seeds: quantification and in silico insights into its anti-cancer potential

Bixin, the key pigment of Bixa orellana L., is an apo-carotenoid found in the seed arils. The present study aimed to quantitatively determine the bixin content of seeds and explore its anti-cancer activity through in silico studies. The bixin content from the seeds of the local genotype, TNMTP8, quantified by RP-HPLC was 4.58 mg per gram. The prediction of pharmacological activity suggested that bixin may serve as a BRAF, MMP9, TNF expression inhibitors, and TP53 expression enhancer. According to molecular docking analysis, bixin interacted with eight different skin cancer targets and had the lowest binding energy compared to the standard drug, 5-fluorouracil. The binding score between bixin and the targets ranged from -4.7 to -8.7 kcal/mol. The targets BRAF and SIRT3 interacted well with bixin, with binding energies as low as -8.3 and -8.7 kcal/mol, respectively. Hence, the dynamic behavior of these two docked complexes throughout a 500 ns trajectory run was investigated further. The Root Mean Square Deviation (RMSD), Root Mean Square Fluctuation (RMSF) values, and total contacts as a function of time recorded during scrutiny suggest that both complexes were stable. This was validated by post-molecular dynamics analysis using Molecular Mechanics Generalized Born Surface Area (MM-GBSA). Principal component analysis (PCA) was used to analyze the significant differences in motion exhibited by BRAF-Bixin and SIRT3-Bixin. The results showed that bixin is a promising source for potential treatment interventions in skin cancer therapies.Communicated by Ramaswamy H. Sarma.

The role of bixin as antioxidant, anti-inflammatory, anticancer, and skin protecting natural product extracted from Bixa orellana L

Since long, medicinal plants or herbs are being used in different traditional treatment systems as therapeutic agents to treat a variety of illnesses. Bixa orellana L., an medicinal plant (family: Bixaceae), is an Ayurvedic herb used to treat dyslipidemia, diarrhoea, and hepatitis since ancient times. B. orellana L., seeds contain an orange-red coloured component known as bixin (C25H30O4), which constitutes 80% of the extract.Chemically, bixin is a natural apocarotenoid, biosynthesized through the oxidative degradation of C40 carotenoids. Bixin helps to regulate the Nrf2/MyD88/TLR4 and TGF-1/PPAR-/Smad3 pathways, which further give it antifibrosis, antioxidant, and anti-inflammatory properties. This current review article presents a comprehensive review of bixin as an anti-inflammatory, antioxidant, anticancer,and skin protecting natural product. In addition, the biosynthesis and molecular target of bixin, along with bixin extraction techniques, are also presented.

Dynamics of annatto pigment synthesis and accumulation in seeds of Bixa orellana L. revealed by integrated chemical, anatomical, and RNA-Seq analyses

Bixin is a commercially valuable apocarotenoid pigment found in the seed aril of Bixa orellana. The dynamics and regulation of its biosynthesis and accumulation during seed development remain largely unknown. Here, we combined chemical, anatomical, and transcriptomic data to provide stage-specific resolution of the cellular and molecular events occurring during B. orellana seed development. Seeds at five developmental stages (S1-S5) were used for analysis of bixin content and seed anatomy, and three of them (S1, S3, and S4) were selected for Illumina HiSeq sequencing. Bixin accumulated in large quantities in seeds compared with other tissues analyzed, particularly during the S2 stage, peaking at the S4 stage, and then decreasing slightly in the S5 stage. Anatomical analysis revealed that bixin accumulated in the large central vacuole of specialized cells, which were scattered throughout the developing mesotesta at the S2 stage, but enlarged progressively at later stages, until they occupied most of the parenchyma in the aril. A total of 13 million reads were generated and assembled into 73,381 protein-encoding contigs, from which 312 were identified as containing 1-deoxy-D-xylulose-5-phosphate/2-C-methyl-D-erythritol-4-phosphate (DOXP/MEP), carotenoid, and bixin pathways genes. Differential transcriptome expression analysis of these genes revealed that 50 of them were sequentially and differentially expressed through the seed developmental stages analyzed, including seven carotenoid cleavage dioxygenases, eight aldehyde dehydrogenases, and 22 methyltransferases. Taken together, these results show that bixin synthesis and accumulation in seeds of B. orellana are a developmentally regulated process involving the coordinated expression of DOXP/MEP, carotenoid, and bixin biosynthesis genes.

