Quantification of the polyphenolic fraction and in vitro antioxidant and in vivo anti-hyperlipemic activities of Hibiscus sabdariffa aqueous extract

Combining Different Natural Plant Extracts to Stabilize the Antioxidative Activity of Dragon's Blood

Dragon's blood () is a traditional Chinese medicine known for its wound hemostasis, blood circulation, and stasis properties. Recently, it has also been utilized in cosmetics, though its antioxidant capacity remains unclear. This study aims to stabilize the bioactivity of dragon's blood using various plant extracts. We evaluated single plant extracts and their combinations to identify the conditions that maintained the antioxidant capacity of dragon's blood the longest. Selected plants included Hibiscus sabdariffa, Clitoria ternatea, Hylocereus sp., Pandanus amaryllifolius, and Camellia sinensis. We used two sources of dragon's blood: Daemonorops draco and Dracaena cochinchinensis. Extraction conditions were optimized and antioxidant activity was assessed using the free radical scavenging ability of 1,1-diphenyl-2-picrylhydrazyl (DPPH), total anthocyanin concentration (TAC), total polyphenol content (TPC), the free radical scavenging activity of ABTS, and a ferric reducing antioxidant power (FRAP) assay. The results showed that all plant extracts exhibited high antioxidant capacity. Clitoria ternatea had the highest DPPH scavenging ability at 93.81%, with the best combination being green tea and Daemonorops draco at 92.57%. Clitoria ternatea had the highest TPC at 9921 mg GAE/100 g, with the best combination (green tea and Dracaena cochinchinensis) at 10500 mg GAE/100 g. ABTS activity was highest for green tea at 98.3%, with the best combination (Clitoria ternatea and Daemonorops draco) at 93.29%. The FRAP assay showed that green tea had the highest electron-donating potential at 3.85 mg/mL, with the best combination (Daemonorops draco and Dracaena cochinchinensis) at 3.71 mg/mL. This study advances our understanding of the antioxidant properties of these plants and the traditional Chinese medicine dragon's blood, enhancing the efficacy of dragon's blood in skincare and cosmetics. Moreover, the application of these extracts could rejuvenate local agriculture, impacting the skincare, cosmetics, and sustainable agriculture sectors.

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.

Determination of anthocyanins, organic acids, and phenolic acids in hibiscus market products using LC/UV/MS

Hibiscus sabdariffa has gained increasing attention from consumers as a natural, healthy food ingredient, leading to a myriad of available products, yet there is a lack of understanding of the quality and chemical diversity among commercially available hibiscus products. Here, we conducted a survey on the chemistry of 29 hibiscus products (calyces, beverages, and extracts). UHPLC-DAD and UHPLC-QQQ/MS methods with high sensitivity and selectivity were developed to evaluate the chemical profiles pertaining to the sensory attributes (color and taste). Two major anthocyanins (delphinidin-3-sambubioside and cyanindin-3-sambubioside), eight organic acids, and 23 phenolic acids were identified and quantified in hibiscus market products. The results showed that hibiscus samples contained < 0.001-2.372% of total anthocyanins, 0.073-78.002% of total organic acids, and 0.001-1.041% of total phenolic acids, and demonstrated significant variations in market products. This is the first time that an in-depth organic acid profiling was conducted on hibiscus products using UHPLC-QQQ/MS. This method can also be extended to chemical profiling, sensory analysis, quality control, authentication, and standardization of other natural products.

Exploring the Health Benefits and Therapeutic Potential of Roselle (Hibiscus sabdariffa) in Human Studies: A Comprehensive Review

Hibiscus sabdariffa (HS), commonly known as Roselle, has a rich history of traditional uses and is recognized for its diverse pharmacological properties, including antihypertensive, anti-inflammatory, antimicrobial, and more. This comprehensive review synthesizes the existing literature on the health benefits associated with the consumption of HS or its ingredients. Key areas of focus include metabolic health, blood sugar, and lipid regulation, wherein studies have reported varying effects on parameters such as fasting blood glucose, insulin sensitivity, and lipid profiles. Furthermore, Roselle exhibits anti-inflammatory properties, as evidenced by its impact on inflammatory markers such as MCP-1 and TNF-α. Additionally, HS extracts have shown notable antibacterial efficacy against various strains, with a potential role in urinary tract infection management. Studies also suggest potential benefits for renal function, with improvements in markers such as blood urea nitrogen and creatinine levels. In this article, we aim to review the existing literature on the health benefits of HS.

Plant compounds for obesity treatment through neuroendocrine regulation of hunger: A systematic review

BACKGROUND

Food intake behavior is influenced by both physiological and psychological complex processes, such as appetite, satiety, and hunger. The neuroendocrine regulation of food intake integrates short- and long-term acting signals that modulate the moment of intake and energy storage/expenditure, respectively. These signals are classified as orexigenic, those that activate anabolic pathways and the desire of eating, and anorexigenic, those that activate the catabolic pathways and a sensation of satiety. Appetite control by natural vegetal compounds is an intense area of research and new pharmacological interventions have been emerging based on an understanding of appetite regulation pathways. Several validated psychometric tools are used to assess the efficacy of these plant ingredients. However, these data are not conclusive if they are not complemented with physiological parameters, such as anthropometric evaluations (body weight and composition) and the analysis of hormones related to adipose tissue and appetite in blood.

PURPOSE

The purpose of this manuscript is the critical analysis of the plant compounds studied to date in the literature with potential for the neuroendocrine regulation of hunger in order to determine if the use of phytochemicals for the treatment of obesity constitutes an effective and/or promising therapeutic tool.

METHODS

Relevant information on neuroendocrine regulation of hunger and satiety for the treatment of obesity by plant compounds up to 2022 in English and/or Spanish were derived from online databases using the PubMed search engine and Google Scholar with relevant keywords and operators.

RESULTS

Accordingly, the comparison performed in this review between previous studies showed a high degree of experimental heterogeneity. Among the studies reviewed here, only a few of them establish comprehensively a potential correlation between the effect of the ingredient on hunger or satiety, body changes and a physiological response.

CONCLUSIONS

More systematic clinical studies are required in future research. The first approach should be to decode the pattern of circulating hormones regulating hunger, satiety, and appetite in overweight/obese subjects. Thereafter, studies should correlate brain connectivity at the level of the hypothalamus, gut and adipose tissue with the hormone patterns modulating appetite and satiety. Extracts whose mode of action have been well characterized and that are safe, can be used clinically to perform a moderate, but continuous, caloric restriction in overweight patients to lose weight excess into a controlled protocol.

