A new method for preparing pentacyclic triterpene rich Centella asiatica extracts

Exploring the composition and properties of Centella asiatica metabolites and investigating their impact on BSA glycation, LDL oxidation and α-amylase inhibition

Centella asiatica (L.) Urb. is a small herbaceous plant belonging to the Apiaceae family that is rich in triterpenes, such as asiaticoside and madecassoside. Centella asiatica finds broad application in promoting wound healing, addressing skin disorders, and boosting both memory and cognitive function. Given its extensive therapeutic potential, this study aimed not only to investigate the Centella asiatica ethanolic extract but also to analyze the biological properties of its organic fractions, such as antioxidant antiglycation capacity, which are little explored. We also identified the main bioactive compounds through spectrometry analysis. The ethanolic extract (EE) was obtained through a static maceration for seven days, while organic fractions (HF: hexane fraction; DF: dichloromethane fraction; EAF: ethyl acetate fraction; BF: n-butanol fraction and HMF: hydromethanolic fraction) were obtained via liquid-liquid fractionation. The concentration of phenolic compounds, flavonoids, and tannins in each sample was quantified. Additionally, the antiglycation (BSA/FRU, BSA/MGO, and ARG/MGO models) and antioxidant (FRAP, ORAC, and DPPH) properties, as well as the ability to inhibit LDL oxidation and hepatic tissue peroxidation were evaluated. The inhibition of enzyme activity was also analyzed (α-amylase, α-glycosidase, acetylcholinesterase, and butyrylcholinesterase). We also evaluated the antimicrobial and cytotoxicity against RAW 264.7 macrophages. The main compounds present in the most bioactive fractions were elucidated through ESI FT-ICR MS and HPLC-ESI-MS/MS analysis. In the assessment of antioxidant capacity (FRAP, ORAC, and DPPH), the EAF and BF fractions exhibited notable results, and as they are the phenolic compounds richest fractions, they also inhibited LDL oxidation, protected the hepatic tissue from peroxidation and inhibited α-amylase activity. Regarding glycation models, the EE, EAF, BF, and HMF fractions demonstrated substantial activity in the BSA/FRU model. However, BF was the only fraction that presented non-cytotoxic activity in RAW 264.7 macrophages at all tested concentrations. In conclusion, this study provides valuable insights into the antioxidant, antiglycation, and enzymatic inhibition capacities of the ethanolic extract and organic fractions of Centella asiatica. The findings suggest that further in vivo studies, particularly focusing on the butanol fraction (BF), may be promising routes for future research and potential therapeutic applications.

Centella asiatica (L.) Urb. and Hydrocotyle umbellata L. identification and quality assessment: A methodology comparison

INTRODUCTION

Centella is an important genus in the Apiaceae family. It includes Centella asiatica, which has significant edible and medicinal values. However, this species is easily confused due to its similar morphological traits to Hydrocotyle umbellata, hindering its utilization in the consumer and pharmacological industries.

OBJECTIVE

The study aims to differentiate these two closely related plant species using reliable methods of confirming the authenticity of natural herbal medicines.

METHODS

Our work mainly focuses on the basic morphological characteristics, chemical markers, genetic fingerprints, and their biological responses.

RESULTS

The plants can be clearly differentiated using their leaf shapes, stipules, petioles, inflorescences, and fruit structures. Although the phytochemical compositions of the C. asiatica extract were similar to that of H. umbellata which included flavonoids, tannins, and saponins important to the plant's ability to reduce inflammation and promote healing of wounds, the H. umbellata extract showed significantly higher toxicity than that of C. asiatica. High-performance liquid chromatography analysis was used to identify chemical fingerprints. The result revealed that C. asiatica had major triterpene glycoside constituents including asiaticoside, asiatic acid, madecassoside, and madecassic acid, which have a wide range of medicinal values. In contrast, triterpenoid saponins were not identified in H. umbellata. Furthermore, using SCoT1-6 primers was possible to effectively and sufficiently created a dendrogram which successfully identified the closeness of the plants and confirmed the differences between the two plant species.

CONCLUSION

Therefore, differentiation can be achieved through the combination of morphometrics, molecular bioactivity, and chemical analysis.

