Hibiscus Rosa-sinensis Flowers Research Articles

Versatility of copper-iron bimetallic nanoparticles fabricated using Hibiscus rosa-sinensis flower phytochemicals: various enzymes inhibition, antibiofilm effect, chromium reduction and dyes removal.

Bimetallic nanoparticles (NPs) are considered superior in terms of stability and function with respect to its monometallic counterparts. Hence, in the present study Hibiscus rosa-sinensis flower extract was used to synthesis copper-iron bimetallic nanoparticles (HF-FCNPs). HF-FCNPs was characterized and its applications (biological and environmental) were determined. HF-FCNPs were spherical in shape with high percentage of copper inducted into the NPs. HF-FCNPs inhibited mammalian glucosidases [maltase (IC50: 548.71 ± 61.01µg/mL), sucrase (IC50: 441.34 ± 36.03µg/mL), isomaltase (IC50: 466.37 ± 27.09µg/mL) and glucoamylase (IC50: 403.12 ± 14.03µg/mL)], alpha-amylase (IC50: 16.27 ± 1.73µg/mL) and acetylcholinesterase [AChE (IC50: 0.032 ± 0.004µg/mL)] activities. HF-FCNPs showed competitive inhibition against AChE, maltase and sucrase activities; mixed inhibition against isomaltase and glucoamylase activities; whereas non-competitive inhibition against α-amylase activity. HF-FCNPs showed zone of inhibition of 16 ± 2mm against S. mutans at 100µg/mL concentration. HF-FCNPs inhibited biofilm formation of dental pathogen, S. mutans. SEM and confocal microscopy analysis revealed the disruption of network formation and bacterial cell death induced by HF-FCNPs treatment on tooth model of S. mutans biofilm. HF-FCNPs efficiently removed hexavalent chromium in pH-independent manner and followed first order kinetics. Through Langmuir isotherm fit the qmax (maximum adsorption capacity) was determined to be 62.5mg/g. Further, HF-FCNPs removed both anionic and cationic dyes. Altogether, facile synthesis of HF-FCNPs was accomplished and its biological (enzyme inhibition and antibiofilm activity) and environmental (catalyst to remove pollutants) applications have been understood.

Inhibition of corrosion of mild steel in simulated oil well waterby aqueous extract of Hibiscus rosa-sinensis flower

controlling the corrosion of mild steel in simulated oil well water (SOWW). Weight loss method reveals that 10 % v/v of the extract offers 82 % inhibition efficiency (IE) to mild steel (MS) immersed SOWW. The mechanistic aspects of corrosion inhibitive effect have been investigated by polarization study and AC impedance spectra. Polarization study reveals that the mixed type of inhibitor in the presence of inhibitor system. The corrosion inhibition effect is confirmed by the increase in the linear polarization resistance value and decrease in the corrosion current value. The protective layer is formed on the metal surface is confirmed by the AC impedance spectra. This is confirmed by the fact that there is increase in charge transfer resistance value and decrease in the double layer capacitance value. The adsorption of inhibitor molecule obey Langmuir adsorption isotherm. The protective coating is characterized by FTIR spectroscopy. It confirms that the inhibitor has coordinated with ferrous ion the metal surface through the active principle component of β-sitosterol, quercetin and kaempferol-3-xylosylglucoside. The surface morphology has been investigated by scanning electron microscopy (SEM). Hence, aqueous extract of Hibiscus rosa-sinensis flower with simulated oil well water good corrosive inhibitive effect on pipeline made of mild steel.

Standardization of Hibiscus rosa-sinensis Flower by HPTLC, HPLC and AAS

Hibiscus rosa-sinesis, a well-known flowering plant in India, is used to worship Lord Ganesha. It is a member of the Malvaceae family. It is used in traditional medicine in many tropical countries to treat wounds, inflammation, fever, diabetes, infections, hair loss, and gastric ulcers. Therapeutic benefits of Hibiscus rosa-sinesis are attributed to flavonoids, tannins, terpenoids, saponins, and alkaloids. Hibiscus rosa-sinesis flowers are a good source of flavonoids, which are important components of herbal and Ayurvedic preparations. The goal of this study was to standardize the flower extract through qualitative phytochemical screening and quantitative HPTLC analysis of quercetin, an active biomarker. The result of the HPTLC analysis was compared to those obtained using HPLC. HPTLC found that the extract contained 0.33% quercetin, while HPLC found that it contained 0.37% quercetin. Further, heavy metals and trace elements were measured using atomic absorption spectroscopy (AAS). Results showed that cadmium, lead, arsenic, copper, chromium, and mercury levels (in ppm±SEM) were within acceptable limits: cadmium (0.018±0.050), lead (0.630±0.025), arsenic (0.041±0.014), copper (2.605±0.045), chromium (0.450±0.025), and mercury (0.023±0.006). This method allows standardization of plant material for raw material and finished product testing, ensuring better efficacy and safety.

