The Nanotech Potential of Curcumin in Pharmaceuticals: An Overview

It is safe to use Curcumin as a cosmetic and therapeutic ingredient in pharmaceutical products. For the uses mentioned above and for fundamental research, it is essential to obtain pure Curcumin from plant sources. There is a requirement for effective extraction and purification techniques that adhere to green chemistry standards for efficiency improvement, process safety, and environmental friendliness. Several outstanding studies have looked into the extraction and purification of Curcumin. This review thoroughly covers the currently available curcumin extraction, synthesis, and transformation techniques. Additionally, Curcumin's poor solubility and low absorption in the human body have limited its potential for pharmaceutical use. However, recent developments in novel curcumin formulations utilizing nanotechnology delivery methods have provided new approaches to transport and maximize the human body's curcumin absorption efficiency. In this review, we explore the various curcumin nanoformulations and the potential medicinal uses of nano curcumin. Additionally, we review the necessary future research directions to recommend Curcumin as an excellent therapeutic candidate.

Exploring the antioxidant potential of fermented turmeric pulp: effect of extraction methods and microencapsulation

Curcumin is one of the major constituents of turmeric which possess multifarious therapeutic properties. However, owing of its limited solubility in water its bioavailability is poor. Thus, attempts have been made to increase the solubility of curcumin by fermenting turmeric followed by extraction and encapsulation. Lactobacillus fermentum was used for the fermentation of raw turmeric pulp. The influence of Lactobacillus fermentation and different extraction methods (conventional solvent extraction (CSE), ultrasound (UAE) and microwave-assisted extraction (MAE)) on total phenolic content (TPC), flavonoid content, antioxidant activity and curcumin content were analyzed. Further, to increase the stability of extract, different concentrations of maltodextrin were used to microencapsulate the curcumin extract. The results showed that, Lactobacillus fermentation increased the TPC and antioxidant activity from 5.59 ± 0.20 to 6.27 ± 0.28 mg GAE/g and 67.49 ± 1.51 to 79.00 ± 2.20%, respectively. MAE showed highest TPC (7.88 ± 0.08 mg GAE/g), antioxidant activity (94 ± 1.57%) and curcumin content (0.866 ± 0.05 mg/g) followed by UAE and CSE. Maximum yield of curcumin extract was observed in MAE, UAE and CSE as 59.93, 47.09 and 29.44% respectively, higher than non-fermented turmeric pulp. Maltodextrin percentage showed a significant influence on bio-functional properties of encapsulated powder. However, 20% maltodextrin exhibited better bio-functional properties as compared to other concentrations.

Impact of Green Extraction on Curcuminoid Content, Antioxidant Activities and Anti-Cancer Efficiency (In Vitro) from Turmeric Rhizomes (Curcuma longa L.)

Turmeric (Curcuma longa L.) powder is widely used as a spice and seasoning in Asian countries. This study investigated the effect of turmeric extracts on the anticancer activity of Huh7 and HCT 116 cells. The curcumin bioactive compounds were extracted using various methods such as microwave-assisted extraction (MAE), ultrasound-assisted extraction (UAE) and traditional extraction (TDE). The yield of dried extracts from MAE was found to be the highest at 17.89%, followed by UAE and TDE, with 11.34% and 5.54%, respectively. Antioxidant activities such as TPC, DPPH and FRAP from MAE were higher than those of UAE and TDE. The total curcuminoid contents from the novel extractions were higher than those from traditional extraction methods. For instance, curcuminoid contents from MAE, UAE and TDE were 326.79, 241.17 and 215.83 mg/g, respectively. Due to having the highest bioactive compounds and extraction yield, turmeric extract from MAE was used to investigate the potential anticancer properties. The extract showed significant cytotoxic potential against the human liver (Huh7) and human colon (HCT116) cell lines, in concentrations ranging from 31.25 to 1000.00 µg/mL. Turmeric extracts using MAE have potential anticancer effects on Huh7 and HCT116 cells. This study serves as scientific data for the chemotherapeutic properties of turmeric extracts and their use as functional ingredients.