Bixin-loaded colloidal nanodelivery systems, techniques and applications

Bixin is the cis-carotenoid from the seed of achiote tree or annatto. It is an approved liposoluble apocarotenoid by FDA as colorant and additive in the food industry. Nonetheless, bixin is unstable in the presence of oxygen, light, high pHs (alkali) and heat; thereby reducing its bioavailability/bioactivity, and also, with a low solubility in water. Some biopolymeric (e.g., nanofibers, nanogels, and nanotubes) and lipid-based nanocarriers (nanoliposomes, niosomes, hexosomes, nanoemulsions, solid-lipid nanoparticles, and nanostructured lipid carriers) have been introduced for bixin. Thus, this review focuses on the updated information regarding bixin-loaded nanodelivery platforms. Moreover, it provides a comprehensive review of bioavailability, physicochemical properties, and applications of nanoencapsulated-bixin as an additive, its release rate and safety issues. These findings will bring potential strategies for the usage of nanocarriers in managing bixin defaults to improve its broad application in various industries.

Bixin and fucoxanthin sensitize human lung cancer and cervical cancer cell to cisplatin in vitro

Objective

Cisplatin is a conventional anticancer drug that generates reactive oxygen species and causes apoptosis. However, many cancer cells develop alterations in the ATP binding cassette transporter responsible for the uptake and efflux process, which leads to resistance. Many natural products have shown potential to compete with ATP binding cassette transporter and may sensitize resistant cells to cisplatin. Studies have shown pro-oxidant effect of carotenoids that promote apoptosis of cancer cells. Bixin and fucoxanthin are well-known carotenoids with known antioxidant properties, however their bioactivity in lung cancer cells, clinically known to develop resistance due to ATP binding cassette transporter, has been minimally studied. This study is the first to investigate the potential of bixin and fucoxanthin to sensitize human lung cancer cell line, A549 and cervical cancer cell line, HeLa, to cisplatin. Drug combination method developed by Chou and Talalay theorem was employed.

Result

Employing the best combination ratio, this study shows selective sensitization of cancer cells to cisplatin after bixin and fucoxanthin treatment. Further study on the mechanism of action in specific types of cancer cells is warranted. It may improve cisplatin sensitivity in tumors and rational use of cancer drugs.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s13104-021-05866-4.

Bixin attenuates carbon tetrachloride induced oxidative stress, inflammation and fibrosis in kidney by regulating the Nrf2/TLR4/MyD88 and PPAR-γ/TGF-β1/Smad3 pathway

Bixin, an natural carotenoid extracted from the seeds of the Bixa orellana has been shown to possess numerous important pharmacological activities. The present study was aimed to investigate the mechanisms of Bixin on carbon tetrachloride (CCl4)-induced kidney inflammation, fibrosis and oxidative stress in mice. Our results showed that Bixin improved renal damage by decreasing the serum levels of creatinine, urea, uric acid and alleviating kidney fibrosis. Bixin ameliorated CCl4-induced inflammation in kidneys by reducing the levels of TNF-α and IL-1β. Bixin suppressed oxidative stress by decreasing the MDA level and increasing the activation of SOD, CAT and GPx. Furthermore, Bixin increased the levels of PPAR-γ, NQO1, HO-1 and the nuclear translocation of Nrf2 in the kidneys of mice. Bixin supplementation inhibited the activation of TLR4, MyD88, NF-κB, TGF-β and Smad3. Thus, this study demonstrated that Bixin possesses anti-oxidant, anti-inflammatory and anti-fibrosis properties through regulating the Nrf2/TLR4/MyD88 and PPAR-γ/TGF-β1/Smad3 pathways.

