Aqueous Extract Of Hibiscus Sabdariffa Research Articles

Fertility and teratogenic study of the aqueous extract of Hibiscus sabdariffa L. in female Sprague Dawley rats

Hibiscus sabdariffa (roselle) has long been gaining attention in phytotherapy research due to its medicinal properties. Despite its benefits, there is very scarce information available on the reproductive toxicity of this plant. The aqueous extract of H. sabdariffa (AEHS) was tested in the present study to investigate its potential effects on fertility and teratogenicity in 40 female Sprague Dawley rats. AESH treatment was administered orally by gavage at four different dosages: 250, 500 and 1000 mg/kg/day or distilled water (control). Treatment began from pre-mating and continued through mating up to the 19th day of pregnancy periods. Throughout this study, the reproductive parameters were evaluated until the day of sacrifice (day 20th of pregnancy). Results obtained revealed no significant differences in general physical health, behaviours and maternal body weights throughout the treatment period. Furthermore, the mean length of the oestrous cycle was not statistically affected, even though a few rats displayed irregular cycles. In addition, there was no statistical significance in the mating and pregnancy indices, number of corpora lutea and implantation sites, percentages of pre-implantation loss and postimplantation death and reproductive organ weights. Foetal parameters such as the number of live foetuses, sex ratio and body weight were also not statistically affected by AESH. Ultimately, there were no signs of teratogenicity observed since none of the foetuses exhibited congenital malformations. In conclusion, these findings imply that the oral administration of AEHS up to 1000 mg/kg/day did not pose any significant toxicity on the fertility and teratogenicity but slightly affected the oestrous cycle in rats.

Hibiscus sabdariffa assisted green fabrication of reduced graphene oxide and its application for methyl orange removal: Optimization employing response surface methodology

Eco-friendly fabrication of reduced graphene oxide (rGO) is of paramount importance among various carbon nanostructures. In the current research, sustainable preparation of rGO via aqueous extract of Hibiscus sabdariffa L. calyces as the green reducer of graphene oxide (GO) without utilizing hazardous chemical agents was described. The structural characteristics of the GO and rGO were studied utilizing Fourier transform infrared (FT-IR) spectroscopy, UV–Visible spectrophotometry, X-ray diffraction (XRD), and scanning electron microscopy (SEM). The prepared nanostructure was applied as the potential adsorbent for effective methyl orange (MO) decolorization and degradation in aqueous solution. The effect of numerous independent parameters on the decolorization process involving rGO dosage, H2O2 volume, process time, and temperature were assessed and optimized via Box-Behnken design/response surface methodology BBD/RSM). A second-order model was proved to express the decolorization efficiency (D %) responses with high values of R2 and adjusted R2. Under optimal condition, the decolorization rate of MO using rGO was higher than 99 % in contact time of 31 min. The reusability of rGO for the MO removal manifested good efficiency in up to five cycles of recyclability. The findings of this research illustrate the feasibility of Hs based rGO as a suitable adsorbent for effective decolorization of MO dye from aqueous medium.

Evaluation of Antibacterial Activity of Selenium and Copper Oxide Nanoparticles Synthesized by Hibiscus sabdariffa L. Extract

The aim of the present study is to synthesize selenium (SeNPs) and copper oxide (CuONPs) nanoparticles utilizing aqueous extract of Hibiscus sabdariffa L. as a reducing agent. The green synthesized Hibiscus sabdariffa L. selenium and copper oxide nanoparticles were identified by color change. The characterization of SeNPs and CuONPs was achieved by Ultraviolet-visible (UV-VIS) spectroscopy, Field Emission Scanning electron microscope (FESEM), Atomic force microscope (AFM), X-Ray diffraction analysis (XRD) and transform infrared spectroscopy (FTIR). These tests are utilized for detecting stability, morphology, size, crystalline nature and functional groups on nanoparticles surface prepared. The outcomes revealed appearance of the prick-red and green color, indicating a specific color of selenium and copper oxide nanoparticles respectively. It also disclosed that UV-VIS spectroscopy indicated band absorbance at 234 and 274 nanometer of intense surface Plasmon resonance, manifesting the formation and stability of prepared SeNPs and CuONPs. The FESEM image displayed mulit-shapes between spherical and vaulted for selenium and copper oxide nanosized. XRD at 2 theta revealed crystalline selenium and copper oxide nanoparticles, with (54.92-57.79) nm average size. FTIR revealed the presence of functional groups of the plant that act as stabilizing and reducing agents. The antibacterial activity of synthesized nanoparticles was studied against five different bacteria causing food spoilage.

