Comparative study of the anti-oxidant activity of the total polyphenols extracted from Hibiscus Sabdariffa L., Glycine max L. Merr., yellow tea and red wine through reaction with DPPH free radicals

A Nature-Inspired Versatile Bio-Adhesive

The application of most hydrogel bio-adhesives is greatly limited due to their high swelling, low underwater adhesion, and single function. Herein, a spatial multi-level physical-chemical and bio-inspired in-situ bonding strategy is proposed, to develop a multifunctional hydrogel bio-glue using polyglutamic acid (PGA), tyramine hydrochloride (TYR), and tannic acid (TA) as precursors and 4-(4,6-dimethoxytriazine-2-yl) -4-methylmorpholine hydrochloride(DMTMM) as condensation agent, which is used for tissue adhesion, hemostasis and repair. By introducing TYR and TA into the PGA chain, it is demonstrated that not only can the strong adhesion of bio-glue to the surface of various fresh tissues and wet materials be realized through the synergistic effect of spatial multi-level physical and chemical bonding, but also this glue can be endowed with the functions of anti-oxidation and hemostasis. The excellent performance of such bio-glue in the repair of the wound, liver, and cartilage is achieved, showing a great potential in clinical application for such bio-glue. This study will open up a brand-new avenue for the development of multifunctional hydrogel biological adhesive.

Phytochemical Profiling and Pharmacological Evaluation of Leaf Extracts of Ruellia tuberosa L.: An In Vitro and In Silico Approach

The present study was designed to appraise the photoprotective, antioxidant, and antibacterial bioactivities of Ruellia tuberosa leaves extracts (RtPE, RtChl, RtEA, RtAc, RtMe, and RtHMe). The results showed that, RtHMe extracts of R. tuberosa was rich in total phenolic content, i. e., 1.60 mgGAE/g dry extract, while highest total flavonoid content was found in RtAc extract, i. e., 0.40 mgQE/g. RtMe showed effective antioxidant activity (%RSA: 58.16) at the concentration of 120 μL. RtMe, RtEA and RtHMe exhibited effective in vitro antibacterial activity against Gram-negative bacteria (E. coli). In silico docking studies revealed that paucifloside (-11.743 kcal/mol), indole-3-carboxaldehyde (-7.519 kcal/mol), nuomioside (-7.275 kcal/mol), isocassifolioside (-6.992 kcal/mol) showed best docking score against PDB ID 2EX8 [penicillin binding protein 4 (dacB) from Escherichia coli, complexed with penicillin-G], PDB ID 6CQA (E. coli dihydrofolate reductase protein complexed with inhibitor AMPQD), PDB ID 2Y2I [Penicillin-binding protein 1B in complex with an alkyl boronate (ZA3)] and PDB ID 2OLV (from S. aureus), respectively. Docked phytochemicals also showed good drug likeness properties.

Antioxidant activity and total phenolic compounds of Commiphora gileadensis extracts obtained by ultrasonic-assisted extraction, with monitoring antiaging and cytotoxicity activities

Commiphora gileadensis (C. gileadensis) has been identified and linked with various health benefits and pharmaceutical potential for its phytochemical activities and chemical constituents. This study aimed to evaluate ultrasonic-assisted extraction (USE) technique for total phenols content from C. gileadensis leaf compared to the hydrodistillation extraction (HDE). Our results showed that the USE operating conditions were identified as: MeOH·H2O solvent-to-fresh sample ratio of 80:20 (v/v); ultrasonic power/frequency at 150 W/20 kHz; and a temperature of 40 ± 1°C; subjected to acoustic waves intermittently for a calculated time (5 min) during the total programmed time of 12 min. The USE exhibited (118.71 ± 0.009 mg GAE/g DM) more amounts of all phenols than HDE (101.47 ± 0.005 mg GAE/g DM), and antioxidant (77.78 ± 0.73%, 75.27 ± 0.59% scavenging inhibition of DPPH), respectively. Anti-aging and Cytotoxicity activities were investigated. The results of biological evaluations showed that the crude extracts of C. gileadensis significantly extended the replicative lifespan of K6001 yeast. In addition, in vitro cytotoxicity against the HepG2 cell line showed significant anticancer activity, and approximately 100 μg/mL is required to decrease viability compared with that of the control. This study is proven for a larger scale to extract and isolate compounds of C. gileadensis for potential utilization in the pharmaceutical industry. In conclusion, advanced methods afford an extract with high activity in the biological properties of the extract.

