Potential of Hibiscus sabdariffa L. and Hibiscus Acid to Reverse Skin Aging

Hibiscus sabdariffa L. (HS) has a long history of edible and medicinal uses. In this study, the biological activities of the extracts, chromatographic fractions, and hibiscus acid obtained from HS were evaluated for their potential bioactivities. Their ability to promote extracellular matrix synthesis in skin fibroblasts was evaluated by enzyme-linked immunosorbent assays. Their anti-inflammatory activity was evaluated in a nitric oxide (NO)–Griess inflammatory experiment. Furthermore, hibiscus acid was found to have a strong anti-oxidative stress effect through the establishment of an oxidative stress model induced by hydrogen peroxide. Several assays indicated that hibiscus acid treatment can effectively reduce extracellular adenosine triphosphate (ATP) secretion and carbonyl protein production, as well as maintain a high level of reduced/oxidized glutathione (GSH/GSSG) in skin cells, thus providing a possible mechanism by which hibiscus acid can counter antioxidative stress. The present study is the first to explore the reversing skin aging potential and the contributory component of HS.     

Exploratory analysis of simultaneous degradation of anthocyanins in the calyces of flowers of the Hibiscus sabdariffa species by PARAFAC model.

A three-way resolution method based on PARAFAC model was applied for the UV-Vis spectra to study the simultaneous degradation of anthocyanins extracted from fresh calyces of flowers of the Hibiscus sabdariffa. This methodology was used to resolve a chemical system, for which there was no a priori information about the composition or the pure spectra, a so-called black system. In the pH range from 1 to 13, seven species were identified: flavylium cation, carbinol, quinoidal base, E- and Z-chalcones and E- and Z-ionized chalcones. The concentration changes were determined as functions of pH at different wavelengths. The pK values for the acidity constants as well as tautomeric constant were estimated as 2.70, 3.54 and 0.14, respectively. The spectral profiles recovered by the chemometric methods are in excellent agreement with bands of experimental spectra reported in the literature for the species measured at specific pH values.     

扶桑花与玫瑰茄微量元素含量的比较研究

测定了扶桑花十种微量元素含含量，并与玫瑰茄作了含量比较研究。     

Hibiscus Acid from Hibiscus sabdariffa L. Inhibits Flagellar Motility and Cell Invasion in Salmonella enterica

Extracts of Hibiscus sabdariffa L. (commonly called Rosselle or “Jamaica flower” in Mexico) have been shown to have antibiotic and antivirulence properties in several bacteria. Here, an organic extract of H. sabdariffa L. is shown to inhibit motility in Salmonella enterica serovars Typhi and Typhimurium. The compound responsible for this effect was purified and found to be the hibiscus acid. When tested, this compound also inhibited motility and reduced the secretion of both flagellin and type III secretion effectors. Purified hibiscus acid was not toxic in tissue-cultured eukaryotic cells, and it was able to reduce the invasion of Salmonella Typhimurium in epithelial cells. Initial steps to understand its mode of action showed it might affect membrane proton balance.     

Effect of Different Drying Methods on the Nutritional Value of Hibiscus sabdariffa Calyces as Revealed by NMR Metabolomics

Red mature calyces of Hibiscus sabdariffa were collected from 16 different locations in Meghalaya, India. Samples were processed using shade drying (SD) and tray drying (TD). NMR spectroscopy was used to assess the metabolic composition of the calyces. In this study, 18 polar metabolites were assigned using 1D and 2D NMR spectra, and 10 of them were quantified. Proximate analysis showed that the TD method is more efficient at reducing moisture and maintaining the ash content of the Hibiscus biomass. NMR metabolomics indicates that the metabolite composition significantly differs between SD and TD samples and is more stable in TD plant processing. The differences in post-harvest drying has a greater impact on the metabolite composition of Hibiscus than the plant location.     