Agronomic Behavior of Mexican Roselle Cultivars Produced under Protected Agricultural Conditions

Growth dynamics and morphological traits are used to define the characteristics of roselle cultivars Hibiscus sabdariffa. The morpho-agronomic variability of plants was evaluated, as well as the concentration of macro and micronutrients in leaves of Mexican roselle cultivars in hydroponic and greenhouse conditions. The following roselle cultivars were studied: 'Cruza Negra', 'UAN16-2', 'Criolla Huajicori', 'UAN 6 Puga', 'UAN 25-1' and '4Q4'. The relative growth rate of the crops was fitted to a positive cubic, negative quadratic and positive linear model, whereas stem diameter, fitted to a linear model, had a negative quadratic response. The foliar surface of the cultivars '4Q4', 'Cruza Negra', 'UAN16-2' and 'Criolla Huajicori' was directly related to the size of the flower, the calyx and the corolla. Nitrogen and potassium are the elements that showed the highest concentration in the cultivars Criolla Huajicori and Cruza Negra, while in the other four cultivars the highest concentrations of minerals in the leaf were nitrogen and calcium. The leaves of cultivar 4Q4 provided the greatest amount of minerals, with 83,565 mg kg^-1 dry basis. Criolla Huajicori was the cultivar that exhibited the tallest height, the most productive branches and the greatest calyx number per plant; however, Cruza Negra exhibited the highest yield by having the longest calyx.

Polyphenol characterization of the aqueous extract from Hubertia ambavilla L. (Asteraceae) by HPLC-DAD-ESI-MSn and assessment of its antioxidant activity

In this work, phytochemical components and the antioxidant property of an aqueous extract obtained from a medicinal plant Hubertia ambavilla , endemic to Reunion Island, were investigated. A total of 37 compounds were detected and identified by high-performance liquid chromatography (UHPLC) using a photodiode-array detector (DAD) coupled with electrospray ionization/mass spectrometry (ESI/MS n ). From calibration curves, the quantity of secondary metabolites in the aqueous extract was calculated. The mean amounts of phenols, flavonoids, and condensed tannins found were respectively 158.38 ± 1.20 mg GAE/g DE, 60.41 ± 1.65 mg AE/g DE and 23.77 ± 1.36 mg CE/g DE. The in vitro antioxidant properties of Hubertia ambavilla plant were measured using three methods: DPPH and ABTS scavenging and ferric reducing antioxidant power. The results showed that crude aqueous extract of H. ambavilla had effective radical scavenging and reducing power in comparison with standard antioxidant compounds. In conclusion, the crude extract herein presented offers a natural alternative biosource of antioxidants with potential applications in food and health industries.

Phytochemical Analysis, Antioxidant, Antimicrobial, and Anti-Swarming Properties of Hibiscus sabdariffa L. Calyx Extracts: In Vitro and In Silico Modelling Approaches

The aim of this study was to investigate the phytochemical composition of dried Roselle calyx (Hibiscus sabdariffa L.) using both ethanolic and aqueous extracts. We report the antimicrobial activities against a wide range of bacteria, yeast, and fungi. The antioxidant activities were tested using 2,2-diphenyl-1-picrylhydrazyl (DPPH), hydroxyl, and 2–2′-azinobis-(3-ethylbenzthiazoline-6-sulfonic acid) radical scavenging assays. We report also for the first time the effect of the swarming motility in Pseudomonas aeruginosa PAO1. Our results showed that the tested two extracts were a rich source of phenols, flavonoids, and tannins with different degrees. Additionally, eleven phytoconstituents were identified by LC/MS technique (Hibiscus acid: 3-caffeoylquinic acid, 5-caffeoylquinic acid, 5-feruloylquinic acid, cyanidin 3-o-glucoside, myricetin, quercetin 7-o-rutinoside, quercetin 3-o-glucoside, delphinidin 3-o-sambubioside, and kaempferol 3-o-p-coumaroyl-glucoside). Also, it was shown that the calyx extract can scavenge 86% of the DPPH radical, while the rate of 53% and 23% of inhibition of the DPPH was obtained only at the concentration of 125 and 50 µg/mL, and a small inhibition was made at a concentration of 5 μg/mL. Roselle extracts inhibited the growth of the selected microorganisms at low concentrations, while higher concentrations are needed to completely kill them. However, no activity against CVB-3 was recorded for both extracts. In addition, the obtained extracts reduced the swarming motility of P. aeruginosa at 2.5 mg/ml. The docking simulation showed acceptable binding affinities (up to −9.6 kcal/mol) and interaction with key residues of 1JIJ, 2QZW, and 2UVO. The obtained results highlighted the potential use of Roselle extract as a source of phytoconstituents with promising antimicrobial, antioxidant, and anti-quorum sensing activities.

Use of Hibiscus sabdariffa Calyxes in Meat Products

In the search for new ingredients that counteract some of the problems associated with the consumption of meat and meat products like high contents of saturated fat, salt, cholesterol, the absence of dietary fiber, and the presence of synthetic additives, Hibiscus sabdariffa calyxes have shown good colorant, antimicrobial, and antioxidant properties. This research paper studies the use of H. sabdariffa roselle calyxes directly or by means of extracts in meat and meat products. Although its application is incipient, the results are promising. The vibrant red color of the calyxes makes calyxes suitable for their use in meat products even though the concentration must be optimized since the acid taste can detract from the overall acceptance. The antimicrobial properties contribute to safer meat products, and antioxidant effects, helping to extend the shelf life of meat products and reducing oxidative processes. Nonetheless, achieving the desired effects is still challenging since several factors can affect these functional properties.

Hibiscus sabdariffa extract improves hepatic steatosis, partially through IRS-1/Akt and Nrf2 signaling pathways in rats fed a high fat diet

Non-alcoholic fatty liver disease (NAFLD) has become a major world-wide health problem and is characterized by lipid accumulation in the liver induced by high fat diet (HFD) consumption. It is usually associated with inflammation, oxidative stress, and insulin resistance. Roselle extract (Hibiscus sabdariffa) is an herb which is used in traditional medicine. However, further study is necessary to represent the mechanism of NAFLD and find new preventive strategies. This study aims to investigate the protective effects of roselle extract on NAFLD rat models. Male Sprague-Dawley rats (n = 35) were divided into 5 groups, control, HFD, HFD + Simvastatin (HFD + SIM), HFD + 250 mg/kg BW, and HFD + 500 mg/kg BW of roselle extract (HFD + R250 and HFD + R500, respectively). The results showed that roselle extract reduced hepatic lipid contents, de novo lipogenesis enzymes, microsomal triglyceride transfer protein, inflammatory cytokines, malondialdehyde, and increased antioxidant properties, transporter related with lipoprotein uptake, and insulin signal proteins. Comparing to SIM, the HFD + R500 group exhibited the greater benefit in terms of anti-hepatic steatosis, antioxidant properties, and an ability to improve insulin resistance. This study demonstrates that roselle extract improved antioxidant properties and attenuated hepatic steatosis, liver inflammation, oxidative stress, and insulin resistance in HFD-induced NAFLD in rats, which could be used for NAFLD prevention.

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

Network pharmacology-based analysis of the anti-hyperglycemic active ingredients of roselle and experimental validation

Diabetes mellitus is one of the top four leading causes of death among noncommunicable diseases worldwide, according to the World Hibiscus sabdariffa 2019. Roselle (Hibiscus sabdariffa L.), a traditional herbal medicine, has shown significant clinical anti-hyperglycemic efficacy. However, the mechanism of the treatment is not yet clear. We found that Roselle has a certain protective effect on vascular endothelial cells through this study. This study was based on network pharmacology and experimental validation. The present study made a comprehensive analysis by combining active ingredient screening, target prediction and signaling pathway analysis to elucidate the active ingredients and possible molecular mechanism of roselle for the first time, which provided theoretical and experimental basis for the development and application of roselle as an antidiabetic drug.

