Hibiscus Sabdariffa Extracts Research Articles

Behavior of 11 Foodborne Bacteria on Whole and Cut Mangoes var. Ataulfo and Kent and Antibacterial Activities of Hibiscus sabdariffa Extracts and Chemical Sanitizers Directly onto Mangoes Contaminated with Foodborne Bacteria

The behavior of foodborne bacteria on whole and cut mangoes and the antibacterial effect of Hibiscus sabdariffa calyx extracts and chemical sanitizers against foodborne bacteria on contaminated mangoes were investigated. Mangoes var. Ataulfo and Kent were used in the study. Mangoes were inoculated with Listeria monocytogenes, Shigella flexneri, Salmonella Typhimurium, Salmonella Typhi, Salmonella Montevideo, Escherichia coli strains (O157:H7, non-O157:H7 Shiga toxin-producing, enteropathogenic, enterotoxigenic, enteroinvasive, and enteroaggregative). The antibacterial effect of five roselle calyx extracts (water, ethanol, methanol, acetone, and ethyl acetate), sodium hypochlorite, colloidal silver, and acetic acid against foodborne bacteria were evaluated on contaminated mangoes. The dry extracts obtained with ethanol, methanol, acetone, and ethyl acetate were analyzed by nuclear magnetic resonance spectroscopy to determine solvent residues. Separately, contaminated whole mangoes were immersed in five hibiscus extracts and in sanitizers for 5 min. All foodborne bacteria attached to mangoes. After 20 days at 25 ± 2°C, all foodborne bacterial strains on whole Ataulfo mangoes had decreased by approximately 2.5 log, and on Kent mangoes by approximately 2 log; at 3 ± 2°C, they had decreased to approximately 1.9 and 1.5 log, respectively, on Ataulfo and Kent. All foodborne bacterial strains grew on cut mangoes at 25 ± 2°C; however, at 3 ± 2°C, bacterial growth was inhibited. Residual solvents were not detected in any of the dry extracts by nuclear magnetic resonance. Acetonic, ethanolic, and methanolic roselle calyx extracts caused a greater reduction in concentration (2 to 2.6 log CFU/g) of all foodborne bacteria on contaminated whole mangoes than the sodium hypochlorite, colloidal silver, and acetic acid. Dry roselle calyx extracts may be a potentially useful addition to disinfection procedures of mangoes.

L-metionina associated with Hibiscus sabdariffa and Boswellia serrata (ACIDIF PLUS®) extracts is able to relief symptoms and improve quality of life in patients affected by recurrent uncomplicated urinary tract infections

L-metionina associated with Hibiscus sabdariffa and Boswellia serrata (ACIDIF PLUS®) extracts is able to relief symptoms and improve quality of life in patients affected by recurrent uncomplicated urinary tract infections

Encapsulation of Hibiscus sabdariffa L. anthocyanins as natural colours in yeast

Hibiscus sabdariffa extracts, a rich source of anthocyanin, were subjected to encapsulation in yeast cells. An encapsulation yield (EY) of 208 μg/100 mg of cells and an encapsulation efficiency (EE) of 27%, were reached after optimisation of the ratios (0.5 g wet yeast cells for 5 ml of anthocyanin extracts at 1 g·L−1) and with 10% of ethanol. The storage stability of encapsulated pigments was investigated in water and buffer pH 1.5 at 5 & 37 °C for 10 days and 90 °C for 30 min. The percentage of loss of colour was determined by colourimetry assays. The microparticles made of yeast with or without heat treatment exhibited different protecting effects (P < 0.01). At 37 °C, the percentage of loss of colour in water was of 2.5% for heat-treated and 36.5% for non-treated yeast microparticles, suggesting that yeast enzymes would be responsible for the loss of anthocyanin during storage. These results are confirmed by the percentage of loss of colour which was far lower in conditions of low enzymatic activity: 3.1% at 5 °C for non-heat-treated cells in water. The pH of solvent had also an important effect on the degradation of encapsulated anthocyanin; in buffer at pH 1.5 and 37 °C with the non-heat-treated cells, the degradation decreased strongly to 9.4% compared with 36.5% in water. These results show that yeast cells are a good mean of encapsulation of pigments for a colouring purpose and that they provide anthocyanins a good protection as long as their enzymes are inactivated.