Development of Antimicrobial Biodegradable Films Based on Corn Starch with Aqueous Extract of Hibiscus sabdariffa L

AbstractThe objective of this work is to prepare biodegradable films of corn starch, replacing a part of the distilled water used in the formulation of the filmogenic solution with an aqueous extract of Hibiscus sabdariffa L. (HSE) and evaluate its functional properties and antimicrobial capacity. The films are made by casting method, adding different HSE:water volume ratios: 100:0, 75:25, 50:50, 25:75, and 0:100 as control. All films with HSE showed an antimicrobial effect, giving positive results against Listeria monocytogenes, Staphylococcus aureus, Salmonella spp., and Escherichia coli. It is observed that, with the increase in the proportion of HSE, the films are more manageable and glossy than those of starch alone and a more intense red color as the extract content increased, significantly improving its mechanical properties, mainly when the HSE content is above 25% on the filmogenic solution. Likewise, the addition of the extract significantly improved the water vapor barrier capacity of the films. According to the results obtained in this study, corn starch films with aqueous extract of H. sabdariffa are an excellent alternative as a biodegradable packaging material for the food industry, with good functional properties and antimicrobial capacity.

Inhibitory Effect of Roselle Aqueous Extracts-HPMC 6000 Gel on the Growth of Staphylococcus Aureus ATCC 25923.

Roselle (Hibiscus sabdariffa L.) is a medicinal plant commonly used as a beverage and herbal medicine. Complex compounds in the aqueous extracts have provided good antibacterial activity by which the growth of gram-negative and -positive bacteria is inhibited. The aims of this research were to formulate hydroxypropyl methylcellulose (HPMC) 6000 gel containing the extract and investigate the inhibitory activity of the extract and its gel formula against Staphylococcus aureus ATCC 25923. Thin layer chromatography (TLC) on silica gel GF254 was used for analyzing flavonoids and polyphenols using butanol: acetic acid: water (4:1:5) and chloroforms: ethyl acetate: formic acid (0.5:9:0.5) as eluent, respectively. A serial dilution of aqueous extract powder in citrate buffer was made to obtain 0.50, 0.25, 0.10, 0.05, and 0.02 mg/mL solution. The roselle aqueous extract (3%) was formulated as a component of gel containing HPMC 6000 in various concentrations (2%, 3%, and 4%). A diffusion agar method on two layers of nutrient agar media was applied using Staphylococcus aureus ATCC 25923 and gentamicin 25 ppm as bacterial test and standard, respectively. After incubation for 24 h at 37°C, the inhibitory effect was denoted by a clear zone around the hole and the inhibitory activity was measured as minimum inhibitory concentration (MIC). The aqueous extract of Hibiscus sabdariffa L. contained flavonoid and polyphenol compounds based on the TLC chromatogram profile. It was found that the gel formula containing 3% HPMC 6000 and 3% aqueous extract gave a good physical characteristic and the lowest MIC (6.0 mg/mL), equivalent to 7.58 ppm of gentamicin standard at 12.0 mg/mL concentration. The HPMC 6000 at 3% (w/w) concentration in roselle aqueous extract gel preparation gave good physical characteristics. The gel preparation exhibited inhibitory activity against Staphylococcus aureus ATCC 25923 shown by MIC 6.0 mg/mL. Formula 2 is recommended and should be further investigated for implementation in topical preparations.

Effects of Hibiscus Sabdariffa Calyces Aqueous Extract on the Antihypertensive Potency of Captopril in the Two-Kidney-One-Clip Rat Hypertension Model.