The Digestibility of Hibiscus sabdariffa L. Polyphenols Using an In Vitro Human Digestion Model and Evaluation of Their Antimicrobial Activity

Hibiscus sabdariffa L. (H.s.) is a polyphenolic-rich plant commonly consumed either as a beverage or spice. The aim of the present study was to evaluate the in vitro digestibility of H.s. polyphenols using an in vitro model of digestion which simulates the human stomach and small intestine. The bioaccessible polyphenols released in the digested samples were analyzed by liquid chromatography coupled to photodiode array and mass spectrometry detection. H.s. anthocyanins (cyanidin-3-O-sambubioside and delphinidin-3-O-sambubioside) content drastically dropped during the digestion process from 2.91 ± 0.03 µg g⁻¹ and 8.53 ± 0.08 µg g⁻¹ (w/w) CG (Cyanidin-glucoside) in the raw extract, respectively, to 0.12 ± 0.01 µg g⁻¹ 0.12 ± 0.01 µg g⁻¹ (w/w) CG at the end of duodenal digestion. Total polyphenols also have shown a decrease from 1192.65 ± 30.37 µg g⁻¹ (w/w) in the raw extract to 282.24 ± 7.21 µg g⁻¹ (w/w) by the end of gastric digestion, in contrast to their increase by the end of duodenal digestion 372.91 ± 3.97 µg g⁻¹ (w/w). On the other hand, the decrease in certain compounds (e.g., caffeoylquinicandcoumaroylquinic acids) was observed during gastric digestion resulting in an increase of quinic acid in the duodenal aliquots, thus suggesting that this compound was derived from the degradation of the more complex hydroxycinnamic acids. H.s. extract also exhibited a bacteriostatic effect against Staphylococcus aureus ATCC 6538 (MIC of 2.5 mg mL⁻¹) and a bactericidal effect against a food isolate of Listeria monocytogenes (MBC of 2.5 mg mL⁻¹). The undigested polyphenols of H.s. in the upper gastrointestinal tract enters the colon, where they are metabolized by the gut microbiota. The present study results showed that resistance of H.s. polyphenols during gastrointestinal digestion might affect their uptake, resulting in a decrease in their digestibility.

Metabolic and Epigenetics Action Mechanisms of Antiobesity Medicinal Plants and Phytochemicals

Ever-growing research efforts are demonstrating the potential of medicinal plants and their phytochemicals to prevent and manage obesity, either individually or synergistically. Multiple combinations of phytochemicals can result in a synergistic activity that increases their beneficial effects at molecular, cellular, metabolic, and temporal levels, offering advantages over chemically synthesized drug-based treatments. Herbs and their derived compounds have the potential for controlling appetite, inhibiting pancreatic lipase activity, stimulating thermogenesis and lipid metabolism, increasing satiety, promoting lipolysis, regulating adipogenesis, and inducing apoptosis in adipocytes. Furthermore, targeting adipocyte life cycle using various dietary bioactives that affect different stages of adipocyte life cycle represents also an important target in the development of new antiobesity drugs. In this regard, different stages of adipocyte development that are targeted by antiobesity drugs can include preadipocytes, maturing preadipocytes, and mature adipocytes. Various herbal-derived active compounds, such as capsaicin, genistein, apigenin, luteolin, kaempferol, myricetin, quercetin, docosahexaenoic acid, quercetin, resveratrol, and ajoene, affect adipocytes during specific stages of development, resulting in either inhibition of adipogenesis or induction of apoptosis. Although numerous molecular targets that can be used for both treatment and prevention of obesity have been identified, targeted single cellular receptor or pathway has resulted in limited success. In this review, we discuss the state-of-the-art knowledge about antiobesity medicinal plants and their active compounds and their effects on several cellular, molecular, and metabolic pathways simultaneously with multiple phytochemicals through synergistic functioning which might be an appropriate approach to better management of obesity. In addition, epigenetic mechanisms (acetylation, methylation, miRNAs, ubiquitylation, phosphorylation, and chromatin packaging) of phytochemicals and their preventive and therapeutic perspective are explored in this review.

A review of the effectiveness of hibiscus for treatment of metabolic syndrome

ETHNOPHARMACOLOGICAL RELEVANCE

Hibiscus species (Family: Malvaceae) have long been used in traditional medicine to treat a variety of maladies such as abscesses, bilious conditions, cancer, cough, fatigue, gastrointestinal discomfort, fever, veisalgia, cardiovascular disorders, neurosis, scurvy, and urinary tract disorders. Its antioxidants have the capacity to destroy free radicals that damage cells and increase risk of inflammatory conditions such as metabolic syndrome, cancer, and cardiovascular disease.

AIM OF THE STUDY

This review synthesizes findings from animal studies and clinical trials to assess effectiveness of hibiscus for treating biomarkers of metabolic syndrome including hyperglycemia, hypertriglyceridemia, low high-density lipoprotein, obesity, and hypertension.

MATERIALS AND METHODS

We searched for 12 edible species of hibiscus in the Google Scholar database. Each scientific name of these species, their common names and their edible plant parts were searched in conjunction with fourteen key words associated with metabolic syndrome. A total of 68 articles met all inclusion criteria for this review, including 18 that tested human subjects, 48 that tested other animals, one that tested humans and other animals, and one that did not specify.

RESULTS

Hibiscus often improved blood glucose, total cholesterol, high-density lipoprotein cholesterol, triglycerides, blood pressure, weight, lipid absorption and oxidation of fatty acids within vital organs around the abdominal cavity. Higher doses led to greater benefits in some cases, especially for body mass of animals, but lower doses were often equally effective. Hibiscus was often equally or more effective than pharmaceuticals in improving some biomarkers of metabolic syndrome, especially blood glucose and insulin sensitivity.

CONCLUSION

Hibiscus shows great promise for improving biomarkers of metabolic syndrome, but there are limitations that need to be addressed by future work, including increasing the number and size of human clinical trials, expanding human trials to include people from a greater diversity of ethnicities, taking into account the health and physical activity of human participants, investigating the influence of growing conditions and extraction/preparation techniques on nutrients in hibiscus, comparing the efficacy of several plant parts and plant products of hibiscus to a reference control group within the same experiment, incorporating rigorous statistical analysis of treatments and investigating the influence of dosage.

Edible Flowers: Antioxidant Compounds and Their Functional Properties

Edible flowers have been widely consumed for ages until now. The attractive colors and shapes, exotic aroma, and delightful taste make edible flowers very easy to attain. Moreover, they also provide health benefits for consumers due to the unique composition and concentration of antioxidant compounds in the matrices. Knowing the bioactive compounds and their functional properties from edible flowers is necessary to diversify the usage and reach broader consumers. Therefore, this reported review could be useful for functional product development, engaging the discussed edible flowers. We present a comprehensive review of edible flower composition and the functional properties of their antioxidant compounds, mainly phenolics.