Activation of NRF2 by topical apocarotenoid treatment mitigates radiation-induced dermatitis

Radiation therapy is a frontline treatment option for cancer patients; however, the effects of radiotherapy on non-tumor tissue (e.g. radiation-induced dermatitis) often worsen patient quality of life. Previous studies have implicated the importance of redox balance in preventing dermatitis, specifically in reference to modulation of the nuclear factor (erythroid-derived 2)-like 2 (NRF2) signaling pathway. Due to the cytoprotective functions of transcriptional target genes of NRF2, we investigated how modulation of NRF2 expression could affect DNA damage, oxidative stress, and cell viability in response to radiotherapy. Specifically, it was noted that NRF2 knockdown sensitized human skin keratinocytes to ionizing radiation; likewise, genetic ablation of NRF2 in vivo increased radiosensitivity of murine epidermis. Oppositely, pharmacological induction of NRF2 via the apocarotenoid bixin lowered markers of DNA damage and oxidative stress, while preserving viability in irradiated keratinocytes. Mechanistic studies indicated that topical pretreatment using bixin as an NRF2 activator antagonized initial DNA damage by raising cellular glutathione levels. Additionally, topical application of bixin prevented radiation-induced dermatitis, epidermal thickening, and oxidative stress in the skin of SKH1 mice. Overall, these data indicate that NRF2 is critical for mitigating the harmful skin toxicities associated with ionizing radiation, and that topical upregulation of NRF2 via bixin could prevent radiation-induced dermatitis.

Using full chloroplast genomes of 'red' and 'yellow' Bixa orellana (achiote) for kmer based identification and phylogenetic inference

Background

Full chloroplast genomes provide high resolution taxonomic discrimination between closely related plant species and are quickly replacing single and multi-locus barcoding regions as reference materials of choice for DNA based taxonomic annotation of plants. Bixa orellana, commonly known as “achiote” and “annatto” is a plant used for both human and animal foods and was thus identified for full chloroplast sequencing for the Center for Veterinary Medicine (CVM) Complete Chloroplast Animal Feed database. This work was conducted in collaboration with the Instituto de Medicina Tradicional (IMET) in Iquitos, Peru. There is a wide range of color variation in pods of Bixa orellana for which genetic loci that distinguish phenotypes have not yet been identified. Here we apply whole chloroplast genome sequencing of “red” and “yellow” individuals of Bixa orellana to provide high quality reference genomes to support kmer database development for use identifying this plant from complex mixtures using shotgun data. Additionally, we describe chloroplast gene content, synteny and phylogeny, and identify an indel and snp that may be associated with seed pod color.

Results

Fully assembled chloroplast genomes were produced for both red and yellow Bixa orellana accessions (158,918 and 158,823 bp respectively). Synteny and gene content was identical to the only other previously reported full chloroplast genome of Bixa orellana (NC_041550). We observed a 17 base pair deletion at position 58,399–58,415 in both accessions, relative to NC_041550 and a 6 bp deletion at position 75,531–75,526 and a snp at position 86,493 in red Bixa orellana.

Conclusions

Our data provide high quality reference genomes of individuals of red and yellow Bixa orellana to support kmer based identity markers for use with shotgun sequencing approaches for rapid, precise identification of Bixa orellana from complex mixtures. Kmer based phylogeny of full chloroplast genomes supports monophylly of Bixaceae consistent with alignment based approaches. A potentially discriminatory indel and snp were identified that may be correlated with the red phenotype.

Incorporation of bixin in aqueous media: Self-formulation with sorbitol ester of norbixin

We have previously reported how the natural food colorant, bixin, was enzymatically modified by appending sorbitol to the bixin scaffold. The resulted product, sorbitol ester of norbixin (SEN) was expected to be more hydrophilic. The present study aimed to investigate the physical behaviour of SEN in aqueous media. The property of SEN was studied together with non-reacted bixin as separation of the two compounds was unsuccessful. The SEN molecules behaved as a bolaamphiphile in aqueous media, underwent self-association and develop a hydrophilic aggregate. SEN-aggregates could uptake the non-reacted bixin molecules inside its hydrophobic moiety and dispersed it in aqueous media. Aggregation of SEN molecules with incorporated bixin resulted in a hypsochromic shift of the absorption spectra indicting H-aggregation. Dynamic light scattering showed the formation of aggregates with an average hydrodynamic radius 38 ± 2 nm. The dispersibility of the aggregates was affected by pH and the ionic strength of the media.

