Five new anthocyanins, ternatins A3, B4, B3, B2, and D2, from Clitoria ternatea flowers

A green method for anthocyanin extraction from Clitoria ternatea flowers cultivated in southern Brazil: Characterization, in vivo toxicity, and biological activity

This study aimed to develop a green method to obtain an anthocyanin-rich edible extract of Clitoria ternatea flowers grown in southern Brazil. The extract was characterized by UHPLC-MSn and analyzed for toxicological potential in an in vivo model, total phenolic content, and biological activities. By using a 23 multivariate design to study the effects of temperature, acidified solvent, and time on the total anthocyanin content (487.25 mg/g), total phenolic content (2242.47 mgGAE/g), it was possible to determine the optimal point (45 °C, 16 min, and 22.5 mL extraction solution). Thirteen anthocyanins and nine non-anthocyanins were quantified. In vivo toxicity assay using Galleria mellonella showed a safe concentration when administered up to 2.2 g of extract per body kg. The extract showed antioxidant activity and antibacterial action against food pathogens, the method proved to have a low environmental impact, in addition to producing an extract with potential for application in food.

Effect-Directed Profiling of Akebia quinata and Clitoria ternatea via High-Performance Thin-Layer Chromatography, Planar Assays and High-Resolution Mass Spectrometry

Two herbal plants, Akebia quinata D. leaf/fruit and Clitoria ternatea L. flower, well-known in traditional medicine systems, were investigated using a non-target effect-directed profiling. High-performance thin-layer chromatography (HPTLC) was combined with 11 different effect-directed assays, including two multiplex bioassays, for assessing their bioactivity. Individual active zones were heart-cut eluted for separation via an orthogonal high-performance liquid chromatography column to heated electrospray ionization high-resolution mass spectrometry (HPLC-HESI-HRMS) for tentative assignment of molecular formulas according to literature data. The obtained effect-directed profiles provided information on 2,2-diphenyl-1-picrylhydrazyl scavenging, antibacterial (against Bacillus subtilis and Aliivibrio fischeri), enzyme inhibition (tyrosinase, α-amylase, β-glucuronidase, butyrylcholinesterase, and acetylcholinesterase), endocrine (agonists and antagonists), and genotoxic (SOS-Umu-C) activities. The main bioactive compound zones in A. quinata leaf were tentatively assigned to be syringin, vanilloloside, salidroside, α-hederin, cuneataside E, botulin, and oleanolic acid, while salidroside and quinatic acids were tentatively identified in the fruit. Taraxerol, kaempherol-3-rutinoside, kaempferol-3-glucoside, quercetin-3-rutinoside, and octadecenoic acid were tentatively found in the C. ternatea flower. This straightforward hyphenated technique made it possible to correlate the biological properties of the herbs with possible compounds. The meaningful bioactivity profiles contribute to a better understanding of the effects and to more efficient food control and food safety.

Antioxidant, cytotoxic, and antibacterial activities of Clitoria ternatea flower extracts and anthocyanin-rich fraction

Clitoria ternatea flower is a traditional medicinal herb that has been used as a natural food colourant. As there are limited studies on investigating the bioactivities of the anthocyanin-rich fraction of Clitoria ternatea flower, this study aimed to determine an efficient column chromatography method to obtain the anthocyanin-rich fraction from this flower and characterise its composition, antioxidant, antibacterial, and cytotoxic activities. Amberlite XAD-16 column chromatography was more efficient in enriching the total anthocyanin content (TAC) of the fraction with the highest TAC to total phenolic content (TPC) ratio of 1:6 than that using C18-OPN. A total of 11 ternatin anthocyanins were characterised in the anthocyanin-rich fraction by LC–MS analysis. The antioxidant activity of the anthocyanin-rich fraction was more potent in the chemical-based assay with an IC₅₀ value of 0.86 ± 0.07 mg/mL using 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay than cellular antioxidant assay using RAW 264.7 macrophages. In vitro cytotoxicity assay using human embryonic kidney HEK-293 cell line showed the anthocyanin-rich fraction to be more toxic than the crude extracts. The anthocyanin-rich fraction had more potent antibacterial activity than the crude extracts against Bacillus cereus, Bacillus subtilis, and Escherichia coli. The anthocyanin-rich fraction of C. ternatea has the potential to be used and developed as a functional food ingredient or nutraceutical agent.

Clitoria ternatea (Linn.) flower extract attenuates vascular dysfunction and cardiac hypertrophy via modulation of Ang II/AT1 R/TGF-β1 cascade in hypertensive rats

BACKGROUND

Clitoria ternatea (CT) (the Fabaceae family) has been reported to elicit several biological responses, such as anti-inflammation and anti-depression effects. This study evaluated the effect of CT flower extract on blood pressure, vascular function, and left ventricular hypertrophy in a two-kidney, one-clip (2K-1C) rat model. Hypertensive rats were treated with CT extract at various doses (100, 300, or 500 mg kg^-1  day^-1 ) or losartan (10 mg kg^-1  day^-1 ) for 4 weeks (n = 8/group).

RESULTS

CT extract reduced blood pressure in a dose-dependent manner, and CT extract at a dose of 300 mg kg^-1 was an effective concentration (P < 0.05). Augmentation of contractile responses to electrical field stimulation and impairment of vascular responses to acetylcholine in mesenteric vascular beds and aortic rings of 2K-1C rats were suppressed by treatment with CT extract or losartan (P < 0.05). Serum angiotensin-converting enzyme activity and plasma angiotensin II concentration were high in 2K-1C rats but alleviated by CT extract or losartan treatment (P < 0.05). Increases in superoxide production and lipid peroxidation were attenuated in 2K-1C rats treated with CT extract or losartan compared with the untreated group (P < 0.05). Increased plasma concentration of nitric oxide metabolites was found in hypertensive rats that received CT extract or losartan. CT extract or losartan suppressed the overexpression of Ang II receptor subtype I (AT₁ -R) and transforming growth factor-β1 (TGF-β1) in 2K-1C rats.

