Clinical effects of Hibiscus sabdariffa Linn. on obesity treatment: A systematic review and meta-analysis of randomized controlled trials

INTRODUCTION

Obesity is associated with many chronic non-communicable diseases, including hypertension, diabetes, cardiovascular and cerebrovascular diseases, cancer, gallbladder disease, bone and joint disorders, skin diseases, fatty liver disease, etc. (Wharton et al., 2020)1 The recent report revealed that overweight and obesity were prevalent in 60 % of the adult population. Several studies have been published to determine the effect of Hibiscus sabdariffa Linn. on obesity treatment, but the findings are still inconclusive. The purpose of this study was to determine the efficacy and safety of H. sabdariffa Linn in the treatment of obesity.

METHODS

We searched PubMed, EMBASE, and CENTRAL from inception to February 2024. Randomized controlled trials (RCTs) were included if they explored the effect of H. sabdariffa on one of the following outcomes: body weight, body mass index (BMI), waist circumference, and waist-to-hip ratio. A random-effects model was used to meta-analyze the data. I2 was used to quantify statistical heterogeneity among the included RCTs. PROSPERO registered protocol: CRD42023408880.

RESULTS

A total of six RCTs with 339 participants were included. Four trials used H. sabdariffa extract in capsules as the intervention of interest compared to placebo, while the other two trials used H. sabdariffa tea compared to black or green tea. Our meta-analyses showed that the mean difference in weight reduction between H. sabdariffa and control was - 0.27 kg (95 % confidence interval (CI); - 1.98 to 1.42, I2 = 0.0 %). The mean differences for BMI and waist circumference reduction were - 0.06 kg/m2 (95 % CI; - 0.58 to 0.47, I2 = 0.0 %) and - 0.20 centimeters (95 % CI; - 2.06 to 1.66, I2 = 0.00 %). No safety concerns were reported in the included studies.

CONCLUSION

Our study did not show a clinical benefit of H. sabdariffa extract in obesity treatment. However, further high-quality RCTs with a longer treatment duration and a standard dose are still warranted.

Medicinal herbs, especially Hibiscus sabdariffa, inhibit oral pathogenic bacteria

OBJECTIVES

Medicinal herbs are plants with potential medicinal and health benefits. In recent years, they are being increasingly used as a treatment alternative owing to their effectiveness against various diseases. In this study, we investigated the inhibitory effects of 15 medicinal herbs on causative bacteria for dental caries and periodontal disease.

METHODS

This study evaluated the effects of the extracts of 15 medicinal herbs on growth and biofilm formation in five oral pathogenic bacterial strains. The herbs were processed into extracts, and bacterial strains were cultured. Then, bacterial growth and biofilm formation were assessed using various methods. Finally, the extract of the herb Hibiscus sabdariffa (hibiscus) was analyzed using high-performance liquid chromatography.

RESULTS

Incubation of bacteria with the herbal extracts showed that hibiscus exerted a significant inhibitory effect on all the oral pathogenic bacterial strains evaluated in this study. In addition, the pigment delphinidin-3-sambubioside, which is found in hibiscus extract, was identified as a particularly important inhibitory component.

CONCLUSIONS

These results lay the ground work for the potential development of novel therapeutic or preventive agents against dental caries and periodontal disease, two major oral diseases.

Hibiscus sabdariffa Linn. Extract Increases the mRNA Expression of the Arcuate Nucleus Leptin Receptor and is Predicted in silico as an Anti-obesity Agent

BACKGROUND

Leptin is predominant in regulating body weight by stimulating energy expenditure through its neuronal action in the brain. Moreover, it is projected to adipose tissue and induces adipocyte browning by activating the β3-adrenergic receptor (β3AR). However, the expression of leptin receptor (Lep-R) and β3AR in people with obesity is downregulated.

AIM

We hypothesized that Hibiscus sabdariffa Linn. extract (HSE) would increase hypothalamus arcuate nucleus (ARC) Lep-R and white adipose tissue (WAT) β3AR mRNA expression in DIO rats. This study also analyzed the potency of H. sabdariffa bioactive compounds as activators of Lep-R and β3AR by an in-silico experiment.

METHODS

Twenty-four male Sprague-Dawley rats were divided into four groups: Control (standard food), DIO (high-fat diet), DIO-Hib200 (HFD+HSE 200 mg/kg BW), and DIO-Hib400 (HFD+HSE400 mg/kg BW). HSE was administered orally for five weeks, once a day.