Methodologies in the Analysis of Phenolic Compounds in Roselle (Hibiscus sabdariffa L.): Composition, Biological Activity, and Beneficial Effects on Human Health

Roselle (Hibiscus sabdariffa L.), as an edible flower, has long provided an array of positive effects on human health. This benefit is a result of phenolic compounds that are naturally present mainly in the calyx. Plentiful medicinal remedies and functional foods based on this flower are available worldwide, as supported by the studies of phenolic compounds in recent decades. This paper aims to provide a comprehensive review of the composition, biological activity, and beneficial effects on human health of phenolic compounds in roselle. This review was performed in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. A structured search in the published literature for phenolics compositions in roselle was required prior to the evaluation on the validity of the reported analytical methods. Reliable identification and quantification of phenolic compounds in roselle can be achieved by employing the proper extraction and separation methods. With ample alternative analytical methods discussed here, this review provided an aid for comprehending and selecting the most appropriate method for a particular study. The applications of the analytical methods highlighted indicated that phenolic acids, flavonoids, and their derivatives have been identified and quantified in roselle with a range of biological activities and beneficial effects on human health. It was also disclosed that the composition and concentration of phenolic compounds in roselle vary due to the growth factors, cultivars, and environmental influence. Finally, apart from the research progress carried out with roselle during the last ten years, this review also proposed relevant future works.

Mechanisms of Action of Nutritionally Rich Hibiscus sabdariffa's Therapeutic Uses in Major Common Chronic Diseases: A Literature Review

Hibiscus sabdariffa, this beverage has been used for millennia as both a delicious cultural beverage and an ancient medicinal therapy. In recent years, many studies have investigated the uses and mechanisms of action of Hibiscus sabdariffa to treat common chronic diseases. In this literature review, we place the spotlight on Hibiscus sabdariffa's medical effect on common chronic diseases, the flower commonly used to make hibiscus tea. The databases PubMed, MEDLINE, Clinical Key, and CINAHL were searched for studies related to Hibiscus sabdariffa's compounds, antioxidative and anti-inflammatory features, mechanism of action on common chronic diseases including hypertension, hyperlipidemia, obesity, diabetes, and Alzheimer's disease. Hibiscus sabdariffa antihypertensive potentials originate from the vasodilator activity, diuretic efficacy, functionality as an ACE inhibitor, adipocyte differentiation inhibitor, heart rate reduction ability, and anti-inflammatory mechanistic. The antihyperlipidemic effect is dose-dependent and stems from the antioxidative effect and the activation of AMPK through phosphorylation and the inhibition of regulatory adipogenic transcription factors PPAR-γ, C/EBP-α, and SREBP-1c, which altogether results in lipid-lowering effect. As an antihyperglycemic, Hibiscus sabdariffa serves as anti-insulin resistance by inhibition of the phosphorylation of IRS-1 beside a similar effect to gliptins. Finally, Hibiscus sabdariffa was proven to protect against neuroinflammation in microglial cell culture exposed to LPS by decreasing IL-1, IL-6, TNF-α expression, and the protective effect against glucotoxicity, improve memory function by inhibiting the formation of hyperphosphorylated tau proteins in the mouse brain. Regular consumption of hibiscus tea or extract is beneficial for a reduction in chronic disease risk and diagnosis. Key teaching pointsHibiscus sabdariffa, or hibiscus, has been used for millennia as both a delicious cultural beverage and an ancient medicinal therapy. Recent studies have investigated the uses of Hibiscus sabdariffa to treat common chronic diseases.Its antihypertensive potential originates from the vasodilator activity, diuretic efficacy, functionality as an ACE inhibitor, adipocyte differentiation inhibitor, heart rate reduction ability, and anti-inflammatory mechanistics.The antihyperlipidemic effect is dose-dependent and stems from the antioxidative effect and the activation of AMPK through phosphorylation and also the inhibition of regulatory adipogenic transcription factors PPAR-γ, C/EBP-α and SREBP-1c which all together results in lipid-lowering effect.As an antihyperglycemic, Hibiscus sabdariffa serves as anti-insulin resistance by inhibition of the phosphorylation of IRS-1 beside the similar effect to gliptins.Hibiscus sabdariffa was proven to protect against neuroinflammation in microglial cell culture exposed to LPS by decreasing IL-1, IL-6, TNF-α expression, and the protective effect against glucotoxicity, improve memory function by inhibiting the formation of hyperphosphorylated tau proteins in the mouse brain.

The Impact of Herbal Infusion Consumption on Oxidative Stress and Cancer: The Good, the Bad, the Misunderstood

The release of reactive oxygen species (ROS) and oxidative stress is associated with the development of many ailments, including cardiovascular diseases, diabetes and cancer. The causal link between oxidative stress and cancer is well established and antioxidants are suggested as a protective mechanism against cancer development. Recently, an increase in the consumption of antioxidant supplements was observed globally. The main sources of these antioxidants include fruits, vegetables, and beverage. Herbal infusions are highly popular beverages consumed daily for different reasons. Studies showed the potent antioxidant effects of plants used in the preparation of some herbal infusions. Such herbal infusions represent an important source of antioxidants and can be used as a dietary protection against cancer. However, uncontrolled consumption of herbal infusions may cause toxicity and reduced antioxidant activity. In this review, eleven widely consumed herbal infusions were evaluated for their antioxidant capacities, anticancer potential and possible toxicity. These herbal infusions are highly popular and consumed as daily drinks in different countries. Studies discussed in this review will provide a solid ground for researchers to have better understanding of the use of herbal infusions to reduce oxidative stress and as protective supplements against cancer development.

Quercetin metabolites from Hibiscus sabdariffa contribute to alleviate glucolipotoxicity-induced metabolic stress in vitro

Polyphenols from Hibiscus sabdariffa (HS) alleviate obesity-related metabolic complications but the metabolites responsible for such effects are unknown. We aimed to elucidate which of the potential plasma metabolites from a polyphenol-enriched HS (PEHS) extract contributed for the reversion of glucolipotoxicity-induced metabolic stress using 3T3-L1 adipocyte and INS 832/13 pancreatic β-cell models under glucolipotoxic conditions. PEHS extract, quercetin (Q) and quercetin-3-O-glucuronide (Q3GA) showed stronger capacity to decrease glucolipotoxicity-induced ROS generation than ascorbic acid or chlorogenic acid. PEHS extract, Q and Q3GA decreased secretion of cytokines (leptin, TNF-α, IGF-1, IL-6, VEGF, IL-1α, IL-1β and CCL2) and reduced CCL2 expression at transcriptional level. In addition, PEHS extract, Q and Q3GA reduced triglyceride accumulation, which occurred through fatty acid synthase (FASN) downregulation, AMPK activation and mitochondrial mass and biogenesis restoration via PPARα upregulation. Electron microscopy confirmed that PEHS extract and Q3GA decreased mitochondrial remodeling and mitophagy. Virtual screening leads us to postulate that Q and Q3GA might act as agonists of these protein targets at specific sites. These data suggest that Q and Q3GA may be the main responsible compounds for the capacity of PEHS extract to revert glucolipotoxicity-induced metabolic stress through AMPK-mediated decrease in fat storage and increase in fatty acid oxidation, though other compounds of the extract may contribute to this capacity.

