Roselle (Hibiscus sabdariffa) seed oil is a rich source of gamma-tocopherol

The potential effect of natural antioxidants on endothelial dysfunction associated with arterial hypertension

Arterial hypertension represents a leading cause of cardiovascular morbidity and mortality worldwide, and the identification of effective solutions for treating the early stages of elevated blood pressure (BP) is still a relevant issue for cardiovascular risk prevention. The pathophysiological basis for the occurrence of elevated BP and the onset of arterial hypertension have been widely studied in recent years. In addition, consistent progress in the development of novel, powerful, antihypertensive drugs and their appropriate applications in controlling BP have increased our potential for successfully managing disease states characterized by abnormal blood pressure. However, the mechanisms responsible for the disruption of endogenous mechanisms contributing to the maintenance of BP within a normal range are yet to be fully clarified. Recently, evidence has shown that several natural antioxidants containing active ingredients originating from natural plant extracts, used alone or in combination, may represent a valid solution for counteracting the development of arterial hypertension. In particular, there is evidence to show that natural antioxidants may enhance the viability of endothelial cells undergoing oxidative damage, an effect that could play a crucial role in the pathophysiological events accompanying the early stages of arterial hypertension. The present review aims to reassess the role of oxidative stress on endothelial dysfunction in the onset and progression of arterial hypertension and that of natural antioxidants in covering several unmet needs in the treatment of such diseases.

The Potential of Roselle (Hibiscus sabdariffa) Plant in Industrial Applications: A Promising Source of Functional Compounds

Roselle is an annual botanical plant that widely planted in different countries worldwide. Its different parts, including seeds, leaves, and calyces, can offer multi-purpose applications with economic importance. The present review discusses the detailed profile of bioactive compounds present in roselle seeds, leaves, and calyces, as well as their extraction and processing, to explore their potential application in pharmaceutical, cosmetic, nutraceutical, food and other industries. Roselle seeds with high phenolics, fiber, and protein contents, which are suitable to use in functional food product development. Besides, roselle seeds can yield 17-20% of roselle seed oil with high content of linoleic acid (35.0-45.3%) and oleic acid (27.1- 36.9%). This unique fatty acid composition of roselle seed oil makes it suitable to use as edible oil to offer the health benefits of essential fatty acid. Moreover, high contents of tocopherols, phenolics, and phytosterols were detected in roselle seed oil to provide nutritional, pharmaceutical, and therapeutic properties. On the other hand, roselle leaves with valuable contents of phenols, flavonoids, organic acid, and tocopherols can be applied in silver nanoparticles, food product development, and the pharmaceutical industry. Roselle calyces with high content of anthocyanins, protocatechuic acids, and organic acids are widely applied in food and colorant industries.

Novel Insight into the Cellular and Molecular Signalling Pathways on Cancer Preventing Effects of Hibiscus sabdariffa: A Review

A category of diseases known as cancer includes abnormal cell development and the ability to infiltrate or spread to other regions of the body, making them a major cause of mortality worldwide. Chemotherapy, radiation, the use of cytotoxic medicines, and surgery are the mainstays of cancer treatment today. Plants or products produced from them hold promise as a source of anti-cancer medications that have fewer adverse effects. Due to the presence of numerous phytochemicals that have been isolated from various parts of the Hibiscus sabdariffa (HS) plant, including anthocyanin, flavonoids, saponins, tannins, polyphenols, organic acids, caffeic acids, citric acids, protocatechuic acid, and others, extracts of this plant have been reported to have anti-cancer effects. These compounds have been shown to reduce cancer cell proliferation, induce apoptosis, and cause cell cycle arrest. They also increase the expression levels of the cell cycle inhibitors (p53, p21, and p27) and the pro-apoptotic proteins (BAD, Bax, caspase 3, caspase 7, caspase 8, and caspase 9). This review highlights various intracellular signalling pathways involved in cancer preventive potential of HS.