Preparation, development, and scale-up of standardized pentacyclic triterpenoid-rich extract from Centella asiatica (L.) Urb. and study of its wound healing activity

This pilot-scale study of an innovative green extraction method shows increased biomarker content in plant extracts. Moreover, green extraction methods decrease the effects on the environment and human health and promote industrial growth. This study optimized the process conditions to obtain a pentacyclic triterpenoid-rich extract (PRE) from Centella asiatica (L.) Urb., which contains asiatic acid, madecassic acid, asiaticoside, and madecassoside, and evaluated its biological activities. PRE preparation was scaled up from laboratory to pilot scale. In the pilot scale, a combination of microwave-assisted extraction with an irradiation power of 4 kW and an ultrasonic-assisted extraction at 0.55 kW was used for C. asiatica extraction. The total pentacyclic triterpene content was 106.02 mg/g of crude extract. Then, the C. asiatica extract was fractionated by a macroporous resin (Diaion® HP-20). The PRE preparation method used 50% and 75% EtOH fractions. This PRE produced a high content of pentacyclic triterpenoids at 681.12 mg/g of crude extract. It presented a high anti-inflammatory effect with an IC50 value of 23.88 μg/mL for nitric oxide inhibition and induced wound healing processes (proliferation, migration, and collagen synthesis) in human dermal fibroblast cells. The information gained from this study can advance the industrial extraction of physiologically active substances from various plant sources for use as medicines or components of supplemental food and cosmeceutical products.

Tuning water chemistry for the recovery of greener products: pragmatic and sustainable approaches

The environmental impact and denaturing propensity of organic solvents in the extraction of plant bioactives pose great challenges in extraction systems. As a result, proactive consideration of procedures and evidence for tuning water properties for better recovery and positive influence on the green synthesis of products become pivotal. The conventional maceration approach takes a longer duration (1-72 h) for product recovery while percolation, distillation, and Soxhlet extractions take about 1 to 6 h. An intensified modern hydro-extraction process was identified for tuning water properties with an appreciable yield similar to organic solvents within 10-15 min. The percentage yield of tuned hydro-solvents achieved close to 90% recovery of active metabolites. The additional advantage of using tuned water over organic solvents is in the preservation of the bio-activities and forestalling the possibility of contamination of the bio-matrices during extractions with an organic solvent. This advantage is based on the fast extraction rate and selectivity of the tuned solvent when compared to the traditional approach. This review uniquely approaches the study of biometabolite recovery through insights from the chemistry of water under different extraction techniques for the very first time. Current challenges and prospects from the study are further presented.

Anti-inflammatory potential of berberine-rich extract via modulation of inflammation biomarkers

Berberine-rich extract (BRE) prepared from Berberis lycium root bark using green extraction approach and its marker compound berberine has a broad spectrum of clinical applications. Berberine's potential pharmacological effects include anticancer, antidiarrheal, antidiabetic, antimicrobial and anti-inflammatory activities. In current work, BRE and berberine were evaluated for their therapeutic prospects in inflammation models. The comparative effect of BRE and berberine against inflammation was determined through in vitro chemiluminescence technique. The in vivo anti-inflammatory evaluation of BRE and berberine (25, 75, and 125 mg/kg) compared to diclofenac (10 mg/kg) was performed in carrageenan and formaldehyde-induced inflammation in Wistar rats. Histopathological and biochemical studies were conducted to find the comparative anti-inflammatory potential of BRE and berberine on pathological hallmarks induced by formaldehyde. Moreover, the modulatory effects on inflammatory biomarkers were also investigated through qPCR. ELISA (enzyme-linked immunoassay test assay) was performed to investigate the expression of pathological protein biomarkers like TNF-α and IL-6 and levels of antioxidant enzymes were estimated in liver homogenates. Both BRE and berberine markedly (p < .001) reduced paw diameter and inflammation in carrageenan and formaldehyde-induced inflammation. The levels of antioxidant enzymes were recovered (p < .001) by BRE and berberine treatments, and compared to the formaldehyde-treated inflammation model. Both BRE and berberine remarkably downregulated the mRNA and protein expression of inflammatory biomarkers. BRE similar to berberine mitigated the level of antioxidant enzymes in liver homogenate. The undertaken study suggests that BRE, a natural, green, and therapeutically bioequivalent to berberine could be used as an economical phytomedicine in the treatment of inflammatory disorders. PRACTICAL APPLICATIONS: Anti-inflammatory drugs like NSAIDS are associated with serious adverse effects like gastrointestinal ulcer, worsening of preexisting cardiovascular disorders, and renal failure. Therefore, there is a constant demand to develop novel, inexpensive therapeutic strategies to treat the inflammatory disorder with the least harmful effects. Pure phytochemicals with anti-inflammatory potential are costly and hard to isolate, therefore green microwave-assisted extraction technique is developed to get the rich bioequivalent extract. Berberis lycium a medicinal plant with berberine as a major bioactive constituent, has wide acceptance in traditionally used medicine and as food. Pharmacological studies revealed its hepatoprotective, anticancer, antidiabetic, and antihypertensive activities. BRE was prepared by green microwave-assisted extraction and enrichment by resin column to get a higher yield of berberine. The comparative anti-inflammatory effect of BRE and berberine was determined by in vitro and in vivo studies. Results obtained from this experimental work contribute beneficial guidance that reinforces the use of the BRE to treat inflammatory disorders.