Hibiscus sabdariffa aqueous extract (HS) is often used as complementary therapy for hypertension. However, some studies have shown that coadministration with a conventional antihypertensive drug can affect drug potency. We compared the effects of HS plus captopril (CAP) coadministration to HS and CAP administration alone on blood pressure and renin-angiotensin-aldosterone system (RAAS) biomarkers in the rat two-kidney-one-clip (2K1C) model of hypertension. Male Sprague Dawley rats were randomly divided into seven groups (n=6/group), a normal control (SHAM) group, and six 2K1C groups. In 2K1C animals, hypertension was induced using a stainless microclip (inner diameter of 0.20 mm). Four weeks after 2K1C surgery, blood pressure was significantly higher than in the SHAM group. Then, model rats were randomly divided into negative control (2K1C, no treatment), positive control (4.5 mg captopril/200 g body weight [BW] orally [p.o.]), HS alone (30 mg/200 g BW; p.o.), and 3 co-treatment groups receiving HS (15, 30, or 60 mg/200 g BW; p.o.) plus 4.5 mg/200 g BW captopril. The treatments were performed for two weeks. Blood pressure was significantly reduced by all the drug treatments to near the level of SHAM controls. Plasma renin level, serum angiotensin converting enzyme (ACE) activity, and plasma angiotensin II level were also significantly elevated in the 2K1C group compared to the SHAM group. Both serum ACE activity and plasma angiotensin II level were significantly reduced to near SHAM group levels by all the drug treatments. Hibiscus sabdariffa aqueous extract alone can reduce blood pressure. This extract appears could be used as a supplement with captopril but may not provide any additional benefit.

Aqueous extract of Hibiscus sabdariffa inhibits pedestal induction by enteropathogenic E. coli and promotes bacterial filamentation in vitro.

Diarrheic diseases account for the annual death of approximately 1.9 million children under the age of 5 years, and it is a major cause of work absenteeism in developed countries. As diarrheagenic bacteria, enteropathogenic Escherichia coli (EPEC) attach to cells in the small intestine, causing local disappearance of microvilli and inducing the formation of actin-rich pedestals that disrupt the intestinal barrier and help EPEC adhere to and infect intestinal cells. Antibiotics and other bioactive compounds can often be found by analyzing traditional medicines. Here a crude aqueous extract of Hibiscus sabdariffa, which typically grows in subtropical and tropical areas and is a popular medicinal tisane in many countries, was analyzed for antibacterial activity against EPEC. In standard microdilution assays, the extract showed a minimum inhibitory concentration of 6.5 mg/ml against EPEC growth. Time-kill kinetics assays demonstrated significant 24 h bactericidal activity at 25 mg/ml. The extract is able to impede pedestal induction. Not only did the extract inhibit preformed pedestals but it prevented pedestal induction as well. Remarkably, it also promoted the formation of EPEC filaments, as observed with other antibiotics. Our results in vitro support the potential of Hibiscus sabdariffa as an antimicrobial agent against EPEC.

Diuretic Activity of <i>Hibiscus sabdariffa</i> L. in Wistar Rats

The diuretic effect of aqueous extract of Hibiscus sabdariffa has always been noted by the early botanists who studied the plant. On the other hand, very little scientific work to confirm this state of affairs has been done. In this pharmacological study, we provide scientific evidence to previous observations. Using an electrolyte analyzer to evaluate urinary volume and ions and appropriate experimental protocols on wistar strain rats, we have shown that: The aqueous extract of Hibiscus sabdariffa (AEHS) administered at doses of 200, 500 and 700 mg / kg BW induces a dose-dependent and significant increase in urinary excretion in rats. This increase was 12.75 ± 1.971 mL / kg, 23.20 ± 2.082 mL / kg and 29.42 ± 2.097 mL / kg BW, respectively is after 24 hours. That is a respective increase of 55.5, 182 and 333% compared to the control. The aqueous extract of Hibiscus sabdariffa (AEHS) uses at the dose of 700 mg / kg BW results in a reduction of the first urination time by 26.30% compared to the control. The determination of electrolytes in rats treated with 700 mg / kg BW after 24 hours showed high concentrations of sodium, potassium and chlorine in the urine. These different concentrations are for sodium of 72.51%, potassium of 76.54% and 58.81% for chlorine relative to the concentration of the controls. Compared to AEHS, hydrochlorothiazide at 25 mg / kg BW results in urinary excretion of 80.79% sodium, 85.30% potassium and 75.97% chlorine. Similarly with furosemide uses at 20 mg / kg BW), the concentrations are 86% sodium, 79% potassium and 71.58% chlorine. Compared with control rats, the Na + / K + ratio did not vary significantly in the treated animals. AEHS is therefore a diuretic substance like hydrochlorothiazide and furosemide.