Exploring the interaction of phytochemicals from Hibiscus rosa-sinensis flowers with glucosidase and acetylcholinesterase: An integrated in vitro and in silico approach

Targeting multiple factors such as oxidative stress, alpha glucosidase and acetylcholinesterase (AChE) are considered advantageous for the treatment of diabetes and diabetes associated-cognitive dysfunction. In the present study, Hibiscus rosa-sinensis flowers anthocyanin-rich extract (HRA) was prepared. Phytochemical analysis of HRA using LC-ESI/MS/MS revealed the presence of various phenolic acids, flavonoids and anthocyanins. HRA showed in vitro antioxidant activity at low concentrations. HRA inhibited all the activities of mammalian glucosidases and AChE activity. The IC50 value of HRA for the inhibition of maltase, sucrase, isomaltase, glucoamylase and AChE was found to be 308.02 ± 34.25 µg/ml, 287.8 ± 19.49 µg/ml, 424.58 ± 34.75 µg/ml, 408.94 ± 64.82 µg/ml and 264.13 ± 30.84 µg/ml, respectively. Kinetic analysis revealed mixed-type inhibition against all the activities except for glucoamylase (competitive) activity. In silico analysis confirmed the interaction of two active constituents cyanidin 3-sophoroside (CS) and quercetin 3-O-sophoroside (QS) with four subunits, n-terminal and c-terminal subunits of human maltase-glucoamylase and sucrase-isomaltase as well as with AChE. Molecular dynamics simulation, binding free energy calculation, DCCM, PCA, PCA-based free energy surface analysis ascertained the stable binding of CS and QS with target proteins studied. HRA could be used as complementary therapy for diabetes and cognitive improvement.

Identification of Phthalates, Methyl Esters and Siloxanes through GCMS analysis, biological investigation, DFT and Molecular Docking studies on Methanolic Subfractions of Hibiscus Rosa Sinensis flower extract

Purpose: Plants are vital source of bioactive molecules, so they play a significant role in prevention and curing of various health disorders. The Hibiscus rosa sinensis, an ornate with attractive flowers, has conventionally been utilized globally as a curative agent for a wide range of ailments. Methods: In current study, we prepared crude methanolic extract of flowers of Hibiscus rosa sinensis and subjected that to in vitro biological evaluation to assess its antidiabetic and antioxidant potential. Outcomes of in vitro evaluation confirmed the excellent antidiabetic and antioxidant potency of Hibiscus flowers. Further crude methanolic extract was fractionated to hexane, ethyl acetate and methanol fractions. Among the three fractions, we subjected methanolic fraction to GCMS analysis to explore the bioactive molecules contained by this fraction. Results: The spectral data obtained from GCMS analysis revealed the existence of a total of 12 compounds including phthalates, methyl esters and siloxanes which are known to have a range of reported pharmacological activities. Successively, we subjected the identified molecules to molecular docking to assess their antidiabetic and antioxidant potential and DFT study to explore the reactivity of their molecular structures. As far as we are aware, it is the first report on the in-silico antidiabetic (128.1µM) and antioxidant (410.0µM) potential assessment of phytoconstituents of methanolic extract of floral part of Hibiscus rosa sinensis. The results revealed the H. Sinensis plat as more viable and good alternative to existing natural remedies.

