Indicaxanthin from Opuntia Ficus Indica (L. Mill) impairs melanoma cell proliferation, invasiveness, and tumor progression

Atriplex hortensis var. 'rubra' extracts and purified amaranthin-type pigments reduce oxidative stress and inflammatory response in LPS-stimulated RAW264.7 cells

The use of direct injection ion mobility mass spectrometry (DI-IM-MS) to detect and identify betacyanin pigments in A. hortensis 'rubra' extracts was explored for the first time, with results compared to conventional LC-MS/MS analysis. The anti-inflammatory activities of leaf and seed extracts, alongside purified amaranthin and celosianin pigments, were investigated using a model of lipopolysaccharide (LPS)-activated murine macrophages. Extracts and purified pigments significantly inhibited the production of prostaglandin E2 and NO by up to 90% and 70%, respectively, and reduced the expression of Il6, Il1b, Nos2, and Cox2. Leaf and seed extracts also decreased secretion of Il6 and Il1b cytokines and reduced protein levels of Nos2 and Cox2. Furthermore, extracts and purified pigments demonstrated potent dose-dependent radical scavenging activity in a cellular antioxidant activity assay (CAA) without any cytotoxic effects. Our research highlights the promising biological potential of edible, climate-resilient A. hortensis 'rubra' as a valuable source of bioactive compounds.

Phytochemicals from Cactaceae family for cancer prevention and therapy

Cancer is a global health issue, increasingly prevalent and a leading cause of mortality. Despite extensive research, conventional treatments remain aggressive, often damaging healthy cells, and exhibit limited efficacy. Addressing drug resistance and enhancing treatment effectiveness are critical challenges in advancing cancer therapy. This review examines the potential of natural plant compounds, particularly phytochemicals and their derivatives, in developing novel anticancer agents. These metabolites have a long history in traditional medicine, with 42% of molecules approved for cancer treatment between 1981 and 2019 being either natural products or derivatives. The Cactaceae family, which comprises more than 1,500 species, represents a largely untapped source of potentially useful chemopreventive and anticancer agents. Although more than 3,000 plants and their derivatives have contributed to chemotherapeutic development, cactus species have received limited attention until recently. Emerging evidence highlights the anticancer potential of fruits, stems, and cladodes from various cactus species. This review provides a comprehensive and current overview of experimental studies on Cactaceae in cancer research, aiming to pave the way for the development of innovative, natural cancer therapeutics and contribute to the ongoing battle against this formidable disease.

Indicaxanthin prevents eryptosis induced by cigarette smoke extract by interfering with active Fas-mediated signaling

A physiological mechanism of programmed cell death called eryptosis occurs in aged or damaged red blood cells (RBCs). Dysregulated eryptosis contributes to abnormal microcirculation and prothrombotic risk. Cigarette smoke extract (CSE) induces a p38 MAPK-initiated, Fas-mediated eryptosis, activating the death-inducing signaling complex (DISC). Indicaxanthin (Ind) from cactus pear fruits, is a bioavailable dietary phytochemical in humans and it is able to incorporate into RBCs enhancing their defense against numerous stimuli. This in vitro work shows that Ind, at concentrations that mimic plasma concentrations after a fruit meal, protects erythrocytes from CSE-induced eryptosis. CSE from commercial cigarettes was prepared in aqueous solution using an impinger air sampler and nicotine content was determined. RBCs were treated with CSE for 3 h in the absence or presence of increasing concentrations of Ind (from 1 to 5 μM). Cytofluorimetric measurements indicated that Ind reduced CSE-induced phosphatidylserine externalization and ceramide formation in a concentration-dependent manner. Confocal microscopy visualization and coimmunoprecipitation experiments revealed that Ind prevented both CSE-triggered Fas aggregation and FasL/FADD/caspase 8 recruitment in the membrane, indicating inhibition of DISC assembly. Ind inhibited the phosphorylation of p38 MAPK, caspase-8/caspase-3 cleavage, and caspase-3 activity induced by CSE. Finally, Ind reduced CSE-induced ATP depletion and restored aminophospholipid translocase activity impaired by CSE treatment. In conclusion, Ind concentrations comparable to nutritionally relevant plasma concentrations, can prevent Fas-mediated RBC death signaling induced by CSE, which suggests that dietary intake of cactus pear fruits may limit the deleterious effects of cigarette smoking.