Fusarium solani infection disrupts metabolism during the germination of roselle (Hibiscus sabdariffa L.) seeds

Fungal infections adversely influence the production and quality of seeds. Previously, Fusarium solani was reported as the causal agent of roselle (Hibiscus sabdariffa L.) seed rot. This study was designed to evaluate the effect of F. solani infection on the germination, biochemical composition, energy reserves, and antioxidant activity of roselle seeds because there is currently a lack of information on the relationship between seed metabolism and infection with F. solani. The results showed that roselle seeds infected with F. solani exhibited a ca. 55% reduction in overall germination. Additionally, the fungal infection decreased antioxidant activity, total phenolic content, protein, sugar (sucrose, fructose, and glucose), and some amino acid (glutamine, serine, and arginine) contents. In contrast, some metabolites were more abundant in infected seeds, including alanine (2.1-fold) and some fatty acids (palmitic acid and heptadecanoic acid by 1.1- and 1.4-fold, respectively). The infection-associated changes in fatty acid profile resulted in the ratio of unsaturated/saturated fatty acids being 2.1-fold higher in infected seeds. Therefore, our results reveal that F. solani infection remarkably altered the biochemical composition of roselle seeds, which may have contributed to the loss of germination and quality of roselle seeds.

Natural Agents as Novel Potential Source of Proteasome Inhibitors with Anti-Tumor Activity: Focus on Multiple Myeloma

Multiple myeloma (MM) is an aggressive and incurable disease for most patients, characterized by periods of treatment, remission and relapse. The introduction of new classes of drugs, such as proteasome inhibitors (PIs), has improved survival outcomes in these patient populations. The proteasome is the core of the ubiquitin-proteasome system (UPS), a complex and conserved pathway involved in the control of multiple cellular processes, including cell cycle control, transcription, DNA damage repair, protein quality control and antigen presentation. To date, PIs represent the gold standard for the treatment of MM. Bortezomib was the first PI approved by the FDA, followed by next generation of PIs, namely carfilzomib and ixazomib. Natural agents play an important role in anti-tumor drug discovery, and many of them have recently been reported to inhibit the proteasome, thus representing a new potential source of anti-MM drugs. Based on the pivotal biological role of the proteasome and on PIs' significance in the management of MM, in this review we aim to briefly summarize recent evidence on natural compounds capable of inhibiting the proteasome, thus triggering anti-MM activity.

Antioxidant, physicochemical, and sensory properties of buffalo meat patties incorporated with roselle (Hibiscus sabdariffa L.), wolfberry (Lycium barbarum L.), and beetroot (Beta vulgaris L.) purées

The present work evaluated the antioxidant, physicochemical, and sensory properties of buffalo meat patties incorporated with 2% roselle (Hibiscus sabdariffa L.), wolfberry (Lycium barbarum L.), or beetroot (Beta vulgaris L.), and chill-stored (4°C) for 11 days. 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, 2-thiobarbituric acid reactive substances (TBARS), shrinkage, cooking yield, water holding capacity, pH, colour, textural properties, and sensory evaluation of the patties were examined. Patties incorporated with roselle, wolfberry, and beetroot had increased scavenging activity, thus decreasing oxidative activity in the patties during storage. Cooking yield was improved in all treatments with significant decrease in pH in both cooked and uncooked roselle-incorporated patties. No changes were observed for the texture of all samples, while roselle-incorporated patties maintained the redness after the 11th day of storage. Sensory attributes of the modified patties were acceptable to all panellists. In conclusion, the incorporation of roselle in buffalo meat patties showed more beneficial effects than the other purées tested in improving the quality of the patties while maintaining their sensory properties.

Efficient green photocatalyst of silver-based palladium nanoparticles for methyle orange photodegradation, investigation of lipid peroxidation inhibition, antimicrobial, and antioxidant activity

Nanotechnology is an interdisciplinary study that has been developing worldwide in recent years and has a serious impact on human life. The fact that the nanoparticles of plant origin are clean, non-toxic, and biocompatible has enabled new fields of study. The Hibiscus sabdariffa (H. sabdariffa) plant has been attracted by scientists because of its impact on health and many other areas. The lipid peroxidation inhibiting activity, antioxidant properties, and antimicrobial properties of H. sabdariffa plant with Ag-Pd metal was ditermined. For the total phenolic component, gallic acid was used as the standard and quarcetin was used for the total flavonoid. The lipid peroxidation inhibition activity of Ag-Pd NPs in ethanol extract was found to be very well compared to the positive control (BHA). The lowest and highest concentrations of DPPH radical scavenging activity were 82.178-97.357%, whereas for BHA these values were found to be 84.142-94.142%. The highest concentration of Ag-Pd NPs at 200 μg/mL the DPPH radical quenching activity was higher than BHA. Ag-Pd NPs showed a good antimicrobial activity against certain pathogenic microorganisms such as Bacillus subtilis, Enterococcus faecalis, Escherichia coli, Pseudomonas aeruginosa, Candida albicans, which are the causative agents of various diseases in humans. The photodegradation activity of Ag-Pd NPs also investigated against Methyl orange dye (MO) under sunlight irradiation for 120 min and was found to be as 67.88.