Development of Oral Microemulsion Spray Containing Pentacyclic Triterpenes-Rich Centella asiatica (L.) Urb. Extract for Healing Mouth Ulcers

Several publications have shown that Centella asiatica (L.) Urb. and its active constituents (pentacyclic triterpenes) are effective in wound healing. The pentacyclic triterpenes-rich C. asiatica extract (PRE) was prepared following a previous study by microwave-assisted extraction (MAE) and fractionation with macroporous resin. This method provided the pentacyclic triterpene content in the extract up to 59.60% w/w. The PRE showed potent anti-inflammatory activity by inhibiting nitric oxide (NO) production with an IC50 value of 20.59 ± 3.48 μg/mL and a potent fibroblast proliferative effect (165.67%) at concentrations of 10 μg/mL. The prepared microemulsion consisted of a water: oil: surfactant mixture of 2: 2: 6, using coconut oil: clove oil (1:1) as the oil phase and Tween 20: Span 20 (2:1) as the surfactant mixture and 1.0, 2.5, and 5.0% PRE. Cell proliferation, migration, and collagen production of the microemulsion base and microemulsions containing 1.0%, 2.5%, and 5.0% PRE were evaluated. The results revealed that the microemulsion containing 1% PRE had the highest proliferation effect (136.30 ± 3.93% to 152.65 ± 3.48% at concentrations of 10 μg/mL), migration activities (100.00 ± 0.0% at 24 h), and collagen production in human dermal fibroblast (HDF) and human gingival fibroblast (HGF) cells when compared with other formulations or blank. Moreover, the anti-inflammatory activity of microemulsions containing 1% PRE was slightly lower than standard indomethacin. Anti-inflammation of the microemulsion containing PRE exhibited a dose-dependent trend, while 5% PRE was more potent than the standard drug. Considering the potent wound-healing activities and the good anti-inflammatory activity of the microemulsion containing PRE, the microemulsion with 1% PRE was identified as the most suitable oral spray formulation for oral ulcer treatment.

Extraction of a Triterpene Solution and Evaluation of the Hypolipidemic Efficacy of the Pleurotus tuber-regium (Fr.) Sing Sclerotium

The total triterpenes in edible mushrooms have high medicinal value, and the sclerotium has various biological activities, such as the regulation of blood pressure and blood glucose. In this study, the total triterpenes of the Pleurotus tuber-regium (Fr.) Sing Sclerotium (PTRSS) were extracted, and their hypolipidemic effects were also investigated. The infrared spectra showed that the total triterpenes were consistent with the characteristic structures of the total triterpenes before and after purification. The binding abilities of total triterpenes to sodium glycocholate, sodium taurocholate, and sodium cholate were investigated, and all of them had a good binding ability to cholate. In vivo experiments showed that zebrafish tolerated the total triterpenes from the mushroom nuclei at a maximum concentration of 500 µg/mL. A correlation analysis showed that the total triterpenes from the mushroom nuclei reduced the lipid accumulation in zebrafish induced by a high-fat diet, and the lipid-lowering effect showed a correlation with dose.

Green extraction optimization of triterpenoid glycoside-enriched extract from Centella asiatica (L.) Urban using response surface methodology (RSM)