CONCLUSION

CT extract had antihypertensive effects that were associated with improving vascular function and cardiac hypertrophy in 2K-1C rats. The mechanisms involved suppression of the renin-angiotensin system, of oxidative stress, and of the AT₁ R/TGF-β1 cascade. © 2021 Society of Chemical Industry.

Spectral Characteristic, Storage Stability and Antioxidant Properties of Anthocyanin Extracts from Flowers of Butterfly Pea (Clitoria ternatea L.)

Anthocyanins from flowers of the butterfly pea (Clitoria ternatea L.) are promising edible blue food colorants. Food processing often faces extreme pHs and temperatures, which greatly affects the color and nutritional values of anthocyanins. This study explored the color, spectra, storage stability, and antioxidant properties of C. ternatea anthocyanin extract (CTAE) at different pHs. The color and absorption spectra of CTAEs at a pH of 0.5–13 were shown, with their underlying structures analyzed. Then, the storage stability of CTAEs were explored under a combination of pHs and temperatures. The stability of CTAE declines with the increase in temperature, and it can be stored stably for months at 4 °C. CTAEs also bear much resistance to acidic and alkaline conditions but exhibit higher thermal stability at pH 7 (blue) than at pH 0.5 (magenta) or pH 10 (blue-green), which is a great advantage in food making. Antioxidant abilities for flower extracts from the butterfly pea were high at pH 4–7, as assessed by DPPH free radical scavenging assays, and decreased sharply when the pH value exceeded 7. The above results provide a theoretical basis for the application of butterfly pea flowers and imply their great prospect in the food industry.

The isolation of water-soluble natural products - challenges, strategies and perspectives

Covering period: up to 2019Water-soluble natural products constitute a relevant group of secondary metabolites notably known for presenting potent biological activities. Examples are aminoglycosides, β-lactam antibiotics, saponins of both terrestrial and marine origin, and marine toxins. Although extensively investigated in the past, particularly during the golden age of antibiotics, hydrophilic fractions have been less scrutinized during the last few decades. This review addresses the possible reasons on why water-soluble metabolites are now under investigated and describes approaches and strategies for the isolation of these natural compounds. It presents examples of several classes of hydrosoluble natural products and how they have been isolated. Novel stationary phases and chromatography techniques are also reviewed, providing a perspective towards a renaissance in the investigation of water-soluble natural products.

Clitoria ternatea Flower Extract Attenuates Postprandial Lipemia and Increases Plasma Antioxidant Status Responses to a High-Fat Meal Challenge in Overweight and Obese Participants

Simple Summary

Supplementation of high-fat meals with edible plants is the principal strategy to control postprandial dysmetabolism and inflammation. This study demonstrated that consumption of Clitoria ternatea flower extract (CTE) decreased postprandial serum triglyceride and serum free fatty acids, and improved plasma antioxidant status and glutathione peroxidase activity responses to a high-fat meal challenge in overweight and obese participants. However, CTE could not reduce the effect of HF meal-induced increase in postprandial glycemia and the level of pro-inflammatory cytokines. The findings of the present study suggest that CTE may be used as an effective ingredient to suppress postprandial lipemia and improve the antioxidant status in overweight and obese individuals that frequently consume HF diets.

Abstract

High-fat (HF) meal-induced postprandial lipemia, oxidative stress and low-grade inflammation is exacerbated in overweight and obese individuals. This postprandial dysmetabolism contributes to an increased risk of cardiovascular disease and metabolic disorders. Clitoria ternatea flower extract (CTE) possesses antioxidant potential and carbohydrate and fat digestive enzyme inhibitory activity in vitro. However, no evidence supporting a favorable role of CTE in the modulation of postprandial lipemia, antioxidant status and inflammation in humans presently exists. In the present study, we determine the effect of CTE on changes in postprandial glycemic and lipemic response, antioxidant status and pro-inflammatory markers in overweight and obese men after consumption of an HF meal. Following a randomized design, sixteen participants (age, 23.5 ± 0.6 years, and BMI, 25.7 ± 0.7 kg/m²) were assigned to three groups that consumed the HF meal, or HF meal supplemented by 1 g and 2 g of CTE. Blood samples were collected at fasting state and then at 30, 60, 90, 120, 180, 240, 300 and 360 min after the meal consumption. No significant differences were observed in the incremental area under the curve (iAUC) for postprandial glucose among the three groups. Furthermore, 2 g of CTE decreased the iAUC for serum triglyceride and attenuated postprandial serum free fatty acids at 360 min after consuming the HF meal. In addition, 2 g of CTE significantly improved the iAUC for plasma antioxidant status, as characterized by increased postprandial plasma FRAP and thiol levels. Postprandial plasma glutathione peroxidase activity was significantly higher at 180 min after the consumption of HF meal with 2 g of CTE. No significant differences in the level of pro-inflammatory cytokines (interleukin-6, interleukin-1β and tumor necrosis factor-α) were observed at 360 min among the three groups. These findings suggest that CTE can be used as a natural ingredient for reducing postprandial lipemia and improving the antioxidant status in overweight and obese men after consuming HF meals.

