Anthocyanins from Hibiscus sabdariffa calyx attenuate in vitro and in vivo melanoma cancer metastasis

Enhancing the Antioxidant Potential of Weissella confusa PP29 Probiotic Media through Incorporation of Hibiscus sabdariffa L. Anthocyanin Extract

Lactic acid bacteria (LAB) produce important metabolites during fermentation processes, such as exopolysaccharides (EPS), which represent powerful natural antioxidants. On the other hand, H. sabdariffa L. anthocyanin extracts protect LAB and support their development. This study uncovers for the first time, the antioxidant profile of Weissella confusa PP29 probiotic media and focuses on elevating its impressive antioxidant attributes by synergistically integrating H. sabdariffa L. anthocyanin extract. The multifaceted potential of this innovative approach is explored and the results are remarkable, allowing us to understand the protective capacity of the fermented product on the intestinal mucosa. The total phenolic content was much lower at the end of the fermentation process compared to the initial amount, confirming their LAB processing. The DPPH radical scavenging and FRAP of the fermented products were higher compared to ascorbic acid and antioxidant extracts, while superoxide anion radical scavenging and lipid peroxidation inhibitory activity were comparable to that of ascorbic acid. The antioxidant properties of the fermented products were correlated with the initial inoculum and anthocyanin concentrations. All these properties were preserved for 6 months, demonstrating the promising efficacy of this enriched medium, underlining its potential as a complex functional food with enhanced health benefits.

Novel Insight into the Cellular and Molecular Signalling Pathways on Cancer Preventing Effects of Hibiscus sabdariffa: A Review

A category of diseases known as cancer includes abnormal cell development and the ability to infiltrate or spread to other regions of the body, making them a major cause of mortality worldwide. Chemotherapy, radiation, the use of cytotoxic medicines, and surgery are the mainstays of cancer treatment today. Plants or products produced from them hold promise as a source of anti-cancer medications that have fewer adverse effects. Due to the presence of numerous phytochemicals that have been isolated from various parts of the Hibiscus sabdariffa (HS) plant, including anthocyanin, flavonoids, saponins, tannins, polyphenols, organic acids, caffeic acids, citric acids, protocatechuic acid, and others, extracts of this plant have been reported to have anti-cancer effects. These compounds have been shown to reduce cancer cell proliferation, induce apoptosis, and cause cell cycle arrest. They also increase the expression levels of the cell cycle inhibitors (p53, p21, and p27) and the pro-apoptotic proteins (BAD, Bax, caspase 3, caspase 7, caspase 8, and caspase 9). This review highlights various intracellular signalling pathways involved in cancer preventive potential of HS.

Hibiscus Anthocyanins Extracts Induce Apoptosis by Activating AMP-Activated Protein Kinase in Human Colorectal Cancer Cells

Apoptosis, a programmed cell death process preventing cancer development, can be evaded by cancer cells. AMP-activated protein kinase (AMPK) regulates energy levels and is a key research topic in cancer prevention and treatment. Some bioactive components of Hibiscus sabdariffa L. (HAs), including anthocyanins, have potential anticancer properties. Our study investigated the in vitro cytotoxic potential and mode of action of HAs extracts containing anthocyanins in colorectal cancer cells. The results showed that Hibiscus anthocyanin-rich extracts induced apoptosis in human colorectal cancer cells through the activation of multiple signaling pathways of AMPK. We observed the dose-response and time-dependent induction of apoptosis with HAs. Subsequently, the activation of Fas-mediated proteins triggered apoptotic pathways associated with Fas-mediated apoptosis-related proteins, including caspase-8/tBid. This caused the release of cytochrome C from the mitochondria, resulting in caspase-3 cleavage and apoptosis activation in intestinal cancer cells. These data elucidate the relationship between Has' regulation of apoptosis-related proteins in colorectal cancer cells and apoptotic pathways.