RESULTS

HSE administration significantly (p <0,05) increased the ARC Lep-R expression. The Lee index significantly decreased to the normal range (≤ 310) with p <0,001 for DIO-Hib200 and p <0,01 for DIO-Hib400. Among 39 bioactive compounds, 5-O-caffeoyl shikimic acid exhibited high free binding scores (-8,63) for Lep-R, and myricetin_3_arabinogalactoside had high free binding scores (-9,39) for β3AR. These binding predictions could activate Lep-R and β3AR.

CONCLUSION

This study highlights that HSE could be a potential therapeutic target for obesity by increasing LepR mRNA and leptin sensitivity, enhancing energy expenditure, and reducing obesity.

Effect of the Combination of Hibiscus sabdariffa in Combination with Other Plant Extracts in the Prevention of Metabolic Syndrome: A Systematic Review and Meta-Analysis

Metabolic syndrome is a complex and multifactorial disorder associated with increased risk of cardiovascular disease and type 2 diabetes, exacerbated by a sedentary lifestyle and situations such as the COVID-19 pandemic. Recent studies have shown that consumption of fruits and vegetables high in polyphenols has a protective effect, reducing cardiovascular risk. Hibiscus sabdariffa (HS) in combination with other plant extracts has recently attracted scientists' attention due to its potential use in the treatment of metabolic syndrome. This systematic review and meta-analysis examines the effects of HS in combination with other plant extracts on the prevention of metabolic syndrome, exploring their synergistic effects and potential as therapeutic agents. For this purpose, a systematic search of randomized clinical trials (RCTs) was conducted in four different databases and the data obtained were then used for a meta-analysis. Initially, the titles and abstracts of 1368 studies were read. From these, 16 studies were examined closely for their eligibility, and finally, seven RCTs with 332 participants were included in both the meta-analysis and the qualitative analysis. Our results show that HS in combination with other plant extracts improved anthropometric parameters, blood pressure, and lipid profile (low density lipoprotein cholesterol and total cholesterol) compared to a placebo control group. It is important to note that although this meta-analysis suggests that HS in combination with other plant extracts may have a beneficial effect on cardiovascular parameters, further research is needed to determine the optimal dose and intake duration.

Short-term effects of a maqui-based nutraceutical on heart rate variability, psycho-physical resilience and on a few metabolic biomarkers: a randomized controlled study

OBJECTIVES

To assess the immediate/short-term outcomes of a maqui berry-based nutraceutical (MBN) supplementation on the autonomic nervous system (ANS), resilience level, metabolism and body composition.

METHODS

A randomized controlled single-blind study was performed on healthy subjects. Throughout 30 days, one group took 1,000 mg/day of an MBN (Maqui 500^®), the control group had no supplementation. On day 0 (T0) and 30 (T3) all subjects performed blood tests, bioimpedance spectroscopy and questionnaires for resilience, perceived stress and short-form 12 (SF12). At T0, 75' after T0 (T1), on day 7 and at T3 the subjects underwent biometric parameter measurement and heart rate variability (HRV) test to investigate psycho-physical resilience.

RESULTS

Fifteen subjects per group were included; abnormal seasonal high temperatures altered individuals' lifestyle and nutrition, influencing the trial's outcomes. Biometric parameters, blood pressure, oxygen saturation and blood tests did not differ between T0 and T3 in both groups. In the MBN group the HRV analysis showed a significant increase of ANS coordination (p=0.05), parasympathetic activity at 75', very low frequencies and total power at T3, whereas these parameters decreased in the control group. SF12 mental score improved in the maqui group (p=0.02); the questionnaire-based outcomes showed no further variations. In the control subjects bioimpedance showed an increase of resistance and fat mass, with decreased total body water and lean mass (p=n.s.).

CONCLUSIONS

The maqui-based nutraceutical improved HRV, namely ANS activation/coordination, and SF12 mental component. Blood tests and bioimpedance/biometric parameters mildly varied. The elapsed hot weather likely biased many investigated variables.