Design, Synthesis and Gene Modulation Insights into Pigments Derived from Tryptophan-Betaxanthin, Which Act against Tumor Development in Caenorhabditis elegans

The use of betalains, which are nitrogenous plant pigments, by the food industry is widespread and reflects their safety after intake. The recent research showed outstanding results for L-tryptophan-betaxanthin, a phytochemical present in traditional Chinese medicine, as an antitumoral agent when the activity was evaluated in the animal model Caenorhabditis elegans. Thus, L-tryptophan-betaxanthin is now presented as a lead compound, from which eleven novel structurally related betaxanthins have been designed, biotechnologically produced, purified, and characterized. The antitumoral effect of the derived compounds was evaluated on the JK1466 tumoral strain of C. elegans. All the tested molecules significantly reduced the tumoral gonad sizes in a range between 31.4% and 43.0%. Among the novel compounds synthesized, tryptophan methyl ester-betaxanthin and tryptophan benzyl ester-betaxanthin, which are the first betalains to contain an ester group in their structures, caused tumor size reductions of 43.0% and 42.6%, respectively, after administration to the model animal. Since these were the two most effective molecules, their mechanism of action was investigated by microarray analysis. Differential gene expression analysis showed that tryptophan methyl ester-betaxanthin and tryptophan benzyl ester-betaxanthin were able to down-regulate the key genes of the mTOR pathway, such as daf-15 and rict-1.

A Combination of Polymethoxyflavones from Citrus sinensis and Prenylflavonoids from Humulus lupulus Counteracts IL-1β-Induced Differentiated Caco-2 Cells Dysfunction via a Modulation of NF-κB/Nrf2 Activation

We here investigated the anti-inflammatory activity of a polymethoxylated flavone-containing fraction (PMFF) from Citrus sinensis and of a prenylflavonoid-containing one (PFF) from Humulus lupulus, either alone or in combination (MIX). To this end, an in vitro model of inflammatory bowel disease (IBD), consisting of differentiated, interleukin (IL)-1β-stimulated Caco-2 cells, was employed. We demonstrated that non-cytotoxic concentrations of either PMFF or PFF or MIX reduced nitric oxide (NO) production while PFF and MIX, but not PMFF, also inhibited prostaglandin E2 release. Coherently, MIX suppressed both inducible NO synthase and cyclooxygenase-2 over-expression besides NF-κB activation. Moreover, MIX increased nuclear factor erythroid 2-related factor 2 (Nrf2) activation, heme oxygenase-1 expression, restoring GSH and reactive oxygen and nitrogen species (RONs) levels. Remarkably, these effects with MIX were stronger than those produced by PMFF or PFF alone. Noteworthy, nobiletin (NOB) and xanthohumol (XTM), two of the most represented phytochemicals in PMFF and PFF, respectively, synergistically inhibited RONs production. Overall, our results demonstrate that MIX enhances the anti-inflammatory and anti-oxidative effects of the individual fractions in a model of IBD, via a mechanism involving modulation of NF-κB and Nrf2 signalling. Synergistic interactions between NOB and XTM emerge as a relevant aspect underlying this evidence.

Molecular and Antioxidant Characterization of Opuntia robusta Fruit Extract and Its Protective Effect against Diclofenac-Induced Acute Liver Injury in an In Vivo Rat Model

A molecular characterization of the main phytochemicals and antioxidant activity of Opuntia robusta (OR) fruit extract was carried out, as well as an evaluation of its hepatoprotective effect against diclofenac (DF)-induced acute liver injury was evaluated. Phenols, flavonoids and betalains were quantified, and antioxidant characterization was performed by means of the ABTS^•+, DPPH and FRAP assays. UPLC-QTOF-MS/MS was used to identify the main biocompounds present in OR fruit extract was carried out via. In the in vivo model, groups of rats were treated prophylactically with the OR fruit extract, betanin and N-acteylcysteine followed by a single dose of DF. Biochemical markers of oxidative stress (MDA and GSH) and relative gene expression of the inducible antioxidant response (Nrf2, Sod2, Hmox1, Nqo1 and Gclc), cell death (Casp3) and DNA repair (Gadd45a) were analyzed. Western blot analysis was performed to measure protein levels of Nrf2 and immunohistochemical analysis was used to assess caspase-3 activity in the experimental groups. In our study, the OR fruit extract showed strong antioxidant and cytoprotective capacity due to the presence of bioactive compounds, such as betalain and phenols. We conclude that OR fruit extract or selected components can be used clinically to support patients with acute liver injury.