Antioxidant capacity and cytotoxic effect of an optimized extract of isabella grape (Vitis labrusca) on breast cancer cells

The phenolic profile of Isabella grape (Vitis labrusca) offers beneficial properties to human health and makes it a functional food product. In order to better understand the phenolic compounds found in this grape variety and the biological effect they induce on breast cancer cells, an ultrasound-assisted extraction was carried out. During the extraction of polyphenols from Isabella grapes organically grown in Antioquia (Colombia), parameters such as frequency (33 kHz and 40 kHz), time and solvent were optimized to finally obtain a crude extract with antioxidant properties (Oxygen Radical Absorbance Capacity, ORAC: 293.22 ± 34.73 μmol of Trolox/g of sample), associated with a total polyphenol content (TPC) of 43.14 ± 5.00 mg GAE/g sample and a total anthocyanin content composed of 17.69 ± 2.59 mg of malvidin-3-glucoside/100 g of sample. MCF-7 breast cancer cells were treated with different concentrations of the optimized extract, and results show a decrease in cell viability related to mitochondrial membrane depolarization, ROS increase, and chromatin condensation. To determine the possible death induction mechanism, molecular docking was simulated to predict the molecular interactions between the most abundant phenolic compounds in Isabella grape and the main apoptosis-related proteins. The results obtained from in silico and in vitro experiments were consistent with each other, suggesting that the phenolic compounds found in Isabella grape can be considered potential adjuvant chemopreventive agents for the treatment of breast cancer.

Toxicity of Persian Gulf shell-less marine mollusc (Peronia peronii) methanolic extract on melanoma tumor mitochondria

INTRODUCTION

Melanoma is known as an aggressive and highly lethal cancer. The poor prognosis and resistance to treatment are characteristics of melanoma. In melanoma cells, apoptosis signaling which relies heavily on the acute activity of mitochondria and reactive oxygen species (ROS) formation is suppressed. Studies have shown that compounds isolated from marine herbs and animals, have been shown to have cytotoxic consequences on cancerous cells in prior research. This study was designed to evaluate the apoptotic effect of methanolic extract of Persian Gulf shell-less marine mollusc (Peronia peronii) on skin mitochondria isolated from animal model of melanoma.

PURPOSE

Melanoma mitochondria obtained from skin of melanoma animal model are studied in this research to see whether extracts from Persian Gulf shell-less marine mollusc (Peronia peronii), has a cytotoxic impact on them.

MATERIAL AND METHOD

In this study, the mitochondria were isolated from melanoma cells via differential centrifugation were treated with various concentrations (650, 1300 and 2600 µg/ml) of methanolic extract of Peronia peronii. Then MTT(3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) viability assay, Reactive oxygen species (ROS) determination, Mitochondrial Membrane Potential (MMP) decline assay, mitochondrial swelling and cytochrome c release determination were performed. Flow cytometry assay of % apoptotic vs necrotic phenotypes was also performed on extract treated melanoma cells.

RESULTS

The results of MTT assay showed that different concentrations of Peronia peronii extract significantly (P < 0.05) decreased the SDH activity in cancerous skin mitochondria with the IC50(1300 μg/ml). The ROS results also showed that all concentrations of Peronia peronii extracts significantly increased ROS production, MMP decline and the release of cytochrome c in cancer groups mitochondria. The swelling of mitochondria was significantly increased compared to the control group. In addition, the results of apoptosis assay showed that addition of root extract of Peronia peronii on melanoma cells increased apoptosis, while it had no effect on control non tumour cells.

DISCUSSION AND CONCLUSION

Based on these results, the presence of potentially bioactive compounds in Peronia peronii make this Persian Gulf coastal herb a strong candidate for further molecular studies and clinical research in the field of melanoma cancer therapy.

Health-promoting foods and food crops of West-Africa origin: The bioactive compounds and immunomodulating potential

The rural communities of the sub-Sahara regions in Africa are rich in diverse indigenous culinary knowledge and foods, food crops, and condiments such as roots/tubers, cereal, legumes/pulses, locust beans, and green leafy vegetables. These food crops are rich in micronutrients and phytochemicals, which have the potentials to address hidden hunger as well as promote health when consumed. Some examples of these are fermented foods such as ogi and plants such as Vernonia amygdalina (bitter leaf), Zingiber officinales (garlic), Hibiscus sabdariffa (Roselle), and condiments. Food crops from West Africa contain numerous bioactive substances such as saponins, alkaloids, tannins, phenolics, flavonoids, and monoterpenoid chemicals among others. These bioresources have proven biological and pharmacological activities due to diverse mechanisms of action such as immunomodulatory, anti-inflammatory, antipyretic, and antioxidant activities which made them suitable as candidates for nutraceuticals and pharma foods. This review seeks to explore the different processes such as fermentation applied during food preparation and food crops of West-African origin with health-promoting benefits. The different bioactive compounds present in such food or food crops are discussed extensively as well as the diverse application, especially regarding respiratory diseases. PRACTICAL APPLICATIONS: The plants and herbs summarized here are more easily accessible and affordable by therapists and others having a passion for promising medicinal properties of African-origin plants.The mechanisms and unique metabolic potentials of African food crops discussed in this article will promote their applicability as a template molecule for novel drug discoveries in treatment strategies for emerging diseases. This compilation of antiviral plants will help clinicians and researchers bring new preventive strategies in combating COVID-19 like viral diseases, ultimately saving millions of affected people.