Insight into the molecular evidence supporting the remarkable chemotherapeutic potential of Hibiscus sabdariffa L

Hibiscus sabdariffa or roselle tea is popular around the globe for its antioxidant capability along with various other health benefits. Besides, it has uses in Ayurvedic and Chinese herbal medicines for the treatment of several diseases. However, the investigation for the anticancer potential of the plant began roughly in the last decade that emerged with encouraging results. Both crude extracts and pure compounds of the plant were reported to induce chemoprevention, selective cytotoxicity, cell cycle arrest, apoptosis, autophagy and anti-metastasis effects in varied types of human cancer cells. The plant contains a high quantity of polyphenolic compounds and at least two of them were proven to induce potent anticancer effects. Although, the molecular mechanism underlying the anticancer activity was roughly estimated in several studies. The present review aimed to assemble all ambiguous information to report the molecular evidence establishing the potent anticancer activity of Hibiscus sabdariffa and its implication for cancer therapy. This study suggests that Hibiscus sabdariffa is an ideal candidate to investigate its role as a herbal supplement for cancer prevention and treatment. With excellent safety and tolerability record, polyphenolic compounds from the plant need better designed clinical trials.

Potential Application of Tetrapleura tetraptera and Hibiscus sabdariffa (Malvaceae) in Designing Highly Flavoured and Bioactive Pito with Functional Properties

Sorghum beer (pito) is an indigenous alcoholic beverage peculiar to northern Ghana and parts of other West African countries. It is overwhelmed with calories, essential amino acids (such as lysine, etc.), B-group vitamins, and minerals. In recent years, there has been a growing demand for highly flavoured yet functional pito in Ghana; however, the local producers lack the prerequisite scientific expertise in designing such products. We propose the utilization of Tetrapleura tetraptera (TT) and Hibiscus sabdariffa (HS) as cheap and readily available materials in designing functional flavoured pito. The addition of TT and HS would not alter the fermentation profile but rather augment the starter with nutrients, thus improving the fermentation performance and shelf life of the final pito. In vitro and in vivo studies provide substantive evidence of antioxidant, nephro- and hepato-protective, renal/diuretic effect, anticholesterol, antidiabetic, and antihypertensive effects among others of the TT and HS, hence enriching the pito with health-promoting factors and consequently boosting the health of the consumer. Herein, we summarise the phytochemical, biological, pharmacological, and toxicological aspects of TT and HS as well as the technology involved in brewing the novel bioactive-flavoured pito. In addition, we also report the incidence of heavy metal in conventional pito.

Anthocyanin Induction by Drought Stress in the Calyx of Roselle Cultivars

Abiotic factors can alter the chemical profile of crops and the number of compounds they contain. In this study, the anthocyanin and anthocyanidin contents, determined by ultra-performance liquid chromatography (UPLC-MS/MS), and the colour attributes of the calyces of three cultivars of Hibiscus sabdariffa subjected to three water stress regimes during the stage of physiological maturity were investigated. The total anthocyanin content in calyx increased relative to the control content under a 65% moisture irrigation regime. Among the cultivars, UAN16-2 showed the greatest increases in the contents of cyanidin, delphinidin 3-O-glucoside, cyanidin 3-O-glucoside, and cyanidin 3-O-sambubioside. The content of cyanidin 3-O-sambubioside showed the greatest increase, increasing by 55% relative to the control level. The contents of these compounds are correlated with colour attributes such as luminosity. Water stress under the 33% moisture condition during plant development led to decreased anthocyanin contents in all of the roselle cultivars.

Antioxidant Capacity and Antigenotoxic Effect of Hibiscus sabdariffa L. Extracts Obtained with Ultrasound-Assisted Extraction Process

Hibiscus sabdariffa (Roselle) is in high demand worldwide due to its beneficial health properties owing to the polyphenols content, mainly in the flower calyx. The objective of this study was to find the best conditions (time and liquid: solid ratio) to extract polyphenols from Roselle using Ultrasound-Assisted Extraction (UAE) (40 kHz, 180 W), with ethanol how solvent; as well as determine the yield of phenols, anthocyanin, flavonoids, tannins, antioxidant activity (DPPH) and antigenotoxic effect (comet assay). A traditional solid-liquid extraction was applied as a reference. Extraction times of 40 and 60 min resulted in the highest polyphenols (13.019 mg GAE/g dry weight (dw)), flavonoids (4.981 CE/g dw), anthocyanins (1.855 mg Cya3GE/g dw), and tannins (0.745 CE/g dw) recoveries and an antioxidant activity (DPPH) of 74.58%. Extracts from white calyces contained similar amounts of phenols and flavonoids, but very little condensed tannins (0.049 CE/g dw) and practically no anthocyanins. Extracts from red and white calyces, showed antigenotoxic activity and repaired capacity of damage caused by mutagens in human lymphocytes.

Mass transfer modeling of the antioxidant extraction of roselle flower (Hibiscus sabdariffa)

The aim of this study was to analyze the equilibrium and dynamic periods for mass transfer during the antioxidant solid-liquid extraction of dry roselle flower (Hibiscus sabdariffa). Extraction kinetics for total phenolic compounds (TPC), total flavonoids (TFL) and total antioxidant capacity (TAC) were obtained at different temperatures (50, 60, 70 or 80 °C) and solvent-to-product mass ratios (100:1, 200:1 or 300:1 g/g) under stirring (220-230 rpm). An analytical solution for unsteady-state mass transfer based on Fick's second law of diffusion was used to mathematically describe solid-liquid extraction curves and for the simultaneous estimation of diffusion coefficients and the final amount of extracted bioactive compounds, which were further related to experimental conditions by a second order model. The amount of extracted bioactive compounds at equilibrium were in the ranges of 30.8-89.8 g GAE/kg d.m. for TPC (0.154-0.373 g GAE/L extract), 40.0-131.6 g catechin/kg d.m. for TFC (0.269-0.559 g catechin/L extract) and 37.5-227.0 g trolox/kg d.m. for TAC (0.346-0.865 g trolox/L extract). On the other hand, diffusion coefficients for TPC, TFC and TAC were in the ranges of 0.72-2.66 × 10^-11, 0.25-2.37 × 10^-11 and 1.19-5.79 × 10^-11 m²/s, respectively.

Study of Acidified Aqueous Extraction of Phenolic Compounds from Hibiscus sabdariffa L. calyces

Introduction:

Hibiscus calyces are important sources from anthocyanins and pigments. The recovery of these bioactive compounds using non-organic solvents becomes very attractive for the food industry.

Methods:

For this reason, the separation of phenolic compounds by acidified aqueous extraction from hibiscus calyces was studied. The experiments were conducted by a fractional factorial design.