Antiproliferative and Proapoptotic Effects of Erucin, a Diet-Derived H2S Donor, on Human Melanoma Cells

Melanoma is the most dangerous form of skin cancer and is characterized by chemotherapy resistance and recurrence despite the new promising therapeutic approaches. In the last years, erucin (ERU), the major isothiocyanate present in Eruca sativa, commonly known as rocket salads, has demonstrated great efficacy as an anticancer agent in different in vitro and in vivo models. More recently, the chemopreventive effects of ERU have been associated with its property of being a H₂S donor in human pancreatic adenocarcinoma. Here, we investigated the effects of ERU in modulating proliferation and inducing human melanoma cell death by using multiple in vitro approaches. ERU significantly reduced the proliferation of different human melanoma cell lines. A flow cytometry analysis with annexin V/PI demonstrated that ERU was able to induce apoptosis and cell cycle arrest in A375 melanoma cells. The proapoptotic effect of ERU was associated with the modulation of the epithelial-to-mesenchymal transition (EMT)-related cadherins and transcription factors. Moreover, ERU thwarted the migration, invasiveness and clonogenic abilities of A375 melanoma cells. These effects were associated with melanogenesis impairment and mitochondrial fitness modulation. Therefore, we demonstrated that ERU plays an important role in inhibiting the progression of melanoma and could represent a novel add-on therapy for the treatment of human melanoma.

Prickly pear fruits from Opuntia ficus-indica varieties as a source of potential bioactive compounds in the Mediterranean diet

Cactus has been used in traditional folk medicine because of its role in treating a number of diseases and conditions. Prickly pear fruit is an excellent source of secondary metabolites (i.e., betalains, flavonoids, and ascorbic acid) with health-promoting properties against many common human diseases, including diabetes, hypertension, hypercholesterolemia, rheumatic pain, gastric mucosa diseases and asthma. In addition, prickly pears are potential candidates for the development of low-cost functional foods because they grow with low water requirements in arid regions of the world. This review describes the main bioactive compounds found in this fruit and shows the in vitro and some clinical studies about the fruit of most important cactus (Opuntia ficus-indica) and its relationship with some chronic diseases. Even though a lot of effort have been done to study the relationship between this fruit and the human health, more studies on Opuntia ficus-indica could help better understand its pharmacological mechanism of action to provide clear scientific evidence to explain its traditional uses, and to identify its therapeutic potential in other diseases.

Redox Properties, Bioactivity and Health Effects of Indicaxanthin, a Bioavailable Phytochemical from Opuntia ficus indica, L.: A Critical Review of Accumulated Evidence and Perspectives

Phytochemicals from plant foods are considered essential to human health. Known for their role in the adaptation of plants to their environment, these compounds can induce adaptive responses in cells, many of which are directed at maintaining the redox tone. Indicaxanthin is a long-known betalain pigment found in the genus Opuntia of cactus pear and highly concentrated in the edible fruits of O. ficus indica, L. whose bioactivity has been overlooked until recently. This review summarizes studies conducted so far in vitro and in vivo, most of which have been performed in our laboratory. The chemical and physicochemical characteristics of Indicaxanthin are reflected in the molecule's reducing properties and antioxidant effects and help explain its ability to interact with membranes, modulate redox-regulated cellular pathways, and possibly bind to protein molecules. Measurement of bioavailability in volunteers has been key to exploring its bioactivity; amounts consistent with dietary intake, or plasma concentration after dietary consumption of cactus pear fruit, have been used in experimental setups mimicking physiological or pathophysiological conditions, in cells and in animals, finally suggesting pharmacological potential and relevance of Indicaxanthin as a nutraceutical. In reporting experimental results, this review also aimed to raise questions and seek insights for further basic research and health promotion applications.

An overview and update on the chemical composition and potential health benefits of Opuntia ficus-indica (L.) Miller

Opuntia ficus-indica (OFI), widely recognized as prickly pear, is native to Mexico and it is distributed in many areas of the world because of its socioeconomic, agronomic, and ecological benefits, besides its large amounts of functional, nutraceutical, and biological activities. Various parts of this plant including the fruit pulp and peel, cladode, and seeds are scientifically proven to have therapeutic potentials and are safe for human use. The contents of phytochemical compounds in each part of the OFI are different. Each pharmacological activity depends on the phytochemical compounds, the components used, and the extraction type. In this review, we summarize the active constituents from different parts of OFI and their pharmacological effects including the antioxidant, wound healing, skin protective, hepatoprotective, anticancer, antidiabetic, antihypercholesterolemic, and anti-obesity activities. Besides its effects on the bone health, cardiovascular system, kidneys, and gastrointestinal tract, its gastroprotective, anti-ulcer, anti-inflammatory, antiviral, neuroprotective, sedative, analgesic, anxiolytic and antimicrobial effects and effects on cognitive and memory function are also mentioned. PRACTICAL APPLICATIONS: Over the past few decades, the health benefits of Opuntia ficus-indica (OFI) have received much attention. All parts of the plant, including the fruit pulp and peel, cladode, and seeds have found use in the treatment of many diseases. The chemical composition of OFI provides both a high nutritional value and various health benefits. Therefore, the aim of this review is to present the up-to-date research carried out on OFI phytochemicals, showing the most important biological activities reported.