The Potential Roles of Dietary Anthocyanins in Inhibiting Vascular Endothelial Cell Senescence and Preventing Cardiovascular Diseases

Cardiovascular disease (CVD) is a group of diseases affecting the heart and blood vessels and is the leading cause of morbidity and mortality worldwide. Increasingly more evidence has shown that the senescence of vascular endothelial cells is the key to endothelial dysfunction and cardiovascular diseases. Anthocyanin is a type of water-soluble polyphenol pigment and secondary metabolite of plant-based food widely existing in fruits and vegetables. The gut microbiome is involved in the metabolism of anthocyanins and mediates the biological activities of anthocyanins and their metabolites, while anthocyanins also regulate the growth of specific bacteria in the microbiota and promote the proliferation of healthy anaerobic flora. Accumulating studies have shown that anthocyanins have antioxidant, anti-inflammatory, and anti-aging effects. Many animal and in vitro experiments have also proven that anthocyanins have protective effects on cardiovascular-disease-related dysfunction. However, the molecular mechanism of anthocyanin in eliminating aging endothelial cells and preventing cardiovascular diseases is very complex and is not fully understood. In this systematic review, we summarize the metabolism and activities of anthocyanins, as well as their effects on scavenging senescent cells and cardioprotection.

Chemical Structure, Sources and Role of Bioactive Flavonoids in Cancer Prevention: A Review

There has been a major shift in the collective mindset around the world in recent decades, both in terms of food and in terms of the treatment of chronic diseases. Increasing numbers of people are choosing to prevent rather than treat, which is why many consumers are choosing plant-based diets, mainly due to their bioactive compounds. A significant case of bioactive compound is flavonoids-a wide subclass of an even wider class of phytochemicals: polyphenols. Flavonoids are a broad topic of study for researchers due to their potential in the prevention and treatment of a broad range of cancers. The aim of this review is to inform/update the reader on the diversity, accessibility and importance of flavonoids as biomolecules that are essential for optimal health, focusing on the potential of these compounds in the prevention of various types of cancer. Along with conventional sources, this review presents some of the possible methods for obtaining significant amounts of flavonoids based on a slightly different approach, genetic manipulation.

Physiological Effects and Human Health Benefits of Hibiscus sabdariffa: A Review of Clinical Trials

Hibiscus sabdariffa Linn. Malvaceae (HS) is characterized by its edible calyxes. The HS calyxes are widely used for cosmetic, food, and medicinal applications. According to ethnobotanical evidence, decoction, infusion, or maceration extracts from HS calyxes have been used in folk medicine to treat many ailments. Moreover, several in vitro and in vivo studies have demonstrated the pharmacological properties and potential human health benefits of HS consumption. On the other hand, the evaluation of the physiological effects and health benefits of HS in clinical studies is most challenging. Therefore, this narrative review summarizes and discusses the physiological effects and health benefits of HS calyxes reported in clinical trials. Preparations obtained from HS calyxes (extracts, infusions, decoction, teas, beverages, capsules, and pills) are used as non-pharmacological therapies to prevent/control diverse chronic non-communicable diseases. The most-reported HS health benefits are its antihypertensive, antidyslipidemic, hypoglycemic, body fat mass reduction, nephroprotective, antianemic, antioxidant, anti-inflammatory, and anti-xerostomic activities; these effects are associated with the phytochemicals found in HS. Moreover, no adverse effects were reported during the clinical trials. However, clinical studies exhibited some limitations; thus, further studies are required to validate the clinical efficacy of HS in large-scale studies with higher doses and a good experimental design