Antioxidant activity and inhibitory potential of Hibiscus rosa-sinensis flower extract against the key enzymes relevant for hyperglycemia: in-vitro and in-silico studies

BACKGROUND: The alteration of endogenous antioxidants and generation of reactive oxygen species induce hyperglycemia which may lead to the emergence of chronic problems in diabetes. The key enzymes responsible for hyperglycemia are α-amylase and α-glucosidase. Owing to the various negative consequences caused by synthetic medicines, there is a requirement for natural antioxidants and inhibitors for α-amylase, and α-glucosidase enzymes to attenuate hyperglycemia. This article entails the antioxidant potential as well as the inhibitory potential of the Hibiscus rosa-sinensis flower extracts in contrast to the enzymes involved in regulating hyperglycemia.METHODS: Flower extracts were prepared using solvents with ascending polarity viz. hexane, chloroform, ethyl acetate, n-butanol, methanol, and distilled water by maceration. Antioxidant capacity was investigated using 2,2-diphenyl-1-picrylhydrazyl free radical activity, 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid cation(s) scavenging assay, ferric ion reducing-antioxidant power assay, and total antioxidant capacity. The inhibitory efficacy against α-amylase and α-glucosidase enzyme were investigated by performing α-amylase, and α-glucosidase inhibitory assays. To validate the observed results in in-vitro assays, the existence of polyphenolic compounds in the most potent extract was detected using ultra-high-performance liquid chromatography (UHPLC). Furthermore, in-silico analysis of the detected polyphenols in the most potent extract was done to understand the binding energies and docking at different sites of α-glucosidase and α-amylase enzymes, and it was contrasted to standard (acarbose).RESULTS: The most significant amount of antioxidant activity was noticed in the ethyl acetate extract in all the assays. Moreover, the ethyl acetate extract had a stronger suppressant effect on α-glucosidase and α-ainilase enzymes than other extracts and it was more in the case of α-glucosidase (IC50 value 53.33 µg/mL) as compared to α-amylase (IC50 value 83.02 µg/mL) enzymes There was a finding that among the polyphenolic compounds detected from the ethyl acetate extract via UHPLC, in which the docking studies were carried out, caffeic acid showed maximum binding energy with the α-glucosidase enzyme while epicatechin showed maximum binding energy with the α-amylase enzyme.CONCLUSIONS: The whole study concluded that caffeic acid and epicatechin have shown good interactions with concerned enzymes, and hence might contribute to the inhibition of hyperglycemic conditions and other diabetic problems caused by oxidative stress.

Topical effect of polyherbal flowers extract on xanthan gum hydrogel patch—induced wound healing activity in human cell lines and male BALB/c mice

Wound or injury is a breakdown in the skin’s protective function as well as damage to the normal tissues. Wound healing is a dynamic and complex phenomenon of replacing injured skin or body tissues. In ancient times the Calendula officinalis and Hibiscus rosa-sinensis flowers were extensively used by the tribal communities as herbal medicine for various complications including wound healing. But loading and delivery of such herbal medicines are challenging because it maintains their molecular structure against temperature, moisture, and other ambient factors. This study has fabricated xanthan gum (XG) hydrogel through a facile process and encapsulated C. officinalis and H. rosa-sinensis flower extract. The resulting hydrogel was characterized by different physical methods like x-ray diffractometer, UV–vis spectroscopy, Fourier transform infrared spectroscopy, SEM, dynamic light scattering, electronkinetic potential in colloidal systems (ZETA) potential, thermogravimetric differential thermal analysis (TGA-DTA), etc. The polyherbal extract was phytochemically screened and observed that flavonoids, alkaloids, terpenoids, tannins, saponins, anthraquinones, glycosides, amino acids, and a few percentages of reducing sugar were present in the polyherbal extract. Polyherbal extract encapsulated XG hydrogel (X@C–H) significantly enhanced the proliferation of fibroblast and keratinocyte cell lines in comparison to the bare excipient treated cells as determined by 3-(4, 5-dimethylthiazol-2-Yl)-2, 5-diphenyltetrazolium bromide assay. Also, the proliferation of these cells was confirmed by BrdU assay and enhanced expression of pAkt. In an in-vivo study, wound healing activity of BALB/c mice was carried out and we observed that X@C–H hydrogel showed significant result compared to the other groups (untreated, X, X@C, X@H). Henceforth, we conclude that this synthesized biocompatible hydrogel could emerge as a promising carrier of more than one herbal excipients.