Centella asiatica (L.) Urban extracts are widely used as food, drugs and cosmetics, and the main active compounds are glycosides (madecassoside and asiaticoside) and aglycones (madecassic acid and asiatic acid). Green extraction is an interesting concept that can produce safe and high-quality extracts that use less solvent, time and energy with the environmental friendly. This study investigated the optimum conditions for extracting a triterpenoid glycoside-enriched C. asiatica extract using microwave-assisted extraction (MAE) and ultrasound-assisted extraction (UAE). Central composite design and response surface methodology (RSM) were used for the experimental design and data analysis. Four-month-old C. asiatica tetraploid plants were selected as the elite raw material containing high amount of triterpenoid glycosides for the extraction experiments, and the triterpenoid content was determined by a validated HPLC method. The results demonstrated that the RSM models and equations were reliable and could predict the optimal conditions to enhance C. asiatica extract yield, glycoside and aglycone amounts. The percent of ethanol was the major factor that had a significant effect on C. asiatica yield and glycoside and aglycone content during MAE and UAE. The maximum triterpenoids content in extract; 7.332 ± 0.386% w/w madecassoside and 4.560 ± 0.153% w/w asiaticoside 0.357 ± 0.013% w/w madecassic acid and 0.209 ± 0.025% w/w asiatic acid were obtained by MAE with 80% ethanol at 100 watts for 7.5 min, whereas the optimal conditions for highest total triterpenoids extraction from dry plant was UAE with 80% ethanol, temperature 48 °C, 50 min enhanced 2.262 ± 0.046% w/w madecassoside, 1.325 ± 0.062% w/w asiaticoside, 0.082 ± 0.009% w/w madecassic acid and 0.052 ± 0.007% w/w asiatic acid as secondary outcome. Moreover, it was found that MAE and UAE consumed energy 59 and 54%, respectively, lower than that of the conventional method, maceration, in term of kilowatt-hour per gram of total triterpenoids. These optimized green conditions could be recommended for C. asiatica extraction for triterpenoid glycoside-enriched extracts production for the pharmaceutical or cosmeceutical industries and triterpenoids quantitative analysis in raw materials.

Mitoprotective Effects of Centella asiatica (L.) Urb.: Anti-Inflammatory and Neuroprotective Opportunities in Neurodegenerative Disease

Natural products remain a crucial source of drug discovery for accessible and affordable solutions for healthy aging. Centella asiatica (L.) Urb. (CA) is an important medicinal plant with a wide range of ethnomedicinal uses. Past in vivo and in vitro studies have shown that the plant extract and its key components, such as asiatic acid, asiaticoside, madecassic acid and madecassoside, exhibit a range of anti-inflammatory, neuroprotective, and cognitive benefits mechanistically linked to mitoprotective and antioxidant properties of the plant. Mitochondrial dysfunction and oxidative stress are key drivers of aging and neurodegenerative disease, including Alzheimer’s disease and Parkinson’s disease. Here we appraise the growing body of evidence that the mitoprotective and antioxidative effects of CA may potentially be harnessed for the treatment of brain aging and neurodegenerative disease.

Comparative Studies on Different Extraction Methods of Centella asiatica and Extracts Bioactive Compounds Effects on Antimicrobial Activities

The interest of consumers in using products containing phytochemicals derived from plants is growing day by day due to the shift of consumers' preferences from convenience to environmental sustainability. One plant utilized in many products is Centella asiatica, a herb commonly used in folk medicine, health supplements, and beauty products. Extraction of bioactive compounds from C. asiatica was performed using conventional methods and modern methods (e.g., microwave or ultrasound-assisted and subcritical water extraction). This review summarizes the variety of methods used to extract active compounds from C. asiatica, their influence on the bioactive compounds and antimicrobial activity in vitro and in vivo, and the safety and toxicology of C. asiatica extract.

Polymers Sorption Properties towards Photosynthetic Pigments and Fungicides

In the present work, extraction with a solvent (cold acetone) was used to extract the assimilation pigments from spinach leaves. Then, the sorption capacity of selected plastics granules (polyvinyl chloride—PVC, polypropylene—PP, polyethylene—PE of different densities) was tested for the selective isolation of chlorophylls. Quantification of chlorophylls by HPLC (Zorbax Eclipse XDB-C18 column, the mobile phase: Acetonitrile/methanol/ethyl acetate 6:2:2, v/v) was based on chlorophyll-a content as the most common chlorophyll. The performed experiments prove that PVC containing electronegative chlorine exhibits favorable interactions toward chlorophyll by creating stable molecular complexes. The Fourier Transform Raman Spectroscopy (FT-Raman) and the molecular modeling were used to elucidate the structure of the created complexes. The optimal extraction requirements, the mass of sorbent, water-acetone ratio, time, and the composition of the elution solvent were all established. The optimized extraction conditions ensured a maximum extraction yield of chlorophylls of 98%. The chlorophyll-rich sorbent was re-extracted by acetone, leading to the recovery of 91% of chlorophylls in one step, adding the possibility of its re-use. The proposed effective and ecological method of obtaining the green dye from plants is cheap, simple, and efficient, avoiding organic solvents, utilizing the most widely used synthetic polymers in the world, being products difficult for utilization. The possibility to remove chosen fungicides cyprodinil, chlorothalonil, and thiabendazone from plant extract by PVC was also examined. The described method proposes a new application of synthetic polymers, which meets the criteria of sustainable green chemistry, simultaneously reaching the growing demand for pure natural compounds in the pharmaceutical and food industries.