Identification of Anthocyanin Compounds in Butterfly Pea Flowers (Clitoria ternatea L.) by Ultra Performance Liquid Chromatography/Ultraviolet Coupled to Mass Spectrometry

Butterfly pea flower have great sensory attraction, but they have not yet been used widely in Vietnam. Extracts of butterfly pea flowers can be used conveniently as a natural blue colorant for food products. In this study, the identification of anthocyanin compounds in butterfly pea flowers was performed by UPLC coupled with a UV and Mass spectrometer instrument. Positive and negative ion electrospray MS/MS chromatograms and spectra of the anthocyanin compounds were determined. By analyzing the chromatograms and spectra for each ion, five anthocyanins were identified in the butterfly pea flower extract; these were delphinidin-3-(6″-p-coumaroyl)-rutinoside, cyanidin 3-(6″-p-coumaroyl)-rutinoside, delphinidin-3-(p-coumaroyl) glucose in both cis- and trans- isomers, cyanidin-3-(p-coumaroyl-glucoside) and delphinidin-3-pyranoside. Additionally, based on their intensity, it was determined that cyanidin-3-(p-coumaroyl-glucoside) was the most abundant anthocyanin, followed by cyanidin 3-(6″-p-coumaroyl)-rutinoside, delphinidin-3-(p-coumaroyl-glucoside), delphinidin-3-(6″-p-coumaroyl)-rutinoside and delphinidin-3-pyranoside. In this study, cyanidin derivatives were discovered in butterfly pea flower extract, where these compounds had not been detected in previous studies.

Protective role of Clitoria ternatea L. flower extract on methylglyoxal-induced protein glycation and oxidative damage to DNA

BACKGROUND

Methylglyoxal (MG) is a highly reactive dicarbonyl precursor for the formation of advanced glycation end products (AGEs) associated with age-related diseases, including diabetes and its complications. Clitoria ternatea L. flower has been reported to possess antioxidant and antiglycating properties. Evidence indicates that the extract of Clitoria ternatea L. flower inhibits fructose-induced protein glycation and oxidative damage to bovine serum albumin (BSA). However, there is no evidence to support the inhibitory effect of CTE against MG-mediated protein glycation and oxidative damage to protein and DNA. Therefore, the aim of the present study was to investigate whether C. ternatea flower extract (CTE) prevents MG-induced protein glycation and oxidative DNA damage.

METHODS

The formation of fluorescent AGEs in BSA was evaluated using spectrofluorometer. The protein carbonyl and thiol group content were used for detecting protein oxidation. DNA strand breakage in a glycation model comprising of MG, lysine and Cu²⁺ or a free radical generator 2,2'-azobis(2-methylpropionamidine) dihydrochloride (AAPH) systems was investigated using gel electrophoresis. Generation of superoxide anions and hydroxyl radicals in the MG/lysine system was assessed by the cytochrome c reduction assay and thiobarbituric acid reactive substances assay, respectively. High performance liquid chromatography (HPLC) was used to measure the MG-trapping ability.

RESULTS

In the BSA/MG system, CTE (0.25-1 mg/mL) significantly inhibited the formation of fluorescent AGEs and protein oxidation by reducing protein carbonyl content as well as preventing the protein thiol depletion. The concentration of CTE at 0.125-1 mg/mL prevented oxidative DNA cleavage in MG/lysine and AAPH systems associated with the inhibition of superoxide anion and hydroxyl radical formation. It also directly trapped MG in a concentration-dependent manner, ranging from 15 to 43%.

CONCLUSIONS

The study findings suggest that the direct carbonyl trapping ability and the free radical scavenging activity of CTE are the underlying mechanisms responsible for the prevention of protein glycation and oxidative DNA damage.

Cosmetic and Dermatological Properties of Selected Ayurvedic Plant Extracts

Due to the constantly growing interest in ingredients of natural origin, this study attempts to evaluate the possibility of using extracts from three Ayurvedic plants in preparations for the care and treatment of skin diseases. Therefore, studies of antioxidant properties were carried out using DPPH and ABTS radicals, obtaining 76% and 88% of these radical scavenging, respectively. A significant decrease in the intracellular level of free radicals and an increase in the activity of the antioxidant enzyme-superoxide dismutase by almost 60% were also observed. In addition, the extracts were assessed for anti-inflammatory and anti-aging properties, obtaining over 70% inhibition of lipoxygenase activity and almost 40% of collagenase. Additionally, the cytoprotective properties of the obtained extracts on skin cells, keratinocytes and fibroblasts, were demonstrated. To assess the content of biologically active compounds, HPLC-electrospray ionization (ESI)-MS/MS multiple reaction monitoring (MRM) analyses were performed. The obtained results show that all three analyzed plants are a valuable source of biologically active substances with desired properties in the context of skin cell protection. Particularly noteworthy is the extract of Epilobium angustifolium L., for which the most promising results were obtained.

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.

Extraction methods of butterfly pea (Clitoria ternatea) flower and biological activities of its phytochemicals

Clitoria ternatea or commonly known as 'Butterfly pea' has been used traditionally in Ayurvedic medicine in which various parts of the plants are used to treat health issues such as indigestion, constipation, arthritis, skin diseases, liver and intestinal problems. The flowers of C. ternatea are used worldwide as ornamental flowers and traditionally used as a food colorant. This paper reviews the recent advances in the extraction and biological activities of phytochemicals from C. ternatea flowers. The application of maceration or ultrasound assisted extraction greatly increased the yield (16-247% of increase) of phytochemicals from C. ternatea flowers. Various phytochemicals such as kaempferol, quercetin and myricetin glycosides as well as anthocyanins have been isolated from C. ternatea flowers. Clitoria ternatea flower extracts were found to possess antimicrobial, antioxidant, anti-inflammatory, cytotoxic and antidiabetic activities which are beneficial to human health. Clitoria ternatea flower is a promising candidate for functional food applications owing to its wide range of pharmacotherapeutic properties as well as its safety and effectiveness.