Experimental and theoretical study of the dye-sensitized solar cells using Hibiscus sabdariffa plant pigment coupled with polyaniline/graphite counter electrode

In this research work, the extraction, characterization, device fabrication, and theoretical investigation of Hibiscus sabdariffa plant extract, for possible application in solid DSSCs, are reported. The plant extract was analyzed using FT-IR and UV–Vis spectrophotometry. Polyaniline on graphene was used as the counter electrode whereas titanium (IV) oxide was used as the photo anode for the fabricated DSSCs. The experimental results obtained for the open circuit voltage, short circuit current density, field factor, maximum power and conversion efficiency are 0.925 V, 0.073 A/cm2, 1.43, 1.04 W, and 0.044 % respectively. The excited states of anthocyanin (delphinidin) and quercetin, the most stable structures of Hibiscus sabdariffa plant extract, were studied using density functional theory method. In addition, the theoretical open circuit voltage, light harvesting efficiency, coupling constant, free energy change, and HOMO–LUMO energy gap were predicted for the photovoltaic properties. The theoretical results suggest that quercetin has relatively better photovoltaic properties and, hence, potentially a better dye for solar cell application.

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.

Systematic Review of Medicinal Plants Used for Treatment of Diabetes in Human Clinical Trials: An ASEAN Perspective

Traditionally, there are some medicinal plants believed to treat diabetes, as they have been proven in research studies to possess antidiabetic properties, such as improved insulin sensitivity and hypoglycemic activities, due to their high level of phenolic compounds, flavonoids, terpenoids, alkaloids, and glycosides. We conducted a systematic review to identify potential medicinal plants used during human clinical trials in the Association of Southeast Asian Nation (ASEAN) countries on prediabetic or type 2 diabetic individuals and to potentially identify any bioactive compounds involved in effectively treating symptoms of diabetes such as lowering of blood glucose. A total of 1209 reference titles were retrieved from four selected databases (Science Direct, Scopus, Springer Link, and PubMed) and only three met the inclusion criteria. Upon evaluation of the selected articles, four medicinal plants were identified: turmeric (Curcuma longa), garlic (Allium sativum L.), bitter melon (Momordica charantia), and Rosella flower (Hibiscus sabdariffa L.). Of these, only the bitter melon study did not show any significant change in the blood glucose of participants after intervention. This review demonstrates the limitations in published articles of human clinical trials for medicinal plants' intervention for diabetes. Upon further investigations on the four identified medicinal plants included in the animal studies, the findings showed positive effects in the management of diabetes, such as hyperglycemia. Hence, further testing and standardization of the methods in the studies can be suggested for human clinical trials for reliable data collections such as methods of extract preparation, duration of intervention, and conditions set for the study design.

Effects of drying methods on oxidative stability of roselle seed oil (Hibiscus Sabdariffa): an optimization approach

The objective of this study was to optimize the extraction of oil from pre-dried roselle seeds using response surface methodology (RSM). We also determined the oxidative stability of oil extracted from oven and freeze-dried roselle seed in terms of iodine value (IV), free fatty acid (FFA) value, peroxide value (PV), P-anisidine and total oxidation values (TOTOX value). The RSM was designated based on the central composite design with the usage of three optimum parameters ranged from 8 to 16 g of sample weight, 250-350 mL of solvent volume, and 6-8 h of extraction time. The highest oil yielded from roselle seed using the optimization process was 22.11% with the parameters at sample weight of 14.4 g, solvent volume of 329.70 mL, and extraction time of 7.6 h. Besides, the oil extracted from the oven dried roselle seed had the values of 89.04, 2.11, 4.13, 3.76 and 12.03 for IV, FFA, PV, P-anisidine, and TOTOX values, respectively. While for the oil extracted from freeze-dried roselle seed showed IV of 90.31, FFA of 1.64, PV of 2.47, P-anisidine value of 3.48, and TOTOX value of 8.42. PV and TOTOX values showed significant differences whereas; IV, FFA, and P-anisidine values showed no significant differences between the oven and freeze-dried roselle seed oils.

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.