Antibacterial Activities of Hibiscus sabdariffa Extracts and Chemical Sanitizers Directly on Green Leaves Contaminated with Foodborne Pathogens

Leafy greens have been associated with foodborne disease outbreaks in different countries. To decrease microbial contamination of leafy greens, chemical agents are commonly used; however, a number of studies have shown these agents to have limited antimicrobial effect against pathogenic bacteria on vegetables. The objective of this study was to compare the antibacterial effect of Hibiscus sabdariffa calyx extracts (water, methanol, acetone, and ethyl acetate), sodium hypochlorite, acetic acid, and colloidal silver against foodborne bacteria on leafy greens. Thirteen foodborne bacteria were used in the study: Listeria monocytogenes, Shigella flexneri, Salmonella serotypes Typhimurium Typhi, and Montevideo, Staphylococcus aureus, Escherichia coli O157:H7, five E. coli pathotypes (Shiga toxin-producing, enteropathogenic, enterotoxigenic, enteroinvasive, and enteroaggregative), and Vibrio cholerae O1. Each foodborne bacterium was separately inoculated on romaine lettuce, spinach, and coriander leaves. Separately, contaminated leafy greens were immersed in four hibiscus extracts and in sanitizers for 5 min. Next, green leaves were washed with sterile tap water. Separately, each green leaf was placed in a bag that contained 0.1% sterile peptone water and was rubbed for 2 min. Counts were done by plate count using appropriate dilutions (in sterile peptone water) of the bacterial suspensions spread on Trypticase soy agar plates and incubated at 35 ± 2°C for 48 h. Statistically significant differences ( P < 0.05) were calculated with an analysis of variance and Duncan's test. All 13 foodborne bacteria attached to leafy greens. Roselle calyx extracts caused a significantly greater reduction ( P < 0.05) in concentration of all foodborne bacteria on contaminated romaine lettuce, spinach, and coriander than did the sodium hypochlorite, colloidal silver, and acetic acid. Dry roselle calyx extracts may potentially be a useful addition to disinfection procedures for romaine lettuce, spinach, and coriander.

EFFECT OF DIFFERENT HIBISCUS SABDARIFFA EXTRACTS ON GLUTATHIONE AND ITS RELATED ENZYMES IN MAMMALIAN LUNG TISSUE AND CULTURE CELLS UNDER INDUCED OXIDATIVE STRESS.

22Oct 2017 EFFECT OF DIFFERENT HIBISCUS SABDARIFFA EXTRACTS ON GLUTATHIONE AND ITS RELATED ENZYMES IN MAMMALIAN LUNG TISSUE AND CULTURE CELLS UNDER INDUCED OXIDATIVE STRESS. Hamed R R , Hussein F E , Guneidy R A , Awad H and Ali E A A. Department of Molecular Biology, National Research Centre, Cairo, Egypt. Department of Cytology and Histology, Faculty of Science, Cairo University. Department of Tanning Materials and Leather Technology, National Research Centre, Cairo, Egypt.

P 203 - Quercetin derivatives from Hibiscus sabdariffa reduce lipid content and increase mitochondrial biogenesis in hypertrophied 3T3-L1 adipocytes

There is evidence that Hibiscus sabdariffa (HS) extracts ameliorate metabolic disturbances related to obesity. Our recent studies postulate quercetin derivatives as candidates to be responsible for such effects. The aim of this study was to determine the effect of several quercetin-related molecules (quercetin, quercetin-3-glucuronide and quercetin-3-glucoside) and other representative antioxidant compounds on triglyceride accumulation in hypertrophied 3T3-L1 adipocytes. In addition, we also studied the effect of these quercetin derivatives on mitochondrial mass and the possible mechanism involved by analyzing key metabolic targets in energy metabolism. The results show that, among all the phenolic compounds from HS tested, quercetin derivatives had the highest capacity to reduce triglyceride accumulation in hypertrophied adipocytes. Furthermore, both HS complete extract and quercetin compounds increased the mitochondrial mass in adipocytes. Specially, quercetin-3-glucuronide seemed to be the most bioactive compound and increased AMPK and PPARα expression and decreased FASN expression. In conclusion, these data suggest that quercetin derivatives from HS may reduce lipid content of hypertrophied adipocytes through the activation of AMPK and inhibition of FASN. Moreover, these flavonoids increased mitochondrial biogenesis which may be also mediated through the modulation of PPARα.