The biotechnology (genetic transformation and molecular biology) of Bixa orellana L. (achiote)

Genetic transformation allows for greater bixin or norbixin production in achiote. Knowledge of genes that control the biosynthesis of these important secondary metabolites will allow for targeted amplification in transgenic plants. Annatto is a natural dye or coloring agent derived from the seeds, or their arils, of achiote (Bixa orellana L.), and is commercially known as E160b. The main active component of annatto dye is water-insoluble bixin, although water-soluble norbixin also has commercial applications. Relative to other antioxidants, bixin is light- and temperature stable and is thus safe for human consumption. Bixin is, therefore, widely applied as a dye and as an antioxidant in the medico-pharmaceutical, food, cosmetic, and dye industries. Even though bixin has also been isolated from leaves and bark, yield is lower than from seeds. More biotechnology-based research of this industrial and medicinal plant is needed. Building on provisional genetic transformation studies, it would be advantageous to transform genes that could result in greater bixin or norbixin production. Reliable protocols for the extraction of bixin and norbixin, as well as deeper knowledge of the genes that control the biosynthesis of these important secondary metabolites will allow for targeted amplification in transgenic plants.

The carotenoid Bixin found to exhibit the highest measured carotenoid oxidation potential to date consistent with its practical protective use in cosmetics, drugs and food

The electrochemical oxidation potentials of cis bixin correspond to the production of the carotenoid radical cation, Car⁺ and dication Car⁺⁺. The oxidation is a two-electron process with oxidation potentials at ~0.94 and ~1.14 V vs SCE (reference to ferrocene at 0.528 V) in THF. These potentials are higher than that of symmetrical canthaxanthin at 0.775 V and 0.972 V and for β-carotene at 0.634 V and 0.605 V respectively. The second oxidation potential for canthaxanthin is higher by 0.20 V than the first. Similar difference is observed for bixin. In contrast, the second oxidation potential for β-carotene is lower by 30 mV than that of the first. Reduction potentials were found to occur at ~-0.69 and ~-1.22 V vs SCE. The lifetime of the radical cation of cis bixin, Car⁺, is short and decays rapidly at ambient temperature. The suggested scavenging ability of cis bixin towards reactive oxidative oxygen species is estimated to be 44. On the other hand, that of β-carotene, symmetrical canthaxanthin and the dicyano substituted carotenoid which exhibit oxidation potentials of 0.634 V, 0.775 V and 0.833 V vs SCE were measured to be 0.64, 1.96 and 23.60 respectively. The non-reversible electrochemical measurements suggest the tendency for bixin to react with trace amounts of reactive oxygen species (OH, O₂^-, OOH).

Hydrophilization of bixin by lipase-catalyzed transesterification with sorbitol

Bixin is one of the most used yellow-orange food colorants in the food industry. The polyene chain of bixin makes it highly hydrophobic and less suitable for water-based food formulations. Lipase-catalyzed reactions of bixin with sorbitol were studied to synthesize a new derivative of bixin with potential hydrophilic properties. Interestingly, we show that the lipase-catalyzed reaction of bixin leads to a transesterification reaction and formation of a transesterified product, sorbitol ester of norbixin (SEN). The reaction efficiency was optimized with various immobilized lipases at different water activity levels in the organic solvent, 2-methyl-2-butanol. Among the examined lipases, immobilized Candida antarctica lipase B (Novozyme 435) provided the highest reaction yield at a water activity close to zero. Tetrahydrofuran (THF) was used as co-solvent to improve bixin solubility. The optimization of the reaction conditions with 20% THF lead to a total reaction yield of 50% of SEN.