Hibiscus cannabinus L. (kenaf) studies: Nutritional composition, phytochemistry, pharmacology, and potential applications

The electronic database was searched up to July 2020, using keywords, kenaf and roselle, chemical constituents of kenaf and roselle, therapeutic uses of kenaf and roselle. Journals, books and conference proceedings were also searched. Investigations of pharmacological activities of kenaf revealed that this edible plant exhibits a broad range of therapeutic potential including antioxidant, antimicrobial, antityrosinase, anticancer, antihyperlipidemia, antiulcer, anti-inflammatory, and hepatoprotective activities. Kenaf also showed versatile utility as a functional ingredient in food, folk medicine, and animal nutritions, as well as in nanotechnology processes. The exploitation of underexploited kenaf by-products can be a significant part of waste management from an economic and environmental point of view. In addition, kenaf showed comparable nutritional, phytochemical, and pharmacological properties with Hibiscus sabdariffa (Roselle). This review has important implications for further investigations and applications of kenaf in food and pharmaceuticals industry.

Ultrasound Assisted Cascade Extraction of Oil, Vitamin E, and Saccharides from Roselle (Hibiscus Sabdariffa L.) Seeds

Roselle seeds, a waste biomass of the roselle calyx processing industry, were utilized to recover valuable compounds of oil, vitamin E, and water-soluble saccharides. Firstly, ultrasound-assisted extraction (UAE) and conventional stirring extraction were conducted for saccharide extraction, and the advantage of UAE was confirmed. Secondly, oil, vitamin E, and saccharides extracted from Vietnamese roselle seeds by UAE were analyzed for the first time. Oil of tri-, di-, and mono-glycerides, fatty acids of linoleic-, oleic-, palmitic-, and stearic-acids, vitamin E of γ- and α-tocopherol, and saccharides of sucrose, raffinose, stachyose, etc. were identified, and the amounts of these components were compared with those in other country's roselle seeds. Thirdly, cascade extraction of oil, vitamin E, and saccharides by UAE was investigated with solvents of hexane, hexane:ethyl acetate binary solvent, and water. The results indicated that the order of using solvents was very important for high and selective extraction: the best order to recover oil (almost 100%), vitamin E (95.7%), and saccharides (86.2%) was hexane, and then water.

Profiling of the lipophilic components of seed oil obtained from two medicinal plants Corchorus capsularis L. and Hibiscus sabdariffa L

The minor lipophilic composition of seed oils obtained from two medicinal plants (C. capsularis and H. sabdariffa L.), tocopherol, tocotrienols, sterols, carotenoids and squalene, was studied. The oil yield from the seeds of H. sabdariffa and C. capsularis was 19.1 and 12.7%, respectively. The main three fatty acids of the oils from both species were - linoleic, oleic, and palmitic acid (over 95% of all). γ-Tocopherol consisted of over 65% of total tocopherol content of four detected homologues, in both species. Nine and ten sterols were detected in H. sabdariffa and C. capsularis seed oil, respectively. β-Sitosterol was the main sterol (over 50% of all). Lutein was the main carotenoid detected in both species. The total amount of tocopherols, carotenoids and sterols in C. capsularis vs. H. sabdariffa seed oil were 117.2 vs. 159.2, 0.27 vs. 0.74, and 247.1 vs. 968.0 mg/100 g oil, respectively.

Kenaf (Hibiscus cannabinus L.) Seed and its Potential Food Applications: A Review

Kenaf belongs to the family Malvaceae noted for their economic and horticultural importance. Kenaf seed is a valuable component of kenaf plant. For several years, it has been primarily used as a cordage crop and secondarily as a livestock feed. The potential for using kenaf seeds as a source of food-based products has not been fully exploited. Consumers are becoming more interested in naturally healthy plant-based food products. Kenaf seed, the future crop with a rich source of essential nutrients and an excellent source of phytocompounds, might serve suitable roles in the production of value-added plant-based foods. At present kenaf seed and its value-added components have not been effectively utilized for both their nutritional and functional properties as either ingredient or major constituent of food products. This review focuses on the possible food applications of kenaf seed and its value-added components based on their nutritional composition and functional properties available in literature, with the purpose of providing an overview on the possible food applications of this underutilized seed. The review focuses on a brief introduction on kenaf plant, nutritional function, lipids and proteins composition and food applications of the seed. The review elaborately discusses the seed in terms of; bioactive components, antioxidants enrichment of wheat bread, antimicrobial agents, as edible flour, as edible oil and a source of protein in food system. The review closes with discussion on other possible food applications of kenaf seed. The need for food scientists and technologists to exploit this natural agricultural product as a value-added food ingredient is of great significance and is emphasized.