Phenolic composition by UHPLC-Q-TOF-MS/MS and stability of anthocyanins from Clitoria ternatea L. (butterfly pea) blue petals

The aim of the present study was to evaluate the phenolic composition of crude lyophilized extracts (CLE) and partially purified (PPE) extracts of C. ternatea blue petals as well as the anthocyanin stability against pH, temperature and light in the presence and absence of fructooligosaccharides. Twelve compounds were tentatively identified by UHPLC-Q-TOF-MS/MS in CLE and PPE extracts. In direct/reverse spectrophotometric titration, anthocyanins showed colour changes between pH 2.25 to 10.20, and colour reversibility, maintaining antioxidant activity against the DPPH radical. The aqueous extracts at pH 3.6 and 5.4 exhibited thermal stability with the presence and absence of fructooligosaccharides with activation energy higher than 99 kJ/mol. The addition of fructooligosaccharides in the extracts at pH 5.4 exposed to light provided a protective effect against anthocyanin photodegradation. The data show the technological potential of aqueous extract of C. ternatea blue petals as a natural colourant in a functional beverage model system.

The Difference in Colour Shifting of Clitoria ternatea L. Flower Extract at pH 1, 4, and 7 During Storage

Objective:

A research to evaluate the colour shift of Clitoria ternatea L. flower (CT) extract at pH 1, 4, and 7 during storage at 30oC in the dark has been conducted.

Methods:

The evaluation comprised of the measurement of colour intensity (CI), violet index (VI), and browning index (BI).

Results:

The extract was very stable at pH 1, although its colour slightly shifted to redder. Conversely, at pH 4 the extract slightly decreased, but the colour hue remained stable. At pH 7, the extract exhibited much less colour stability by demonstrating considerable decrease of CI and VI.

Conclusion:

The absence and presence of the colour shift at pH 4 and 7, respectively, indicated that there were two different ways of the colour fading. It was proposed that the colour degradation at pH 4 occurred through the unfolding of hydrophobic interaction, while at pH 7 through the deacylation. The deacylation was proven by the high-performance liquid chromatography analysis equipped by diode array detector at 530 nm.

Impact of Clitoria ternatea (butterfly pea) flower on in vitro starch digestibility, texture and sensory attributes of cooked rice using domestic cooking methods

The effect of Clitoria ternatea flower (CTE) incorporated into cooked rice using domestic cooking methods on starch digestibility was determined. The incorporation of 1.25% and 2.5% (w/v) CTE caused a reduction in the starch digestibility of cooked rice using an electric rice cooker. In addition, there was significant alteration on the starch digestibility of cooked rice incorporated with 2.5% CTE using a microwave oven. Moreover, CTE significantly reduced the level of rapidly digestible starch and increased the level of undigested starch in cooked rice using an electric rice cooker. In the textural characteristics, the hardness of cooked rice with CTE remained unchanged, whereas a reduction in stickiness of cooked rice with CTE was observed. The sensory evaluation of cooked rice with CTE given by panelists demonstrated a good overall acceptability. Overall, the results show that CTE is a useful ingredient to incorporate with cooked rice for reduction of starch digestibility.

Butterfly Pea (Clitoria ternatea), a Cyclotide-Bearing Plant With Applications in Agriculture and Medicine

The perennial leguminous herb Clitoria ternatea (butterfly pea) has attracted significant interest based on its agricultural and medical applications, which range from use as a fodder and nitrogen fixing crop, to applications in food coloring and cosmetics, traditional medicine and as a source of an eco-friendly insecticide. In this article we provide a broad multidisciplinary review that includes descriptions of the physical appearance, distribution, taxonomy, habitat, growth and propagation, phytochemical composition and applications of this plant. Notable amongst its repertoire of chemical components are anthocyanins which give C. ternatea flowers their characteristic blue color, and cyclotides, ultra-stable macrocyclic peptides that are present in all tissues of this plant. The latter are potent insecticidal molecules and are implicated as the bioactive agents in a plant extract used commercially as an insecticide. We include a description of the genetic origin of these peptides, which interestingly involve the co-option of an ancestral albumin gene to produce the cyclotide precursor protein. The biosynthesis step in which the cyclic peptide backbone is formed involves an asparaginyl endopeptidase, of which in C. ternatea is known as butelase-1. This enzyme is highly efficient in peptide ligation and has been the focus of many recent studies on peptide ligation and cyclization for biotechnological applications. The article concludes with some suggestions for future studies on this plant, including the need to explore possible synergies between the various peptidic and non-peptidic phytochemicals.

Clitoria ternatea Flower Petal Extract Inhibits Adipogenesis and Lipid Accumulation in 3T3-L1 Preadipocytes by Downregulating Adipogenic Gene Expression

Clitoria ternatea (commonly known as blue pea) flower petal extract (CTE) is used as a natural colorant in a variety of foods and beverages. The objective of study was to determine the inhibitory effect of CTE on adipogenesis in 3T3-L1 preadipocytes. The phytochemical profiles of CTE were analyzed by liquid chromatography and tandem mass spectrometry (LC-MS/MS). Anti-adipogenesis effect of CTE was measured by using Oil Red O staining, intracellular triglyceride assay, quantitative real-time PCR and western blot analysis in 3T3-L1 adipocytes. Cell cycle studies were performed by flow cytometry. Lipolysis experiments were performed using a colorimetric assay kit. In early stages, CTE demonstrated anti-adipogenic effects through inhibition of proliferation and cell cycle retardation by suppressing expression of phospho-Akt and phospho-ERK1/2 signaling pathway. The results also showed that CTE inhibited the late stage of differentiation through diminishing expression of adipogenic transcription factors including PPARγ and C/EBPα. The inhibitory action was subsequently attenuated in downregulation of fatty acid synthase and acetyl-CoA carboxylase, causing the reduction of TG accumulation. In addition, CTE also enhanced catecholamine-induced lipolysis in adipocytes. These results suggest that CTE effectively attenuates adipogenesis by controlling cell cycle progression and downregulating adipogenic gene expression.