In vivo pharmacodynamic and pharmacokinetic interactions of Hibiscus sabdariffa calyces extracts with simvastatin.

Increasing number of patients use herbs with their medications. Such practice may result in beneficial or harmful herb-drug interactions. A recent survey reported that some participants co-administered Hibiscus sabdariffa, a widely used beverage, or tea, with their antihyperlipidaemic medications. This study therefore evaluated the effect of concomitant administration of Hibiscus sabdariffa calyces' extracts with simvastatin on hyperlipidaemia and pharmacokinetics of the drug in vivo. Factorial experimental designs were used to evaluate the comparative effectiveness and interactions between simvastatin and aqueous extract of Hibiscus sabdariffa (AEHS) on lipid profile parameters in hyperlipidaemia-induced Wistar rats. Different combinations of low (AEHS 250mg/kg; simvastatin 10mg/kg) and high doses (AEHS 500mg/kg; simvastatin 20mg/kg) were administered individually and concurrently daily for 2 and 4weeks. Lipid profile parameters were assessed at these treatment periods. Subsequently, the effect of aqueous beverage of Hibiscus sabdariffa (ABHS) on the pharmacokinetics of single-dose 40mg simvastatin was also evaluated in six healthy human volunteers using two-period randomized crossover design. Blood samples were collected at predetermined times for 24hours. The plasma obtained was analysed for simvastatin using RP-HPLC/UV method. Aqueous extract of Hibiscus sabdariffa reduced total cholesterol (Tc ) better than simvastatin (P=.031). Low-dose AEHS and low-dose simvastatin used concomitantly caused 38.3% and 57.4% reductions in Tc and triglyceride levels, respectively, compared with low-dose simvastatin (P<.05). Also, ABHS increased clearance and reduced peak concentration of simvastatin by 44.6% and 18.0%, respectively (P<.05). The geometric mean ratio of simvastatin AUC0-∞ with or without ABHS was 0.646 with the 90% confidence interval (0.564, 0.758) falling outside the bioequivalent range. Aqueous extract of Hibiscus sabdariffa lowered Tc better than simvastatin and enhanced the antihyperlipidaemic activity of the drug when co-administered at low doses in an animal model. However, aqueous beverage of Hibiscus sabdariffa caused a significant herb-drug interaction resulting in overall reduction in exposure to simvastatin in humans. Caution should thus be placed on clinical judgement or recommendations based on the animal results. Nevertheless, co-administration of the beverage with simvastatin should be discouraged until more clinical data are available.

Hibiscus sabdariffa L. and Its Bioactive Constituents Exhibit Antiviral Activity against HSV-2 and Anti-enzymatic Properties against Urease by an ESI-MS Based Assay.

For decades, Hibiscus sabdariffa L. and its phytochemicals have been shown to possess a wide range of pharmacologic properties. In this study, aqueous extract of Hibiscus sabdariffa (AEHS) and its bioactive constituent protocatechuic acid (PCA), have been evaluated in vitro for their antiviral activity against HSV-2 clinical isolates and anti-enzymatic activity against urease. Antiherpetic activity was evaluated by the titer reduction assay in infected Vero cells, and cytotoxicity was evaluated by the neutral red dye-uptake method. Anti-urease activity was determined by a developed Electrospray Ionization-Mass Spectrometry (ESI-MS)-based assay. PCA showed potent anti-HSV-2 activity compared with that of acyclovir, with EC50 values of 0.92 and 1.43 µg∙mL−1, respectively, and selectivity indices > 217 and > 140, respectively. For the first time, AEHS was shown to exert anti-urease inhibition activity, with an IC50 value of 82.4 µg∙mL−1. This, combined with its safety, could facilitate its use in practical applications as a natural urease inhibitor. Our results present Hibiscus sabdariffa L. and its bioactive compound PCA as potential therapeutic agents in the treatment of HSV-2 infection and the treatment of diseases caused by urease-producing bacteria.