A stability-indicating HPLC-UV method for the quantification of anthocyanin in Roselle (Hibiscus Sabdariffa L.) spray-dried extract, oral powder, and lozenges

Hibiscus sabdariffa L. (H.S.) plant and its calyces have received much attention from researchers because of their potential medicinal and nutritional values. Calyces are the major source of anthocyanin in this plant. Therefore, a well-developed, efficient, and accurate analytical method is needed to assure proper standardization and control the quality of H.S. plant herbal and nutraceutical products. The objective of this work is to develop a simple, rapid, stability-indicating HPLC-UV method for the quantitative determination of anthocyanin in spray-dried aqueous extract (SDE), oral powder, and compressible lozenges formulations using Delphinidin-3-O-sambubioside (Dp3S) as a marker compound. The chromatographic conditions were optimized using Eclipse plus® C18 column. The mobile phase comprised water acidified with 0.2% formic acid (FA) and acetonitrile (ACN) (90:10, v/v) using a gradient system at a flow rate of 0.8 mL/min. The detection wavelength was 525 nm. The column was maintained at 45 °C, and the injection volume was 15 μL. The developed method was validated according to the international conference of harmonization (ICH) guidelines for linearity, detection and quantitation limits, accuracy, precision, specificity, and robustness. Forced degradation studies under acid, base, oxidation, heat, and U.V light, were performed on the pure compound, extract, and the H.S. developed formulations. Significant degradation of the compound was observed under all tested conditions except U.V. light, where degradation was minimum. There was no interference from impurities, degradation products, or excipients at the retention time of Dp3S 3.2 min indicating the specificity of the method. The developed method was statistically confirmed to be accurate, precise, and reproducible. This simple, rapid, and specific method can be employed efficiently to determine anthocyanin in H.S. plant extract and nutraceutical products.

Antioxidant, Anticancer, and PXR-Dependent CYP3A4 Attributes of Schweinfurthia papilionacea (Burm.f.) Boiss., Tricholepis glaberrima DC. and Viola stocksii Boiss

Present study established the biological potential of Schweinfurthia papilionacea, Tricholepis glaberrima and Viola stocksii extracts for their potential applications in drug formulations. Initially, FTIR was performed to ascertain functional groups and then plant extracts were prepared using five solvents depending on the polarity. Total phenolic contents were observed in the range of 36.36 ± 1.08 mg GAE/g to 95.55 ± 2.46 mg GAE/g while flavonoid contents were found in the range of 10.51 ± 0.25 mg QE/g to 22.17 ± 1.79 mg QE/g. Antioxidant activity was determined using TRP, CUPRAC, TAC and DPPH assays and was recorded highest in S. papilionacea followed by T. glaberrima extracts. TPC and TFC were found to be strongly correlated with TRP (r > 0.50), CUPRAC (r > 0.53) and DPPH (r = 0.31 and 0.72) assay while weakly correlated with TAC (r = 0.08 and 0.03) as determined by Pearson correlation analysis. Anticancer activity showed that S. papilionacea chloroform extracts possess highest cell viability (85.04 ± 4.24%) against HepG2 cell lines while T. glaberrima chloroform extracts exhibited highest activity (82.80 ± 2.68%) against HT144 cell lines. Afterwards, highest PXR activation was observed in T. glaberrima (3.49 ± 0.34 μg/mL fold) at 60 μg/mL and was correlated with increase in CYP3A4 activity (15.0 ± 3.00 μg/mL IC50 value). Furthermore, antimalarial activity revealed >47600 IC50 value against P. falciparum D6 and P. falciparum W2 and antimicrobial assay indicated highest activity (32 ± 2.80 mm) in S. papilionacea against C. neoformans. At the end, GC-MS analysis of n-hexane plant extracts showed 99.104% of total identified compounds in T. glaberrima and 94.31% in V. stocksii. In conclusion, present study provides insight about the different biological potentials of S. papilionacea and T. glaberrima extracts that rationalize the applications of these extracts in functional foods and herbal drugs for the management of oxidative-stress related diseases, antimicrobial infections and liver and skin cancer.

Encapsulation of bioactive compounds extracted from plants of genus Hibiscus: A review of selected techniques and applications

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.