Erythrocyte osmotic fragility and general health status of adolescent Sprague Dawley rats supplemented with Hibiscus sabdariffa aqueous calyx extracts as neonates followed by a high-fructose diet post-weaning.

High-fructose diets (HFD) can cause oxidative damage to tissues including erythrocyte cell membranes. Hibiscus sabdariffa (HS) has protective antioxidant properties. Rats were used to investigate whether the consumption of HS by neonates would result in long-term effects on their erythrocyte osmotic fragility (EOF) and general health when later fed a high-fructose diet post-weaning through adolescence. Eighty of four-day-old Sprague Dawley rat pups were divided randomly into three treatment groups. The controls (n=27) received distilled water at 10ml/kg b. w, while the other groups received either 50mg/kg (n=28) or 500mg/kg (n=25) of an HS aqueous calyx extract orally till post-natal day 14. The rats in each group were weaned and divided into two subgroups; one continued on normal rat chow, and the other received fructose (20% w/v) in their drinking water for 30days. Blood was collected in heparinised tubes and added to serially diluted (0.0-0.85%) phosphate-buffered saline to determine the EOF. Clinical markers of health status were determined with an automated chemical analyser. HS extracts did not programme metabolism in the growing rats to alter their general health and EOF in response to the HFD.

Antioxidant Activity of Hibiscus sabdariffa Extracts Incorporated in an Emulsion System Containing Whey Proteins: Oxidative Stability and Polyphenol–Whey Proteins Interactions

This study was designed within the scope of industrial exploitation of antioxidant extracts from Hibiscus sabdariffa. Efficiency in the extraction of antioxidants (total phenolics, flavonoids and anthocyanins) from calyces was assessed through different processes involving solvents (water, 80% acetone and 80% methanol), microwaves and ultrasounds. Results indicated that microwave extraction with 80% acetone gave the highest yield for total phenolics, expressed as gallic acid equivalents (GAE) per g dry weight (DW) (3.73 GAE/100 g DW), while the highest results for total flavonoids and anthocyanins were found in the microwaved aqueous extracts. Antioxidant activity of the extracts reported the highest reducing power for aqueous extracts with microwave extraction, while 80% acetone and methanol samples exhibited the highest antioxidant activity by high-performance thin-layer chromatography (HPTLC) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) reagent. HPTLC performed for screening of phenolic compounds revealed the occurrence of anthocyanins in dimer-like bands. Laboratory tests showed high protection against lipid oxidation of the whey spread emulsion (22.32 h) incorporated with the sonicated aqueous extract. Results of peptide sequencing data by liquid chromatography electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS), after sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analysis, revealed protein–polyphenols interactions by the formation of dimers between polyphenols and protein/peptides. These interactions were found without effect on the oxidative stability of the emulsions. These study suggest that H. sabdariffa’s calyces have the potential to be used like food antioxidants.

Antibacterial And Antifungal Effect Of Some Natural Extracts And Their Potential Use As Photosensitizers

One of the threats on the health sector is the appearance of multi antibiotic resistant microorganisms. Thus, this occurs because of using natural and synthetic antimicrobial agents in excessive doses. Now, many scientists all around the world are performing research on natural extracts that have antimicrobial activity using photodynamic therapy (PDT) which involves light activation. The aim of this study, however, is to evaluate the effect of photodynamic antimicrobial chemotherapy using extracts from Pomegranate (Punica granatum), Cinnamon (Cinnamomum verum), Roselle (Hibiscus sabdariffa), Carob (Ceratonia siliqua), and Nigella or black cumin oil (Nigella sativa) against two gram-positive and two gram-negative bacteria (Bacillus cereus, Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa) respectively; and three different fungi (Aspergillus niger, Mucor sp., and Rhizopus sp.), using agar well diffusion method. The prepared methanolic extracts presented absorption between 300 and –900 nm wavelengths. The maximum activity of Roselle (Hibiscus sabdariffa) was against Staphylococcus aureus in total darkness with 52.5 ± 2.5 mm inhibition zone diameter. Also, the most sensitive fungi was Mucor sp. Cinnamon (Cinnamomum verum) extract was with 31.0 ± 1.0 mm inhibition zone diameters. The results showed that there was an inhibitory effect of Cinnamon (Cinnamomum verum) and Roselle (Hibiscus sabdariffa) extracts against most of the tested species.