Enzymatic and Microwave Pretreatments and Supercritical CO2 Extraction for Improving Extraction Efficiency and Quality of Origanum vulgare L. spp. hirtum Extracts

The goal of the study was to establish a procedure for improving the efficiency of supercritical carbon dioxide (scCO₂) extraction of Origanum vulgare L. spp. hirtum (Greek oregano) and enhancing the quality of obtained extracts. Microwave and enzymatic pretreatments of the plant material were applied prior to the scCO₂ extraction. It was determined that the microwave pretreatment with irradiation power 360 W during 2 min accelerated the extraction of lipophilic compounds and provided a twofold higher extraction yield compared to the control. Moreover, this pretreatment also led to an increase in oxygenated monoterpenes content and the most dominant component carvacrol, as well as the extracts' antioxidant activity. The enzymatic pretreatment caused a significant increase in the extraction yield and the attainment of the extract with the most potent antioxidant properties. Coupling the pretreatments with scCO₂ extraction improves the process of obtaining high value lipophilic products of oregano in terms of utilization of the plant material, acceleration of the extraction with the possibility to adjust its selectivity and quality of extracts, and enhancement of biological activity.

Application of Emerging Cell Disintegration Techniques for the Accelerated Recovery of Curcuminoids from Curcuma longa

Curcuminoids, the bioactive compounds with many beneficial effects on human health, exist in Curcuma longa (turmeric). In the present study, the impact of different cell disintegration techniques to enhance total curcuminoid recovery (TC) from fresh and dried turmeric was investigated. The impact of thermal pretreatment (TP), ultrasound pretreatment (UP), enzyme pretreatment (EP), and pulsed electric field pretreatment (PEF) on the recovery of curcumin (CUR), demethoxycurcumin (DMC), and bis-demethoxycurcumin (BDMC) from fresh and dried turmeric were studied. The cell disintegration index (Zp) and high-performance liquid chromatography (HPLC) analysis of curcuminoids were performed to evaluate the efficiency of the applied techniques. With fresh turmeric, the highest curcuminoid recovery was 83.6 mg/g dry basis with EP. The highest structural tissue damage was obtained with UP achieving a cell disintegration level of 92.5%. The technology with the highest time-saving and low specific energy input was PEF with a total curcuminoid recovery of 80.9 mg/g dry basis. Working with dried turmeric, the drying required high specific energy input for 72 h at 50 °C; however, the untreated dried sample reached 125.3 mg/g dry basis of TC without further pretreatment after drying.

Process intensification for enzyme assisted turmeric starch hydrolysis in hydrotropic and supercritical conditions

The turmeric rhizome (Curcuma longa) contains curcuminoids embedded in the starch matrix. It is thus important to target starch hydrolysis to enhance extraction of curcuminoids. In the case of starch hydrolysis, α-amylase is more efficient when the starch is in a gelatinised form than when it is in its natural form. The present work includes hydrolysis of turmeric starch in its natural and gelatinised forms using α-amylase in hydrotrope solution (HS) and scCO2. The optimum rate of starch hydrolysis was obtained using 200 IU cm−3 of α-amylase, at reaction conditions of 6.5 pH at 328 K when 10% w/w of turmeric powder was stirred at 900 rpm in HSs. The hydrolysis in 15 MPa scCO2 at room temperature required a phase modifier and 40 min of residence time (RT). The enzyme treatment of turmeric powder in HSs increased the filtration rate for curcuminoid extraction (gelatinised and native) compared to untreated turmeric powder.

Facile NMR approach for profiling curcuminoids present in turmeric

Curcumin, together with demethoxycurcumin and bisdemethoxycurcumin as a whole called curcuminoids, is an active phytochemical constituent present in the turmeric. When it comes to their analysis, most will rely on UV-Visible spectroscopy, HPLC and LC-MS methods. Looking to improve productivity, time and simplicity, we are proposing a ¹H NMR based approach for curcuminoids analysis and its applications to different geographical regions. In the present work, sample preparation protocol is reported for the simultaneous determination of curcuminoids using ¹H NMR. For the quantification of curcuminoids, 6-7 ppm vinylic proton region in the ¹H NMR spectrum was used, where acetone was observed as the suitable solvent in terms of curcuminoids solubility and proper resolution of peak. The result shows that curcumin (46.8-59.50%) was major among all varieties, followed by DMC (22.15-27.70%) and BDMC (17.52-30.29%) except in Andhrapradesh variety, where BDMC (30.29%) was more than DMC (22.89%). These studies were further supported by HPLC analysis.

