Purification of Tea Saponins and Evaluation of its Effect on Alcohol Dehydrogenase Activity

Experimental characterization and dual-temperature molecular dynamics simulation on the intervention of tea saponin in starch chain dynamic behavior

In this work, the typical properties of starchy products were innovatively described as six types of chain dynamic behaviors. Dual-temperature molecular dynamic simulations, alongside multi-experimental methods, were employed to tandemly explore the intervention effect and mechanism of tea saponin (TS, 0 %-40 % w/w) on these behaviors. The findings reveal that the hydrophilic and hydrophobic ends of TS provide numerous sites for hydrogen bonding and steric hindrance, respectively, which hinder the formation of hydrogen bonds between starch chains. This interaction mode facilitated the chain unwinding (pasting temperature: 79.8 → 76.4 °C) and movement (viscosity: 267.67 → 38.92 Pa.s), and also retarded chain short/long-term reassociation (elastic modulus: 0.41 → 0.14 Pa/min; hardening rate: 2.72 → 0.07 gf/d) and rearrangement (hardness: 15.50 → 10.00 gf). Notably, a critical TS content was observed between 10 % and 20 % w/w, beyond which textural collapse (hardness: 15.50 → 10.00 gf) occurred. This research offers a new strategy and relevant theoretical backing for the property regulation of starch products.

Tea (Camellia sinensis) Seed Saponins Act as Sebosuppression Agents via the AMPK/mTOR Pathway

BACKGROUND

Excessive lipogenesis of the skin triggers some dermatological concerns, such as enlarged pores, acne, and blackheads. Although topical drug treatments can offer temporary relief, their prolonged usage may lead to side effects of dryness, irritation, or allergic reactions. Consequently, the development of safer and efficacious ingredients in cosmetics for managing sebum overproduction represents a significant yet challenging endeavor.

AIM

Saponins were extracted from tea (Camellia sinensis) seed meal and purified by macroporous resin in order to investigate the impact of tea seed saponins (TSS) on lipid production in human immortalized sebaceous cells. Moreover, we attempted to reveal the underlying mechanism of TSS on the sebosuppression effect in SZ95 sebocytes stimulated by linoleic acid (LA).

METHODS

The compositions and chemical structures of TSS were determined using UV-vis absorption spectrum, Fourier transform-infrared (FTIR) spectrum, and ultra-high-performance liquid chromatography-mass spectrometry analysis. An in vitro model of cellular lipid accumulation induced by LA was established. Total lipid synthesis in intracellular SZ95 sebocytes was assessed through Nile Red staining, while triglyceride, cholesterol, and fatty acids were quantified by commercially assay kits. Western blot and quantitative real-time polymerase chain reaction were employed to analyze the protein expression levels involved in the AMP-activated protein kinase (AMPK)/mammalian target of rapamycin (mTOR) pathway as well as the downstream protein and mRNA expressions of sterol regulatory element-binding protein-1 (SREBP-1), peroxisome proliferator-activated receptor γ (PPARγ), and fatty acid synthase (FAS). The localizations of SREBP-1 within the cytoplasm or nucleus were characterized using immunofluorescence staining.

RESULTS

Five saponins were identified in the extracted TSS, all of which were oleanic acid-type pentacyclic triterpenes. TSS treatment significantly alleviated LA-induced lipid accumulation in SZ95 sebocytes. In addition, TSS activated the AMPK/mTOR pathway and downregulated the downstream protein and mRNA expression of transcription factors and enzymes, including SREBP-1, PPARγ, and FAS. Moreover, the TSS blocked the nuclear transfer of SREBP-1 from cytoplasm to nucleus.

CONCLUSION

In human sebocytes, TSS exhibited sebosuppressive effect as revealed by the inhibited production of total lipids as well as triglyceride, cholesterol, and fatty acids. Moreover, the anti-lipogenesis mechanism by TSS involved the activation of the AMPK/mTOR pathway and downregulated downstream transcription factors and enzymes of SREBP-1, PPARγ, and FAS. Additionally, TSS blocked the SREBP-1 nuclear translocation. These results may justify the potent of TSS as a new candidate for modulating lipogenesis in human SZ95 sebocytes.