Moroccan medicinal plants traditionally used for the treatment of skin diseases: From ethnobotany to clinical trials

ETHNOPHARMACOLOGICAL RELEVANCE

Skin diseases are among the most common human health affections. A healthy skin promotes a healthy body that can be achieved through modern, allopathic and natural medicines. Therefore, medicinal plants can be a reliable therapy in treating skin diseases in humans through a diverse range of bioactive molecules they contain.

AIM OF THE STUDY

This review aims to provide for the first-time scientific evidence related to the dermatological properties of Morocco's medicinal plants and it aims to provide a baseline for the discovery of new drugs having activities against skin issues.

METHODS

This review involved an investigation with different search engines for Moroccan ethnobotanical surveys published between 1991 and 2021. The plants used to treat skin diseases have been determined. Information regarding pharmacological effects, phytochemical, and clinical trials related to the plants listed in this review was collected from different scientific databases like PubMed, Science Direct, Google Scholar, Web of Science and Scopus. The data were analyzed and summarized in the review.

RESULTS

A total of 401 plants belonging to 86 families mainly represented by Asteraceae, Lamiaceae, Fabaceae, and Apiaceae which have been documented to be in common use by Moroccans for managing skin diseases. Among those plants recorded, the most commonly used are Allium cepa L, Chamaeleon gummifer (L.) Cass and Salvia rosmarinus Schleid. Mill. Leaves were the most commonly used plant part, while powder and decoction were the most common method of traditional drug preparation. 107 of the 401 plants (27%) have undergone pharmacological validation. A total of 44 compounds isolated from 27 plants were investigated to treat different types of skin diseases, and 25 plants have been clinically studied for their activities against skin diseases.

CONCLUSION

The beneficial effects of using Moroccan medicinal plants to treat skin diseases, according to traditional practices, have been proven in numerous scientific studies. Therefore, other studies should focus on isolating and identifying specific bioactive compounds from plant extracts, revealing more valuable therapeutic properties. Furthermore, additional reliable clinical trials are needed to confirm their beneficial effect on patients with skin diseases.

Olive leaf extract inhibits metastatic melanoma spread through suppression of epithelial to mesenchymal transition

Olive tree leaves are an abundant source of bioactive compounds with several beneficial effects for human health, including a protective role against many types of cancer. In this study, we investigated the effect of an extract, obtained from olive tree (Olea europaea L.) leaves (OLE), on proliferation, invasion, and epithelial to mesenchymal transition (EMT) on metastatic melanoma, the highly aggressive form of skin cancer and the deadliest diseases. Our results demonstrated that OLE inhibited melanoma cells proliferation through cell cycle arrest and induction of apoptotic cell death. Moreover, OLE suppressed the migration, invasion, and colonies formation of human melanoma cells. Similar to our in vitro findings, we demonstrated that the oral administration of OLE inhibited cutaneous tumor growth and lung metastasis formation in vivo by modulating the expression of EMT related factors. In addition, the anti-proliferative and anti-invasive effects of OLE against melanoma were also related to a simultaneous targeting of mitogen-activated protein kinase and PI3K pathways, both in vitro and in vivo. In conclusion, our findings suggest that OLE has the potential to inhibit the metastatic spread of melanoma cells thanks to its multifaceted mechanistic effects, and may represent a new add-on therapy for the management of metastatic melanoma.

Lipophilic Compounds and Antibacterial Activity of Opuntia ficus-indica Root Extracts from Algeria

The chemical composition, investigated by gas chromatography-mass spectrometry, and antibacterial activity of lipophilic extractives of three varieties of Opuntia ficus-indica roots from Algeria are reported in this paper for the first time. The results obtained revealed a total of 55 compounds, including fatty acids, sterols, monoglycerides and long chain aliphatic alcohols that were identified and quantified. β-Sitosterol was found as the major compound of the roots of the three varieties. Furthermore, considerable amounts of essential fatty acids (ω3, ω6, and ω9) such as oleic, linoleic, and linolenic acids were also identified. The green variety was the richest among the three studied varieties. The antibacterial activity, evaluated with disc diffusion method, revealed that lipophilic extracts were effective mainly against Gram-positive Staphylococcus aureus and methicillin-resistant Staphylococcus aureus (MRSA) (19~23 mm). Gram-negative strains mainly Pseudomonas aeruginosa gave an inhibition zone of 18 mm, which is considered high antibacterial activity. The minimal inhibitory concentrations of the tested bacteria revealed interesting values against the majority of bacteria tested: 75–100 µg mL⁻¹ for Bacillus sp., 250–350 µg/mL for the two Staphylococcus strains, 550–600 µg mL⁻¹ for E. coli, and 750–950 µg mL⁻¹ obtained with Pseudomonas sp. This study allows us to conclude that the lipophilic fractions of cactus roots possess interesting phytochemicals such as steroids, some fatty acids and long chain alcohols that acted as antibiotic-like compounds countering pathogenic strains.

