The red-orange flowered clade of Hawaiian Hibiscus species in sect. Lilibiscus are discussed and a botanical key provided. Four species are recognised, viz. Hibiscus kokio Hillebr., H. clayi O. Deg. ...& I. Deg., H. kahilii C.N. Forbes, and H. saintjohnianus M. Roe. These species are uncommon or rare in nature, but vital elements in the diverse ecosystems in which they occur. Surprisingly, distinctive hibiscus species in this group are still being confused. An incomplete and contested understanding of the taxonomy of these species has hindered their conservation—both in situ and ex situ—and effective use in horticulture and landscaping. Recommendations are provided on conservation measures required to maintain and enhance genetic diversity within these four species, which are threatened by extreme weather events and climate change, invasive alien species, habitat loss, and land degradation.
The aim of the study was to evaluate the bioavailability and clinical benefits of oral new formulation (HB sub(12)) of hydroxocobalamin (Hdrx) with Hibiscus sabdariffa (HS). First, in an ...observational study, a cohort of 30 vitamin B sub(12)-deficient patients (vit B sub(12) < 200 pg/mL) with neurological symptoms received oral fixed dose of Hdrx containing 15 mg Hdrx daily for 10 days followed by 15 mg monthly. Clinical benefits were evaluated on haematological and biochemical parameters, and neurological improvement at days 10 and 90 compared to day 0. To understand the mechanism, intestinal mucosa from mice were mounted in vitro in Ussing chambers to measure Hdrx Fluxes. In the clinical study, serum vitamin B sub(12) level increased from 55.1 plus or minus 36.9 to 1330 plus or minus 335.5 pg/mL at day 10 and 431.0 plus or minus 24.27 pg/mL at day 90, without overt adverse effects. In mice ileum, (i) intestinal bioavailability of Hdrx increased in dose-dependent manner with HB sub(12). The apparent permeability of Hdrx was P sub(app) = 34.9 plus or minus 4.6 10 super(-6) cm/s in the presence of 3 mg/mL (HB sub(12)B) compared to the control P sub(app) = 6.2 plus or minus 0.7 10 super(-6) cm/s. (ii) Total transepithelial electrical conductance (G sub(t)) increased in dose-dependent manner with HB sub(12), G sub(t) = 161.5 plus or minus 10.8 mS/cm super(2) with HB sub(12)B (Hdrx 1 mg + HS 3 mg) compared to the control Hdrx, G sub(t) = 28.7 plus or minus 4.0 mS/cm super(2). In conclusion, the clinical study suggests that injections are not required when Hdrx is given orally. Intestinal bioavailability of Hdrx increased in vitro when it was used concomitantly with HS.
Hibiscus sabdariffa calyces are mainly used for different agro-food and beverages applications. The residual biomass generated contains various useful substances that were extracted and ...characterized. It contained 23% (w/w) soluble pectic material, a food additive, extracted with hot acidified water (80 degree C, pH = 1.5) and precipitated with ethanol. The molecular weight (28.5 and 109.7 kDa), the degree of methylation (70.6 and 44.3%) and the degree of acetylation (19.0 and 4.9%) were determined for two Senegalese cultivars (koor and vimto, respectively). The effect of the extraction method on these parameters was highlighted. The residual lignocellulosic material (LCM) was chemically degraded to monosaccharides and the amount of glucose and xylose (39% of dry LCM) determined to estimate its potential as feedstock for biofuels production. However, an enzymatic degradation test revealed a recalcitrant LCM, as only 50 to 55% of its polymeric glucose content was degraded to monosaccharides without pretreatment. Xylo-oligosaccharides (XOS) are functional foods with a real market potential as prebiotics, characterized by their degree of polymerization (DP). The production of XOS synthetized by the enzymatic degradation of LCM was monitored. The results of analyses performed showed that XOS produced had mainly DP3 and DP4 values.
No previous study has been reported on the salt-modulated gene(s) of roselle (Hibiscus sabdariffa L.). Identifying the potentially novel transcripts responsible for salt stress tolerance in roselle ...will increase knowledge of the molecular mechanism underlying salt stress responses. In this study, differential display reverse transcriptase PCR (DDRT-PCR) was used to compare the overall differences in gene expression between salt-stressed and control plants. A total of 81 primer combinations were used and false positive clones were rejected during a screening and quality control assay. The remaining nine cDNA transcript fragments were extracted from the gel, reamplified, cloned and sequenced. A homology search revealed that four transcripts showed significant homology with known genes. Out of five transcripts, real-time PCR demonstrated that four exhibited high expression in salt-stressed root tissues relative to the control and one transcript was down-regulated. These transcripts may be useful for improving tolerance in salt stress-sensitive plants.