Effects of Allium sativum Stem Extract on Growth and Migration in Melanoma Cells through Inhibition of VEGF, MMP-2, and MMP-9 Genes Expression

The present study investigated the effects of Allium sativum stem extract (ASE) on B16-F0 cell growth and metastasis. Evaluation of the effects of ASE on B16-F0 cells’ viability and migration showed that 0.5 mg/mL ASE inhibited B16-F0 cells’ growth by 30.2% and migration by 38.5%, which indicates that the ASE has anticancer and antimetastatic effects on B16-F0 cells. To study the anticancer and antimetastatic mechanism, mRNA levels of vascular endothelial growth factor (VEGF), matrix metalloproteinases-2 (MMP-2), and matrix metalloproteinases-9 (MMP-9) expressions were evaluated with reverse transcription polymerase chain reaction, and 0.25 and 0.5 mg/mL ASE was found to exert significant inhibition on mRNA expressions of VEGF, MMP-2, and MMP-9 in B16-F0 cells. Thus, ASE reduce extracellular matrix degradation through inhibitions of expression of MMP-2 and MMP-9, and also showed an angiogenesis inhibitory effect through reduction of VEGF expression. High-performance liquid chromatography analysis showed that among various polyphenols, gallic acid (2.1 mg/g) was a major compound of ASE. Overall, our results demonstrated that ASE inhibited the growth and migration of B16-F0 cells through downregulation of the VEGF, MMP-2, and MMP-9 genes expression, which indicates ASE could be applied for the prevention and treatment of melanoma.

Recent Advances in Phenolic Metabolites and Skin Cancer

Skin cancer represents any tumor development from the cutaneous structures within the epidermis, dermis or subcutaneous tissue, and is considered to be the most prevalent type of cancer. Compared to other types of cancer, skin cancer is proven to have a positive growth rate of prevalence and mortality. There are available various treatments, including chemotherapy, immunotherapy, radiotherapy and targeted therapy, but because of the multidrug resistance development, a low success has been registered. By this, the importance of studying naturally occurring compounds that are both safe and effective in the chemoprevention of skin cancer is emphasized. This review focuses on melanoma because it is the deadliest form of skin cancer, with a significantly increasing incidence in the last decades. As chemopreventive agents, we present polyphenols and their antioxidant activity, anti-inflammatory effect, their ability to balance the cell cycle and to induce apoptosis and their various other effects on skin melanoma. Besides chemoprevention, studies suggest that polyphenols can have treating abilities in some conditions. The limitations of using polyphenols are also pointed out, which are related to their poor bioavailability and stability, but as the technology is well developed, it is possible to augment the efficacy of polyphenols in the case of melanoma.

Food Bioactive Compounds and Emerging Techniques for Their Extraction: Polyphenols as a Case Study

Experimental studies have provided convincing evidence that food bioactive compounds (FBCs) have a positive biological impact on human health, exerting protective effects against non-communicable diseases (NCD) including cancer and cardiovascular (CVDs), metabolic, and neurodegenerative disorders (NDDs). These benefits have been associated with the presence of secondary metabolites, namely polyphenols, glucosinolates, carotenoids, terpenoids, alkaloids, saponins, vitamins, and fibres, among others, derived from their antioxidant, antiatherogenic, anti-inflammatory, antimicrobial, antithrombotic, cardioprotective, and vasodilator properties. Polyphenols as one of the most abundant classes of bioactive compounds present in plant-based foods emerge as a promising approach for the development of efficacious preventive agents against NCDs with reduced side effects. The aim of this review is to present comprehensive and deep insights into the potential of polyphenols, from their chemical structure classification and biosynthesis to preventive effects on NCDs, namely cancer, CVDs, and NDDS. The challenge of polyphenols bioavailability and bioaccessibility will be explored in addition to useful industrial and environmental applications. Advanced and emerging extraction techniques will be highlighted and the high-resolution analytical techniques used for FBCs characterization, identification, and quantification will be considered.