Aqueous Extracts of Hibiscus sabdariffa Calyces to Control Aichi Virus.

Aqueous Hibiscus sabdariffa extracts possess antimicrobial properties with limited information available on their antiviral effects. Aichi virus (AiV) is an emerging foodborne pathogen that causes gastroenteritis. Vaccines are currently unavailable to prevent their disease transmission. The objective of this study was to determine the antiviral effects of aqueous H. sabdariffa extracts against AiV. AiV at ~5 log PFU/ml was incubated with undiluted (200mg/ml), 1:1 (100mg/ml) or 1:5 (40mg/ml) diluted aqueous hibiscus extract (pH 3.6), phosphate-buffered saline (pH 7.2 as control), or malic acid (pH 3.0, acid control) at 37°C over 24h. Treatments were stopped by serially diluting in cell-culture media containing fetal bovine serum and titers were determined using plaque assays on confluent Vero cells. Each treatment was replicated thrice and assayed in duplicate. AiV did not show any significant reduction with 1:1 (100mg/ml) or 1:5 (40mg/ml) diluted aqueous hibiscus extracts or malic acid after 0.5, 1, or 2h at 37°C. However, AiV titers were reduced to non-detectable levels after 24h with all the three tested concentrations, while malic acid showed only 0.93 log PFU/ml reduction after 24h. AiV was reduced by 0.5 and 0.9 log PFU/ml with undiluted extracts (200mg/ml) after 2 and 6h, respectively. AiV treated with 1:1 (100mg/ml) and 1:5 (40mg/ml) diluted extracts showed a minimal ~0.3 log PFU/ml reduction after 6h. These extracts show promise to reduce AiV titers mainly through alteration of virus structure, though higher concentrations may have improved effects.

Development of functional beverages from blends of Hibiscus sabdariffa extract and selected fruit juices for optimal antioxidant properties

The demand for functional foods and drinks with health benefit is on the increase. The synergistic effect from mixing two or more of such drinks cannot be overemphasized. This study was carried out to formulate and investigate the effects of blends of two or more of pineapple, orange juices, carrot, and Hibiscus sabdariffa extracts (HSE) on the antioxidant properties of the juice formulations in order to obtain a combination with optimal antioxidant properties. Experimental design was carried out using optimal mixture model of response surface methodology which generated twenty experimental runs with antioxidant properties as the responses. The DPPH (1,1‐diphenyl‐2‐picrylhydrazyl) and ABTS [2,2′‐azino‐bis(3‐ethylbenzothiazoline‐6‐sulphonic acid)] radical scavenging abilities, ferric reducing antioxidant potential (FRAP), vitamin C, total phenolics, and total carotenoids contents of the formulations were evaluated as a test of antioxidant property. In all the mixtures, formulations having HSE as part of the mixture showed the highest antioxidant potential. The statistical analyzes, however, showed that the formulations containing pineapple, carrot, orange, and HSE of 40.00, 16.49, 17.20, and 26.30%, respectively, produced optimum antioxidant potential and was shown to be acceptable to a research laboratory guidance panel, thus making them viable ingredients for the production of functional beverages possessing important antioxidant properties with potential health benefits.