Cactaceae plants as sources of active bioavailable phytochemicals

Arid-land plants from the Cactaceae family are endemic to the Americas and cultivated worldwide. Cactaceous plants and their fruits contain phenolic compounds, betalains, vitamins, carotenoids, minerals, and soluble fiber. Edible cactaceous matrices can be considered functional foods since their consumption may confer health benefits. These plants could be a source of novel bioactive compounds relevant to the area of phytomedicine. However, consumption of high concentrations of active molecules is not necessarily correlated to beneficial physiological effects because phytochemicals must be released from the food matrices under physiological conditions, resist digestion-associated chemical transformations, and remain in their active state in systemic circulation until the target tissues are reached. Notably, although digestion may either increase or decrease the bioactive phytochemicals' activity and stability, non-absorbed compounds may also be relevant for human health. Additionally, food matrices' type and composition and their technological processing operations may influence the compounds' release, stability, and accessibility. Thus, this review provides insights on the feasibility of using Cactaceae plants as sources of functional compounds. It is focused on compounds' bioactivity, bioaccessibility, and overall bioavailability after their metabolic transformation. Also, it addresses the influence of food processing on bioactive compounds. Many Cactaceae species are unexplored, and our understanding of how they confer health benefits is limited. To better understand the physiological relevance, nutraceutical potential, and therapeutic feasibility of cactaceous bioactive phytochemicals, future research should focus on the metabolic stability and safety of these compounds, as well as their assimilation mechanisms (absorption, distribution, and metabolic fate).

In Silico Design, Synthesis, and Biological Evaluation of Anticancer Arylsulfonamide Endowed with Anti-Telomerase Activity

Telomerase, a reverse transcriptase enzyme involved in DNA synthesis, has a tangible role in tumor progression. Several studies have evidenced telomerase as a promising target for developing cancer therapeutics. The main reason is due to the overexpression of telomerase in cancer cells (85–90%) compared with normal cells where it is almost unexpressed. In this paper, we used a structure-based approach to design potential inhibitors of the telomerase active site. The MYSHAPE (Molecular dYnamics SHared PharmacophorE) approach and docking were used to screen an in-house library of 126 arylsulfonamide derivatives. Promising compounds were synthesized using classical and green methods. Compound 2C revealed an interesting IC₅₀ (33 ± 4 µM) against the K-562 cell line compared with the known telomerase inhibitor BIBR1532 IC₅₀ (208 ± 11 µM) with an SI ~10 compared to the BALB/3-T3 cell line. A 100 ns MD simulation of 2C in the telomerase active site evidenced Phe494 as the key residue as well as in BIBR1532. Each moiety of compound 2C was involved in key interactions with some residues of the active site: Arg557, Ile550, and Gly553. Compound 2C, as an arylsulfonamide derivative, is an interesting hit compound that deserves further investigation in terms of optimization of its structure to obtain more active telomerase inhibitors

Betalain plant sources, biosynthesis, extraction, stability enhancement methods, bioactivity, and applications

Betalains are plant pigments with functional properties used mainly as food dyes. However, they have been shown to be unstable to different environmental factors. This paper provides a review of (1) Betalain plant sources within several plant families such as Amaranthaceae, Basellaceae, Cactaceae, Portulacaceae, and Nyctaginaceae, (2) The biosynthesis pathway of betalains for both betacyanins and betaxanthins, (3) Betalain extraction process, including non-conventional technologies like microwave-assisted, ultrasound-assisted, and pulsed electrical field extraction, (4) Factors affecting their stability, mainly temperature, water activity, light incidence, as well as oxygen concentration, metals, and the presence of antioxidants, as well as activation energy as a mean to assess stability, and novel food-processing technologies able to prevent betalain degradation, (5) Methods to increase shelf life, mainly encapsulation by spray drying, freeze-drying, double emulsions, ionic gelation, nanoliposomes, hydrogels, co-crystallization, and unexplored methods such as complex coacervation and electrospraying, (6) Biological properties of betalains such as their antioxidant, hepatoprotective, antitumoral, and anti-inflammatory activities, among others, and (7) Applications in foods and other products such as cosmetics, textiles and solar cells, among others. Additionally, study perspectives for further research are provided for each section.