Selective extraction, separation, and identification of anthocyanins from Hibiscus sabdariffa L. using solid phase extraction-capillary electrophoresis-mass spectrometry (time-of-flight /ion trap)

A method for selective extraction using SPE, electrophoretic separation at basic condition and the identification by using exact masses and fragmentation patterns has been developed in order to know the anthocyanins in dried calyces of Hibiscus sabdariffa L. A detailed and comparative study of several extraction procedures has been carried out to obtain the maximum number of anthocyanidins from the calyces and then a CE-TOF-MS method in positive mode using ESI has been developed for the separation and rapid identification of anthocyanins in H. sabdariffa L. Delphinidin-3-sambubioside, cyanidin-3-sambubioside have been detected as main components and cyanidin-3-O-rutinoside, delphinidin-3-O-glucoside and cyanidin-3,5-diglucoside, and chlorogenic acid as minor constituents. The confirmation of the anthocyanidins and chlorogenic acid was carried out using fragmentation ions with the IT-mass spectrometer (IT-MS).     

紫荆花与玫瑰茄微量元素含量的比较研究

首次报道紫荆花十种微量元素含量，并与玫瑰茄作了含量比较研究．     

Hibiscus sabdariffa synthesized gold nanoparticles ameliorate aluminum chloride induced memory deficits through inhibition of COX-2/BACE-1 mRNA expression in rats

Alzheimer’s disease (AD) is a major health challenge worldwide, especially among the elderly. The disease is associated with cognitive and memory deficits. This study investigated the effect of Hibiscus sabdariffa synthesized-gold nanoparticles (HS-AuNPs) on AlCl₃-induced memory deficits in rats. Forty-two male Wistar rats were divided into six groups (n = 7). Group I served as control. Rats in group II - V were exposed to AlCl₃ (100 mg/kg) to induce AD. Group III - V rats were treated with 5 mg/kg donepezil, 5 and 10 mg/kg HS-AuNPs, respectively, for 14 days. Behavioral tests were carried out on the rats on day 28 and 42. At the end of animal experiment, rats were sacrificed and used for various biochemical assays and gene expression. The AD rats showed memory and learning impairment, and these conditions were ameliorated by HS-AuNPs. Significant (p < 0.05) elevation in the activities of acetylcholinesterase, monoamine oxidase and adenosine deaminase, as well as malondialdehyde levels was noted. A significant reduction in the activities of superoxide dismutase (SOD), glutathione peroxidase (GPx) and reduced glutathione (GSH) noted in AlCl₃-induced rats were ameliorated by the 5 and 10 mg/kg b.w. doses of HS-AuNPs. In addition, the increased mRNA expression of cyclooxygenase-2 (COX-2) and beta-secretase 1 (BACE-1) caused by AlCl₃ were assuaged by the HS-AuNPs treatment. Based on the activities of HS-AuNPs against AlCl₃-induced AD, HS-AuNPs could be considered a potential therapeutic agent for managing AD.     

Modulation of Renal Function in a Metabolic Syndrome Rat Model by Antioxidants in Hibiscus sabdariffa L.

Metabolic syndrome (MS) is the association of three or more pathologies among which obesity, hypertension, insulin resistance, dyslipidemia, and diabetes are included. It causes oxidative stress (OS) and renal dysfunction. Hibiscus sabdariffa L. (HSL) is a source of natural antioxidants that may control the renal damage caused by the MS. The objective of this work was to evaluate the effect of a 2% HSL infusion on renal function in a MS rat model induced by the administration of 30% sucrose in drinking water. 24 male Wistar rats were divided into 3 groups: Control rats, MS rats and MS + HSL rats. MS rats had increased body weight, systolic blood pressure, triglycerides, insulin, HOMA index, and leptin (p ≤ 0.04). Renal function was impaired by an increase in perfusion pressure in the isolated and perfused kidney, albuminuria (p ≤ 0.03), and by a decrease in clearance of creatinine (p ≤ 0.04). The activity of some antioxidant enzymes including the superoxide dismutase isoforms, peroxidases, glutathione peroxidase, glutathione-S-transferase was decreased (p ≤ 0.05). Lipoperoxidation and carbonylation were increased (p ≤ 0.001). The nitrates/nitrites ratio, total antioxidant capacity, glutathione levels and vitamin C were decreased (p ≤ 0.03). The treatment with 2% HSL reversed these alterations. The results suggest that the treatment with 2% HSL infusion protects renal function through its natural antioxidants which favor an improved renal vascular response. The infusion contributes to the increase in the glomerular filtration rate, by promoting an increase in the enzymatic and non-enzymatic antioxidant systems leading to a decrease in OS and reestablishing the normal renal function.     