Efficacy of Hibiscus sabdariffa and Telfairia occidentalis in the attenuation of CCl4-mediated oxidative stress

ObjectiveTo assess the efficacy of Hibiscus sabdariffa (H. sabdariffa) and Telfairia occidentalis (T. occidentalis) extracts in the attenuation of CCl4-mediated oxidative stress. MethodsSeventy-two healthy matured male albino rats weighing between (120±20) g were divided into 6 groups (A-F) in a 2×6 factorial experiment using completely randomized design. Rats in Group A received only water, B received 1 mL/kg CCl4, C received 300 mg/kg, D received 600 mg/kg, E received CCl4+300 mg/kg while F received CCl4+600 mg/kg for each of the extract, respectively. Semen from epididymes was obtained for sperm analysis while blood was obtained through cardiac puncture for biochemical analysis, after the treatment regimen. ResultsOur results showed that CCl4 induction elevated aspartate aminotransferase, alanine transaminase, alkaline phosphatase, total protein, globulin levels significantly (P<0.05) while albumin was reduced. For sperm profile after CCl4 induction, sperm count, viability and motility were significant (P<0.05) reduced while sperm head abnormality increased. However, administering H. sabdariffa and T. occidentalis extracts at the doses of 300 and 600 mg/kg caused the reversal of these effects significantly. ConclusionsImplicitly, the implication of our results is that H. sabdariffa and T. occidentalis extracts might be ted and optimized for the management of oxidative stress-related organ injuries, including infertility, though further researches are needed.

Comparative chemical and biochemical analysis of extracts of Hibiscus sabdariffa

Hibiscus sabdariffa extracts have attracted attention because of potentially useful bioactivity. However, there have been no systematic studies of extraction efficiencies of H. sabdariffa. The nature of extracts used in different studies has varied considerably, making comparisons difficult. Therefore, a systematic study of extracts of H. sabdariffa made with different solvents was carried out using water, methanol, ethyl acetate and hexane in the presence/absence of formic acid, using different extraction times and temperatures. The extracts were analysed for total polyphenol content, antioxidant capacity using DPPH, FRAP and TEAC assays, and specific anthocyanins were determined using HPLC and LC–MS. The results showed the highest antioxidant capacities were obtained by extracting using water, with or without formic acid, for 10min at 100°C. These extracts provided the highest concentrations of cyanidin 3-sambubioside and delphinidin 3-sambubioside. It will be important to use extraction conditions giving optimal extraction efficiencies for subsequent bioactivity experiments.

Hibiscus sabdariffa extract inhibits obesity and fat accumulation, and improves liver steatosis in humans

Obesity is associated with a great diversity of diseases including non-alcoholic fatty liver disease. Our previous report suggested that Hibiscus sabdariffa extracts (HSE) had a metabolic-regulating and liver-protecting potential. In this study, we performed a clinical trial to further confirm the effect of HSE. Subjects with a BMI ≧ 27 and aged 18-65, were randomly divided into control (n = 17) and HSE-treated (n = 19) groups, respectively, for 12 weeks. Our data showed that consumption of HSE reduced body weight, BMI, body fat and the waist-to-hip ratio. Serum free fatty acid (FFA) was lowered by HSE. Anatomic changes revealed that HSE improved the illness of liver steatosis. Ingestion of HSE was well tolerated and there was no adverse effect during the trial. No alteration was found for serum α-amylase and lipase. The clinical effect should mainly be attributed to the polyphenols of HSE, since composition analysis showed that branched chain-amino acids, which is associated with obesity, is not obviously high. In conclusion, consumption of HSE reduced obesity, abdominal fat, serum FFA and improved liver steatosis. HSE could act as an adjuvant for preventing obesity and non-alcoholic fatty liver.

Aqueous extracts of Hibiscus sabdariffa calyces as an antimicrobial rinse on hot dogs against Listeria monocytogenes and methicillin-resistant Staphylococcus aureus