Annatto carotenoids attenuate oxidative stress and inflammatory response after high-calorie meal in healthy subjects

The aim of this study was to evaluate the effect of annatto carotenoids intake associated to a single high-calorie meal (high fat and high carbohydrate) in postprandial biochemical, inflammatory and oxidative stress markers. Twelve healthy subjects (6 men, 6 women) were included in this randomised, controlled crossover study. Baseline blood samples were collected from fasting subjects that immediately received high-calorie meal without carotenoid (placebo) or containing 1.2mg/kg bixin (BIX) or 0.06mg/kg norbixin (NBIX). Blood samples were taken 60, 120 and 240min after meal intake. NBIX intake did not affect biochemical blood markers but reduced the postprandial levels of inflammatory cytokines (IL-1, IL-6 and TNF-α) and lipid oxidation 60-120min after meal. BIX only partially prevented postprandial-induced lipid oxidation. Results indicate that the intake of NBIX may be an alternative to reduce the postprandial inflammatory and oxidative stress responses to high-calorie meals.

Achiote (Bixa orellana L.): a natural source of pigment and vitamin E

Commercialization of agricultural products, including seeds and its derived products, represents an important economic source for developing countries. Natural colorants obtained from the seeds of achiote plant (annatto) have been used since pre-Hispanic times. Also, production of this crop has been important for Mayan cuisine. Annual world production of achiote seeds is approximately 14,500 tons (dry weight). Two thirds of the production is commercialized as dried seeds and the rest as colorant. Latin America produces 60% of the total world production, followed by Africa (27%) and Asia (12%). The main producers in Latin America are Peru, Brazil and Mexico. The purpose of the present paper is to review the most recent literature on Bixa orellana L. focusing on bixin, norbixin, tocotrienols and tocopherols biosynthesis, use and industrial applications of annatto extracts, as well as its nutraceutical potential and its benefits for human health.

Bixin ameliorates high fat diet-induced cardiac injury in mice through inflammation and oxidative stress suppression

Diabetic cardiomyopathy is known as an essential complication of diabetes, a main reason leading to mortality for diabetic patients, and novel therapeutic strategies for treatment are urgently required. Bixin (BX), isolated from the seeds of Bixa orellana, is a carotenoid, possessing anti-inflammatory, anti-tumor and anti-oxidant activities. In our study, we attempted to calculate the role of bixin in cardiac injury progression, and reveal the possible molecular mechanism. Bixin treatment ameliorated cardiac dysfunction through inhibiting fibrosis, inflammation and reactive oxygen species (ROS) generation. It reduced fibrosis levels via collagen deposition down-regulation. Inflammatory response was attenuated by reducing pro-inflammatory cytokines secretion via Toll-like receptor 4/nuclear factor kappa B (TLR4/NF-κB) signaling pathway inactivation in mice induced by high fat diet. Also, in in vitro studies, lipopolysaccharide (LPS)-treated cardiac muscle cells exhibits pro-inflammatory cytokines over-expression, which was reduced by bixin through blocking TLR4/NF-κB pathway. Additionally, oxidative stress triggered by high fat in vivo and LPS in vitro was down-regulated for bixin administration via nuclear factor-E2-related factor 2 (Nrf2) signaling pathway activation. Our study suggested that bixin might be a novel and protective agent with therapeutic activity against cardiac injury by suppressing fibrosis, inflammation and oxidative stress.

Development of carotenoid storage cells in Bixa orellana L. seed arils

The arils of Bixa orellana L. seeds contain carotenoid storage cells (CSCs). The main compounds in these cells include bixin and norbixin, which are important pigments in the food and pharmaceutical industries. Although many studies have been conducted on these chemical constituents, the cellular events that occur during the development of the carotenoid-accumulating cells in the arils and their relationship with the final carotenoid accumulation in the vacuoles remain unknown. In this study, the development of the CSCs in B. orellana arils was analyzed by light and transmission electron microscopy. Carotenoids formed in specialized cells, whose number and size increased during aril development. At various stages of development, the cytoplasm of the CSCs contained chromoplasts that held an extensive network of tubules and plastoglobules. Next to the chromoplasts, lipid droplets may fuse one another to form osmiophilic bodies. In addition, vesicles were observed next to the tonoplast. At the final stages of development, both the osmiophilic bodies and vesicles, which became quadrangular or rectangular, were stored in the vacuoles of the CSCs. This study reported for the first time the occurrence of different storage unit types within the vacuole of carotenoid storage cells.