Result and Conclusion:

Four factors were evaluated: temperature, time, stirring speed and enzyme concentration. The extracts produced were subjected to analysis of color (L*,a*,b*andChroma), total monomeric anthocyanins, antioxidant capacity by ABTS and fourteen phenolic compounds were quantified. The results showed that the best condition to obtain hibiscus calyces extract was using an enzyme concentration of 50 µL/1000 g hibiscus extract, 400 rpm of stirring speed at 55 ºC by 4 hours of extraction, that corresponded to concentrations of 17595, 7516, 2568 μg/g, expressed on a dry basis, for total phenolic compounds, delphinidin 3-sambubioside and cyanidin 3-sambubioside, respectively, and antioxidant capacity measured by ABTS of 7.8 µmol of Trolox equivalent per gram.

Hibiscus and lemon verbena polyphenols modulate appetite-related biomarkers in overweight subjects: a randomized controlled trial

TRIAL DESIGN

Plant-derived polyphenols have shown potential to alleviate obesity-related pathologies by a multi-targeted mechanism in animal models and human intervention studies. A dietary supplement based on a combination of Lippia citriodora (LC) and Hibiscus sabdariffa (HS) polyphenolic extracts was assayed in a double blind and placebo-controlled intervention study with 54 overweight subjects.

METHODS

Blood pressure, body weight, height, triceps, biceps and abdominal skinfold thickness, and arm and abdominal circumferences were taken at the baseline, 30 and 60 days of the intervention period. The validated Visual Analogue Scale used to record hunger and satiety-related sensations was passed at the beginning and at 15, 30, 45 and 60 days of the intervention. Subjective health status was assessed through the validated SF-36 questionnaire at the beginning and end of the study. Finally, plasma from fasting blood samples was obtained at the beginning, 30 and 60 days of the study.

RESULTS

The results showed an improvement of anthropometric measurements, decreased blood pressure and heart rate and a more positive perception in the overall health status. We also observed that plant polyphenols increased anorexigenic hormones (glucagon-like peptide-1) and decreased orexigenic hormones (ghrelin).

CONCLUSIONS

Based on previous evidence we postulate that AMP-activated protein kinase may have a role in such effects through its capability to modulate energy homeostasis, total daily energy expenditure and lipid management. Although further research may be required, we propose that this polyphenolic combination may be used for weight management by increasing long-term weight loss maintenance through the modulation of appetite biomarkers. This may help to avoid the undesired weight regain typical of calorie restriction diets.

Monitoring anthocyanin degradation in Hibiscus sabdariffa extracts with multi-curve resolution on spectral measurement during storage

This study aims to monitor composition changes in an anthocyanin-rich beverage during storage by the means of UV-VIS measurements associated with a multi-curve resolution procedure. Hibiscus sabdariffa extract was stored at 37 °C for 50 days and UV-VIS spectra were measured on the extract and the fractions of the extract every 5 days. MCR was carried out in two steps, first with the fraction and then the extract spectra. The results enabled the main polyphenols initially present to be identified, anthocyanins and chlorogenic acid, but also found the nature of the main degradation products: the polymers from anthocyanin condensation and scission products. In addition, comparison with HPLC analysis results showed that the MCR procedure recovered the correct shapes of the concentration profiles particularly of anthocyanin and polymer kinetics during storage. This work gives perspective for the use of a rapid and efficient technique to monitor pigment-rich beverage processing or storage.

Roselle Anthocyanins: Antioxidant Properties and Stability to Heat and pH

Roselle is rich in anthocyanins and is traditionally used to prepare a bright red beverage by decoction. However, heat treatment and different pH environments are often encountered during food processing, and these factors are often detrimental to anthocyanins. Therefore, it is very important to understand the influence of pH and heat treatment on anthocyanins for the application of roselle. This study determined the antioxidant properties of roselle extract, explored changes in the color and anthocyanin content in different pH environments, and evaluated the thermal stability of roselle anthocyanins using kinetic equations. The results showed that the roselle extract is rich in anthocyanins and has good antioxidant capacity (DPPH IC50 = 4.06 mg/mL, ABTS IC50 = 3.7 mg/mL). The anthocyanins themselves exhibited a certain degree of heat resistance and good color stability in an acidic environment. In contrast, they degraded very quickly and exhibited significant changes in color in a low-acid environment. The activation energy (Ea) ranges of the anthocyanins in the acidic and low-acid environments were quite different at 55.8–95.7 and 31.4–74.9 kJ/mol, respectively. Thus, it can be concluded that roselle anthocyanins are susceptible to heat treatment in a low-acid environment, affecting their quality and appearance; however, they can serve as a good source of functional ingredients and color in an acidic environment.

A review on phytochemistry and therapeutic uses of Hibiscus sabdariffa L

Hibiscus sabdariffa L. (roselle) belonging to the Malvaceae family is widely grown in many countries. This plant is often used in the traditional medicine being rich in phytochemicals like polyphenols especially anthocyanins, polysaccharides and organic acids thus having enormous prospective in modern therapeutic uses. The study aimed to review and document all the available evidence and information about the calyces of Hibiscus sabdariffa (roselle) with the special focus on their nutritional composition, bioactive constituents and therapeutic uses. The electronic database was searched up to 2017, using keywords Hibiscus sabdariffa, chemical constituents of roselle, therapeutic uses of roselle. Journals, books and conference proceedings were also searched. The review provides valuable information about the nutraceutical component of Hibiscus sabdariffa L. and their utilization for curing various degenerative diseases like hypertension, hyperlipidemia, cancer and other inflammatory diseases of liver and kidney. Their toxicological effects have also been discussed from a safety point of view. Most studies supported and provided the scientific basis for the statement that Hibiscus sabdariffa and their active constituents play an important role in the prevention of chronic and degenerative diseases that are associated with oxidative stress. Our study suggests, that good research is needed, to establish a potential strategy that can balance the pharmacological and toxic effects of roselle and standardized fingerprint of Hibiscus sabdariffa is required internationally for quality control.

Hibiscus sabdariffa anthocyanins-rich extract: Chemical stability, in vitro antioxidant and antiproliferative activities

Hibiscus sabdariffa calyx is a rich source of anthocyanins and other bioactive compounds but no study reported the effects of experimental conditions on the extraction of these chemical compounds. Therefore, the effects of time and extraction temperature on the bioactive compounds and antioxidant activity of Hibiscus sabdariffa calyx were evaluated. In addition, the effects of copigmentation and pH on the stability of anthocyanins were assessed and the cytotoxic effects (LC₅₀, IC₅₀, and GC₅₀) of the extracts were determined in relation to tumor cell lines - Caco-2, HepG-2, HCT8, and A549. The temperature significantly influenced the total anthocyanins and flavonoids contents. The interaction between time/temperature influenced the total phenolic content and ascorbic acid. The t_1/2 and the percentage of colour retention decreased markedly at temperatures above 80 °C. Variations in pH conserved the antioxidant activity of the anthocyanins, and the protonation-deprotonation process of the extract was reversible. The treatment of cells with purified anthocyanin extract or crude extracts at 5-800 μg mL^-1 did not show significant cytotoxic effects on the cell lines, corroborating the chemical antioxidant effect of the extracts (DPPH assay). Cyanidin-3-glucoside, delphinidin-3-sambubioside, delphinidin-3-glucoside, and cyanidin-3-sambubioside were identified in the extracts by LC-ESI-MS.