Changes in Physicochemical Properties and Volatile Compounds of Roselle (Hibiscus sabdariffa L.) Calyx during Different Drying Methods

Fresh roselle are high in moisture and deteriorate easily, which makes drying important for extending shelf-life and increasing availability. This study investigated the influence of different drying methods (oven-drying, freeze-drying, vacuum-drying, and sun-drying) on the quality of roselle calyx expressed as physicochemical properties (moisture content, water activity, soluble solids, color), volatile compounds, and microstructure. Oven-drying and freeze-drying reduced moisture content most while vacuum-drying and sun-drying were not as efficient. All drying methods except sun-drying resulted in water activities low enough to ensure safety and quality. Vacuum-drying had no impact on color of the dry calyx and only small impact on color of water extract of calyx. Drying reduced terpenes, aldehydes, and esters but increased furans. This is expected to reduce fruity, floral, spicy, and green odors and increase caramel-like aroma. Sun-drying produced more ketones, alcohols, and esters. Scanning electron microscopy revealed that freeze-drying preserved the cell structure better, and freeze-dried samples resembled fresh samples most compared to other drying techniques. The study concludes that freeze-drying should be considered as a suitable drying method, especially with respect to preservation of structure.     

High-Performance Thin-Layer Chromatographic Method for Screening Antioxidant Compounds and Discrimination of Hibiscus sabdariffa L. by Principal Component Analysis

JPC – Journal of Planar Chromatography – Modern TLC - The leaves of Hibiscus sabdariffa L. are one of the sources of food and traditional medicine. A combination of high-performance...     

Untargeted GC-MS Metabolomics applied to wild leaves and callus produced by plant tissue culture of Hibiscus sabdariffa L.

Hibiscus sabdariffa L. is a naturalized medicinal species in Brazil commonly called a “vinagreira” and is a member of the Malvaceae Juss. family, which has a rich potential of bioactive compounds presenting extracts with antioxidant, antibacterial, anti-inflammatory, hepatoprotective, antiviral, antidiabetic, and antiobesity, among others. The production of secondary metabolites of medicinal plants using biotechnological tools such as the culture of callus of plant tissues is increasingly being used to produce high-quality compounds under in vitro conditions. From this perspective, the objective of this work was to analyze the chemical compounds of the leaves and callus culture of H. sabdariffa using techniques of Gas Chromatography Coupled to the Mass Spectrum (GC-MS),. The analysis methodology used consisted of removal of liposoluble compounds, acid hydrolysis, and derivatization, all stages were submitted to ultrasonic-assisted agitation, using a reduced amount of biomass. Based on the results obtained in the study, a total of 38 metabolites identified by GC-MS analysis can be observed. Among the identified substances, protocatechuic acid (26A) stands out as the main constituent, with a relative abundance of 26.86% and 16.68% for leaves and callus of H. sabdariffa, respectively. The principal component analysis (PCA) allowed the discrimination of the chemical composition of each sample, being useful for the observation and detection of the compounds trends patterns. The analysis of the hierarchical group combined with the heat map represented the visual relationship between the samples of the data set indicating the values of higher and lower concentrations of chemical compounds respectively, confirming that protocatechuic acid is the most abundant, for the leaves and callus of H. sabdariffa, followed by eicosanoid and isocitric acid, produced only in callus. It was concluded that the GC-MS technique combined with chemometric tools, helped identify the diversity of the compounds present in the leaves and callus of H. sabdariffa and that callus culture enables the production of bioactive compounds continuously and uniformly in a controlled environment and free of contamination.     