Nature-derived compounds modulating Wnt/ -catenin pathway: a preventive and therapeutic opportunity in neoplastic diseases

The Wnt/β-catenin signaling is a conserved pathway that has a crucial role in embryonic and adult life. Dysregulation of the Wnt/β-catenin pathway has been associated with diseases including cancer, and components of the signaling have been proposed as innovative therapeutic targets, mainly for cancer therapy. The attention of the worldwide researchers paid to this issue is increasing, also in view of the therapeutic potential of these agents in diseases, such as Parkinson's disease (PD), for which no cure is existing today. Much evidence indicates that abnormal Wnt/β-catenin signaling is involved in tumor immunology and the targeting of Wnt/β-catenin pathway has been also proposed as an attractive strategy to potentiate cancer immunotherapy. During the last decade, several products, including naturally occurring dietary agents as well as a wide variety of products from plant sources, including curcumin, quercetin, berberin, and ginsenosides, have been identified as potent modulators of the Wnt/β-catenin signaling and have gained interest as promising candidates for the development of chemopreventive or therapeutic drugs for cancer. In this review we make an overview of the nature-derived compounds reported to have antitumor activity by modulating the Wnt/β-catenin signaling, also focusing on extraction methods, chemical features, and bio-activity assays used for the screening of these compounds.

Effect of blanching pretreatment and microwave-vacuum drying on drying kinetics and physicochemical properties of purple-fleshed sweet potato

In this study, drying kinetics and quality of purple-fleshed sweet potato (PFSP) subjected to microwave-vacuum drying were investigated. The effects of hot water and steam blanching pretreatment on physicochemical characteristics of the dried products were also considered. The samples were dehydrated in a custom-made microwave-vacuum system at different power levels including 450, 600 and 850 W. Hot air drying at 70 °C was also conducted for comparison. The results showed that drying time of PFSP under microwave-vacuum conditions ranged from 6 to 12 min, significantly reduced as compared to that of hot air drying (600 min). The improvement of drying rate was also evidenced by increased effective moisture diffusivity (2.22 × 10^-7-4.05 × 10^-7 m²/s) of the samples. Drying kinetics of PFSP was best fitted by Page and logarithmic model with R² ranging from 0.991 to 0.998, and RMSE from 0.016 to 0.030. PFSP dried under microwave-vacuum condition had lower water absorption index and swelling capacity than hot air drying. Color, antioxidant activity and total phenolic content of dried PFSP were also improved under microwave-vacuum drying. The effects of blanching pretreatment on quality of dried PFSP were more dominant in hot air than microwave-vacuum dried samples.

Rapid extraction of watermelon seed proteins using microwave and its functional properties

Solid food industry waste like watermelon seed is an excellent source of value-added components such as proteins, oil, and carbohydrate. In the present study, protein extraction was carried out using microwave energy from defatted watermelon seeds (DWS), containing 50% of proteins. Microwave-assisted extraction (MAE) was optimized with different parameters, namely, solid to solvent ratio (1:10-1:40), pH (7-10), microwave power (30 W, 50 W, 70 W), extraction time (30 s-8 min) and moisture content or pre-leaching effect. Maximum protein recovery was achieved with 50 W microwave power, solid to solvent ration of 1:30, and pH 10 in 2 minutes of microwave irradiation time. MAE gave higher yield in less time compared to conventional extraction. SDS-PAGE confirmed the molecular weight of watermelon seed proteins (WSP) in the range of 25-250 kDa. A comparative study showed 90% protein recovery with MAE in 2 min with 1:30 (w/v) solid to solvent ratio, whereas ultrasound gave 87% in 9 min with 1:50 (w/v) ratio and batch 72% in 25 min with 1:70 (w/v) ratio. Watermelon seed proteins obtained from MAE method possess excellent functional properties with reference to conventional extraction method indicating its application in food products.

Stability of 3-deoxyanthocyanin pigment structure relative to anthocyanins from grains under microwave assisted extraction

Sorghum derived 3-deoxyanthocyanin (DXA) pigments are stable relative to their anthocyanin analogs, and are of growing interest in food applications. However, the 3DXA are poorly extractable from grain tissue. This work aimed to determine the relative stability and extractability of sorghum 3-DXA vs anthocyanins from maize and cowpea under microwave-assisted extraction (MAE). UV-Vis and UPLC-MS/MS spectrometry were used to characterize the properties. The 3-DXA remained structurally stable to MAE conditions up to 1200 W/100 °C/30 min. MAE increased sorghum 3-DXA yield 100% versus control (3100 vs 1520 mg/g). On the other hand, both maize and cowpea anthocyanins were unstable and rapidly degraded under MAE. Cell wall-derived ferulate esters were detected in sorghum and maize MAE extracts, indicating cell wall degradation occurred during MAE. Thus the enhanced extraction of 3-DXA under MAE was due to their structural stability, along with improved diffusion from cell matrix due to microwave-induced sorghum cell wall disruption.