Potent hepatoprotective activity of common rattan (Calamus rotang L.) leaf extract and its molecular mechanism

BACKGROUND

Calamus rotang L. (CR) is an Indian shrub. The leaves and other organs of the plant are traditionally used in India for treatment of various diseases. The in vitro antioxidant property of the leaves extract was previously established. Thus, the current study aimed to evaluate the antioxidant and hepatoprotective effects of CR ethyl acetate extract at a dose of 350 mg/kg on CCl₄ induced hepatotoxic rats through different mechanisms.

METHODS

Histopathological examination of the treated rats' group in comparison with positive and negative controls were performed. Quantitative measuring of the proinflammatory cytokines (TNF α), inflammatory regulators (Arginase, PPAR α) and the antiapoptotic protein Bcl-2 in comparison with positive and negative control groups was achieved using immunohistochemical examination. HPLC profiling of the polyphenol contents and molecular docking of the identified compounds against BH3 proapoptotic protein were correspondingly studied to evaluate the potential antiapoptotic property.

RESULTS

The CR extract greatly protects the liver tissue through the suppression of TNF α, arginase and PPAR α induced by CCl₄ as well as its enhancement of the antiapoptotic Bcl-2 protein. Fourteen polyphenols of different classes were identified in CR extract and tested via molecular docking for their potential antiapoptotic activities against BH3 protein. Naringin, rutin, 7-hydroxy flavone, and ellagic acid compounds exhibit the highest affinity and potential inhibition of pro-apoptotic protein BH3 via molecular docking study.

CONCLUSIONS

The ethyl acetate fraction of the leaves of C. rotang is rich in polyphenols that exhibited potent hepatoprotective effect on CCl₄ induced hepatotoxic rats through its antioxidant, anti-inflammatory, anti-steatosis and antiapoptotic properties.

Hibiscus sabdariffa: Genetic variability, seasonality and their impact on nutritional and antioxidant properties

This study consisted of the physicochemical, phytochemical and antioxidant characterisation of two varieties of Hibiscus sabdariffa, to evaluate the influence of genetic and environmental factors on these parameters leading to an objective and rigorous classification of our extracts. To this end, calyxes and seeds of the red and white phenotypes were collected in Bobo-Dioulasso, Dano and Nouna respectively in December 2019 and 2020. Principal component analysis showed that physico-chemical and biochemical parameters could potentially be used to discriminate varieties. The calyxes of the sabdariffa variety showed the best physicochemical profile (total phenolics, flavonoids, ascorbic acid), pigments (anthocyanins, chlorophyll) and antioxidant activity (free radical scavenging and SOD activity) while the seeds showed the best carbohydrate, lipid and peroxidation inhibition content. In view of these results, the red phenotype has an interesting nutritional and therapeutic potential. It could therefore be interesting candidate in the pharmaceutical and food industries.

Biosynthesis of Gold Nanoparticles Mediated by Andaliman Fruit Water Extract and Its Application as Antioxidants

Plant extract-mediated green synthesis of gold nanoparticles (AuNPs) is currently gaining significant interest in the field of nanotechnology. In this study, AuNPs were synthesized using an aqueous extract of Andaliman fruit (Zanthoxylum acanthopodium DC.). The formation of AuNPs was confirmed by observing the color change of the solution from clear to cherry red. The reaction parameters, namely the extract concentration and the ratio of the mixture of the extract with HAuCl4 solution, were optimized for the AuNPs biosynthesis. The gold nanoparticles were characterized using a UV-Vis spectrophotometer, SEM-EDS, and particle size analyzer. The characterization suggested that AuNPs had a maximum wavelength ranging of 540–559 nm, with spherical crystals morphology where the highest component was gold at 36.01% and the size below 100 nm on average. The antioxidant activity of the synthesized AuNPs was determined using the DPPH method. It showed that the highest free radical scavenging activity was 83%, given by 20 ppm AuNPs.