Natural products from Camellia oleifera fruit and its comprehensive utilisation

Camellia oleifera (C. oleifera) is a woody oil plant with a good reputation of 'Oriental Olive Oil' in China. The national understanding of the health-care benefits of Camellia oil are already widespread, but the production of C. oleifera fruit has not been achieved large-scale industrialisation. In this review, we focus on the properties and commercial value of its natural products, and processing technology, performance characterisation, and novel modification strategies of its processed products. In addition, we briefly summarised the research progress of breeding and put forward the comprehensive utilisation of C. oleifera fruit based on the tandem of extraction and processing. This review might attract more researchers to make profound study regarding it as an alternative of olive oil.

Structural variations of lignin and lignin-carbohydrate complexes from the fruit shells of Camellia oleifera during ripening

Camellia oleifera fruit shell (CFS), a waste lignocellulosic biomass resulting from Camellia oleifera oil production industry, is abundantly available in Southern China. Herein, to understand the structural variations of CFS lignins and lignin-carbohydrate complexes (LCC) during ripening, the native lignin and LCC fractions from CFS (harvested every seven days from October 1 to 30, 2022) were isolated and characterized systematically. The molecular weights of both MWL and DEL fractions steadily increased during ripening. CFS lignins contained abundance of β-O-4' linkages (maximum of 58.6 per 100Ar in DEL-2), and had low S/G ratios (S/G < 0.6). Moreover, the amounts of β-O-4' linkages in MWL, DEL, and LCC-AcOH fractions increased first and then decreased during ripening. The main lignin-carbohydrate linkages in the LCC-AcOH fractions were benzyl-ether (7.0-9.4 per 100Ar) and phenyl-glycoside (4.5-5.2 per 100Ar) bonds. Based on the quantitative results, the potential structural diagrams of lignins from different ripening stages of CFS were proposed. Additionally, the LCC-AcOH fractions exhibited pronounced antioxidant capacity and were promising as natural antioxidants. The properties and functions of lignin in plant cell walls, as well as its further appreciation, are crucial for the design and selection of feasible pretreatment strategies for the lignocellulosic materials.

Highly efficient isolation and purification of high-purity tea saponins from industrial camellia oil production by porous polymeric adsorbents

BACKGROUND

Recovery of high-purity tea saponin (TS), a promising non-ionic surfactant with well-documented properties, is one of the major challenges to broadening its industrial applications. In this study, an innovative and sustainable strategy for the highly-efficient purification of TS was developed by using well-designed highly-porous polymeric adsorbents.

RESULTS

The prepared Pp-A with controllable macropores (~96 nm) and appropriate surface hydrophobic properties was found more favorable for achieving high adsorption efficiency towards TS/TS-micelles. Kinetic results showed the adsorption follows the pseudo-second-order model (R2  = 0.9800), and the Langmuir model is more qualified to explicate the adsorption isotherms with Qe-TS  ~ 675 mg g-1 . Thermodynamic studies revealed the monolayer adsorption of TS was an endothermic process that was conducted spontaneously. Interestingly, ethanol-driven desorption (90% v/v ethanol) of TS was rapidly (< 30 min) complete due to the possible ethanol-mediated disassembling of TS-micelles. A possible mechanism that involves the interactions between the adsorbents and TS/TS-micelles, the formation and disassembling of TS-micelles was proposed to account for the highly efficient purification of TS. Afterwards, Pp-A-based adsorption method was developed to purify TS directly from industrial camellia oil production. Through selective adsorption, pre-washing, and ethanol-driven desorption, the applied Pp-A enabled the direct isolation of high-purity TS (~96%) with a recovery ratio > 90%. Notably, Pp-A exhibited excellent operational stability and is of high potential for long-term industrial application.