Indicaxanthin from Opuntia ficus-indica Fruit Ameliorates Glucose Dysmetabolism and Counteracts Insulin Resistance in High-Fat-Diet-Fed Mice

Obesity-related dysmetabolic conditions are amongst the most common causes of death globally. Indicaxanthin, a bioavailable betalain pigment from Opuntia ficus-indica fruit, has been demonstrated to modulate redox-dependent signalling pathways, exerting significant anti-oxidative and anti-inflammatory effects in vitro and in vivo. In light of the strict interconnections between inflammation, oxidative stress and insulin resistance (IR), a nutritionally relevant dose of indicaxanthin has been evaluated in a high-fat diet (HFD) model of obesity-related IR. To this end, biochemical and histological analysis, oxidative stress and inflammation evaluations in liver and adipose tissue were carried out. Our results showed that indicaxanthin treatment significantly reduced body weight, daily food intake and visceral fat mass. Moreover, indicaxanthin administration induced remarkable, beneficial effects on HFD-induced glucose dysmetabolism, reducing fasting glycaemia and insulinaemia, improving glucose and insulin tolerance and restoring the HOMA index to physiological values. These effects were associated with a reduction in hepatic and adipose tissue oxidative stress and inflammation. A decrease in RONS, malondialdehyde and NO levels, in TNF-α, CCL-2 and F4-80 gene expression, in p65, p-JNK, COX-2 and i-NOS protein levels, in crown-like structures and hepatic inflammatory foci was, indeed, observed. The current findings encourage further clinical studies to confirm the effectiveness of indicaxanthin to prevent and treat obesity-related dysmetabolic conditions.

Evaluation of the IKKβ Binding of Indicaxanthin by Induced-Fit Docking, Binding Pose Metadynamics, and Molecular Dynamics

Background: Indicaxanthin, a betaxanthin belonging to the betalain class of compounds, has been recently demonstrated to exert significant antiproliferative effects inducing apoptosis of human melanoma cells through the inhibition of NF-κB as the predominant pathway. Specifically, Indicaxanthin inhibited IκBα degradation in A375 cells. In resting cells, NF-κB is arrested in the cytoplasm by binding to its inhibitor protein IκBα. Upon stimulation, IκBα is phosphorylated by the IKK complex, and degraded by the proteasome, liberating free NF-κB into the nucleus to initiate target gene transcription. Inhibition of the IKK complex leads to the arrest of the NF-κB pathway.

Methods: To acquire details at the molecular level of Indicaxanthin’s inhibitory activity against hIKKβ, molecular modeling and simulation techniques including induced-fit docking (IFD), binding pose metadynamics (BPMD), molecular dynamics simulations, and MM-GBSA (molecular mechanics-generalized Born surface area continuum solvation) have been performed.

Results: The computational calculations performed on the active and inactive form, and the allosteric binding site of hIKKβ, revealed that Indicaxanthin inhibits prevalently the active form of the hIKKβ. MM-GBSA computations provide further evidence of Indicaxanthin’s stability inside the active binding pocket with a binding free energy of −22.2 ± 4.3 kcal/mol with respect to the inactive binding pocket with a binding free energy of −20.7 ± 4.7 kcal/mol. BPMD and MD simulation revealed that Indicaxanthin is likely not an allosteric inhibitor of hIKKβ.

Conclusion: As a whole, these in silico pieces of evidence show that Indicaxanthin can inhibit the active form of the hIKKβ adding novel mechanistic insights on its recently discovered ability to impair NF-κB signaling in melanoma A375 cells. Moreover, our results suggest the phytochemical as a new lead compound for novel, more potent IKKβ inhibitors to be employed in the treatment of cancer and inflammation-related conditions.

Amyloid-Beta Induces Different Expression Pattern of Tissue Transglutaminase and Its Isoforms on Olfactory Ensheathing Cells: Modulatory Effect of Indicaxanthin