Contamination of ready-to-eat meat products by foodborne pathogens is a major concern in the food industry. Novel methods to control foodborne pathogens are made necessary by continuing outbreaks as well as the development of antibiotic-resistant pathogens. Hibiscus sabdariffa extracts could be useful as a natural source of antimicrobial rinse on ready-to-eat products to control pathogens. In this study, lyophilized Hibiscus flower extracts were examined for their antimicrobial activity as a rinse on all-beef hot dogs against Listeria monocytogenes and methicillin-resistant Staphylococcus aureus (MRSA). Beef hot dogs were dip inoculated in overnight cultures of 1:1 mixtures of L. monocytogenes strains Scott A and 101 or MRSA strains ATCC 33591 and ATCC 33593 and were placed at 4°C overnight to allow for bacterial attachment. Hot dogs were rinsed with extracts (120, 240mg/mL) or water (control) for 5, 15, 30, or 60min and then plated immediately (0h; no storage) or stored at 4°C overnight and plated at 24h. Serial dilutions were plated in duplicate on both TSA and selection media, Modified Oxford (Listeria) or Baird Parker (MRSA), and the entire experiment was replicated 3 times. Higher extract concentrations, longer rinse times, and longer storage times were the most effective at inhibiting and/or killing L. monocytogenes and MRSA on hot dogs. L. monocytogenes was reduced to ca. 1.5logCFU/g while MRSA was reduced to undetectable levels following rinsing of hot dogs with extracts at 240mg/mL for 60min and stored for 24h. Both L. monocytogenes and MRSA were reduced ca. 2logCFU/g following rinsing of hot dogs with extracts at 120mg/mL for 60min and stored for 24h. This research demonstrates the effectiveness of Hibiscus extracts against L. monocytogenes and MRSA as an antimicrobial rinse on ready-to-eat meat products.

Effects of Orthosiphon grandiflorus, Hibiscus sabdariffa and Phyllanthus amarus Extracts on Risk Factors for Urinary Calcium Oxalate Stones in Rats

We evaluated the antilithic effect of Orthosiphon grandiflorus, Hibiscus sabdariffa and Phyllanthus amarus extracts on known risk factors for calcium oxalate stones in rats. We divided 30 male Wistar rats into 5 equal groups. Controls were fed a standard diet and the remaining groups received a 3% glycolate diet for 4 weeks to induce hyperoxaluria. One glycolate fed group served as the untreated group and the others were given oral extracts of Orthosiphon grandiflorus, Hibiscus sabdariffa or Phyllanthus amarus at a dose of 3.5 mg daily. We collected 24-hour urine and blood samples. Kidneys were harvested for histological examination. We measured the renal tissue content of calcium and oxalate. The Hibiscus sabdariffa group showed significantly decreased serum oxalate and glycolate, and higher oxalate urinary excretion. The Phyllanthus amarus group showed significantly increased urinary citrate vs the untreated group. Histological examination revealed less CaOx crystal deposition in the kidneys of Hibiscus sabdariffa and Phyllanthus amarus treated rats than in untreated rats. Those rats also had significantly lower renal tissue calcium content than untreated rats. All parameters in the Orthosiphon grandiflorus treated group were comparable to those in the untreated group. Hibiscus sabdariffa and Phyllanthus amarus decreased calcium crystal deposition in the kidneys. The antilithic effect of Hibiscus sabdariffa may be related to decreased oxalate retention in the kidney and more excretion into urine while that of Phyllanthus amarus may depend on increased urinary citrate. In contrast, administering Orthosiphon grandiflorus had no antilithic effect.

Effects of Hibiscus sabdariffa extract powder and preventive treatment (diet) on the lipid profiles of patients with metabolic syndrome (MeSy)