A mechanical, electrical dual autonomous self-healing multifunctional composite hydrogel

The versatile properties make hydrogels a potential multipurpose material that finds wide applications. However, the preparation of multipurpose hydrogels is very challenging. Here, we report a method based on free radical reaction and composite mechanisms to prepare mechanical and electrical self-healing multifunctional hydrogels. In this study, the introduction of imidazolium salt ionic liquids and glycerol in the hydrogel system endows the gels with good antibacterial, conductive, and adhesive properties and excellent antifreeze properties. The testing results show that the as-prepared hydrogel has stable mechanical and electrical properties even under the extremely cold condition of -50°C after self-healing. Moreover, the active esters formed in the dynamic radical reaction have better reducibility, thus further investing the as-prepared hydrogel with high antioxidant activity. The application results show that these comprehensive properties make such hydrogel system very useful in wound repair and wearable strain sensors.

Action Mechanism of Rosella (Hibiscus sabdariffa L.) Used to Treat Metabolic Syndrome in Elderly Women

Objective

Rosella is a safe medicinal herb used by people in Indonesia. They believe that rosella is effective in controlling metabolic syndrome, working with antihypertension, antidiabetic, antidyslipidemia and antiobesity effects. The purpose of this study was to determine the effect of rosella in controlling metabolic syndrome through the secretion of blood nitric oxide (NO) and the cortisol pathway.

Methods

This study was a quasiexperimental, pretest-posttest with control group design. The total subjects were 18 people, women, and the elderly. Subjects were selected randomly into 2 groups: control group (n = 8) and treatment group (n = 8). The treatment was rosella tea, a dose of 2 grams, duration 2 times a day, given in the morning (08.00–8.30 a.m.) and evening (06.30–7.00 p.m.) after meals for 21 days. Examination of NO and cortisol levels was carried out using the enzyme-linked immunosorbent assay (ELISA) method.

Results

There was a significant decrease in bodyweight (BW) (p = 0.021), systolic blood pressure (SBP) (p = 0.001), diastolic blood pressure (DBP) (p = 0.049), glucose preprandial (FPG) (p = 0.014), total cholesterol (CT) (p = 0.001), triglycerides (TGs) (p = 0.014), high-density lipoprotein (HDL) (p = 0.001), and low-density lipoprotein (LDL) (p = 0.010) after consuming rosella. NO levels were significantly increased (p = 0.012), whereas cortisol levels decreased significantly (p = 0.008) after therapy with rosella tea in elderly women.

Conclusion

Rosella has shown evidence to control and lower blood pressure, blood glucose, lipid profile, and cortisol in the elderly with metabolic syndrome. Rosella is a traditional medicine that has the potential to be developed as a therapy for metabolic syndrome patients.

The protective effect of Hibiscus sabdariffa calyxes extract against cypermethrin induced oxidative stress in mice

Cypermethrin (Cyp) is a kind of pyrethroids compound that is broadly used against different species of insects and pests. Cyp can also elicit a range of neurotoxic, immunotoxic, genotoxic and reproductive toxic effects on various experimental organisms. The aim of this study was to evaluate the protective effects of Hibiscus sabdariffa against the toxicity damage induced by Cyp exposure. The Hibiscus sabdariffa calyxes extract was given to mice (200-500 mg/kg bw). The mice, which were treated with Cyp and Hibiscus sabdariffa, were divided into six groups of six mice each. Groups I, IV and VI were used as control and groups II C_YP control (20 mg/kg body weight)., groups III and V were treated with Hibiscus sabdariffa extract (200 and 500 mg/kg body weight) plus (20 mg/kg body weight) for 21 days Furthermore, HPLC was used to identify the compound fraction. This result showed Cyp -induced biochemical changes in all organs of mice. Cyp caused decreased CAT activity, inhibition of AChE activity and increased the levels of H₂O₂ and MDA in brain, heart, liver and kidney. Hibiscus sabdariffa exhibited antioxidant effect and significantly attenuated the neurotoxicity of Cyp. Hibiscus sabdariffa exhibits neuroprotective effects and can be an effective and novel alternative approach to reduce the risk caused by pyrethroid compound.