Herein, we assessed the effect of full native peptide of amyloid-beta (Aβ) (1-42) and its fragments (25-35 and 35-25) on tissue transglutaminase (TG2) and its isoforms (TG2-Long and TG2-Short) expression levels on olfactory ensheathing cells (OECs). Vimentin and glial fibrillary acid protein (GFAP) were also studied. The effect of the pre-treatment with indicaxanthin from Opuntia ficus-indica fruit on TG2 expression levels and its isoforms, cell viability, total reactive oxygen species (ROS), superoxide anion (O₂⁻), and apoptotic pathway activation was assessed. The levels of Nestin and cyclin D1 were also evaluated. Our findings highlight that OECs exposure to Aβ(1-42) and its fragments induced an increase in TG2 expression levels and a different expression pattern of its isoforms. Indicaxanthin pre-treatment reduced TG2 overexpression, modulating the expression of TG2 isoforms. It reduced total ROS and O₂⁻ production, GFAP and Vimentin levels, inhibiting apoptotic pathway activation. It also induced an increase in the Nestin and cyclin D1 expression levels. Our data demonstrated that indicaxanthin pre-treatment stimulated OECs self-renewal through the reparative activity played by TG2. They also suggest that Aβ might modify TG2 conformation in OECs and that indicaxanthin pre-treatment might modulate TG2 conformation, stimulating neural regeneration in Alzheimer’s disease.

The Phytochemical Indicaxanthin Synergistically Enhances Cisplatin-Induced Apoptosis in HeLa Cells via Oxidative Stress-Dependent p53/p21waf1 Axis

Combining phytochemicals with chemotherapics is an emerging strategy to treat cancer to overcome drug toxicity and resistance with natural compounds. We assessed the effects of indicaxanthin (Ind), a pigment obtained from Opuntia ficus-indica (L. Mill) fruit, combined with cisplatin (CDDP) against cervical cancer cells (HeLa). Measured cell viability via Trypan blue assay; cell morphology via fluorescence microscopy; apoptosis, cell cycle, mitochondrial membrane potential (MMP) and cell redox balance via flow-cytometry; expression levels of apoptosis-related proteins via western blot. Cell viability assays and Chou-Talalay plot demonstrated that the combination of CDDP and Ind had synergistic cytotoxic effects. Combined treatment had significant effects (p < 0.05) on phosphatidylserine externalization, cell morphological changes, cell cycle arrest, fall in MMP, ROS production and GSH decay compared with the individual treatment groups. Bax, cytochrome c, p53 and p21^waf1 were over-expressed, while Bcl-2 was downregulated. Pre-treatment with N-acetyl-l-cysteine abolished the observed synergistic effects. We also demonstrated potentiation of CDDP anticancer activity by nutritionally relevant concentrations of Ind. Oxidative stress-dependent mitochondrial cell death is the basis of the chemosensitizing effect of Ind combined with CDDP against HeLa cancer cells. ROS act as upstream signaling molecules to initiate apoptosis via p53/p21^waf1 axis. Ind can be a phytochemical of interest in combo-therapy.

Effects of betalains on atherogenic risk factors in patients with atherosclerotic cardiovascular disease

This study evaluated the potential impacts of supplementation with betalain-rich extracts of foods on some atherosclerotic risk factors in coronary artery disease patients. During an acute phase, 48 male patients received about 50 mg betalain/betacyanin, and their blood and urine samples were collected at 3, 8, and 24 hours after supplementations. Also, in a pilot randomized crossover trial, these participants were allocated to two-week interventions (a betacyanin-rich supplement of Opuntia stricta, a betalain-rich supplement of red beetroot and a placebo) with two-week washout periods. Then, their plasma samples were collected at the baseline after a two-week period. The concentrations of betanin in plasma and urine samples were determined using HPLC. Also, homocysteine and glucose levels, lipid profile, and blood pressure were analyzed. Additionally, quality of life and dietary intake were assessed. After these interventions, minimal amounts of betanin were found in plasma and about 0.13-0.93% in urine. Also, both supplements significantly decreased the concentration of homocysteine, glucose, total cholesterol, triglyceride, and LDL. Also, betalain-rich supplements lowered both systolic and diastolic blood pressures. Nevertheless, the clinically meaningful changes were only found in the case of Hcy, LDL, and non-HDL-c concentrations. It seems that food sources of betalains can be considered as functional foods because they improve the lipid profile and levels of homocysteine, glucose, blood pressure, and quality of life to some extent.

Repurposing of plant alkaloids for cancer therapy: Pharmacology and toxicology

Drug repurposing (or repositioning) is an emerging concept to use old drugs for new treatment indications. Phytochemicals isolated from medicinal plants have been largely neglected in this context, although their pharmacological activities have been well investigated in the past, and they may have considerable potentials for repositioning. A grand number of plant alkaloids inhibit syngeneic or xenograft tumor growth in vivo. Molecular modes of action in cancer cells include induction of cell cycle arrest, intrinsic and extrinsic apoptosis, autophagy, inhibition of angiogenesis and glycolysis, stress and anti-inflammatory responses, regulation of immune functions, cellular differentiation, and inhibition of invasion and metastasis. Numerous underlying signaling processes are affected by plant alkaloids. Furthermore, plant alkaloids suppress carcinogenesis, indicating chemopreventive properties. Some plant alkaloids reveal toxicities such as hepato-, nephro- or genotoxicity, which disqualifies them for repositioning purposes. Others even protect from hepatotoxicity or cardiotoxicity of xenobiotics and established anticancer drugs. The present survey of the published literature clearly demonstrates that plant alkaloids have the potential for repositioning in cancer therapy. Exploitation of the chemical diversity of natural alkaloids may enrich the candidate pool of compounds for cancer chemotherapy and -prevention. Their further preclinical and clinical development should follow the same stringent rules as for any other synthetic drug as well. Prospective randomized, placebo-controlled clinical phase I and II trials should be initiated to unravel the full potential of plant alkaloids for drug repositioning.