Rapid measurements of curcumin from complex samples coupled with magnetic biocompatibility molecularly imprinted polymer using electrochemical detection

Curcumin widely exists in food, and rapid selective and accurate detection of curcumin have great significance in chemical industry. In this experiment, a new magnetic biocompatibility molecularly imprinted polymer was prepared with nontoxic and biocompatible Zein to adsorb curcumin selectively. The polymer has high biocompatibility, good adsorption capacity, and specific adsorption for curcumin. Combined with portable electrochemical workstations, the polymer can be used to detect curcumin rapidly and cost-effectively. Using curcumin as a template and Zein as the crosslinking agent, the polymers were synthesized on the surface of Fe₃ O₄ particles for solid phase extraction. The experimental results showed that the polymer reached large adsorption capacity (32.12 mg/g) with fast kinetics (20 min). The adsorption characteristic of the polymer followed the Langmuir isotherm and pseudo-second-order kinetic models. Hexacyanoferrate was used as electrochemical probe to generate signals, and the linear range was 5-200 µg/mL for measuring curcumin. The experimental analysis showed that the polymer was an ideal material for selective accumulation of curcumin from complex samples. This approach has been successfully applied to the determination of curcumin in food samples with electrochemical detection, indicating that this is a feasible and practical technique.

Curcumin: Biological, Pharmaceutical, Nutraceutical, and Analytical Aspects

Turmeric is a curry spice that originated from India, which has attracted great interest in recent decades because it contains bioactive curcuminoids (curcumin, demethoxycurcumin, and bisdemethoxycurcumin). Curcumin (1,7-bis-(4-hydroxy-3-methoxyphenyl)-hepta-1,6-diene-3,5-dione), a lipophilic polyphenol may work as an anticancer, antibiotic, anti-inflammatory, and anti-aging agent as suggested by several in vitro, in vivo studies and clinical trials. However, poor aqueous solubility, bioavailability, and pharmacokinetic profiles limit curcumin’s therapeutic usage. To address these issues, several curcumin formulations have been developed. However, suboptimal sample preparation and analysis methodologies often hamper the accurate evaluation of bioactivities and their clinical efficacy. This review summarizes recent research on biological, pharmaceutical, and analytical aspects of the curcumin. Various formulation techniques and corresponding clinical trials and in vivo outcomes are discussed. A detailed comparison of different sample preparation (ultrasonic, pressurized liquid extraction, microwave, reflux) and analytical (FT-IR, FT-NIR, FT-Raman, UV, NMR, HPTLC, HPLC, and LC-MS/MS) methodologies used for the extraction and quantification of curcuminoids in different matrices, is presented. Application of optimal sample preparation, chromatographic separation, and detection methodologies will significantly improve the assessment of different formulations and biological activities of curcuminoids.

Extraction of curcuminoids from Curcuma longa: comparative study between batch extraction and novel three phase partitioning

Curcuminoids, the active components of dried rhizome of Curcuma longa have been extracted using batch extraction and three-phase partitioning (TPP) process. The effect of different processing parameters, namely different solvents, extraction time, ammonium sulfate concentration, slurry to tert-butanol ratio, and solute to aqueous ratio on extraction efficiency of TPP, was studied to attain maximum extraction yield. The highest yield of 58.38 mg/g was achieved at 40±2 °C in 150 min, with saturated ammonium sulfate 30% (w/v), slurry to tert-butanol ratio 1:1 (v/v), and turmeric powder to water ratio 1:40 (w/v) in TPP. However, batch extraction using ethanol as a solvent yielded 52.77 mg/g in 180 min extraction time at 40±2 °C with 1:40 (w/v) turmeric powder to water ratio and 400 rpm agitation speed. In view of reference method, i.e., Soxhlet extraction (100%), TPP showed 65.63% yield in 150 min and batch exhibited 59.92% in 180 min. The turmeric extracts obtained by different methods exhibited excellent antioxidant and anti-inflammatory activities equivalent to their respective reference standards. Hence, TPP extraction process assures a rapid and improved recovery of curcuminoids with excellent therapeutic properties.