Antioxidant Capacity and Antigenotoxic Effect of Hibiscus sabdariffa L. Extracts Obtained with Ultrasound-Assisted Extraction Process

Hibiscus sabdariffa (Roselle) is in high demand worldwide due to its beneficial health properties owing to the polyphenols content, mainly in the flower calyx. The objective of this study was to find the best conditions (time and liquid: solid ratio) to extract polyphenols from Roselle using Ultrasound-Assisted Extraction (UAE) (40 kHz, 180 W), with ethanol how solvent; as well as determine the yield of phenols, anthocyanin, flavonoids, tannins, antioxidant activity (DPPH) and antigenotoxic effect (comet assay). A traditional solid-liquid extraction was applied as a reference. Extraction times of 40 and 60 min resulted in the highest polyphenols (13.019 mg GAE/g dry weight (dw)), flavonoids (4.981 CE/g dw), anthocyanins (1.855 mg Cya3GE/g dw), and tannins (0.745 CE/g dw) recoveries and an antioxidant activity (DPPH) of 74.58%. Extracts from white calyces contained similar amounts of phenols and flavonoids, but very little condensed tannins (0.049 CE/g dw) and practically no anthocyanins. Extracts from red and white calyces, showed antigenotoxic activity and repaired capacity of damage caused by mutagens in human lymphocytes.

Sterculia and Brachychiton: a comprehensive overview on their ethnopharmacology, biological activities, phytochemistry and the role of their gummy exudates in drug delivery

OBJECTIVES

Sterculia and Brachychiton are two related genera (Malvaceae) containing more than 300 species. Most of these species are ornamental trees that are native to Australia and widely cultivated in many countries. Different members of the two genera were used by various cultures for medicinal and economical purposes. This review sheds light on the medicinal values and chemical composition of various species of these two genera.

KEY FINDINGS

Sterculia and Brachychiton species were used traditionally for the treatment of gastrointestinal disorders, microbial infection, skin diseases, inflammation and many other conditions. The seeds of various species were roasted and eaten by many traditional tribes. Plants from the two genera revealed their anti-inflammatory, antioxidant, antimicrobial, antidiabetic, antiulcer, insecticidal and analgesic activity. These activities may be attributed to the presence of a wide range of secondary metabolites as flavonoids, phenolic acids, coumarins, terpenoids particularly sesquiterpenes and triterpenes in addition to sterols and fatty acids. Moreover, the gummy exudates obtained from some members of these genera played an important role in different pharmaceutical dosage forms and drug-delivery systems.

CONCLUSIONS

More research is recommended on other species of Sterculia and Brachychiton to discover new molecular entities with potential biological and economic values.

Yellow tea (Camellia sinensis L.), a promising Chinese tea: Processing, chemical constituents and health benefits

Yellow tea, also known as huángchá in Chinese, is a lightly fermented tea unique to China. As a rare and precious variety of tea, it has gained increasing popularity in recent years because of its pleasant mellow taste and known health benefits such as anti-oxidation, anti-inflammation and anti-cancer properties. Yellow tea is similar to green tea in many ways. The initial production process of both teas is the same, but the production of yellow tea requires additional steps. A unique procedure called "sealed yellowing" is always involved in yellow tea processing to increase the oxidation level and remove the characteristic grassy smell associated with green tea while still preserving its health benefits. Compared to other types of teas, yellow tea is much less well-known and studied. In this review, the history and classification of yellow tea are introduced. The processing procedures, including detailed information about "sealed yellowing", are presented. The bioactive chemical compounds common in various types of teas or unique to yellow tea are discussed. Finally, future needs in research and development of yellow tea are proposed.

Hibiscus sabdariffa L. as a source of nutrients, bioactive compounds and colouring agents

The nutritional and bioactive composition of plants have aroused much interest not only among scientists, but also in people's daily lives. Apart from the health benefits, plants are a source of pigments that can be used as natural food colorants. In this work, the nutritional composition of Hibiscus sabdariffa L. was analysed, as well as its bioactive compounds and natural pigments. Glucose (sugar), malic acid (organic acid), α-tocopherol (tocopherol) and linoleic acid (fatty acid) were the major constituents in the corresponding classes. 5-(Hydroxymethyl) furfural was the most abundant non-anthocyanin compound, while delphinidin-3-O-sambubioside was the major anthocyanin both in its hydroethanolic extract and infusion. H. sabdariffa extracts showed antioxidant and antimicrobial activities, highlighting that the hydroethanol extract presents not only lipid peroxidation inhibition capacity, but also bactericidal/fungicidal inhibition ability for all the bacteria and fungi tested. Furthermore, both extracts revealed the absence of toxicity using porcine primary liver cells. The studied plant species was thus not only interesting for nutritional purposes but also for bioactive and colouring applications in food, cosmetic and pharmaceutical industries.