Nopal (Opuntia spp.) and its Effects on Metabolic Syndrome: New Insights for the Use of a Millenary Plant

Background:

Nopal (Opuntia spp.) is by excellence the most utilized cactus in human and animal nutrition. It is also a very noble plant; its main physicochemical, nutritional and nutraceutical characteristics allow the use of nopal in diverse food applications. Special focus has been given over the past decades in the use of Opuntia for the treatment of metabolic syndrome (MetS), which is predominantly related to Diabetes Mellitus. In this sense, the prevalence of MetS is increasing at a worldwide level. This in turn has led to a notorious demand for natural and nutraceutical food sources.

Methods:

The objective of this work was to summarize the main contributions in the field of Opuntia spp. research highlighting the potential use of nopal fruits or cladodes in MetS treatment, providing the reader with historical and novel information in this field. Nevertheless, the present work is not a meta-analysis. We included mainly information from recognized scientific databases, such as PubMed, Scopus, Web of Science and Google Scholar. No homeopathic based studies were included since they lack scientific validation. To the best of our knowledge, this is the first review that fairly categorizes the majority of the information in this field into subsections, which can be of interest for the reader, such as the effect of nopal against cardiovascular disease, type 2 diabetes mellitus, and obesity among others.

Conclusion:

Nopal constitutes one of the most studied members of the Cactaceae family; its potential effects on human health have been described since ancient times, mostly through traditional medicine. The present work highlights the importance of this plant in the treatment of MetS related maladies and points out the importance of elucidating new compounds and their validation for the interactions of nutraceutical compounds which could be related to MetS.

Indicaxanthin, a multi-target natural compound from Opuntia ficus-indica fruit: From its poly-pharmacological effects to biochemical mechanisms and molecular modelling studies

Over the latest years phytochemical consumption has been associated to a decreased risk of both the onset and the development of a number of pathological conditions. In this context indicaxanthin, a betalain pigment from Opuntia ficus-indica fruit, has been the object of sound research. Explored, at first, for its mere antioxidant potential, Indicaxanthin is now regarded as a redox-active compound able to exert significant poly-pharmacological effects against several targets in a number of experimental conditions both in vivo and in vitro. This paper aims to provide an overview on the therapeutical effects of indicaxanthin, ranging from the anti-inflammatory to the neuro-modulatory and anti-tumoral ones and favored by its high bioavailability. Moreover, biochemical and molecular modelling investigations are aimed to identify the pharmacological targets the compound is able to interact with and to address the challenging development in the future research.

Opuntia ficus-indica (L.) Mill. fruit as source of betalains with antioxidant, cytoprotective, and anti-angiogenic properties

The aim of this work was to investigate the phytochemical profile and biological properties of different colours of betalain cactus pear extracts, evaluating their antioxidant, cytoprotective, and anti-angiogenic properties by cell-free, cell-based, and in vivo assays. A QuEChERS extraction method followed by RP-LC-DAD-MS/MS analysis showed that indicaxanthin and betanin were the main compounds (≥94.32% and ≥96.95%, respectively). Orange cactus pear extracts exert the best antioxidant activity in all assays carried out, in particular into ORAC (17,352.55 ± 987.407 mg trolox equivalents/100 g dry weight) and β-carotene bleaching (60.35%) assays. The red ones, instead, showed the best cytoprotective activity decreasing the cell mortality, LDH, and Caspase-3 release ranging from 4.0 to 55%. According to antioxidant results, the orange cactus pear extracts showing also the highest anti-angiogenic activity (IC₅₀ 19.31 μg/ml), followed by the red (IC₅₀ 23.55 μg/ml) and the yellow ones (IC₅₀ 33.97 μg/ml). In light of the results and correlation analysis, the behaviour of these molecules varies a lot according to their structure and physicochemical features and synergistic activity between betalain classes may be postulated; so the plant complex could be of greater interest compared with the isolated molecules for potential nutraceutical and pharmaceutical uses.