Compositions of Hibiscus rosasinensis floral extract infusion and its prospects of use as a health tonic

Herbal remedies are being practiced expeditiously. The beneficial effects of these herbal remedies on health problems have been observed and experienced by humans for thousands of years. Indigenous medicinal plants are more valued because they are acquirable and have low side effects. Nutritional composition and medicinal use of Hibiscus rosa-sinensis flowers have been conducted in this study. Hibiscus rosa-sinensis has medicinal properties for anti-tumor, anti- fertility, antipyretic, hypoglycemic, anti inflammatory, analgesic, antimicrobial, CNS depressant, and hypertensive activity and is a primary ingredient in many herbal teas. Among the different bioactive compounds contained in the flowers, polyphenol compounds are of the utmost importance for their antioxidant properties. Flowers have a wide range of pharmacological actions, which may be therapeutically beneficial for overall health and wellness of population, the need of the hour is for further research in clinical aspects. Consumption of tea made from the abovementioned flower petals is being followed by a large number of people to control various lifestyle diseases. Since plants are easily available and no special conditions are required to cultivate and collect them, it could be a better choice to treat ailments.

Screening the possible anti-cancer constituents of Hibiscus rosa-sinensis flower to address mammalian target of rapamycin: an in silico molecular docking, HYDE scoring, dynamic studies, and pharmacokinetic prediction.

One of the most common malignancies diagnosed and the leading cause of death for cancer-stricken women globally is breast cancer. The molecular subtype affects therapy options because it is a complex disorder with multiple subtypes. By concentrating on receptor activation, mTOR (mammalian target of rapamycin) can be employed as a therapeutic target. The goal of this work was to screen a number of inhibitors produced from Hibiscus rosa-sinensis for possible target to inhibit the mTOR and to determine which has the greatest affinity for the receptor. Primarily, the ionization states of the chosen compounds were predicted using the ChemAxon web platform, and their pKa values were estimated. Given the significance of interactions between proteins in the development of drugs, structure-based virtual screening was done using AutoDock Vina. Approximately 120 Hibiscus components and ten approved anti-cancer drugs, including the mTOR inhibitor everolimus, were used in the comparative analysis. By using Lipinski's rule of five to the chosen compounds, the ADMET profile and drug-likeness characteristics were further examined to assess the anti-breast cancer activity. The compounds with the highest ranked binding poses were loaded using the SeeSAR tool and the HYDE scoring to give interactive, desolvation, and visual ΔG estimation for ligand binding affinity assessment. Following, the prospective candidates underwent three replicas of 100ns long molecular dynamics simulations, preceded with MM-GBSA binding free energy calculation. The stability of the protein-ligand complex was determined using root mean square deviation (RMSD), root mean square fluctuation (RMSF), and protein-ligand interactions. The results demonstrated that the best mTOR binding affinities were found for stigmastadienol (107), lupeol (66), and taraxasterol acetate (111), which all performed well in comparison to the control compounds. Thus, bioactive compounds isolated from Hibiscus rosa-sinensis could serve as lead molecules for the creation of potent and effective mTOR inhibitors for the breast cancer therapy.

The Influence of Season on Phenotypic Plasticity Symptoms in Hibiscus rosa-sinensis Crested Peach Flowers

The variation of Hibiscus rosa-sinensis flower in the form of a crested peach is thought to show phenotypic plasticity symptoms in nature. Phenotypic plasticity is a condition in which genotypes give rise to different phenotypes in different environments. The aim of this study was to determine the plasticity response of H. rosa-sinensis crested peach flowers to seasonal changes, both morphologically and anatomically. Flower samples were taken from the residential area of Bojong Gede, Bogor, in two different seasons: the dry season in 2018 and the rainy season in 2021. Morphological observations were made by calculating the number and size of each flower section using measuring instruments and a Dino-Lite microscope. Anatomical observations were made by observing the internal structure of the ovaries using a 4× magnification light microscope. Measurement of environmental parameters, such as temperature, humidity, and light intensity, was also carried out in this study to determine the symptoms of phenotypic plasticity. The phenotypic plasticity responses of H. rosa-sinensis crested peach flower are clearly observed in the number and composition of the stamen, staminodium petaloid, intermediate stamen-petal, and external-internal structure of the ovary. H. rosa-sinensis, in the form of crested flowers, showed a different phenotypic plasticity response in different seasons. The light intensity and temperature factors play an important role in phenotypic plasticity. Research with various observation times is still needed to determine the range of phenotypic plasticity responses of the H. rosa-sinensis flower form of crested peach in nature.