Biofabrication of Fe nanoparticles in aqueous extract of Hibiscus sabdariffa with enhanced photocatalytic activities

Hibiscus sabdariffa is a strongly basic dye with a large number of medicinal applications and is used for various diagnostic purposes.

English

Aqueous extract of Hibiscus sabdariffa L. is widely consumed in Nigeria as a local beverage used to quench thirst and also because of its antihypertensive action. The present study investigated the effect of consumption of aqueous extract of H. sabdariffa on thirst perception (TP) in mild to moderate hypertensive Nigerians. Fifty mild to moderate hypertensive patients attending medical out-patients clinic of Enugu State University Teaching Hospital were recruited for the study. They were randomly divided into two groups: A and B. &nbsp;Those in group A were given equivalent dose of placebo while group B received 150 mg/kg of H. sabdariffa daily for 4 weeks. All the subjects were given weekly appointments and a week worth of infusion. Thirst perception, serum electrolytes and blood pressure (BP) were measured at baseline and weekly during treatment. TP reduced significantly (p&lt;0.001) in H. sabdariffa group compared to placebo throughout the duration of the experiment. Serum Na+ reduced significantly (p&lt;0.001) in H. sabdariffa compared to placebo group in weeks 3 and 4. Blood pressure (SBP, DBP and MAP) also reduced significantly (p&lt;0.001) in weeks 3 and 4. Thus, consumption of H. sabdariffa reduced thirst perception in mild to moderate hypertensive Nigerians. This validates its traditional use to &lsquo;quench thirst&rsquo; and complements its antihypertensive action. Reduction in serum Na+ may be the possible mechanism of action. &nbsp; Key words: Hibiscus sabdariffa, thirst perception, essential hypertension, serum electrolytes.

PHYSIOLOGICAL EVALUATION OF THE ANTI-DIABETIC PROPERTIES OF Hibiscus sabdariffa ON RATS

Effects of different quantities (75g, 100g and 125g) of Hibiscus sabdariffa leaf, stem and root aqueous extracts and combination of 300g Hibiscus sabdariffa +100g Allium sativum+100g Zingiber officinale on alloxan-induced diabetic Wister albino rats at 1ml/kg/day for17 days were investigated. Body weight and fasting blood glucose level of rats were monitored before and during the experiment. Quantitative analysis of secondary plant products of various parts of the investigated plants was also studied. Results showed that 1ml/kg/day of 75g Hibiscus sabdariffa aqueous extract did not cause significant (p>0.05) sugar reduction compared with basal values as high sugar level was still observed in alloxan-induced rats treated with 1ml/kg /day of 75 Hibiscus sabdariffa leaf (246.00+6.00mg/dl) and stem (207.50+3.50 mg/dl) extracts except root (196.00+1.20mg/dl). Combination of the extracts caused significant (P>0.05) sugar reduction compared with any of the single parts.1ml/kg of 100g Hibiscus sabdariffa leaf extracts ameliorated rats’ weights loss by 14.75%.1ml/kg of 125g Hibiscus sabdariffa leaf, stem and root extracts significantly (p<0.05) reduced the glucose level of diabetic treated rats by 54.08%, 58.95% and 62.44% compared with glibenclamide (22.77%). Phytochemical analysis revealed that flavonoids (0.79mg/g) and alkaloids (0.86mg/g) were significantly higher (p<0.05) in root than in stem and leaf of Hibiscus sabdariffa. The combination 300gHibiscus sabdariffa + 100g Allium sativum 100g Zingiber officinale revealed significantly (p<0.05) higher flavonoids (0.85mg/g), saponins (0.95mg/g) alkaloids (1.81mg/g) and tannins (0.56mg/g). Combination of 300g Hibiscus sabdariffa +100g Allium sativum+100g Zingiber officinale produced the best hypoglycaemic effect (71.05%). Â