Antioxidant properties, total phenolic and total flavonoid content of the Slovak white wines - welschriesling and chardonnay

The biologically active compounds in wines, especially phenolics, are responsible for reduced risk of developing chronic diseses (cardiovascular diseases, cancer, diabetes, Alzheimer disease, etc.), due to their antioxidant activities. Twenty six Slovak white wines, produced from different geographical origins, were examined in this study. The antioxidant activity, total phenolic and flavonoid contents of two types monovarietal wines - Welschriesling and Chardonnay were evaluated. All three mentioned parameters were determined by UV-VIS absorption spectrometry. The results showed that both types of Slovak white wines were high in polyphenols (average content was 303.2 mg GAE.L-1 in Welschriesling, resp. 355.6 mg GAE.L-1 in Chardonnay) and flavonoids (average content was 51.9 mg CE.L-1 in Welschriesling, resp. 60.1 mg CE.L-1 in Chardonnay), as well as a high antioxidant activity (average value was 35.0% inhibition of DPPH in Welschriesling, resp. 43.3% inhibition of DPPH in Chardonnay), comparable to the wines produced in other regions in the world. Among the white wines, Chardonnay had higher content of total polyphenols, as well as flavonoids and higher values of antioxidant activity. Our results confirmed very strong linear correlations between all three analysed parameters (TPC, TFC and AA): TPC and TFC (r = 0.818), AA and TPC (r = 0.699), resp. TFC and AA (r = 0.693).

Synthesis and characterization of silver nanoparticles using Caesalpinia pulcherrima flower extract and assessment of their in vitro antimicrobial, antioxidant, cytotoxic, and genotoxic activities

Caesalpinia pulcherrima flower extract mediated synthesis of silver nanoparticles was attempted in the present work including optimization of some procedure parameters. Characterization of synthesized silver nanoparticles was done by various spectral analyses. The size of synthesized silver nanoparticles was 12 nm and they were spherical in shape. The green synthesized silver nanoparticles were further evaluated for antimicrobial, antioxidant, cytotoxic, and genotoxic activities; they showed good antimicrobial, antioxidant, and cytotoxic effects. Genotoxic study revealed non-toxic nature at lower concentration. Overall results suggest that the synthesized silver nanoparticles have pronounced applicability in pharmaceutical and biomedical field.

High antiviral effects of hibiscus tea extract on the H5 subtypes of low and highly pathogenic avian influenza viruses

Viral neuraminidase inhibitors are widely used as synthetic anti-influenza drugs for the prevention and treatment of influenza. However, drug-resistant influenza A virus variants, including H5N1 highly pathogenic avian influenza viruses (HPAIVs), have been reported. Therefore, the discovery of novel and effective antiviral agents is warranted. We screened the antiviral effects of 11 herbal tea extracts (hibiscus, black tea, tencha, rosehip tea, burdock tea, green tea, jasmine tea, ginger tea, lavender tea, rose tea and oak tea) against the H5N1 HPAIV in vitro. Among the tested extracts, only the hibiscus extract and its fractionated extract (frHibis) highly and rapidly reduced the titers of all H5 HPAIVs and low pathogenic AIVs (LPAIVs) used in the pre-treatment tests of Madin–Darby canine kidney (MDCK) cells that were inoculated with a mixture of the virus and the extract. Immunogold electron microscopy showed that anti-H5 monoclonal antibodies could not bind to the deformed H5 virus particles pretreated with frHibis. In post-treatment tests of MDCK cells cultured in the presence of frHibis after infection with H5N1 HPAIV, the frHibis inhibited viral replication and the expression of viral antigens and genes. Among the plants tested, hibiscus showed the most prominent antiviral effects against both H5 HPAIV and LPAIV.