A Study on the Effect of Gold Nanoparticles for Dye Sensitized Solar Cell Using Hibiscus Rosa-Sinensis as Photosensitizer

Dye-sensitized solar cells (DSSC) mainly use organic components as an alternative way of light harvesting element to replace the traditional silicon solar cells. N atural dye alternatively is being used as sensitizers to overcome the limitation of inorganic ruthenium dye which contains heavy metal. In this study, DSSC is expected to enhance its optical properties and light absorption by implementing gold (Au) nanoparticles. Various natural and organic sources can be extracted and acted as a photosensitizer to trap solar energy. Fresh Hibiscus Rosa-Sinensis flowers are one of the good candidates to give higher light absorption in DSSC. The characteristics of the dye photosensitizer will be observed under UV-Vis-NIR Spectrophotometer. The efficiency of complete DSSC will be determined by using LIV tester. An attempt to enhance light-harvesting efficiency and hence the light to current conversion efficiency by mixing Au nanoparticles TiO₂ paste. Au nanoparticle was selected because it can act as a medium between the dye and TiO₂ to increase the electron transmission speed. The Hibiscus dye in DSSC achieved an efficiency of 0.14%. However, the efficiency reduced to 0.000178% as Au NPs was added. The effects of the addition of Au nanoparticles are discussed.

Formulation and Evaluation of Polyherbal Hair Oil Containing Vitamin B7

In the last few years there has been an extraordinary growth in the field of herbal & ayurvedic medicines. Herbal formulations have less side effects and are safe to use. The goal of the present study is involves preparation & evaluation of polyherbal hair oil using plant materials. The different extracts of different part of plant showed promising pharmacological activities. Formulation of polyherbal hair oil prepared by using extract of hibiscus rosa sinensis flower and powder of curry leaves, henna leaves, fenugreek seeds, tulsi leaves & shikakai. After preparation capsules of vitamin B7 is added in oil, it stimulates keratin production. The prepared polyherbal hair oil evaluated different parameters such as phytochemical screening, organoleptic characterization, physical evaluation, specific gravity, pH and also stability study. Antimicrobial assay of the polyherbal hair oil was carried out by using cup plate method and these helps reduces dandruffs and scalp of hairs. And to provide nutrition’s to hairs. The antioxidant activity of the oil was studied by DPPH radical scavenging activity. Hence, these polyherbal hair oil increases hair growth, reduces hair loss, providing protection against dandruff.

Green Synthesis of Iron Oxide Nanoparticles Using Hibiscus rosa sinensis Flowers and Their Antibacterial Activity

Iron oxide nanoparticles (α- Fe2O3) were synthesized using an unconventional, eco-friendly technique utilizing a Hibiscus rosa sinensis flower (common name, China rose) extract as a reducer and stabilizer agent. The microwave method was successfully used for the synthesis of iron oxide nanoparticles. Various volume ratios of iron chloride tetrahydrate to the extract were taken and heated by the microwave oven for different periods to optimize iron oxide nanoparticle production. The synthesized iron oxide nanoparticles were characterized using the ultraviolet-visible spectrometer (UV-Vis), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), and X-ray diffraction (XRD). X-ray diffraction confirmed the formation of α- Fe2O3 nanoparticles (hematite). The average size of iron oxide nanoparticles was found to be 51 nm. The antibacterial activity of the synthesized iron nanoparticles was investigated against different bacteria such as Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumonia, and Escherichia coli. The results showed that the synthesized iron nanoparticles exhibited an inhabitation effect on all studied bacteria.

Antihypertensive and Vasorelaxant Effects of Hibiscus rosa-sinensis through Angiotensin-Converting Enzyme-2 (ACE-2), and Ca2+ channels Pathways.