Phenolic compounds: current industrial applications, limitations and future challenges

Phenolic compounds are natural bioactive molecules found mainly in plant tissues that have shown interesting bioactivities, such as antioxidant, antimicrobial, anti-inflammatory, and antiproliferative activities, among others, which has led to great interest in their use by several industries. However, despite the large number of scientific studies on this topic, some issues still need to be studied and solved, such as the understanding of the main actions of these compounds in organisms. Besides their large potential applicability in industry, phenolic compounds still face some issues making it necessary to develop strategies to improve bioavailability, sustainable technologies of extraction and refinement, and stability procedures to increase the range of applicability. This review focuses on the most recent advances in the applications of phenolic compounds in different technological and medicinal areas. In addition, techniques to improve their sustainable resourcing, stability and bioavailability will be presented and discussed.

The Impact of Herbal Infusion Consumption on Oxidative Stress and Cancer: The Good, the Bad, the Misunderstood

The release of reactive oxygen species (ROS) and oxidative stress is associated with the development of many ailments, including cardiovascular diseases, diabetes and cancer. The causal link between oxidative stress and cancer is well established and antioxidants are suggested as a protective mechanism against cancer development. Recently, an increase in the consumption of antioxidant supplements was observed globally. The main sources of these antioxidants include fruits, vegetables, and beverage. Herbal infusions are highly popular beverages consumed daily for different reasons. Studies showed the potent antioxidant effects of plants used in the preparation of some herbal infusions. Such herbal infusions represent an important source of antioxidants and can be used as a dietary protection against cancer. However, uncontrolled consumption of herbal infusions may cause toxicity and reduced antioxidant activity. In this review, eleven widely consumed herbal infusions were evaluated for their antioxidant capacities, anticancer potential and possible toxicity. These herbal infusions are highly popular and consumed as daily drinks in different countries. Studies discussed in this review will provide a solid ground for researchers to have better understanding of the use of herbal infusions to reduce oxidative stress and as protective supplements against cancer development.

Anthocyanins, Vibrant Color Pigments, and Their Role in Skin Cancer Prevention

Until today, numerous studies evaluated the topic of anthocyanins and various types of cancer, regarding the anthocyanins' preventative and inhibitory effects, underlying molecular mechanisms, and such. However, there is no targeted review available regarding the anticarcinogenic effects of dietary anthocyanins on skin cancers. If diagnosed at the early stages, the survival rate of skin cancer is quite high. Nevertheless, the metastatic form has a short prognosis. In fact, the incidence of melanoma skin cancer, the type with high mortality, has increased exponentially over the last 30 years, causing the majority of skin cancer deaths. Malignant melanoma is considered a highly destructive type of skin cancer due to its particular capacity to grow and spread faster than any other type of cancers. Plants, in general, have been used in disease treatment for a long time, and medicinal plants are commonly a part of anticancer drugs on the market. Accordingly, this work primarily aims to emphasize the most recent improvements on the anticarcinogenic effects of anthocyanins from different plant sources, with an in-depth emphasis on melanoma skin cancer. We also briefly summarized the anthocyanin chemistry, their rich dietary sources in flowers, fruits, and vegetables, as well as their associated potential health benefits. Additionally, the importance of anthocyanins in topical applications such as their use in cosmetics is also given.

Insight into the molecular evidence supporting the remarkable chemotherapeutic potential of Hibiscus sabdariffa L

Hibiscus sabdariffa or roselle tea is popular around the globe for its antioxidant capability along with various other health benefits. Besides, it has uses in Ayurvedic and Chinese herbal medicines for the treatment of several diseases. However, the investigation for the anticancer potential of the plant began roughly in the last decade that emerged with encouraging results. Both crude extracts and pure compounds of the plant were reported to induce chemoprevention, selective cytotoxicity, cell cycle arrest, apoptosis, autophagy and anti-metastasis effects in varied types of human cancer cells. The plant contains a high quantity of polyphenolic compounds and at least two of them were proven to induce potent anticancer effects. Although, the molecular mechanism underlying the anticancer activity was roughly estimated in several studies. The present review aimed to assemble all ambiguous information to report the molecular evidence establishing the potent anticancer activity of Hibiscus sabdariffa and its implication for cancer therapy. This study suggests that Hibiscus sabdariffa is an ideal candidate to investigate its role as a herbal supplement for cancer prevention and treatment. With excellent safety and tolerability record, polyphenolic compounds from the plant need better designed clinical trials.