Sempervivum davisii: phytochemical composition, antioxidant and lipase-inhibitory activities

CONTEXT

Sempervivum davisii Muirhead (Crassulaceae) is a traditional medicinal herb from Eastern Anatolia. To date the composition of phytochemicals and physiological properties of this herb were not subjected to any research.

OBJECTIVE

This study identifies compounds in S. davisii hydrophilic extracts and evaluates their potential biological properties.

MATERIALS AND METHODS

Ethanol-based lyophilized extracts were obtained from aerial parts of plant (10 g of ground dry plant material in 200 mL of acidified aqueous ethanol, shaken for 2 h at 22 °C with supernatant collected and freeze-dried under vacuum). Phytochemical composition was investigated by liquid chromatography mass spectrometry (LC-MS/MS, phenolics) and gas chromatography mass spectrometry (GC-MS, volatiles). Phenolic compounds were quantified by high-performance liquid chromatography (HPLC) and the Folin-Ciocalteu assay. Subsequently, antioxidant capacity [ferric reducing antioxidant power (FRAP), oxygen radical absorbance capacity (ORAC) assays] and enzyme inhibitory properties (isolated porcine pancreatic lipase) of the extracts were determined.

RESULTS

Polyphenolic compounds were the main constituents of lyophilized extracts, among which kaempferol glycosides and quercetin hexoside dominated. The extracts exhibited potent antioxidant (FRAP values of 1925.2-5973.3 μM Fe²⁺/g DW; ORAC values of 1858.5-4208.7 μM Trolox Eq./g DW) and moderate lipase inhibitory (IC₅₀: 11.6-2.96 mg/mL) activities. Volatile compounds (nonanal, dehydroxylinalool oxide isomers, 2-decenal, 2-undecenal, 2,6-di-tetr-butylphenol) were also found.

CONCLUSIONS

Phenolic compounds with the dominating kaempferol and quercetin derivatives are the sources of potent antioxidant properties of S. davisii hydrophilic extracts. The extracts exhibit moderate inhibitory properties towards isolated pancreatic lipase.

Ethnomedicinal, Phytochemical and Ethnopharmacological Aspects of Four Medicinal Plants of Malvaceae Used in Indian Traditional Medicines: A Review

The ethnomedicinal values of plants form the basis of the herbal drug industry. India has contributed its knowledge of traditional system medicines (Ayurveda and Siddha) to develop herbal medicines with negligible side effects. The World Health Organization has also recognized the benefits of drugs developed from natural products. Abutilon indicum, Hibiscus sabdariffa, Sida acuta and Sida rhombifolia are ethnomedicinal plants of Malvaceae, commonly used in Indian traditional system of medicines. Traditionally these plants were used in the form of extracts/powder/paste by tribal populations of India for treating common ailments like cough and cold, fever, stomach, kidney and liver disorders, pains, inflammations, wounds, etc. The present review is an overview of phytochemistry and ethnopharmacological studies that support many of the traditional ethnomedicinal uses of these plants. Many phytoconstituents have been isolated from the four ethnomedicinal plants and some of them have shown pharmacological activities that have been demonstrated by in vivo and/or in vitro experiments. Ethnomedicinal uses, supported by scientific evidences is essential for ensuring safe and effective utilization of herbal medicines.

Polyphenols reported to shift APAP-induced changes in MAPK signaling and toxicity outcomes

Due to its widespread availability, acetaminophen (APAP) is the leading cause for drug-induced liver injury in many countries including United States and United Kingdom. When used as recommended, APAP is relatively safe. However, in overdose cases, increased metabolism of APAP to N-acetyl-para-benzoquinoneimine (NAPQI), a reactive metabolite, leads to glutathione (GSH) depletion, oxidative stress, and cellular injury. Throughout this process, a variety of factors play important roles in propagating toxicity, including c-Jun N-terminal kinase (JNK), a member of the mitogen-activated protein kinase (MAPK) family. Because of its involvement in multiple cellular processes, biomarkers associated with MAPK signaling have generated interest as a mechanistic target for protecting against APAP-induced liver injury and hepatocellular injury, in general. This review summarizes mechanistic details by which natural products, specifically those containing polyphenolic moieties, are capable of attenuating APAP-induced toxicity, at least in part through an ability to modulate MAPKs. These compounds include carnosic acid, chlorogenic acid, davallialactone, extracts from Hibiscus sabdariffa, quercetin-based compounds, and resveratrol. Despite variations in the experimental designs across these studies, common pathways and biomarkers were implicated in cytoprotection when polyphenolic compounds were given with APAP, such as enhanced antioxidant gene expression and reversal of APAP-induced changes in oxidative stress markers and MAPK signaling. Overall, an emphasis should be placed on method standardization for future studies if we are to gain a more in-depth understanding of how polyphenolic moieties contribute to cytoprotection during an APAP overdose event.

Multi-Targeted Molecular Effects of Hibiscus sabdariffa Polyphenols: An Opportunity for a Global Approach to Obesity

Improper diet can alter gene expression by breaking the energy balance equation and changing metabolic and oxidative stress biomarkers, which can result in the development of obesity-related metabolic disorders. The pleiotropic effects of dietary plant polyphenols are capable of counteracting by modulating different key molecular targets at the cell, as well as through epigenetic modifications. Hibiscus sabdariffa (HS)-derived polyphenols are known to ameliorate various obesity-related conditions. Recent evidence leads to propose the complex nature of the underlying mechanism of action. This multi-targeted mechanism includes the regulation of energy metabolism, oxidative stress and inflammatory pathways, transcription factors, hormones and peptides, digestive enzymes, as well as epigenetic modifications. This article reviews the accumulated evidence on the multiple anti-obesity effects of HS polyphenols in cell and animal models, as well as in humans, and its putative molecular targets. In silico studies reveal the capacity of several HS polyphenols to act as putative ligands for different digestive and metabolic enzymes, which may also deserve further attention. Therefore, a global approach including integrated and networked omics techniques, virtual screening and epigenetic analysis is necessary to fully understand the molecular mechanisms of HS polyphenols and metabolites involved, as well as their possible implications in the design of safe and effective polyphenolic formulations for obesity.

Herbal products containing Hibiscus sabdariffa L., Crataegus spp., and Panax spp.: Labeling and safety concerns

Herbs have been used from ancient times for infusion preparation based on their potential health effects. In particular, the consumption of Hibiscus sabdariffa L., Crataegus spp. and Panax spp. has been largely associated to cardiovascular benefits. In this work, the label information of 52 herbal products for infusion preparation containing the referred herbs was analyzed and discussed, taking into consideration the European Union regulation for herbal products, which intends to protect public health and harmonize the legal framework in Member States. Details about the cardiovascular-related statements and warning notifications about consumption were considered. Also, regulatory issues and possible herb-drug interactions were explored and discussed. A total of 14 of the 52 herbal products selected presented health claims/statements on the label. Hibiscus was present in the majority of the products and, in some cases, it was mentioned only in the ingredients list and not on the product front-of-pack. Despite the promising outcomes of these plants to modulate cardiovascular risk markers, consumers with some sort of cardiovascular dysfunction and/or under medication treatments should be aware to carefully analyze the labels and consult additional information related to these herbal products. Manufacturers have also a huge responsibility to inform consumers by presenting awareness statements. Lastly, health professionals must advise and alert their patients about possible interactions that could occur between the concomitant consumption of drugs and herbs. Overall, there is still a real need of additional studies and clinical trials to better understand herbs effects and establish a science-based guidance to assess their safety.