In vitro synergistic effect of Hibiscus sabdariffa aqueous extract in combination with standard antibiotics against Helicobacter pylori clinical isolates

Context The increasing problem of drug-resistant strains has led to the failure of current treatment regimens of Helicobacter pylori (HP) infection. Recently, a new treatment strategy has been developed to overcome the problem by using natural products in combination with antibiotics to enhance the treatment efficacy.Objective The antimicrobial combinatory effect of the aqueous extract of Hibiscus sabdariffa L. (Malvaceae) (AEHS) with antibiotics (clarithromycin, CLA; amoxicillin, AMX; metronidazole, MTZ) has been evaluated in vitro against HP strains.Materials and methods Hibiscus calyces (35 g) were brewed in 250 mL of boiled water for 30 min, and minimum inhibitory concentrations (MICs) were determined by agar dilution method. The checkerboard assay was used to evaluate the antimicrobial combinatory effect according to the sum of fractional inhibitory concentration (∑FIC) indices.Results In this study, AEHS exerted remarkable bacteriostatic effect against all HP strains tested with MICs values ranging from 9.18 to 16.68 μg/mL. Synergy effect of AEHS with CLA or MTZ was obtained against four of seven HP strains tested with ∑FIC ranging from 0.21 to 0.39. The additive effect of AEHS with AMX was obtained against five of seven HP strains tested with ∑FIC ranging from 0.61 to 0.91.Conclusion This study presents AEHS as a potent therapeutic candidate alone, or in combination with antibiotics for the treatment of HP infection.

Insulin response in peripheral tissues in animals chronically treated with aqueous extract of Hibiscus sabdariffa L.

Materials and methods Male Wistar rats were primary divided into two groups: Control (C) received standard chow and water ad libitum; Fructose (F) received standard chow and water containing 7% of fructose ad libitum. At 90 days of age they were one more time re-divided into 4 groups: Control treated with water (C, n=7); Control treated with HS (CHib, n=6); Fructose treated with water (F, n=8); Fructose treated with HS (FHib, n=9). Treatment with HS was daily for 4 weeks at a dose of 800 mg/kg. After treatment period, all rats were submitted to insulin tolerance tests (ITT) with two types of insulin (intermediary and short acting) in order to assess the peripheral tissues in response the action of insulin. Data obtained was estimated glucose uptake index (GUI). All data statistically analyzed with 5% significance. Results TTI performed with insulin NPH (intermediary) show that only C group decreased glycaemia at timepoint 15′ compared to fasting glycemia (0′). The analyses between groups shows that CHib animals increased at timepoint 15′ and F group decreased at fasting and 5′ timepoints. The GUI data showed the F group had lowered the glucose uptake capacity compared to C group. The TTI performed with insulin Lispro (short acting) showed that CHib group decreased glucose concentration at timepoint 15′. On the other hand, F and FHib groups decreased in 10′ and 15′ compared to its fasting glycemia. Evaluations between groups shows the CHib rats lowered the serum glucose at 15′, F rats decreased at timepoints 5′, ‘10’ and 15′ and finally the FHib rats decreased this biomarker at 10′ and 15′. GUI data for Lispo ITT shows the fructose treatment improved the glucose uptake when compared to control rats

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.

Assessment of Hepatorenal Indices in Rats Fed with Aqueous Extract of Hibiscus Sabdariffa

The effects of sub-chronic administration of aqueous extract of Hibiscus sabdariffa (HS) on liver and kidney functions were investigated in Wistar rats. Thirty Wistar rats were randomly divided into six groups of 5 rats each. Group A served as the control and was given 5ml/kg of normal saline. Groups B to F were administered HS extract at 100, 500, 1000, 2000 and 5000mg/kg respectively for 6 weeks. Indices of liver and kidney functions were measured and body weight changes monitored. A dose-dependent increase in the activities of liver enzymes and kidney indices was observed. The activities of aspartate aminotranferase, alanine aminotransferase and alkaline phosphatase increased significantly (p<0.05) at doses of 2000mg/kg and above when compared to control while urea, creatinine and uric acid increased significantly (p<0.05) at 1000mg/kg and above. There was a significant (p<0.05) and dose-dependent decrease in weights of rats in the experimental groups. Signs of renal impairment were observed at 1000mg/kg and above while hepatic impairment occurred at 2000mg/kg and above. Thus, the present study has shown that below 1000mg/kg, HS consumption is safe and will not affect the functions of the liver and kidney.