Insulin resistance, obesity, hypertension, and dyslipidemia are strongly associated with metabolic syndrome (MeSy), which is considered to be a reversible clinical stage before its evolution to coronary heart disease and diabetes. Currently, the antihypertensive and hypolipidemic properties of aqueous Hibiscus sabdariffa extracts (HSE) have been demonstrated in clinical trials and in vivo experiments. The aim of the present study was to evaluate the effects of a Hibiscus sabdariffa extract powder (HSEP) and a recognized preventive treatment (diet) on the lipid profiles of individuals with and without MeSy according to the National Cholesterol Education Program Adult Treatment Panel III (NCEP-ATP III) criteria. The protocol was a follow-up study carried out in a factorial, randomized design (T1=preventive treatment comprises Diet, T2=HSEP, T3=HSEP+preventive treatment (Diet) X MeSy, non-MeSy individuals). A total daily dose of 100 mg HSEP was orally administered in capsules for one month. The preventive treatment (diet) was selected according to NCEP-ATP III recommendations and adjusted individually. Total cholesterol, LDL-c, HDL-c, VLDL-c, triglycerides, glucose, urea, creatinine, AST, and ALT levels in the blood were determined in all individuals pre- and post-treatment. The MeSy patients treated with HSEP had significantly reduced glucose and total cholesterol levels, increased HDL-c levels, and an improved TAG/HDL-c ratio, a marker of insulin resistance (t-test p<0.05). Additionally, a triglyceride-lowering effect was observed in MeSy patients treated with HSEP plus diet, and in individuals without MeSy treated with HSEP. Significant differences in total cholesterol, HDL-c, and the TAG/HDL-c ratio were found when the means of absolute differences among treatments were compared (ANOVA p<0.02). Therefore, in addition to the well documented hypotensive effects of Hibiscus sabdariffa, we suggest the use of HSEP in individuals with dyslipidemia associated with MeSy.

Inhibition of angiotensin convertin enzyme (ACE) activity by the anthocyanins delphinidin- and cyanidin-3- O-sambubiosides from Hibiscus sabdariffa

Ethnopharmacological relevance The beverages of Hibiscus sabdariffa calyces are widely used in Mexico as diuretic, for treating gastrointestinal disorders, liver diseases, fever, hypercholesterolemia and hypertension. Different works have demonstrated that Hibiscus sabdariffa extracts reduce blood pressure in humans, and recently, we demonstrated that this effect is due to angiotensin converting enzyme (ACE) inhibitor activity. Aim of the study The aim of the current study was to isolate and characterizer the constituents responsible of the ACE activity of the aqueous extract of Hibiscus sabdariffa. Materials and methods Bioassay-guided fractionation of the aqueous extract of dried calyces of Hibiscus sabdariffa using preparative reversed-phase HPLC, and the in vitro ACE Inhibition assay, as biological monitor model, were used for the isolation. The isolated compounds were characterized by spectroscopic methods. Results The anthocyanins delphinidin-3- O-sambubioside ( 1) and cyanidin-3- O-sambubioside ( 2) were isolated by bioassay-guided purification. These compounds showed IC 50 values (84.5 and 68.4 μg/mL, respectively), which are similar to those obtained by related flavonoid glycosides. Kinetic determinations suggested that these compounds inhibit the enzyme activity by competing with the substrate for the active site. Conclusions The competitive ACE inhibitor activity of the anthocyanins 1 and 2 is reported for the first time. This activity is in good agreement with the folk medicinal use of Hibiscus sabdariffa calyces as antihypertensive.

Antibacterial activity of &lt;i&gt;Hibiscus sabdariffa&lt;/i&gt;, &lt;i&gt;Acacia seyal var. seyal&lt;/i&gt; and &lt;i&gt;Sphaeranthus suaveolens var. suaveolens&lt;/i&gt; against upper respiratory tract pathogens

Introduction: Medicinal plants constitute an effective source of both traditional and modern medicines. The emergence of drug resistant bacteria mandates the need for newer antibiotics. Objective: To evaluate the antibiotic effect of Hibiscus sabdariffa. Methods: Three medicinal plants have been selected for investigation of their antibacterial activities; Hibiscus sabdariffa. (Dried calyces), acacia seyal var. seyal (fresh stem bark) and Sphaeranthus suaveolens var suaveolens (herbs) The extracts of these plants at concentration of 100mg/ml have been tested against seven strains of bacteria.; qualitative tests using the Agar Well Diffusion Method have been carried out. Results: E coli showed higher resistance to the plant extracts whereas Pseudomonas aeruginosa is more sensitive. Conclusion: Hibiscus sabdariffa extracts showed extensive inhibition zone and were, therefore, effective as antibacterial ingredient. Keywords: Hibiscus sabdariffa; Acacia seyal var. seyal; Sphaeranthus suaveolens var. suaveolens; antibacterial activities; respiratory tract pathogens. Sudan Journal of Medical Science Vol. 1 (2) December 2006: 121-126