Binding of Clitoria ternatea L. flower extract with α-amylase simultaneously monitored at two wavelengths using a photon streaming time-resolved fluorescence approach

The binding of an extract from the flowers of Clitoria ternatea L. to the digestive enzyme α-amylase was investigated. This extract is a mixture of flavonoids, including anthocyanins, and has been previously shown to inhibit the activity this enzyme. This has implications for modulating starch digestion. In order to investigate the kinetics, we made use of time-resolved fluorescence to simultaneously monitor two different emission bands emanating from the extract. This measurement was enabled by the use of a "photon streaming" approach and changes in fluorescence lifetime and intensity were used to follow the interaction. A longer wavelength band (655 nm) was ascribed to anthocyanins in the mixture and these were observed to bind at a rate an order of magnitude slower than other flavonoids present in the extract, monitored at a shorter wavelength (485 nm). Changes in the fluorescence emission of the extract upon binding were further assessed by the use of decay associated spectra.

Impact of ultrasound and conventional extraction techniques on bioactive compounds and biological activities of blue butterfly pea flower (Clitoria ternatea L.)

The present study was conducted to evaluate the influence of ultrasound on bioactive compounds and biological activities of blue butterfly pea flower (Clitoria ternatea L.). For this purpose, optimized conditions (temperature 50 °C, time 150 min, solid to liquid ratio 1 g:15 ml, 70% amplitude and 240 W, 20 kHz frequency, 3 s on and 3 s off) of ultrasound (US) and conventional extraction (AGE: Agitation, water bath for 150 min, 50 °C at 150 rmp) were used. The results showed significant (p < 0.05) effect of US and AGE on total phenolics (TPCs), flavonoids (TFCs) and antioxidant activities (DPPH, ABTS, FRAP, reducing activity, Cu²⁺ and H₂O₂) of butterfly pea flower extract (BPFE). The results showed an increased trend in yield, TPCs, TFCs and antioxidant activities of US treated BPFE with comparison to AGE. However, insignificant (p > 0.05) effect of US and AGE over TFlaCs and PACs were observed. Moreover, the results of Fourier-transform infrared spectroscopy (FTIR) showed little changes in spectrum and US does not affect the functional group of bioactive compounds structure. Additionally, extracts (500-2000 µg/ml) protect pBR322 plasmid DNA damage induced by (1 mM H₂O₂ and 1 mM FeSO₄), plasma oxidation (induced by 250 µM CuCl₂) and inhibit erythrocyte hemolysis (induced by 200 mM AAPH, 34.6 to 66.73%). Sonication can be applied successfully for the extraction of bioactive compounds from plant materials with high biological activities.

Application of Butterfly Pea Flower Extract in Mask Development

(1) Background: Clitoria ternatea (butterfly pea), a plant species belonging to the Leguminosae (Fabaceae) family, is useful for medical treatments and has been used in folk medicines and to cure different diseases. The antioxidation ability of the total phenolic compounds of butterfly pea is useful for preserving flavor, and colour and for preventing vitamin destruction in processed foods. In this study, a butterfly pea flower fermentation solution was added to cosmetics as a whiting ingredient. (2) Methods: After the phenolics, flavonoids and ascorbic acid content of the butterfly pea flower extraction had been determined, lactic acid bacteria fermented the extraction. The whitening and moisturizing effect was assayed by SSC3 and NF333 analyzers. (3) Results: This study demonstrated that the butterfly pea flower fermentation solution has free radical scavenging ability, a reducing power in high concentrations, a moisturizing effect, and a whiting effect. (4) Conclusions: The results showed that the butterfly pea flower fermentation solution not only inhibits redness, itching, allergies, and irritation to the skin, but also has antioxidation properties and promotes moisture retention and whitening effects, and the results increase as the concentration increases. Therefore, butterfly bean flowers may be suitable as a raw material for natural beauty care products.

Influence of Clitoria ternatea Flower Extract on the In Vitro Enzymatic Digestibility of Starch and Its Application in Bread

This study aimed to assess the effect of the Clitoria ternatea L. flower extract (CTE), on the inhibition of pancreatic α-amylase, in vitro starch hydrolysis, and predicted the glycemic index of different type of flours including potato, cassava, rice, corn, wheat, and glutinous rice flour. The application in a bakery product prepared from flour and CTE was also determined. The results demonstrated that the 1% and 2% (w/v) CTE inhibited the pancreatic α-amylase activity by using all flours as a substrate. Moreover, 0.5%, 1%, and 2% (w/v) CTE showed a significant reduction in the glucose release, hydrolysis index (HI), and predicted glycemic index (pGI) of flour. In glutinous rice flour, 1% and 2% (w/v) CTE had a significantly lower level of rapidly digestible starch (RDS) and slowly digestible starch (SDS) with a concomitant higher level of undigested starch. The statistical analysis demonstrated strong positive significant correlations between the percentage of CTE and the undigested starch of wheat and cassava. The addition of 5%, 10%, and 20% (w/w) CTE significantly reduced the rate of starch digestion of the wheat bread. The pGI of bread incorporated with 5% CTE (w/w) was significantly lower than that of the control bread. Our findings suggest that CTE could reduce the starch digestibility, the HI, and pGI of flour through the inhibition of carbohydrate digestive enzymes. Taken together, CTE may be a potent ingredient for the reduced glycemic index of flours.