CONCLUSION

Results ensured the practical feasibility of the prepared porous adsorbents in purifying TS, and the proposed methodology is a promising industrial-scale purification strategy. © 2023 Society of Chemical Industry.

Synthesis of mesoporous zeolite Y using Sapindus rarak extract as natural organic surfactant for deoxygenation of Reutealis trisperma oil to biofuel

Saponin is a plant-derived chemical with an amphiphilic glycoconjugate structure extracted from sapindaceae plants like Sapindus rarak. This study investigated saponin extract of Sapindus rarak as a natural template for formation of mesoporous zeolite Y. Surface area and mesoporosity of zeolite Y were improved with optimization of Sapindus rarak extract (SRE) concentration (Y-Ln; n = 2, 5, 10 or 15 mL), reaching 216.26 m2 mesoporous area and 0.214 cm3 g-1 mesoporous volume for Y-L10 samples. A different loading of Ni was impregnated onto Y-L10 zeolite to improve Lewis/Brønsted acidity as catalysts in the deoxygenation of Reutealis trisperma oil (RTO) into hydrocarbon fuels. Impregnating 15% Ni on NaY zeolite enhanced Lewis acidity to 0.4556 mmol g-1, producing 48.8% liquid oil with 85.43% degree of deoxygenation. A high selectivity towards C15 and C17 hydrocarbon was analyzed from liquid yield, indicating the contributing factor from Lewis acidity and mesoporosity to enhance deoxygenation and prevent the hydrocracking reaction.

Extraction optimization of tea saponins from Camellia oleifera seed meal with deep eutectic solvents: Composition identification and properties evaluation

Traditional organic solvent extractions of tea saponins have many drawbacks. This study aimed to establish an environment-friendly and efficient technology based on deep eutectic solvents (DESs) to extract tea saponins from Camellia oleifera seed meal. The solvent consisting of choline chloride and methylurea was screened as optimal DES. Under the optimal extraction conditions obtained by response surface methodology, the extraction yield of tea saponins reached 94.36 mg/g, which increased by 27% compared with ethanol extraction, while the extraction time was reduced by 50%. Analysis of UV, FT-IR, and UPLC-Q/TOF-MS indicated tea saponins did not alter during DES extraction. Surface activity and emulsification evaluation showed that extracted tea saponins could reduce interfacial tension at the oil-water interface with excellent foamability and foam stability, and they could form nanoemulsions (d₃₂ < 200 nm) with excellent stability. This study provides a suitable approach for the efficient extraction of tea saponins.

Characterization of saponins from the leaves and stem bark of Jatropha curcas L. for surface-active properties

In this study, saponins extracted from leaves and stem bark of Jatropha curcas L. were investigated for surface-active properties. Conductivity and surface tension measurements revealed the micellar character of J. curcas saponin, with the average CMC, determined to be 0.50 g/L and 0.75 g/L for leaf and stem bark saponin, respectively. Stem bark saponin reduced the surface tension of water to a greater extent (γCMC= 37.65 mN/m) compared to leaf saponin (γCMC= 49.27 mN/m) indicating its efficient surface activity and potential detergency. pH measurement confirmed the weakly acidic nature of saponin with a pH value lying slightly below the range suitable for hair and skin. Stem bark saponin showed better cleaning ability, foaming ability and foam stability than leaf saponin, due to a sufficient reduction in the surface tension of water. The results obtained suggest that the saponin extracted from both the leaves and stem bark of J. curcas can be used as environmentally friendly alternatives to synthetic surfactants.