Beneficial effects of Hibiscus rosa-sinensis L. flower aqueous extract in pregnant rats with diabetes

Purpose

The Hibiscus rosa-sinensis flower is widely used in Brazilian traditional medicine for the treatment of diabetes and has shown antifertility activity in female Wistar rats. However, there is no scientific confirmation of its effect on diabetes and pregnancy. The aim of this study was evaluate the effect of aqueous extract of H. rosa-sinensis flowers on maternal-fetal outcome in pregnant rats with diabetes.

Methods

Diabetes was induced by streptozotocin (STZ, 40 mg/kg) in virgin, adult, female Wistar rats. After diabetes induction, the rats were mated. The pregnant rats were distributed into four groups (n minimum = 11 animals/group): non-diabetic, non-diabetic treated, diabetic, and diabetic treated. Oral aqueous extract of Hibiscus rosa-sinensis was administered to rats in the treatment groups during pregnancy. At term pregnancy, maternal reproductive outcomes, fetal parameters, and biochemical parameters were analyzed.

Results

The non-diabetic treated group showed decreased high density lipoprotein cholesterol, increased atherogenic index (AI) and coronary artery risk index (CRI), and increased preimplantation loss rate compared to the non-diabetic group. Although treatment with H. rosa-sinensis led to no toxicity, it showed deleterious effects on cardiac and reproductive functions. However, the diabetic treated group showed increased maternal and fetal weights, reduced AI and CRI, and reduced preimplantation loss rate compared to the untreated diabetic group.

Conclusion

Our results demonstrate beneficial effects of this flower only in pregnant rats with diabetes and their offspring. Although these findings cannot be extrapolated to human clinical use, they show that the indiscriminate intake of H. rosa-sinensis may be harmful to healthy individuals and its use should be completely avoided in pregnancy.

Comparison of metabolic profiles and bioactivities of the leaves of three edible Congolese Hibiscus species

Methanolic and dichloromethane extracts from the leaves of Congolese Hibiscus species were characterised by chromatographic and spectroscopic techniques and their in vitro biochemical activities against ROS production were evaluated in cellular models and on an enzyme, myeloperoxidase (MPO), involved in inflammation. Hibiscus acetosella has a chemical fingerprint different from Hibiscus cannabinus and Hibiscus sabdariffa both having similar fingerprints. Major compounds were polyphenols, represented mainly by caffeoyl-hydroxycitric acid for H. acetosella and neochlorogenic acid for the two other species. All extracts displayed high cellular antioxidant activity with IC₅₀ values ranging from 0.5 to 3 μg mL^-1 using lucigenin on neutrophils. Dichloromethane extracts showed more efficient effects on extracellular ROS production and MPO activity. Antioxidant and anti-inflammatory activities of caffeoyl-hydroxycitric acid were significantly higher than those of neochlorogenic acid. The bioactivities of Hibiscus species were positively correlated with their phytochemical content and could justify their use as local nutraceutical resources and medicines.

The estimation of the traditionally used yarrow (Achillea millefolium L. Asteraceae) oil extracts with anti-inflamatory potential in topical application

ETHNOPHARMACOLOGICAL RELEVANCE

Olive or sunflower oil yarrow extracts have been extensively used against inflammatory disorders and skin wound healing in traditional medicine.

AIM OF THE STUDY

To evaluate oil yarrow extracts traditional use in treatment of topical/dermatological skin impairments, sodium lauryl sulfate test was applied, and in vivo measuring of the biophysical parameters (erythema index, skin capacitance and the pH of the skin) in the artificially irritated skin was performed. As traditionally olive and sunflower oil have been used equally for extracts production, the experiment was carried out to investigate whether any of the oil extractants has the advantage over the other, and if the method of extraction might influence the desired activity. The observed activity has been connected to the chemical profile of the investigated extracts and their antioxidative properties.

MATERIALS AND METHODS

In vivo measurements were performed using the appropriate probes for measuring skin capacitance, pH of the skin and erythema index (EI). The designed experiment enabled the evaluation of the anti-inflammatory effects of a seven-day application of oil yarrow extracts known in traditional medicine, on artificially irritated skin of volunteers. The chemical profile for the investigated samples was achieved applying the HPLC and UHPLC-MS methods. Also, ferric reducing antioxidant power (FRAP) test was performed to assess the antioxidant properties of the investigated samples.

RESULTS

The application of tested oil extracts on artificially irritated skin in vivo demonstrated the ability to re-establish their optimal pH and hydration of skin to the values measured prior to the irritation. Considering the EI transition, the investigated samples succeeded in re-establishing the baseline values, with no significant difference after three- and seven-day application.

CONCLUSIONS

The data obtained in the study showed that the oil yarrow extracts had an evident anti-inflammatory property. Namely, the investigated extracts demonstrated significant anti-inflammatory effect in an in vivo double blind randomized study, using a sodium lauryl sulfate test. The skin parameters assessed in the study (skin capacitance, pH and EI) were restored to the basal values after three- and seven-day treatment with the tested extracts. The shown effects were attributed to yarrow oil extracts composition. The yarrow oil extracts might be used as promising base in the phytopreparations designed for dermatological application as anti-inflammatory agents with a positive impact on the skin pH and its moisture content.

Validation of the AlamarBlue® Assay as a Fast Screening Method to Determine the Antimicrobial Activity of Botanical Extracts

Plant compounds are a potential source of new antimicrobial molecules against a variety of infections. Plant extracts suppose complex phytochemical libraries that may be used for the first stages of the screening process for antimicrobials. However, their large variability and complexity require fast and inexpensive methods that allow a rapid and adequate screening for antimicrobial activity against a variety of bacteria and fungi. In this study, a multi-well plate assay using the AlamarBlue® fluorescent dye was applied to screen for antimicrobial activity of several botanical extracts and the data were correlated with microbial colony forming units (CFU). This correlation was performed for three pathogenic model microorganisms: Escherichia coli (Gram negative bacteria), Staphylococcus aureus (Gram positive bacteria) and for the yeast-like fungi Candida albicans. A total of ten plant extracts from different Mediterranean plants, including several Cistus and Hibiscus species, were successfully tested. HPLC-DAD-ESI-MS/MS analysis was utilized for the characterization of the extracts in order to establish structure-activity correlations. The results show that extracts enriched in ellagitannins and flavonols are promising antibacterial agents against both Gram positive and Gram negative bacteria. In contrast, phenolic acids, anthocyanidins and flavonols may be related to the observed antifungal activity.