To investigate the physiological effect of Hibiscus sabdariffa, in vitro antioxidant activities and neuroprotective effects against high glucose-induced oxidative stress were examined. The ethyl ...acetate fraction (EtOAc-Fr) from H. sabdariffa contained high total phenolic contents compared with other fractions but total anthocyanin contents were lower than 80% Ethanol extract showed the highest 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt radical scavenging activity and malondialdehyde inhibitory effect. Furthermore, the EtOAc-Fr decreased the intracellular reactive oxygen species level, and protected the neuron-like PC12 cells from high glucose-induced cytotoxicity. The EtOAc-Fr also presented inhibitory effects against acetylcholinesterase as an acetylcholine hydrolase enzyme. Finally, chlorogenic acids as main phenolics by high performance liquid chromatography analysis.
The chemical composition of calyces and seeds of three ecotypes of Roselle from Niger was compared. The results indicate that calcium (Ca), potassium (K), sodium (Na), magnesium (Mg) and protein ...contents in calyces are significantly different (P<0.005) among ecotypes. The highest concentrations of K, Na, Mg and protein in calyces were recorded for ecotype E7 (35.66, 3.40, 6.01 and 101 mg/g d.w., respectively). Ecotype E9 had the highest Ca content in calyces (34.41 mg/g d.w.); while E3 and E7 had similar and lower contents. The protein content in calyces for E9 (52 mg/g d.w.) was approximately halved compared to those of E3 and E7. For all ecotypes, the concentrations of Ca, K, Mn, Na and Fe in the calyces were higher compared to those in the seeds. In contrast, P content was higher in seeds. The highest K, Na, Mg and P concentrations in seeds were registered for E7 and the lowest ones for E9. Ecotypes E3 and E9 recorded higher and similar Cu, Fe and Mn contents in calyces and in seeds compared to E7. The highest Zn concentrations in seeds were obtained for E3 and E7.
Yield study was carried out during the 2006 summer season in the field of Research Institute, University of Zabol at Sistan (latitude 30 degree 54' N and longitude 61 degree 41'E). The goal of the ...study was to evaluate the reaction of roselle cultivar to different chemical fertilizers alone or in combination with organic manure. Ten fertilization treatments were used for this study (mineral fertilizer, hen manure, cattle manure, ostrich manure, mineral fertilizer plus hen manure, mineral fertilizer plus cattle manure, mineral fertilizer plus ostrich manure, hen manure plus cattle manure, hen manure plus ostrich manure and ostrich manure plus cattle manure). Rates of NPK fertilizers were 300, 200 and 200 Kg ha super(-1), respectively and organic manure included cattle, hen and ostrich manures with combination of others. This study was done in a randomized complete block design (RCBD) arrangement with three replications. Application of ostrich in addition to hen manure significantly (P<0.05) increased plant height, branch number/plant, weight of dry stem and calyx yield compared with other treatments but did not show significant difference in number of pods of roselle. Calyx yield of 1.6 t/ha was significantly different (P<0.05) compared to other manure. The highest of calyx yield was obtained by using ostrich plus hen manure compared to other organic manures. Results of this study indicate that maximum calyx yield of roselle is grown when ostrich plus hen manure is used.
The composition of roselle seed from oil, protein, ash, fiber, fatty acids and amino acids was determined and compared in three cultivars in order to use it as an unconventional nutritional source. ...Aswan cv. occupies the highest significant rank in protein (31.51), oil (23.70) and fiber (4.87%) contents. Aswan and Sewa cvs. had the highest significant unsaturated fatty acid composition, especially oleic and linoleic acids, with oleic acid having values of 36.22 and 33.34% and linoleic acid, 14.95 and 15.10% values. Protein of Aswan cv. had the highest significant values of seven essential amino acids and four non-essential amino acids, especially lysine and phenylalanine.
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•Spray drying is the main technique to encapsulate bioactive compounds of Hibiscus.•H. acetosella, H. sabdariffa and H. cannabinus are the only exploited species.•Anthocyanins from H. ...sabdariffa calyces are the main encapsulated compounds.•Encapsulated extracts of Hibiscus plants increased stability of food formulations.•Researches on biological effects of encapsulated extracts of Hibiscus are missing.
The genus Hibiscus includes more than 250 species, and many studies showed that these plants contain bioactive compounds with technological potential to be used in the development of functional foods. However, the instability of these compounds during typical food processing conditions, such as exposure to high temperatures, pH changes and presence of light and oxygen have stimulated the use of encapsulation techniques to increase their stability and applicability. Among the existing Hibiscus species, only H. sabdariffa, H. cannabinus, and H. acetosella have been investigated in encapsulation studies, being spray drying the most common method approached. Considering the high technological potential offered by the incorporation of encapsulated bioactive compounds from plants of the genus Hibiscus in food formulations, this review discusses key information of selected encapsulation techniques, which represents promising alternatives to increase food systems' stability and stimulate the design of new functional foods. Relevant gaps in the literature were also noticed, mainly the lack of systematic studies regarding the composition of bioactive compounds after encapsulation, instead of total determinations, and biological activities in different analytical systems, such as antioxidant, antimicrobial and anti-inflammatory properties as well as bioaccessibility and bioavailability.
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