Acute effect of Clitoria ternatea flower beverage on glycemic response and antioxidant capacity in healthy subjects: a randomized crossover trial

Background

Clitoria ternatea L., a natural food-colorant containing anthocyanin, demonstrated antioxidant and antihyperglycemic activity. The aim of this study was to determine the effects of Clitoria ternatea flower extract (CTE) on postprandial plasma glycemia response and antioxidant status in healthy men.

Methods

In a randomized, crossover study, 15 healthy men (ages 22.53 ± 0.30 years; with body mass index of 21.57 ± 0.54 kg/m²) consumed five beverages: (1) 50 g sucrose in 400 mL water; (2) 1 g CTE in 400 mL of water; (3) 2 g CTE in 400 mL of water; (4) 50 g sucrose and 1 g CTE in 400 mL of water; and (5) 50 g sucrose and 2 g CTE in 400 mL of water. Incremental postprandial plasma glucose, insulin, uric acid, antioxidant capacities and lipid peroxidation were measured during 3 h of administration.

Results

After 30 min ingestion, the postprandial plasma glucose and insulin levels were suppressed when consuming sucrose plus 1 g and 2 g CTE. In addition, consumption of CTE alone did not alter plasma glucose and insulin concentration in the fasting state. The significant increase in plasma antioxidant capacity (ferric reducing ability of plasma (FRAP), oxygen radical absorbance capacity (ORAC), trolox equivalent antioxidant capacity (TEAC), and protein thiol) and the decrease in malondialdehyde (MDA) level were observed in the subjects who received 1 g and 2 g CTE. Furthermore, consumption of CTE protected sucrose-induced reduction in ORAC and TEAC and increase in plasma MDA.

Conclusions

These findings suggest that an acute ingestion of CTE increases plasma antioxidant capacity without hypoglycemia in the fasting state. It also improves postprandial glucose, insulin and antioxidant status when consumed with sucrose.

Trial registration

Thai Clinical Trials Registry: TCTR20170609003. Registered 09 September 2017.

‘retrospectively registered’.

Protective Role of Ternatin Anthocyanins and Quercetin Glycosides from Butterfly Pea (Clitoria ternatea Leguminosae) Blue Flower Petals against Lipopolysaccharide (LPS)-Induced Inflammation in Macrophage Cells

Twelve phenolic metabolites (nine ternatin anthocyanins and three glycosylated quercetins) were identified from the blue flowers of Clitoria ternatea by high-performance liquid chromatography diode array detection and electrospray ionization/mass spectrometry (HPLC-DAD-ESI/MS(n)). Three anthocyanins not reported in this species before show fragmentation pattern of the ternatin class. Extracts were fractionated in fractions containing flavonols (F3) and ternatin anthocyanins (F4). In general, C. ternatea polyphenols showed anti-inflammatory properties in lipopolysaccharide (LPS)-induced inflammation in RAW 264.7 macrophage cells with distinct molecular targets. Flavonols (F3) showed strong inhibition of COX-2 activity and partial ROS suppression. On the other hand, the ternatin anthocyanins (F4) inhibited nuclear NF-κB translocation, iNOS protein expression, and NO production through a non-ROS suppression mechanism. Accordingly, quercetin glycosides and ternatin anthocyanins from the blue flower petals of C. ternatea may be useful in developing drugs or nutraceuticals for protection against chronic inflammatory diseases by suppressing the excessive production of pro-inflammatory mediators from macrophage cells.

Contribution to Flower Colors of Flavonoids Including Anthocyanins: A Review

Flavonoids are one of the major pigments in higher plants, together with chlorophylls and carotenoids. Though ca. 8,000 kinds of flavonoids have been reported in nature, anthocyanins, chalcones, aurones and some flavonols act as major flower pigments. Flavonoids are present as major components in many flowers. On the other hand, flavones and flavonols, which are colorless or extremely pale yellow, function as copigment substances. Moreover, expression of the flower colors is diversified by inter-molecular and intra-molecular copigmentation, metal chelation, pH change and so on. In this review, I describe the distribution of the flavonoids which act as the pigments, and contribution to flower colors, e.g., yellow, scarlet, red, red-purple, violet, purple, blue and so on, of flavonoids, especially anthocyanins, chalcones, aurones and flavonols.

Inhibitory effect of Clitoria ternatea flower petal extract on fructose-induced protein glycation and oxidation-dependent damages to albumin in vitro

BACKGROUND

The accumulation of advanced glycation end products (AGEs) in body tissue has been implicated in the progression of age-related diseases. Inhibition of AGE formation is the imperative approach for alleviating diabetic complications. Clitoria ternatea extract (CTE) has been demonstrated to possess anti-diabetic activity. However, there is no scientific evidence supporting its anti-glycation activity. The objective of this study was to determine the inhibitory effect of CTE on fructose-induced formation of AGEs and protein oxidation. Antioxidant activity of CTE was also assessed by various methods.

METHODS

The aqueous extract of CTE (0.25-1.00 mg/ml) was measured for the content of total phenolic compounds, flavonoid, and anthocyanin by Folin-Ciocalteu assay, AlCl3 colorimetric method, and pH differential method, respectively. The various concentrations of CTE were incubated with BSA and fructose at 37°C for 28 days. The formation of fluorescent AGEs, the level of fructosamine, protein carbonyl content, and thiol group were measured. The in vitro antioxidant activity was measured by the 1,1-diphenyl 2-picrylhydrazyl (DPPH) scavenging activity, trolox equivalent antioxidant capacity (TEAC), ferric reducing antioxidant power (FRAP), hydroxyl radical scavenging activity (HRSA), superoxide radical scavenging activity (SRSA), and ferrous ion chelating power (FICP).