Anti-Multiple Myeloma Potential of Secondary Metabolites from Hibiscus sabdariffa

Multiple myeloma (MM) belongs to hematological cancers and its incidence is increasing worldwide. Despite recent advances in its therapy, MM still causes many deaths every year. In fact, current therapies sometimes fail and are associated with severe adverse effects, including neurotoxicity. As a part of our ongoing efforts to discover new potential therapies against MM, we prepared Hibiscus sabdariffa extracts obtained by a microwave-assisted solvent extraction and investigate their activity by in vitro assays on the RPMI-8226 cell line. The bioguided fractionation of the crude ethanolic extract allowed the identification of HsFC as the most effective extract. We assessed cell viability (MTT and Tripan blue test), cell migration (Boyden chamber assay), and neurotoxicity (DRG neurotoxicity assay). The promising results prompted us to further fractionate HsFC and we obtained two molecules effective against RPMI-8226 cells without neurotoxic effects at their active concentrations. Moreover, both compounds are able to significantly reduce cell migration.

Antibacterial and cytotoxicity activities and phytochemical analysis of three ornamental plants grown in Mexico

This study evaluates the antibacterial, cytotoxic activities, and phytochemical composition, of Callistemon citrinus, Hibiscus rosa-sinensis and Plumbago auriculata leaves and flowers, three ornamental plants in Mexico. However, in other countries offers a range of other uses. Ethanol extracts of C. citrinus leaf and flower presented stronger antibacterial activity than the extracts obtained from the other two plants. C. citrinus leaf showed low cytotoxicity (LC50 <600 µg/mL) on the brine shrimp test, whereas the ethanol extracts of H. rosa-sinensis and P. auriculata leaves showed no cytotoxic activity. Flower extracts obtained from the three plants did no exhibit cytotoxicity. GC-MS analysis revealed that the ethanol extract of P. auriculata leaf contained lupeol triterpene and lupeol acetate, neither of them have been previously reported in this genus. Gamma sitosterol was present in the leaf and flower extracts of P. auriculata. Higher contents of linoleic and linolenic acids were found in extracts of H. rosa-sinensis leaves and flowers. The ability of the ethanol extracts of C. citrinus leaves and flowers to inhibit the growth of Gram-positive and Gram-negative bacteria indicates a potentially broad antimicrobial spectrum. Moreover, the absence of cytotoxicity suggests the potential use of this plant to treat microbial infections.

Exploring the chemical and bioactive properties of Hibiscus sabdariffa L. calyces from Guinea-Bissau (West Africa)

Different external factors influence the chemical characteristics of natural products, varying according to the geographic origin. The present study determined the nutritional and chemical composition of Hibiscus sabdariffa L. dried calyces (Guinea-Bissauan origin), as well as the phenolic composition, antioxidant, anti-inflammatory, cytotoxicity and antimicrobial activity of its infusion and hydroethanolic extracts. Among the chemical components, glucose and quinic acid showed the major concentration for sugars and organic acids, respectively. Palmitic acid and α-tocopherol were the most abundant lipophilic compounds. The individual phenolic compounds were analysed through HPLC-DAD-ESI/MS. Thirteen compounds were identified in the hydroethanolic extract, while twelve were identified in the infusion, 3-O-caffeoylquinic acid being the major non-anthocyanin compound. Three anthocyanins were identified, delphinidin-3-O-sambubioside being the most abundant. Both extracts showed promising results in all the bioactive assays. This study exhibited the beneficial properties of H. sabdariffa and also emphasized the potential applications of this plant in different industrial sectors.