Systemic administration of the apocarotenoid bixin protects skin against solar UV-induced damage through activation of NRF2

Exposure to solar ultraviolet (UV) radiation is a causative factor in skin photodamage and carcinogenesis, and an urgent need exists for improved molecular photoprotective strategies different from (or synergistic with) photon absorption. Recent studies suggest a photoprotective role of cutaneous gene expression orchestrated by the transcription factor NRF2 (nuclear factor-E2-related factor 2). Here we have explored the molecular mechanism underlying carotenoid-based systemic skin photoprotection in SKH-1 mice and provide genetic evidence that photoprotection achieved by the FDA-approved apocarotenoid and food additive bixin depends on NRF2 activation. Bixin activates NRF2 through the critical Cys-151 sensor residue in KEAP1, orchestrating a broad cytoprotective response in cultured human keratinocytes as revealed by antioxidant gene expression array analysis. Following dose optimization studies for cutaneous NRF2 activation by systemic administration of bixin, feasibility of bixin-based suppression of acute cutaneous photodamage from solar UV exposure was investigated in Nrf2(+/+) versus Nrf2(-/-) SKH-1 mice. Systemic administration of bixin suppressed skin photodamage, attenuating epidermal oxidative DNA damage and inflammatory responses in Nrf2(+/+) but not in Nrf2(-/-) mice, confirming the NRF2-dependence of bixin-based cytoprotection. Taken together, these data demonstrate feasibility of achieving NRF2-dependent cutaneous photoprotection by systemic administration of the apocarotenoid bixin, a natural food additive consumed worldwide.

Phytochemistry, biological activities and potential of annatto in natural colorant production for industrial applications - A review

Bixa orellana commonly known as annatto is one of the oldest known natural dye yielding plants native to Central and South America. Various parts of annatto have been widely used in the traditional medical system for prevention and treatment of a wide number of health disorders. The plethora of traditional uses has encouraged researchers to identify and isolate phytochemicals from all parts of this plant. Carotenoids, apocarotenoids, terpenes, terpenoids, sterols, and aliphatic compounds are main compounds found in all parts of this plant and are reported to exhibit a wide range of pharmacological activities. In recent years annatto has received tremendous scientific interest mainly due to the isolation of yellow-orange natural dye from its seeds which exhibits high biodegradability, low toxicity, and compatibility with the environment. Considerable research work has already been done and is currently underway for its applications in food, textile, leather, cosmetic, solar cells, and other industries. The present review provides up-to-date systematic and organized information on the traditional usage, phytochemistry and pharmacology of annatto. It also highlights its non-food industrial applications in order to bring more interest on this dye plant, identifies the existing gaps and provides potential for future studies. Studies reported in this review have demonstrated that annatto holds a great potential for being exploited as source of drugs and a potential natural dye. However, further efforts are required to identify extract biomolecules and their action mechanisms in exhibiting certain biological activities in order to understand the full phytochemical profile and the complex pharmacological effects of this plant.

Aprotic solvents effect on the UV-visible absorption spectra of bixin

We describe here the effects of aprotic solvents on the spectroscopic characteristics of bixin. Bixin was dissolved in dimethyl sulfoxide, acetone, dichloromethane, ethyl acetate, chloroform, dimethyl carbonate, cyclohexane and hexane, separately, and its spectra in the resulting solutions were determined by UV-visible spectrophotometry at normal pressure and room temperature. We analyzed the effect of aprotic solvents on λmax according to Onsager cavity model and Hansen theory, and determined the approximate absorption coefficient with the Beer-Lambert law. We found that the UV-visible absorption spectra of bixin were found to be solvent dependent. The S0→S2 transition energy of bixin in solution was dependent principally on the refractive index of the solvents and the bixin-solvent dispersion interaction. There was a small influence of the solvents dielectric constant, permanent dipole interaction and hydrogen bonding occurred between bixin and solvents. The absorbance of bixin in various solvents, with the exception of hexane, increased linearly with concentration.