The aim of the study was to assess the antihypertensive activity of Hibiscus rosa-sinensis. Hibiscus rosa-sinensis is used traditionally to treat hypertension. The goal of the study was to investigate the effect of the aqueous extract of Hibiscus rosa-sinensis flowers (AEHRS) on resting blood pressure in rats. In the present study, AEHRS was prepared and its antihypertensive activity was evaluated using in vivo and in vitro studies. In the in vivo study, hypertensive and normotensive rats were treated by AEHRS (100 mg/kg) orally for 6 hours in the acute treatment and for 7 days in the subchronic treatment. Systolic, diastolic, and mean arterial blood pressure values and heart rate were then recorded using a tail cuff and a computer-assisted monitoring device. To assess the vasorelaxant activity of AEHRS, isolated thoracic aortic rings were suspended in a tissue bath and changes in tension were recorded using a data acquisition system. Potential pathways involved in the vasorelaxant activity were evaluated using several standard pharmacological agents. The results indicated that repeated oral administration of AEHRS during 7 days lowered systolic, diastolic, and mean arterial blood pressure in hypertensive rats without affecting normotensive rats. Furthermore, the data revealed that AEHRS exerts vasorelaxant properties via an endothelium-independent pathway. More interestingly, the study demonstrates that the vasorelaxant capacity of AEHRS seems to be exerted through the stimulation of angiotensin-converting enzyme-2 (ACE-2) and the inhibition of Ca2+ channels pathway. The present study revealed that aqueous extract of Hibiscus rosa-sinensis has a significant antihypertensive activity and that its vasorelaxant effect may be mediated through stimulation of ACE-2, and inhibition of the Ca2+ channels.

A BUCOLIC REMEDY OF FORMULATION AND EVALUATION OF POLYHERBAL HAIR OIL

Objective: The birth of cosmetics forms an incessant narrative throughout the past of man as they developed. The present study aimed to formulate polyherbal hair oil using various efficient herbs. Methods: Hair oil formulation of Cocos nucifera (oil), Ricinus communis (oil), Brassica juncea (oil), Trigonella foenum-graecum (Seeds), Murraya koenigii (Leaf), Hibiscus rosa-sinensis (Flowers), Nigella sativa (seeds), and Cinnamomum camphora in the form of polyherbal oil using boiling method. These ingredients are rich in various phytochemicals, vitamins, proteins, antioxidants, and so many other constituents which are important for the growth and rejuvenation of the hair cycle. Evaluation of hair oil carries out by various parameters such as sensitivity test, acid value, saponification value, phytochemical screening, pH, specific gravity, viscosity, and irritation test. Results: All the values of evaluation are within the acceptable limit. As compared to market formulations, this herbal oil having minimal or zero adverse effects. Conclusion: It is concluded that formulated hair oil boost hair growth, decrease hair fall, dandruff, gray hair, and gives lustrous and shiny hairs.

Hibiscus rosa-sinensis as Flavoring Agent for Alcoholic Beverages

The present work is an evaluation of the chemical composition of the aroma and the sensorial characters of a beer flavored with Hibiscus rosa-sinensis flowers. Moreover, the total polyphenol, flavonoid and anthocyanin contents and the antioxidant activity of the plant materials and beers were assessed. A comparison with a liqueur flavored with the same hibiscus flowers was also performed. Non-terpene derivatives constituted the main class of components of the aroma of both samples, representing 96.4% of the whole volatilome in the control beer and 99.0% in the hibiscus one. Among this class, esters were the most abundant compounds, being significantly higher in the treated sample (77.6%) than in the control (68.4%), followed by the alcohols (20.9% in control beer and 18.8% in hibiscus beer). From a sensorial point of view, the control beer was characterized by malty and hoppy notes, attributable to the noticeable content in myrcene and α-humulene in its headspace, while in the hibiscus beer, floral and fruity notes, typical of esters and alcohols, prevailed. The polyphenol content was significantly higher in the treated beer (143.96 mg/g) than in the control, as well as the total flavonoids and the total anthocyanins, and, consequently, the antioxidant activity (DPPH-assay).