Development of a Mucoadhesive and an in Situ Gelling Formulation Based on κ-Carrageenan for Application on Oral Mucosa and Esophagus Walls. II. Loading of a Bioactive Hydroalcoholic Extract

The aim of the present work was to load a Hibiscus sabdariffa (HS) hydroalcoholic extract into in situ gelling formulations for the treatment of oral mucositis and esophagitis. Such formulations, selected as the most promising options in a previous work of ours, were composed by κ-carrageenan (κ-CG), a sulfated marine polymer able to gelify in presence of saliva ions, hydroxypropyl cellulose (HPC), used as mucoadhesive agent, and CaCl₂, salt able to enhance the interaction κ-CG/saliva ions. HS extract, which is rich in phytochemicals such as polyphenols, polysaccharides and organic acids, was selected due to its antioxidant and anti-inflammatory properties. For HS extraction, three different methodologies (maceration, Ultrasound Assisted Extraction (UAE) and Microwave Assisted Extraction (MAE)) were compared in terms of extraction yield and extract antioxidant activity, revealing that MAE was the best procedure. Rheological and mucoadhesive properties of HS-loaded formulations were investigated. Such formulations were characterized by a low viscosity at 25 °C, guaranteeing an easy administration, a proper in situ gelation behavior and marked elastic and mucoadhesive properties at 37 °C, functional to a protective action towards the damaged mucosa. Finally, the biocompatibility and the proliferative effect of HS-loaded formulations, as well as their antioxidant and anti-inflammatory properties, were proved in vitro on human dermal fibroblasts.

Composition analysis of carotenoids and phenolic compounds and antioxidant activity from hibiscus calyces (Hibiscus sabdariffa L.) by HPLC-DAD-MS/MS

INTRODUCTION

The hibiscus flower has received increasing interest because it contains high levels of bioactive compounds with remarkable functional properties. To the best of our knowledge, for the first time a detailed description of the carotenoid composition of hibiscus calyces is reported.

OBJECTIVES

Identification and quantification of carotenoids, phenolic compounds and antioxidant activity from hibiscus calyces.

MATERIAL AND METHODS

The composition of the carotenoids and phenolic compounds from hibiscus calyces was determined by high-performance liquid chromatography coupled to a diode array detector and tandem mass spectrometry (HPLC-DAD-MS/MS). Antioxidant activity was assessed using 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical scavenging and hydroxyl radicals scavenging assays.

RESULTS

Twenty-one carotenoids were found and from these compounds 15 were identified or tentatively identified. The major carotenoids were all-trans-lutein (316.43 ± 19.92 μg/100 g) and all-trans-β-carotene (147.76 ± 5.59 μg/100 g). Twenty phenolic compounds were found, from which 14 compounds were identified or tentatively identified. The major phenolic compounds were delphinidin 3-sambubioside (218.17 ± 12.69 mg/100 g) and 3-caffeoylquinic acid (79.22 ± 7.01 mg/100 g), representing almost 60% (w/w) of the total phenolic compounds from hibiscus calyces. The hibiscus presented low vitamin A activity, measure as retinol activity equivalent (13.52 μg/100 g). The scavenging activity of ABTS and hydroxyl radicals were 7.8 μmol Trolox equivalent/g and 81%, respectively.

CONCLUSION

In this study we have shown that the hibiscus calyces can be considered as a food rich in lutein, chlorogenic acids and anthocyanins (delphinidin 3-sambubioside).

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.

Anti-inflammatory activities of essential oil isolated from the calyx of Hibiscus sabdariffa L

Hibiscus sabdariffa Linn., belonging to the family of Malvaceae, is considered to be a plant with health care applications in China. The main purpose of this study was to analyze the composition of its essential oil and assess its potential therapeutic effect on anti-inflammatory activity. A water steam distillation method was used to extract the essential oil from H. Sabdariffa. The essential oil components were determined by gas chromatography/mass spectrometry (GC-MS) analysis and a total of 18 volatile constituents were identified, the majority of which were fatty acids and ester compounds. Biological activity showed that the essential oil extracted from H. Sabdariffa exhibited excellent anti-inflammatory activity in lipopolysaccharide (LPS)-stimulated macrophage RAW 264.7 cells. The nitric oxide (NO) inhibition rate reached 67.46% when the concentration of the essential oil was 200 μg mL^-1. Further analysis showed that the anti-inflammatory activity of the essential oil extracted from H. Sabdariffa might be exerted through inhibiting the activation of NF-κB and MAPK (JNK and ERK1/2) signaling pathways to decrease NO and pro-inflammatory cytokine (IL-1, IL-6, TNF-α, COX-2, and iNOS) production. Thus, the essential oil extracted from H. Sabdariffa is a good source of a natural product with a beneficial effect against inflammation, and it may be applied as a food supplement and/or functional ingredient.

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.