Green synthesis of palladium nanoparticles using Hibiscus sabdariffa L. flower extract: Heterogeneous and reusable nanocatalyst in Suzuki coupling reactions

An elementary and ecological method has been designed for the biosynthesis of palladium nanoparticles, through the utilization of aqueous extract of red tea (Hibiscus sabdariffa L.) as a reducing and stabilizing agent. The nanoparticles obtained were characterized through UV–visible spectroscopy, transmission election microscopy, X‐ray diffraction, Fourier transform infrared spectroscopy, scanning election microscopy, energy‐dispersive X‐ray analysis and inductively coupled plasma analysis. The nanoparticles with spherical shape and dimensions of approximately 10 nm were used as a heterogeneous catalyst for Suzuki coupling reactions under mild conditions. The high efficiency of the catalytic reaction was affirmed by the good yields of products, easy work‐up, absence of palladium leached from the support and smooth recovery of catalyst.     

Mild steel corrosion inhibition by acid extract of leaves of Hibiscus sabdariffa as a green corrosion inhibitor and sorption behavior

A new corrosion inhibitor, namely acid extract of leaves of Hibiscus sabdariffa, has been synthesized, and its inhibiting action on the corrosion of mild steel in acidic bath (1.2 N HCl and 1.2 N H₂SO₄) has been investigated by corrosion-monitoring techniques. The results of the present study show that this compound has decent inhibiting property for mild steel corrosion in 1.2 N H₂SO₄ than 1.2 N HCl. Four sorption isotherms are tested for the data, namely Langmuir, Frumkin, Florry–Huggins, and Langmuir–Freundlich isotherms; of these the Langmuir isotherm fits the data well having correlation coefficient over 0.99 in both the acid environments.     

Variations in chemical fingerprints and major flavonoid contents from the leaves of thirty‐one accessions of Hibiscus sabdariffa L.

The leaves of Hibiscus sabdariffa L. have been used as traditional folk medicines for treating high blood pressure and fever. There are many accessions of H. sabdariffa L. throughout the world. To assess the chemical variations of 31 different accessions of H. sabdariffa L., fingerprinting analysis and quantitation of major flavonoids were performed by high‐performance liquid chromatography (HPLC). The HPLC method was validated for linearity, sensitivity, precision, repeatability and accuracy. A quadrupole‐time‐of‐flight mass spectrometry (Q‐TOF‐MS) was applied for the characterization of major compounds. A total of 9 compounds were identified, including 6 flavonoids and 3 phenolic acids. In the fingerprint analysis, similarity analysis (SA) and principal component analysis (PCA) were used to differentiate the 31 accessions of H. sabdariffa L. Based on the results of PCA and SA, the samples No. 15 and 19 appeared much different from the main group. The total content of five flavonoids varied greatly among different accessions, ranging from 3.35 to 23.30 mg/g. Rutin was found to be the dominant compound and the content of rutin could contribute to chemical variations among different accessions. This study was helpful to understand the chemical variations between different accessions of H. sabdariffa L., which could be used for quality control. © 2015 The Authors Biomedical Chromatography Published by John Wiley & Sons Ltd.     

Effects of melatonin on reproductive and accessory reproductive organs in male rats.

Effects of daily injections of melatonin on male rat reproductive and accessory reproductive organs were studied. The weight of the prostate was decreased by treatment with a high dose of melatonin (8.0 mg/kg, s.c., injection time; 17:00) once daily for 30 d. The weights of the other accessory reproductive organs and testes were not influenced by melatonin. Lower doses (0.8, 2.4, 4.8 mg/kg), had no effect. After the successive treatment with melatonin (8.0 mg/kg), the testosterone levels in testes and in serum and the conversion rate of [3H]testosterone to [3H]dihydrotestosterone in the prostate were not influenced. The activity of acid phosphatase and the uptake of [3H]testosterone by the prostate, in contrast, were significantly decreased after the successive treatment with melatonin. These data suggest that melatonin may have a direct inhibitory action on male rat prostate, though only at a high dose.     