Green reduction of graphene oxide by Hibiscussabdariffa L. to fabricate flexible graphene electrode

The aqueous extract of Hibiscus sabdariffa L., which is inherently non-toxic, environmentally friendly and cost effective, was used as a green reducing agent to chemically reduce graphene oxide (GO). The GO and reduced graphene oxide by the aqueous extract of Hibiscus sabdariffa L. (HRGO), prepared under different conditions, were characterized. The characterization was conducted to better understand the evolution of HRGO from GO. The flexible graphene film electrodes were fabricated using the synthesized HRGO as a primary material that exhibited a good specific capacitance of 133.07Fg−1, which attributed to the surface modification of the HRGO using the extract of Hibiscus sabdariffa L. Furthermore, over four orders of magnitude in electric conductivity (while the sheet resistance decreased from 0.63MΩ/sq. to 36.50Ω/sq.) were achieved with an excellent specific capacitance of 204.38Fg−1 when the HRGO was treated in a household microwave oven.

Hibiscus sabdariffa L. aqueous extract attenuates hepatic steatosis through down-regulation of PPAR-γ and SREBP-1c in diet-induced obese mice

The growing incidence of obesity is a worldwide public health problem leading to a risk factor for non-alcoholic fatty liver disease, which extends from steatosis to steatohepatitis and cirrhosis. We investigated whether the aqueous extract of Hibiscus sabdariffa L. (Hs) reduces body weight gain and protects the liver by improving lipid metabolism in high fat diet-induced obese C57BL/6NHsd mice. We found that oral administration of the Hs extract reduced fat tissue accumulation, diminished body weight gain and normalized the glycemic index as well as reduced dyslipidemia compared to the obese mice group that did not receive Hs treatment. In addition, Hs treatment attenuated liver steatosis, down-regulated SREBP-1c and PPAR-γ, blocked the increase of IL-1, TNF-α mRNA and lipoperoxidation and increased catalase mRNA. Our results suggest that the anti-obesity, anti-lipidemic and hepatoprotective effects of the Hs extract are related to the regulation of PPAR-γ and SREBP-1c in the liver.

Hibiscus Sabdariffa Linnaeus (Malvaceae), Curcumin and Resveratrol as Alternative Medicinal Agents Against Metabolic Syndrome

Metabolic syndrome (MS) is an obesity-associated collection of disorders, each of which contributes to cardiovascular risk. For patients with MS, it is difficult to follow a diet/exercise regime that would improve their symptoms. Therefore, the investigation of agents that may deal with its more serious aspects is an important medical field for research. Numerous experimental studies have confirmed the important role of medicinal plants or their active components in the prevention and treatment, and in lowering risk factors of MS. As oxidative stress and inflammation are involved in the association between obesity, insulin resistance (IR) and hypertension, antioxidant and anti-inflammatory plant components like polyphenols might be useful as a treatment for MS. The aqueous extract of Hibiscus Sabdariffa L (HSE), rich in several polyphenols, is commonly and effectively used in native medicines against hypertension, diabetes and liver disorders. HSE has also shown therapeutic promise in the prevention of MS in patients, probably due to its polyphenol content. Curcumins, derived from the spice turmeric, and resveratrol, polyphenols found in grapes and red wine respectively, in addition to their antioxidant and anti-inflammatory properties, inhibit preadipocyte proliferation, de novo lipogenesis and fat accumulation in liver. Thus, due to their efficacy in the regulation of multiple targets, polyphenols have received considerable interest as potential therapeutic agents for the prevention and treatment of MS. This review discusses the therapeutic use of HSE, as well as curcumin and resveratrol, in the context of obesity as an initiator of insulin resistance and hypertension, the two main features of MS, together with the underlying mechanisms of action.