Effect of a Food Supplement Containing L-Methionine on Urinary Tract Infections in Pregnancy: A Prospective, Multicenter Observational Study

OBJECTIVE

Adjuvants or alternatives to antibiotics in urinary tract infections (UTIs) during pregnancy seem advisable because of possible fetal stress. The present study assessed the effectiveness of a food supplement containing L-methionine and Hibiscus sabdariffa L. and Boswellia serrata Roxb. extracts as a treatment for symptomatic UTIs in pregnancy.

DESIGN

Pregnant patients with symptomatic cystitis were screened for UTIs in three different clinical centers. Those unwilling to take antibiotics were offered two alternative treatments: (A) a 1-week treatment with the food supplement or (B) a week in which they were advised to increase their fluid consumption to more than 1.5 L daily. After 1 week, group B patients who still had positive urine cultures (UCs) or had no UC performed took the food supplement for an additional week. UCs were performed on all patients at the first visit (w0) and on most of them at 7 days (w1). Patients who were still positive at w1 or had no UC performed at w1 had UC performed 14 days (w2) thereafter.

RESULTS

Of 264 pregnant women enrolled, 216 joined group A, while 48 joined group B. At w1, 70.0% of group A patients and 43.2% of those in group B had negative UCs (p = 0.003). The reduction of bacterial load was 42.2% ± 8.0% and 4.5% ± 9.2%, respectively (p < 0.0001). At w1, symptoms disappeared in 135 patients (62.5%) in group A and 22 patients (45.8%) in group B (p = 0.03). At w2, 30 of 32 group B patients who switched to taking the supplement for the second week had negative UCs, including 20 who had been positive at w1. At w2, all group A patients had negative UCs. No side effects were reported.

CONCLUSIONS

The food supplement provided effective treatment and might be an adjuvant or alternative to antibiotic therapy of symptomatic UTI in pregnancy.

Hibiscus sabdariffa Leaf Extract Inhibits Human Prostate Cancer Cell Invasion via Down-Regulation of Akt/NF-kB/MMP-9 Pathway

Hibiscus sabdariffa leaf has been previously shown to possess hypoglycemic, hypolipidemic, and antioxidant effects, and induce tumor cell apoptosis. However, the molecular mechanisms involved in the anticancer activity of H. sabdariffa leaf extract (HLE) are poorly understood. The object of the study was to examine the anti-invasive potential of HLE. First, HLE was demonstrated to be rich in polyphenols. The results of wound-healing assay and in vitro transwell assay revealed that HLE dose-dependently inhibited the migration and invasion of human prostate cancer LNCaP (lymph node carcinoma of the prostate) cells under non-cytotoxic concentrations. Our results further showed that HLE exerted an inhibitory effect on the activity and expressions of matrix metalloproteinase-9 (MMP-9). The HLE-inhibited MMP-9 expression appeared to be a consequence of nuclear factor-kappaB (NF-κB) inactivation because its DNA-binding activity was suppressed by HLE. Molecular data showed all these influences of HLE might be mediated via inhibition of protein kinase B (PKB, also known as Akt)/NF-κB/MMP-9 cascade pathway, as demonstrated by the transfection of Akt1 overexpression vector. Finally, the inhibitory effect of HLE was proven by its inhibition on the growth of LNCaP cells and the expressions of metastasis-related molecular proteins in vivo. These findings suggested that the inhibition of MMP-9 expression by HLE may act through the suppression of the Akt/NF-κB signaling pathway, which in turn led to the reduced invasiveness of the cancer cells.

Hibiscus sabdariffa leaf polyphenolic extract induces human melanoma cell death, apoptosis, and autophagy

Melanoma is the least common but most fatal form of skin cancer. Previous studies have indicated that an aqueous extract of Hibiscus sabdariffa leaves possess hypoglycemic, hypolipidemic, and antioxidant effects. In this study, we want to investigate the anticancer activity of Hibiscus leaf polyphenolic (HLP) extract in melanoma cells. First, HLP was exhibited to be rich in epicatechin gallate (ECG) and other polyphenols. Apoptotic and autophagic activities of HLP and ECG were further evaluated by DAPI stain, cell-cycle analysis, and acidic vascular organelle (AVO) stain. Our results revealed that both HLP and ECG induced the caspases cleavages, Bcl-2 family proteins regulation, and Fas/FasL activation in A375 cells. In addition, we also revealed that the cells presented AVO-positive after HLP treatments. HLP could increase the expressions of autophagy-related proteins autophagy-related gene 5 (ATG5), Beclin1, and light chain 3-II (LC3-II), and induce autophagic cell death in A375 cells. These data indicated that the anticancer effect of HLP, partly contributed by ECG, in A375 cells. HLP potentially could be developed as an antimelanoma agent.