RESULTS

The results demonstrated that the content of total phenolics, flavonoids and total anthocyanins in CTE was 53 ± 0.34 mg gallic acid equivalents/g dried extract, 11.2 ± 0.33 mg catechin equivalents/g dried extract, and 1.46 ± 0.04 mg cyanidin-3-glucoside equivalents/g dried extract, respectively. Moreover, CTE (0.25-1.00 mg/ml) significantly inhibited the formation of AGEs in a concentration-dependent manner. CTE also markedly reduced the levels of fructosamine and the oxidation of protein by decreasing protein carbonyl content and preventing free thiol depletion. In the DPPH radical scavenging activity and SRSA, CTE had the IC50 values of 0.47 ± 0.01 mg/ml and 0.58 ± 0.04 mg/ml. Furthermore, the FRAP and TEAC values of CTE were 0.38 ± 0.01 mmol FeSO4 equivalents/mg dried extract and 0.17 ± 0.01 mg trolox equivalents/mg dried extract. However, CTE showed weak scavenging activity on hydroxyl radical and a weak antioxidant iron chelator.

CONCLUSIONS

The results showed that CTE has strong antiglycation and antioxidant properties and might have therapeutic potentials in the prevention of AGE-mediated diabetic complications.

Anti-inflammatory and anti-periductal fibrosis effects of an anthocyanin complex in Opisthorchis viverrini-infected hamsters

The pharmacological activities of herbal extracts can be enhanced by complex formation. In this study, we manipulated cyanidin and delphinidin-rich extracts to form an anthocyanin complex (AC) with turmeric and evaluated activity against inflammation and periductal fibrosis in Opisthorchis viverrini-infected hamsters. The AC was prepared from anthocyanins extracted from cobs of purple waxy corn (70%), petals of blue butterfly pea (20%) and turmeric extract (10%), resulting in an enhanced free-radical scavenging capacity. Oral administration of AC (175 and 700 mg/kg body weight) every day for 1 month to O. viverrini-infected hamsters resulted in reduced inflammatory cells and periductal fibrosis. Fourier transform infrared spectroscopy and partial least square discriminant analysis suggested nucleic acid changes in the O. viverrini-infected liver samples, which were partially prevented by the AC treatment. AC reduced 8-oxodG formation, an oxidative DNA damage marker, significantly decreased levels of nitrite in the plasma and alanine aminotransferase activity and increased the ferric reducing ability of plasma. AC also decreased the expression of oxidant-related genes (NF-κB and iNOS) and increased the expression of antioxidant-related genes (CAT, SOD, and GPx). Thus, AC increases free-radical scavenging capacity, decreases inflammation, suppresses oxidative/nitrative stress, and reduces liver injury and periductal fibrosis in O. viverrini-infected hamsters.

Protection of Clitoria ternatea flower petal extract against free radical-induced hemolysis and oxidative damage in canine erythrocytes

The present study assessed the antioxidant activity and protective ability of Clitoria ternatea flower petal extract (CTE) against in vitro 2,2'-azobis-2-methyl-propanimidamide dihydrochloride (AAPH)-induced hemolysis and oxidative damage of canine erythrocytes. From the phytochemical analysis, CTE contained phenolic compounds, flavonoids, and anthocyanins. In addition, CTE showed antioxidant activity as measured by oxygen radical absorbance capacity (ORAC) method and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay. CTE (400 µg/ml) remarkably protected erythrocytes against AAPH-induced hemolysis at 4 h of incubation. Moreover, CTE (400 µg/ml) reduced membrane lipid peroxidation and protein carbonyl group formation and prevented the reduction of glutathione concentration in AAPH-induced oxidation of erythrocytes. The AAPH-induced morphological alteration of erythrocytes from a smooth discoid to an echinocytic form was effectively protected by CTE. The present results contribute important insights that CTE may have the potential to act as a natural antioxidant to prevent free radical-induced hemolysis, protein oxidation and lipid peroxidation in erythrocytes.

Blue flower color development by anthocyanins: from chemical structure to cell physiology

Blue flower colors are primarily due to anthocyanin, a flavonoid pigment. Anthocyanin itself is purple in neutral aqueous solutions, ans its color is very unstable and quickly fades. Therefore, the mechanism of blue color development in living flower petals is one of the most intriguing problems in natural product chemistry. Much progress has been made in understanding blue flower coloration since the comprehensive review by Goto and Kondo in 1991. This review focuses on the advances in the last 15 years, and cites 149 references.

The Ayurvedic medicine Clitoria ternatea--from traditional use to scientific assessment

Clitoria ternatea L. (CT) (Family: Fabaceae) commonly known as 'Butterfly pea', a traditional Ayurvedic medicine, has been used for centuries as a memory enhancer, nootropic, antistress, anxiolytic, antidepressant, anticonvulsant, tranquilizing and sedative agent. A wide range of secondary metabolites including triterpenoids, flavonol glycosides, anthocyanins and steroids has been isolated from Clitoria ternatea Linn. Its extracts possess a wide range of pharmacological activities including antimicrobial, antipyretic, anti-inflammatory, analgesic, diuretic, local anesthetic, antidiabetic, insecticidal, blood platelet aggregation-inhibiting and for use as a vascular smooth muscle relaxing properties. This plant has a long use in traditional Ayurvedic medicine for several diseases and the scientific studies has reconfirmed those with modern relevance. This review is an effort to explore the chemical constituents, pharmacological and toxicity studies of CT, which have long been in clinical use in Ayurvedic system of medicine along with a critical appraisal of its future ethnopharmacological potential in view of many recent findings of importance on this well known plant species.