Physiological Effects and Human Health Benefits of Hibiscus sabdariffa: A Review of Clinical Trials

Hibiscus sabdariffa Linn. Malvaceae (HS) is characterized by its edible calyxes. The HS calyxes are widely used for cosmetic, food, and medicinal applications. According to ethnobotanical evidence, decoction, infusion, or maceration extracts from HS calyxes have been used in folk medicine to treat many ailments. Moreover, several in vitro and in vivo studies have demonstrated the pharmacological properties and potential human health benefits of HS consumption. On the other hand, the evaluation of the physiological effects and health benefits of HS in clinical studies is most challenging. Therefore, this narrative review summarizes and discusses the physiological effects and health benefits of HS calyxes reported in clinical trials. Preparations obtained from HS calyxes (extracts, infusions, decoction, teas, beverages, capsules, and pills) are used as non-pharmacological therapies to prevent/control diverse chronic non-communicable diseases. The most-reported HS health benefits are its antihypertensive, antidyslipidemic, hypoglycemic, body fat mass reduction, nephroprotective, antianemic, antioxidant, anti-inflammatory, and anti-xerostomic activities; these effects are associated with the phytochemicals found in HS. Moreover, no adverse effects were reported during the clinical trials. However, clinical studies exhibited some limitations; thus, further studies are required to validate the clinical efficacy of HS in large-scale studies with higher doses and a good experimental design

Effectiveness of a polyphenolic extract (Lippia citriodora and Hibiscus sabdariffa) on appetite regulation in overweight and obese grade I population: an 8-week randomized, double-blind, cross-over, placebo-controlled trial

INTRODUCTION

Polyphenols have shown capacity to improve appetite sensation, leading to enhanced control of body weight. However, despite being related with hunger-related hormones, metabolic and mechanism are not well known.

METHODS

The effectiveness of a nutraceutical composed of extract to Lippia citriodora and Hibiscus sabdarrifa (Lc-Hs) for controlling satiety and hunger was analyzed in a cross-over, placebo-controlled (Pla) clinical intervention. The study was divided in two 60-day periods separated by 30-day length wash-out period. At the end of each period, overweight and obese subjects (n = 33; age = 33.76 ± 12.23; BMI = 28.20 kg/m2 ± 2.47; fat mass 30.65 ± 8.39%; both sexes were proposed to eat an ad-libitum meal. Meanwhile, appetite sensation was determined by visual analog scales at different times. Moreover, blood extraction was performed to determine biochemical parameters (lipid and glucidic profile and safety parameters) and to evaluate hunger-related hormones (insulin, leptin, ghrelin, adiponectin, GLP-1 and peptide YY).

RESULTS

A decrease in appetite sensation was observed in Lc-Hs treatment, showing higher satiety quotient (Pla = 3.36 ± 2.33%mm/kcal; Lc-Hs = 5.53 ± 2.91%mm/kcal; p < 0.0001). Area under the curve was higher in Pla compared to Lc-Hs during the test, from baseline to minute 240 (240 (Pla 9136.65 ± 2261.46% x min-1; Lc-Hs 8279.73 ± 2745.71% x min-1; p < 0.014). Energy consumption was lower for subjects treated with Lc-Hs (774.44 ± 247.77 kcal) compared to those treated with Pla (849.52 ± 246.54 kcal) (p < 0.004). Leptin values varied from baseline (Pla 12.36 ± 1.98 ng/mL; Lc-Hs 13.13 ± 1.99 ng/mL) to the end of the study (Pla 12.60 ± 2.02 ng/mL; Lc-Hs 12.06 ± 2.05 ng/mL; p < 0.047). GLP-1 values varied (p < 0.001) in Lc-Hs treatment from baseline (4.34 ± 0.49 ng/mL) to the end of the study (3.23 ± 0.52 ng/mL).

CONCLUSION

The supplementation with the Lc-Hs extract decreases appetite sensation in overweight and obese population, reducing calorie intake after an ad-libitum meal. Due to variation on hunger-related hormones and the relationship between satiety feeling, it would be interesting to develop future research focused on the variation of the hormones themselves.

New Insights in (Poly)phenolic Compounds: From Dietary Sources to Health Evidence

Nowadays, there is a gap between the theoretical bioactivity of (poly)phenols and their real influence in health, once ingested. Due to this, new studies, including in vitro and in vivo models that allow for exploring bioaccessibility, bioavailability, and bioactivity, need to be developed to understand the actual importance of consuming functional foods, rich in these plant secondary metabolites. Moreover, current new strategies need to be developed to enhance the content of these foods, as well as setting up new formulations rich in bioaccessible and bioavailable compounds. Altogether, it could give a new horizon in therapy, expanding the use of these natural functional compounds, ingredients, and foods in the clinical frame, reducing the use of synthetic drugs. As a result, the joint contribution of multidisciplinary experts from the food science, health, and nutrition areas, together with the industrial sector, would help to reach these objectives. Taking this into account, diverse studies have been included in this study, which comprises different strategies to approach these objectives from different, complementary, points of view, ranging from the enrichment of by-products in bioactive compounds, through different agricultural techniques, to the assimilation of these compounds by the human body, both in vitro and in vivo, as well as by clinical studies.