Development of a colorless Centella asiatica (L.) Urb. extract using a natural deep eutectic solvent (NADES) and microwave-assisted extraction (MAE) optimized by response surface methodology

This study outlines a green process for Centella asiatica (L.) Urb. (CA) extraction. Natural deep eutectic solvents (NADESs) and microwave-assisted extraction (MAE) were combined to provide a high bioactive compound yield and high antioxidant activity. Among the NADESs evaluated, the combination of acetylcholine chloride : malic acid : water (1 : 2 : 2): water (40 : 60) was the best for extraction. These conditions provide high madecassoside (MS) (21.7 mg g-1 dry weight) and asiaticoside (AS) (12.7 mg g-1 dry weight) yields, with greater than 80% (v/v) EtOH (13.3 mg g-1 MS and 7.80 mg g-1 AS). In addition, the extracts from this process showed higher antioxidant activity (IC50 = 0.26 mg mL-1) than the CA aqueous EtOH and water extracts. Moreover, the color of the extract products was less green than that of the extracts prepared using EtOH and aqueous EtOH as solvents, which are suitable for cosmeceutical products. Response surface methodology (RSM) was used for MAE optimization. The ANOVA data from the central composition design (CCD) of RSM were fitted with quadratic models yielding acceptable R 2 (>0.93), adjusted R 2 (>0.87), predicted R 2 (>0.81), and nonsignificant lack of fit (p  > 0.05) values. The quadratic model was validated using optimal conditions (30 s, power 300 W, and a liquid to solid ratio 20 mL g-1), and the model validation showed more than 80% accuracy in both MS and AS yields. This research presented an effective green process for CA extraction, which resulted in an environmentally friendly CA extract requiring little energy consumption and no organic solvents.

Strategies for Improving Healing of the Gastric Epithelium Using Oral Solid Dispersions Loaded with Pentacyclic Triterpene-Rich Centella Extract

The pentacyclic triterpenoid compounds in Centella asiatica extract, mainly consisting of asiaticoside (AS), asiatic acid (AA), madecassoside (MS), and madecassic acid (MA), possess wound healing and anti-ulcer properties, but their low aqueous solubility and dissolution rate are disadvantageous for oral administration. In this study, pentacyclic triterpene-rich centella extract (PRE) was combined with Eudragit® EPO as a hydrophilic polymer using solvent evaporation to produce a solid dispersion (PRE-ESD). The optimum PRE/Eudragit ratio of 1:2 enhanced the solubility and dissolution of glycosides (AS > 3.5 folds, MS > 2 folds) and aglycones (AA > 65 folds and MA > 56 folds) in 0.1 N hydrochloric acid (pH 1.2). DSC, XRD, and FT-IR analysis showed that the four pentacyclic triterpenes in PRE existed in the amorphous state in the solid dispersion. Moreover, almost 100% of the compounds were released from the solid dispersion within 2 h. The effects of PRE-ESD on cell proliferation and wound healing in vitro were investigated in human gastric epithelial cell lines (AGS cells). Exposure to PRE-ESD (equivalent to PRE concentration of 10 μg/mL) promoted cell proliferation and enhanced 'wound closure' in the scratch assay of wound healing by 82% compared with non-treated groups. Unformulated MA and AA aglycones did not exhibit a wound healing effect. Moreover, PRE-ESD was found to accelerate wound closure compared with either AS or MS, indicating that the wound healing properties of PRE-ESD are conferred by the active compounds AS and MS that are presented in PRE.

Rosmarinus officinalis L. (rosemary) as therapeutic and prophylactic agent

Rosmarinus officinalis L. (rosemary) is a medicinal plant native to the Mediterranean region and cultivated around the world. Besides the therapeutic purpose, it is commonly used as a condiment and food preservative. R. officinalis L. is constituted by bioactive molecules, the phytocompounds, responsible for implement several pharmacological activities, such as anti-inflammatory, antioxidant, antimicrobial, antiproliferative, antitumor and protective, inhibitory and attenuating activities. Thus, in vivo and in vitro studies were presented in this Review, approaching the therapeutic and prophylactic effects of R. officinalis L. on some physiological disorders caused by biochemical, chemical or biological agents. In this way, methodology, mechanisms, results, and conclusions were described. The main objective of this study was showing that plant products could be equivalent to the available medicines.