Intensification of extraction of curcumin from Curcuma amada using ultrasound assisted approach: Effect of different operating parameters

Curcumin, a dietary phytochemical, has been extracted from rhizomes of Curcuma amada using ultrasound assisted extraction (UAE) and the results compared with the conventional extraction approach to establish the process intensification benefits. The effect of operating parameters such as type of solvent, extraction time, extraction temperature, solid to solvent ratio, particle size and ultrasonic power on the extraction yield have been investigated in details for the approach UAE. The maximum extraction yield as 72% was obtained in 1h under optimized conditions of 35°C temperature, solid to solvent ratio of 1:25, particle size of 0.09mm, ultrasonic power of 250W and ultrasound frequency of 22kHz with ethanol as the solvent. The obtained yield was significantly higher as compared to the batch extraction where only about 62% yield was achieved in 8h of treatment. Peleg's model was used to describe the kinetics of UAE and the model showed a good agreement with the experimental results. Overall, ultrasound has been established to be a green process for extraction of curcumin with benefits of reduction in time as compared to batch extraction and the operating temperature as compared to Soxhlet extraction.

RSM optimized Moringa oleifera peel extract for green synthesis of M. oleifera capped palladium nanoparticles with antibacterial and hemolytic property

Palladium nanoparticles (Pd NPs) are the very good catalytic agents in many coupling reactions, also these are very well biological agents against bacteria and fungus. M. oleifera capped Pd NPs were synthesized from microwave assisted methanolic extract of M. oleifera peel. To optimize the extraction process RSM (Response Surface Methodology) was applied. To get a good extraction yield BBD (Box-Behnken Design) was employed. The better optimized conditions for the extraction was found as 400W, 25mL of CH3OH at 65°C for 2min. We observed 61.66mg of extract yield from this method. Eco-friendly M. oleifera capped Pd NPs were synthesized using M. oleifera peel extract and confirmed using the different characterization techniques like UV- Vis spectroscopy, XRD, SEM and HR-TEM analysis. We found the size of the M. oleifera capped Pd NPs nanoparticles as 27±2nm and shape of the particles as spherical through the TEM analysis. M. oleifera capped Pd NPs exhibits good antibacterial activity against S. aureus (Staphylococcus aureus) and E. coli (Escherichia coli) bacterial strains and we found the zone inhibition as 0.6 and 0.7mm. The synthesized M. oleifera capped Pd NPs are screened for hemolytic activity and it proved the M. oleifera capped Pd NPs are non-toxic on RBCs cells.

Optimisation of pulsed ultrasonic and microwave-assisted extraction for curcuminoids by response surface methodology and kinetic study

A response surface methodology and a kinetic study were used to optimise the pulsed ultrasonic and microwave techniques in the extraction of curcuminoids. Microwave-assisted extraction had the same efficiency as pulsed ultrasonic-assisted extraction, and both methods were better than continuous ultrasonic extraction of curcuminoids. For the pulsed ultrasonic-assisted extraction, the optimal conditions were 60% amplitude (AMP), 83% ethanol (v/v), 3/1 (s/s) pulsed duration/interval time and 10 min irradiation time. For the microwave-assisted extraction, the optimal conditions were 82% ethanol, 10% power level and 7 min of extraction time. Both methods used a 1:200 mass to solvent ratio.

Solvent effects on focused microwave assisted extraction of polyphenolic acids from Eucommia ulmodies

An open microwave-assisted extraction system was used to extract gallic acid, protocatechuic acid, chlorogenic acid and caffeic acid from Eucommia ulmodies. The effect of extraction variables, especially solvent, on the recoveries of these polyphenolic compounds was investigated using factorial design. As extracting solvent for these compounds, methanol produced a higher recovery than pure water. For straight chain alcohol solvents, the lower the carbon number, the higher the recoveries of the polyphenolic acids. The optimal ratio of methanol:water:glacial acetic acid in the solvent mixture used in microwave-assisted extraction was 2:8:0.3 (v/v) and this solvent could be directly used as the mobile phase in HPLC separation without additional intermittent treatment as reported in literature. The extraction under the condition of 50% microwave power and 30 s irradiation at a solvent:sample ratio of 10 (mL/g) was found to be the most advantageous. The repeatability test of extraction and chromatographic analysis was satisfactory for the analysis of these polyphenolic compounds.