The Colors of Health: Chemistry, Bioactivity, and Market Demand for Colorful Foods and Natural Food Sources of Colorants

There is an increasing consumer demand for natural colors in foods. However, there is a limited number of available natural food sources for use by the food industry because of technical and regulatory limitations. Natural colors are less stable and have less vibrant hues compared to their synthetic color counterparts. Natural pigments also have known health benefits that are seldom leveraged by the food industry. Betalains, carotenoids, phycocyanins, and anthocyanins are major food colorants used in the food industry that have documented biological effects, particularly in the prevention and management of chronic diseases such as diabetes, obesity, and cardiovascular disease. The color industry needs new sources of stable, functional, and safe natural food colorants. New opportunities include sourcing new colors from microbial sources and via the use of genetic biotechnology. In all cases, there is an imperative need for toxicological evaluation to pave the way for their regulatory approval.

Reversing UVB-induced photoaging with Hibiscus sabdariffa calyx aqueous extract

BACKGROUND

Hibiscus sabdariffa is commonly used in daily life and its extract is applied widely in food and cosmetics. However, it has not been evaluated for its anti-aging effects.

RESULTS

Hibiscus sabdariffa calyx aqueous extract (HSCAE) has shown potential collagenase activity suppression effects, together with tyrosinase activity inhibition, and anti-oxidation as a free radical scavenger. The current investigation demonstrated that HSCAE was not cytotoxic in skin fibroblasts, and it significantly decreased ultraviolet B (UVB)-induced reactive oxygen species (ROS) on a flow cytometry assay. Moreover, HSCAE reduced matrix metalloproteinase (MMP) expression, increased tissue inhibition of metalloproteinase (TIMP)-1 level, and enhanced collagen content by inhibiting collagenase activity. It also blocked mRNA and protein expressions of melanin production pathway key factors, including the microphthalmia-associated transcription factor (MITF), tyrosinase, tyrosinase-related protein-1 (TRP-1), and dopachrome tautomerase-2 (TRP-2).

CONCLUSION

These results demonstrated, for the first time, the potential of HSCAE as a natural antioxidant with the ability to maintain collagen production and to decrease melanin syntheses under UVB radiation, for anti-aging effects. © 2019 Society of Chemical Industry.

Extraction of Anthocyanins and Total Phenolic Compounds from Açai (Euterpe oleracea Mart.) Using an Experimental Design Methodology. Part 1: Pressurized Liquid Extraction

Currently, açai is one of the most important fruits present in the world. Several studies have demonstrated its high content in phenolic compounds and anthocyanins. Both of them are responsible of interesting properties of the fruit such as anti-inflammatory, antioxidant or anticancer. In the present study, two optimized pressurized liquid extraction (PLE) methods have been developed for the extraction of anthocyanins and total phenolic compounds from açai. A full factorial design (Box–Behnken design) with six variables (solvent composition (25–75% methanol-in-water), temperature (50–100 °C), pressure (100–200 atm), purge time (30–90 s), pH (2–7) and flushing (50–150%)) were employed. The percentage of methanol in the extraction solvent was proven to be the most significant variable for the extraction of anthocyanins. In the case of total phenolic compounds, the extraction temperature was the most influential variable. The developed methods showed high precision, with relative standard deviations (RSD) of less than 5%. The applicability of the methods was successfully evaluated in real samples. In conclusion, two rapid and reliable PLE extraction methods to be used for laboratories and industries to determine anthocyanins and total phenolic compounds in açai and its derived products were developed in this work.

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.

Preparation and pH Controlled Release of Fe3O4/Anthocyanin Magnetic Biocomposites