Protective Effect of Tea Saponins on Alcohol-Induced Gastric Mucosal Injury in Mice

Excessive alcohol consumption harms the human body, particularly the digestive system, by causing damage to the gastric mucosa. Tea saponin is a natural active substance extracted from tea tree seeds that has gastroprotective potential against alcohol-induced mucosal damage. However, the protective mechanism of tea saponins is not fully understood. The current study aimed to explore the protective mechanism of tea saponins against alcohol-induced gastric mucosal injury in mice. Histopathological changes, immunohistochemistry, immunoblotting, and gastric mucosa-related cytokine levels were analyzed in three groups of male mice: model, control, and tea saponin-treated. Compared to the model group, the tea saponin group prominently ameliorated alcohol-induced gastric mucosal injury by improving cell necrosis, inflammatory cell infiltration, and edema. Downregulation of inflammation-related factors cluster of differentiation 68 (CD68), myeloperoxidase (MPO), tumor necrosis factor-α (TNF-α), and interleukin-1β (IL-1β) was also found in the tea saponin group. These results suggest that tea saponins have a protective effect against alcohol-induced gastric mucosal damage in mice. Therefore, tea saponin may serve as a food additive for gastric mucosal protection.

Application of response surface methodology to optimise the extraction of tea saponin from Camellia oleifera, and their verification by HPLC

Single factor combined with response surface methodology was used to optimise the process parameters of tea saponin extraction from Camellia oleifera. Four factors including material-liquid ratio, extraction temperature, extraction time, and ethanol concentration were selected as the influencing factors on the basis of single factor. The extraction rate of tea saponin was used as the response factor to analyse the response of these four factors and three levels. Results showed that extraction temperature of 81.69°C, material-liquid ratio of 1:11.85 g/mL, time of 6.17 h, and ethanol concentration of 56.69% were the best extraction conditions. The estimated yield of extraction was 7.46%. Analysis of the tea saponin samples by using high performance liquid chromatography showed that the main peak time was 6.668 min, and the absorption peaks and peaks were symmetric.

Properties of curcumin-loaded zein-tea saponin nanoparticles prepared by antisolvent co-precipitation and precipitation

The properties of nutraceutical-loaded biopolymer nanoparticles fabricated by antisolvent co-precipitation (ASCP) and precipitation (ASP) were compared. Curcumin-loaded zein-tea saponin nanoparticles were fabricated using both methods and then their structural and physicochemical properties were characterized. The diameter of the nanoparticles prepared by ASCP were smaller (120-130 nm) than those prepared by ASP (140-160 nm). The encapsulation efficiency of the ASCP-nanoparticles (80.0%) was higher than the ASP-ones (71.0%) at a zein-to-curcumin mass ratio of 3:1, which was also higher than previous studies. The storage and light stability of curcumin was higher in zein-saponin nanoparticles than in zein nanoparticles. All nanoparticles had good water dispersibility after freeze-drying and rehydration. This study shows that nanoparticles produced by antisolvent co-precipitation have superior properties to those produced by antisolvent precipitation. The co-precipitation method leads to a higher encapsulation efficiency, smaller particle size, and greater storage stability, which may be advantageous for some applications.

Development of a General PAT Strategy for Online Monitoring of Complex Mixtures—On the Example of Natural Product Extracts from Bearberry Leaf (Arctostaphylos uva-ursi)

For the first time, a universally applicable and methodical approach from characterization to a PAT concept for complex mixtures is conducted—exemplified on natural products extraction processes. Bearberry leaf (Arctostaphylos uva-ursi) extract is chosen as an example of a typical complex mixture of natural plant origin and generalizable in its composition. Within the quality by design (QbD) based process development the development and implementation of a concept for process analytical technology (PAT), a key enabling technology, is the next necessary step in risk and quality-based process development and operation. To obtain and provide an overview of the broad field of PAT, the development process is shown on the example of a complex multi-component plant extract. This study researches the potential of different process analytical technologies for online monitoring of different component groups and classifies their possible applications within the framework of a QbD-based process. Offline and online analytics are established on the basis of two extraction runs. Based on this data set, PLS models are created for the spectral data, and correlations are conducted for univariate data. In a third run, the prediction potential is researched. Conclusively, the results of this study are arranged in the concept of a holistic quality and risk-based process design and operation concept.