Study of Hibiscus Rosasinensis as a Feedstock for Natural Colorant to Food

The application of coloring to food is widespread around the globe. Some of the artificial food colorants are highly carcinogenic. Exploration of new natural colorants has therefore been under research. The present study was aimed to evaluate Hibiscus rosasinensis flower as a potential feedstock for natural colorant. Crude anthocyanin was first extracted from Hibiscus rosasinensis flower using a Soxhlet apparatus with ethanol as the solvent. Flower to solvent ratio was found to affect the extraction largely. A ratio of 1:20 was found to give the highest fraction of extract. The cytotoxicity of crude anthocyanin extract was subsequently determined by Brine Shrimp Lethality Test. The LC50 value for crude anthocyanin extract was 2332 μg/ml, which is higher than the required minimum threshold value. Hence the findings of present study would be useful towards the application of H. rosasinensis flower as a feedstock for natural colorant to food.
 Chemical Engineering Research Bulletin 21(2020) 32-36

Use of natural plant extracts as a novel microbiological quality indicator in raw milk: An alternative for resazurin dye reduction method

In the present study, we propose a novel field-scale analytical tool for rapid screening of microbiological quality in raw milk using aqueous extracts of plant materials, i.e. flowers (e.g. Hibiscus rosa-sinensis L. and Clitoria ternatea), taproots (e.g. Beta vulgaris) and pricklypears (e.g. Opuntia dillenii). For each plant extract, the colour changes in raw milk were evaluated between 4.5 and 6.5 pH against the resazurin dye as a control. The plant anthocyanin content in each extract was analyzed by the differential pH method using a spectrophotometer. The Hibiscus rosa-sinensis flower extract was opted to further test since it had a pH-sensitive colour change (6.5; maroon to 6.2; light-pink) compared to other plant extracts, which did not indicate a noticeable colour variation with pH. Anthocyanin content of the Hibiscus extract was 0.59 g/mL. The novel method showed high linearity (R2 = 0.95), 100% accuracy and greater repeatability with an intermediate level of precision. The limit of quantification and detection was 0.46 and 0.15 g/mL, respectively. In conclusion, we demonstrated the potential in using water extract of Hibiscus rosa-sinensis L. flowers as an alternative to the resazurin dye reduction method for rapid and accurate microbiological quality control for raw milk procurement in remote areas.

Wound Healing Activity of Herbal Ointment Containing the Extracts of Hibiscus rosa-sinensis Flowers and Curcuma longa Rhizomes

Objectives: To evaluate wound healing activity of herbal ointment containing the extracts of Hibiscus rosa-sinensis flowers and Curcuma longa rhizomes. Methodology: H. rosa-sinensis flowers and C. longa rhizomes were extracted using 95% ethanol. H. rosa-sinensis and Hibiscus rosa-sinensis ointment were prepared using paraffin wax, lanolin and petroleum jelly. Ointment formulation was applied once daily on the excision wound made on Sprague Dawley rats for 20 days. Results: On day 20, the treatment group showed a significant increase in wound contraction which was 93.52 ± 1.38% when compared to control (87.62 ± 1.48%). Conclusion: Herbal ointment exhibited significant wound healing activity in rat excision wound model.

Growth-Inhibiting, Bactericidal, Antibiofilm, and Urease Inhibitory Activities of Hibiscus rosa sinensis L. Flower Constituents toward Antibiotic Sensitive- and Resistant-Strains of Helicobacter pylori.

The aim of the present study was to assess antimicrobial effects of naringenin (NRG), luteolin (LUT), myricetin (MCT), and protocatechuic acid (PCA) identified in a Hibiscus rosa sinensis flower against two reference strains and five clinical isolates of Helicobacter pylori. NRG displayed the most growth inhibitory and bactericidal activities to seven bacterial strains including six strains resistant to one or several antibiotics, azithromycin (MIC, 16–32 mg/L), erythromycin (MIC, 32 mg/L), levofloxacin (MIC, 32 mg/L), and/or metronidazole (24–64 mg/L), followed by LUT and MCT, while PCA showed weak activities toward the strains. These constituents had similar antibacterial activities toward the seven tested strains suggesting that these constituents and the antibiotics do not have a common mechanism of anti-H. pylori activity. NRG, LUT, and MCT resulted in a high percentage of coccoid forms of H. pylori. NRG exhibited the highest anti-biofilm formation activity. MCT produced the strongest inhibition of urease activity followed by LUT and PCA, whereas the activity of NRG was similar to standard inhibitor thiourea. The four constituents had no significant toxicity to human cell lines. A global attempt to decrease utilization of antibiotics justifies the need for further research on H. rosa sinensis derived materials containing NRG, LUT, MCT, and PCA as potential products or lead compounds for the prevention or treatment of diseases caused by H. pylori infection.