Anthocyanins are a class of antioxidants extracted from plants, with a variety of biochemical and pharmacological properties. However, the wide and effective applications of anthocyanins have been limited by their relatively low stability and bioavailability. In order to expand the application of anthocyanins, Fe3O4/anthocyanin magnetic biocomposite was fabricated for the storage and release of anthocyanin in this work. The magnetic biocomposite of Fe3O4 magnetic nanoparticle-loaded anthocyanin was prepared through physical intermolecular adsorption or covalent cross-linking. Scanning electron microscopy (SEM), Dynamic light scattering (DLS), Fourier-transform infrared spectroscopy (FTIR), X-ray diffractometry (XRD) and thermal analysis were used to characterize the biocomposite. In addition, the anthocyanin releasing experiments were performed. The optimized condition for the Fe3O4/anthocyanin magnetic biocomposite preparation was determined to be at 60 °C for 20 h in weak alkaline solution. The smooth surface of biocomposite from SEM suggested that anthocyanin was coated on the surface of the Fe3O4 particles successfully. The average size of the Fe3O4/anthocyanin magnetic biocomposite was about 222 nm. Under acidic conditions, the magnetic biocomposite solids could be repeatable released anthocyanin, with the same chemical structure as the anthocyanin before compounding. Therefore, anthocyanin can be effectively adsorbed and released by this magnetic biocomposite. Overall, this work shows that Fe3O4/anthocyanin magnetic biocomposite has great potential for future applications as a drug storage and delivery nanoplatform that is adaptable to medical, food and sensing.

Advances on Natural Polyphenols as Anticancer Agents for Skin Cancer

Polyphenols are one of most important phytochemicals distributing in herb plants, vegetables and fruits, which known as important anticancer agents. Given the high incidence and mortality of skin cancer, this study aimed to uncover the chemopreventive effects of polyphenols against skin cancer metastasis. Electronic databases including Scopus, PubMed, and Cochrane library were used to compile the literature from 2000 to August 2019. Only in vivo mechanistic studies with English full-texts were chosen for this review. Polyphenols were included in this study if they were administered in purified form; while total extract and fractions were excluded. Among the 8254 primarily selected papers, only a final number of 34 studies were included. The chemopreventive effects of polyphenols as anthocyanins, ellagitanins, EGCG, oleuropeindihydroxy phenyl, punicalagin, quercetin, resveratrol and theaflavin, were mainly examined in treatment of melanoma as the highly metastatic form of this cutaneous cancer. Those properties are mediated by modulation of angiogenesis, apoptosis, inflammation, metastasis, proliferation, pathways such as EGFR/MAPK, mTOR/PI3K/Akt, JAK/STAT, FAK/RTK2, PGE-2/VEGF, PGE-1/ERK/HIIF-1α, and modulation of related signals including NF-κB, P21^WAF/CIP1, Bim, Bax, Bcl2, Bclx, Bim, Puma, Noxa, ILs and MMPs. Chemopreventive effects of polyphenols are mediated by several signaling pathways against skin carcinogenesis and metastasis, implying the importance of polyphenols to open up new horizons in development of anti-skin cancer therapeutic strategies.

Antidiabetic activity-guided isolation of gallic and protocatechuic acids from Hibiscus sabdariffa calyxes

We isolated and identified gallic and protocatechuic acids as the antidiabetic principles in Hibiscus sabdariffa using solvent extraction, column chromatographic fractionation, and nuclear magnetic resonance (NMR) spectroscopy. Ethylacetate fraction of the aqueous extract of H. sabdariffa inhibited α-amylase and α-glucosidase with IC₅₀ of 411.73 and 433.93 μg/ml, respectively. Furthermore, fractions I and II obtained from column chromatography inhibited α-amylase with IC₅₀ of 27.03 and 20.12 μg/ml, and α-glucosidase with IC₅₀ of 24.30 and 22.29 μg/ml, respectively. In addition, the principles reduced the serum glucose and lipid peroxide levels of diabetic rats and with an improvement in the rat lipid profiles and antioxidant defenses. Fractions I and II were identified as protocatechuic acid and gallic acid, respectively, using ¹ H and ¹³ C NMR. Protein-ligand docking showed that these compounds form multiple favorable interactions with the active-site residues of the two glycosidases. Overall, protocatechuic and gallic acids emerge as natural antidiabetic agents. PRACTICAL APPLICATIONS: Hibiscus sabdariffa (Zoborodo) is a refreshment drink for ceremonial gatherings in Nigeria. Also, its pharmacological use includes diabetes, hypertension, hyperlipidemia, metabolic syndrome, and hepatoprotection. The consumption of this food drink could improve diabetes, hypertension, dyslipidemia, metabolic syndrome, and liver disease. Furthermore, the inhibition of α-amylase and α-glucosidase could prevent diabetic complications associated with postprandial glucose. Developing the extract of H. sabdariffa calyx as food supplement could be used in managing diabetes and its associated complications such as dyslipidemia, hypertension, and metabolic syndrome.