Freshwater Clam as a Potential Bioindicator for Silver/Saponin Nanocomposites Toxicity

Despite the progress in using silver nano products in many fields, including medicine, food, and industry, their effects on the environment need more attention. Therefore, the current study aimed to assess the effect of silver/saponin nanocomposites (Ag/S NCs) for the first time on the aquatic environment by using freshwater clam, Caelatura aegyptiaca, as a fundamental bioindicator in the freshwater system. Following the preparation and characterization of Ag/S NCs by using atomic absorption spectrophotometer, UV-Vis spectrophotometer, X-ray diffraction, transmission electron microscopy, and acute toxicity study, we exposed the clam to three different doses of Ag/S NCs (12.5, 25 and 50 mg L^-1) for consecutive 6 days. All Ag/S NCs concentrations caused a significant increase in malondialdehyde and nitric oxide while induced a notable decrease in glutathione and catalase levels in all studied organs. Moreover, the histological alternations were observed in gills, labial palp, and foot tissues, particularly at dose 50 mg L^-1. From the results of our work, we concluded that toxicity of Ag/S NCs on freshwater clam leads to an oxidative stress response as well as histopathological changes. Besides, we assumed that Coelatura aegyptiaca could be used as a sensitive bioindicator for monitoring water pollution caused by different nanoparticles. Therefore, we do recommend performing further studies by using fresh clam to provide a better assessment for our aquatic environment to prevent water pollution locally and globally.

Composition, Anticholinesterase and Antipedicular Activities of Satureja capitata L. Volatile Oil

The emergence of resistance for antipedicular agents and the need of potent acetylcholinesterase (AChE) therapeutics for the treatment of a neurodegenerative disorder such as Alzheimer disease has led researchers to the exploration of new therapeutic alternatives such as natural volatile oils. Therefore, the current investigation aimed to identify the components of Satureja capitata L. volatile oil (VO), and examine the VO anticholinesterase, and antipedicular activities. The plant phytoconstituents were identified using Gas chromatography mass spectrometry (GC-MS) method, while the anticholinesterase activity was determined against butyryl- and acetyl-cholinesterase using Ellman’s method. In addition, antipedicular activity was established using the diffusion method. The obtained GC-MS results identified 16 compounds in S. capitata VO with the major constituents being carvacrol, γ-terpinene, and p-cymene. Anticholinesterase analysis showed a marked inhibition potential against acetyl- and butyryl-cholinesterase enzymes with half maximal inhibitory concentration (IC50) values of 28.24±0.97 μg/ml and 92.31±1.22 μg/ml, respectively in comparison with the reference compound galantamine, which has IC50 values against the same enzymes of 5.21±0.07 μg/ml and 10.33±0.37 μg/ml, respectively. In addition, the VO, at a concentration of 20%, was effective against head lice, similar to benzyl benzoate, which resulted in 100% mortality. In addition, the VO completely inhibited the emergence of lice nits after 6 and 14 days. On the basis of the obtained results, S. capitata VO is a promising natural alternative to synthetic antipedicular and anticholinesterase drugs, which can be employed in drug development, and may lead to new candidates against head lice and neurodegenerative diseases.

Health Functions and Related Molecular Mechanisms of Tea Components: An Update Review

Tea is widely consumed all over the world. Generally, tea is divided into six categories: White, green, yellow, oolong, black, and dark teas, based on the fermentation degree. Tea contains abundant phytochemicals, such as polyphenols, pigments, polysaccharides, alkaloids, free amino acids, and saponins. However, the bioavailability of tea phytochemicals is relatively low. Thus, some novel technologies like nanotechnology have been developed to improve the bioavailability of tea bioactive components and consequently enhance the bioactivity. So far, many studies have demonstrated that tea shows various health functions, such as antioxidant, anti-inflammatory, immuno-regulatory, anticancer, cardiovascular-protective, anti-diabetic, anti-obesity, and hepato-protective effects. Moreover, it is also considered that drinking tea is safe to humans, since reports about the severe adverse effects of tea consumption are rare. In order to provide a better understanding of tea and its health potential, this review summarizes and discusses recent literature on the bioactive components, bioavailability, health functions, and safety issues of tea, with special attention paid to the related molecular mechanisms of tea health functions.