Purification and characterization of UDP-glucose: anthocyanin 3',5'-O-glucosyltransferase from Clitoria ternatea

A UDP-glucose: anthocyanin 3',5'-O-glucosyltransferase (UA3'5'GT) (EC 2.4.1.-) was purified from the petals of Clitoria ternatea L. (Phaseoleae), which accumulate polyacylated anthocyanins named ternatins. In the biosynthesis of ternatins, delphinidin 3-O-(6''-O-malonyl)-beta-glucoside (1) is first converted to delphinidin 3-O-(6''-O-malonyl)-beta-glucoside-3'-O-beta-glucoside (2). Then 2 is converted to ternatin C5 (3), which is delphinidin 3-O-(6''-O-malonyl)-beta-glucoside-3',5'-di-O-beta-glucoside. UA3'5'GT is responsible for these two steps by transferring two glucosyl groups in a stepwise manner. Its substrate specificity revealed the regioselectivity to the anthocyanin's 3'- or 5'-OH groups. Its kinetic properties showed comparable k (cat) values for 1 and 2, suggesting the subequality of these anthocyanins as substrates. However, the apparent Km value for 1 (3.89 x 10(-5) M), which is lower than that for 2 (1.38 x 10(-4) M), renders the k(cat)/Km value for 1 smaller, making 1 catalytically more efficient than 2. Although the apparent Km value for UDP-glucose (6.18 x 10(-3) M) with saturated 2 is larger than that for UDP-glucose (1.49 x 10(-3) M) with saturated 1, the k(cat) values are almost the same, suggesting the UDP-glucose binding inhibition by 2 as a product. UA3'5'GT turns the product 2 into a substrate possibly by reversing the B-ring of 2 along the C2-C1' single bond axis so that the 5'-OH group of 2 can point toward the catalytic center.

Why are grape/fresh wine anthocyanins so simple and why is it that red wine color lasts so long?

Vitis vinifera red berries are characterized by anthocyanins whose chemical structures are among the simplest encountered in higher plants. On the contrary, many plants, including orchids, petunias, red cabbage, elderberries, potatoes for instance, have developed very complicated anthocyanins featuring side-chains at the available positions of the aglycone skeleton. Such pigments were shown to possess bio-physico-chemical properties not to be seen with the grape common anthocyanins. Among beverages (water, tea, beer, wine, coffee, juices, milk), red wine is the only one whose organoleptic properties improve with time and this is called ageing. The grape/fresh red wine pigments, after a few months, disappear from the wine giving birth to new pigments resulting from the wine spontaneous chemistry allowing it to remain red for many years. What are the wine pigments and why are they so stable is the purpose of this mini-review. The structural simplicity of grape anthocyanins and the long lasting colour of red wine is another French paradox; we call it French paradox II.

Deep blue anthocyanins from blue Dianella berries

Three anthocyanins, all acylated delphinidin 3,7,3',5'-tetraglucosides, and a naphthalene glycoside, 2-acetyl-1,5-dihydroxy-3 methyl-8-O(xylosyl-(1-->6)-glucosyl) naphthalene, have been isolated from the berries of two Dianella species, D. nigra and D. tasmanica. The anthocyanins show exceptional blueness at in vivo pH values due to effective intramolecular copigmentation involving p-coumaroyl-glucose units (GC) at the 7, 3' and 5' of the delphinidin anthocyanidin. Evidence is presented to show that the effectiveness of the copigmentation can be ranked; 3',5' GC>7 GC>3 GC.

alpha-Glucosidase inhibitory action of natural acylated anthocyanins. 1. Survey of natural pigments with potent inhibitory activity

alpha-Glucosidase (AGH) inhibitory study by natural anthocyanin extracts was done. As the result of a free AGH assay system, 12 anthocyanin extracts were found to have a potent AGH inhibitory activity; in particular, Pharbitis nil (SOA) extract showed the strongest maltase inhibitory activity, with an IC(50) value of 0.35 mg/mL, as great as that of Ipomoea batatas (YGM) extract (IC(50) = 0.36 mg/mL). Interestingly, neither extract inhibited the sucrase activity at all. For the immobilized assay system, which may reflect the pharmacokinetics of AGH at the small intestine, SOA and YGM extracts gave more potent maltase inhibitory activities than those of the free AGH assay, with IC(50) values of 0.17 and 0.26 mg/mL, respectively. Both extracts also inhibited alpha-amylase action, indicating that anthocyanins would have a potential function to suppress the increase in postprandial glucose level from starch.

Eight new anthocyanins, ternatins C1-C5 and D3 and preternatins A3 and C4 from young clitoria ternatea flowers

Eight new anthocyanins 1-8 (ternatins C1, C2, C3, C4, C5, and D3 and preternatins A3 and C4) were isolated from Clitoria ternatea flowers. By the application of chemical, UV-vis, and FABMS methods, the structures of 1-6 were postulated as delphinidin 3-malonylglucoside having 3'-GCGC-5'-G, 3'-GCGCG-5'-G, 3'-GC-5'-G, 3'-GCG-5'-G, 3'-G-5'-G, and 3'-GC-5'-GC, and compounds 7 and 8 as delphinidin 3-glucoside having 3'-GCG-5'-GCG and 3'-GCG-5'-G as side chains, respectively, in which Dp is delphinidin, G is D-glucose, and C is p-coumaric acid. The structures of the compounds 1, 3-5, and 7 were established completely by additional NMR methods.