Direct characterization of aqueous extract of Hibiscus sabdariffa using HPLC with diode array detection coupled to ESI and ion trap MS

The phenolic fraction and other polar compounds of the Hibiscus sabdariffa were separated and identified by HPLC with diode array detection coupled to electrospray TOF and IT tandem MS (DAD‐HPLC‐ESI‐TOF‐MS and IT‐MS). The H. sabdariffa aqueous extract was filtered and directly injected into the LC system. The analysis of the compounds was carried out by RP HPLC coupled to DAD and TOF‐MS in order to obtain molecular formula and exact mass. Posterior analyses with IT‐MS were performed and the fragmentation pattern and confirmation of the structures were achieved. The H. sabdariffa samples were successfully analyzed in positive and negative ionization modes with two optimized linear gradients. In positive mode, the two most representative anthocyanins and other compounds were identified whereas the phenolic fraction, hydroxycitric acid and its lactone were identified using the negative ionization mode.     

Three-way chemometric method study and UV-Vis absorbance for the study of simultaneous degradation of anthocyanins in flowers of the Hibiscus rosa-sinensys species

Ultraviolet-visible spectra of flower extracts of the Hibiscus rosa-sinensys L. var. regius maximus species have been measured between 240.02 and 747.97 nm at pH values ranging from 1.1 to 13.0. Deconvolution of these spectra using the Parallel Factor Analysis (PARAFAC) model permitted the study of anthocyanin systems without isolation and purification of the individual species. Seven species were identified: flavilium cation, carbinol, quinoidal base, and E and Z-chacone and their ionized forms. The concentration changes of flavilium cation, quinoidal basen, and E and Z ionized chalcones were determined as function of pH at the different wavelengths. The flavilium cation, quinoidal base, and ionized E-clacone are involved in tho stage kinetic processes, a fast one followed by a slower one. Ionized Z-chalcone obeys a simple first-order processes. The spectral profiles recovered by PARAFAC model are in excellent agreement with bands of experimental spectra reported in the literature for the individual species measured at specific pH values. These results complement those obtained using chemical and simple mathematical techniques and demonstrate how chemometric methods can resolve problems for complex systems.     

Bio-supported of Cu nanoparticles on the surface of Fe3O4 magnetic nanoparticles mediated by Hibiscus sabdariffa extract: Evaluation of its catalytic activity for synthesis of pyrano[3,2-c]chromenes and study of its anti-colon cancer properties

In this work, we have described the biogenic synthesized copper nanoparticles being supported over plant phytochemicals modified magnetic Fe₃O₄ nanoparticles. Hibiscus sabdariffa extract was used as a green reducing agent and an excellent stabilizer of the synthesized NPs. The biomolecules are adorned as a protective shell over the core ferrite NPs. Physicochemical characterization of the as-synthesized Cu-Hibiscus@Fe₃O₄ nanocomposite was carried out through Fourier transformed infrared spectroscopy (FT-IR), electron microscopy (SEM and TEM), energy dispersive X-ray spectroscopy (EDX), elemental mapping (WDX), vibrating sample magnetometer (VSM), X-ray diffraction (XRD) and inductively coupled plasma-optical emission spectroscopy (ICP-OES). The as-synthesized bio-nanomaterial was used as an excellent heterogeneous and magnetically retrievable catalyst in the three-component condensation of 4-hydroxycoumarin, malononitrile and various aldehydes in refluxing aqueous media. A broad range of aromatic aldehydes underwent the reaction to produce diverse pyrano[3,2-c]chromene derivatives in very good yields irrespective of the nature of bearing functional groups or their respective geometrical positions. Due to superparamagentic character, the material was easily magnetically decanted out and recycled for 8 successive times with preservation of its catalytic activity. After the chemical applications we also explored the material biologically in the resistance of human colon cancer and thereby studied the cytotoxicity over two standard cell lines, HT-29 and Caco-2. The conventional MTT assay was carried out over them which revealed an increase in % cell viability dose dependantly. In addition, DPPH radical scavenging test was performed for studying anti-oxidant activity, using BHT as the positive control. The IC50 values observed in the two cell lines were 490.12 μg/ml and 412.23 μg/ml respectively. The results validate the administration of Cu-Hibiscus@Fe₃O₄ as a competent colon protective drug in the clinical trial studies over human.