Recent advances on the use of biochemical extracts as filaricidal agents

Lymphatic filariasis is a parasitic infection that causes a devastating public health and socioeconomic burden with an estimated infection of over 120 million individuals worldwide. The infection is caused by three closely related nematode parasites, namely, Wuchereria bancrofti, Brugia malayi, and B. timori, which are transmitted to human through mosquitoes of Anopheles, Culex, and Aedes genera. The species have many ecological variants and are diversified in terms of their genetic fingerprint. The rapid spread of the disease and the genetic diversification cause the lymphatic filarial parasites to respond differently to diagnostic and therapeutic interventions. This in turn prompts the current challenge encountered in its management. Furthermore, most of the chemical medications used are characterized by adverse side effects. These complications urgently warrant intense prospecting on bio-chemicals that have potent efficacy against either the filarial worms or thier vector. In lieu of this, we presented a review on recent literature that reported the efficacy of filaricidal biochemicals and those employed as vector control agents. In addition, methods used for biochemical extraction, screening procedures, and structure of the bioactive compounds were also presented.

Modification of the liver fatty acids by Hibiscus sabdariffa Linnaeus (Malvaceae) infusion, its possible effect on vascular reactivity in a metabolic syndrome model

We investigated the effects of Hibiscus sabdariffa Linnaeus (HSL)-fed infusion on the fatty acid (FA) profile in liver of metabolic syndrome (MS) rats and its possible effect on vascular reactivity. Body mass, intra-abdominal fat, triglycerides, insulin, blood pressure, saturated, monounsaturated FA, NEFAs, Δ(9)-, Δ(6)-desaturases and vasoconstriction were increased, while vasorelaxation, polyunsaturated FA, endothelial nitric oxide and [Formula: see text]/[Formula: see text] ratio decreased in MS versus Control, but HSL infusion modified it and increased Δ(5)-desaturase. The results suggest that the alteration in FA liver metabolism in the MS contributes to impaired vascular reactivity, but treatment with of HSL infusion can improve this condition.

Hibiscus sabdariffa leaf polyphenolic extract inhibits LDL oxidation and foam cell formation involving up-regulation of LXRα/ABCA1 pathway

The oxidative modification of low-density lipoprotein (LDL) is involved in the pathogenesis of atherosclerotic lesions through the formation of macrophage-derived foam cells. In the present study, we aimed to investigate the anti-atherosclerotic effect of Hibiscus sabdariffa leaf polyphenolic extract (HLP), which is rich in flavonoid. The inhibitory effect of HLP on oxidation and lipid peroxidation of LDL was defined in vitro. HLP showed potential in reducing foam cell formation and intracellular lipid accumulation in oxidised-LDL (ox-LDL)-induced macrophage J774A.1 cells under non-cytotoxic concentrations. Molecular data showed these influences of HLP might be mediated via liver-X receptor α (LXRα)/ATP-binding cassette transporter A1 (ABCA1) pathway, as demonstrated by the transfection of LXRα siRNA. Our data implied that HLP up-regulated the LXRα/ABCA1 pathway, which in turn led to stimulation of cholesterol removal from macrophages and delay atherosclerosis. These results suggested that HLP potentially could be developed as an anti-atherosclerotic agent.

Functional properties of roselle (Hibiscus sabdariffa L.) seed and its application as bakery product

Roselle (Hibiscus sabdariffa L.) seed is a valuable food resource as it has an excellent source of dietary fibre. Therefore, this study examined the functional properties of roselle seeds. Replacement of cookie flour with roselle seed powder at levels of 0-30 % was investigated for its effect on functional and nutritional properties of cookies. Among the four formulations cookies, the most preferred by panelists was 20 % roselle seed powder cookie (F3), followed by 10 % roselle seed powder cookie (F2) and 30 % roselle seed powder cookie (F4). The least preferred formulation among all was control cookie (F1). Cookie with 20 % roselle seed powder added showed higher content of total dietary fibre (5.6 g/100 g) as compared with control cookie (0.90 g/100 g). Besides that, cookies incorporated with roselle seed powder exhibited improved antioxidant properties. Thus, roselle seed powder can be used as a dietary fibre source and developed as a functional ingredient in food products.