Extraction optimization of gallic acid, (+)-catechin, procyanidin-B2, (-)-epicatechin, (-)-epigallocatechin gallate, and (-)-epicatechin gallate: their simultaneous identification and quantification in Saraca asoca

Aromatase inhibitors identified from Saraca asoca to treat infertility in women with polycystic ovary syndrome via in silico and in vivo studies

Polycystic ovary syndrome (PCOS) is a widely occurring metabolic disorder causing infertility in 70%-80% of the affected women. Saraca asoca, an ancient medicinal herb, has been shown to have therapeutic effects against infertility and hormonal imbalance in women. This study was aimed to identify new aromatase inhibitors from S. asoca as an alternative to the commercially available ones via in silico and in vivo approaches. For this, 10 previously reported flavonoids from S. asoca were chosen and the pharmacodynamic and pharmacokinetic properties were predicted using tools like Autodock Vina, GROMACS, Gaussian and ADMETLab. Of the 10, procyanidin B2 and luteolin showed better interaction with higher binding energy when docked against aromatase (3S79) as compared to the commercial inhibitor letrozole. These two compounds showed higher stability in molecular dynamic simulations performed for 100 ns. Molecular mechanics Poisson-Boltzmann surface analysis indicated that these compounds have binding free energy similar to the commercial inhibitor, highlighting their great affinity for aromatase. Density functional theory analysis revealed that both compounds have a good energy gap, and ADMET prediction exhibited the drug-likeness of the two compounds. A dose-dependent administration of these two compounds on zebrafish revealed that both the compounds, at a lower concentration of 50 µg/ml, significantly reduced the aromatase concentration in the ovarian tissues as compared to the untreated control. Collectively, the in silico and in vivo findings recommend that procyanidin B2 and luteolin could be used as potential aromatase inhibitors for overcoming infertility in PCOS patients with estrogen dominance.Communicated by Ramaswamy H. Sarma.

Procyanidin B2: A promising multi-functional food-derived pigment for human diseases

Natural edible pigments play a paramount part in the food industry. Procyanidin B2 (PB2), one of the most representative naturally occurring edible pigments, is usually isolated from the seeds, fruits, and leaves of lots of common plants, such as grapes, Hawthorn, black soybean, as well as blueberry, and functions as a food additive in daily life. Notably, PB2 has numerous bioactivities and possesses the potential to treat/prevent a wide range of human diseases, such as diabetes mellitus, diabetic complications, atherosclerosis, and non-alcoholic fatty liver disease, and the underlying mechanisms were partially elucidated, including mediating signaling pathways like NF-κB, MAPK, PI3K/Akt, apoptotic axis, and Nrf-2/HO-1. This paper presents a review of the natural sources, bioactivities, and the therapeutic/preventive potential of PB2 and the possible mechanisms, with the aim of promoting the development of PB2 as a functional food and providing references for its clinical application in the treatment of diseases.

RP-HPLC-based phytochemical screening of different polyphenolic compounds from floral extract of four species of Saraca L. (Leguminosae)

Background

Saraca L. is one of the treasures throve of medicinally important plants in Indian subcontinent with its four species among which two are naturally distributed. It is one of the important resources of highly active phytochemicals due to which it proclaims a legendary position from ancient medicinal practices to modern ages. The crude extracts of flowers of four species were prepared using Soxhlet apparatus in petroleum benzene, ethyl acetate and 90% methanol sequentially. RP-HPLC (reverse-phase high-performance liquid chromatography)-based analysis of the presence of different phytochemicals using 15 different polyphenolic phytochemical standards was done to assess and quantify different phytochemicals.

Results

RP-HPLC-based evaluation revealed the presence different polyphenolic compounds like catechins, chlorogenic acid, vanillic acid, caffeic acid, gallic acid, t-cinnamic acid, anthrol, p-coumaric acid, biochanin A, etc., in a considerable amount which is very crucial for the phytomedicinal field. The correlations of the presence of known phytochemicals give a basis of phytochemical correlation among the four species. The RP-HPLC chromatographic data were applied to develop the complete phytochemical coding according to the complete set of chemicals found among the species to evaluate phytochemical correlation among them in a different way. This application also produces strong evidence of distinguishing features of S. indica and S. asoca that were considered as same species by some traditional taxonomy.

Conclusion

Extracts of S. thaipingensis contain highest amount of polyphenolic compounds, and the lowest amount was found in S. declinata. The phytochemical relations among S. asoca and S. declinata are high, and S. indica also has close relations with them, but S. thaipingensis has distinct divergence.

Sequential Extraction of Proanthocyanidin Fractions from Ficus Species and Their Effects on Rumen Enzyme Activities In Vitro

Three proanthocyanidin fractions per species were sequentially extracted by 50% (v/v) methanol−water, 70% (v/v) acetone−water, and distilled water from leaves of Ficus racemosa (fractions FR) and F. religiosa (fractions FRL) to yield fractions FR-50, FR-70, FR-DW, FRL-50, FRL-70, and FRL-DW. Fractions were examined for their molecular structure, effect on ruminal enzyme activities, and principal leaf protein (Rubisco) solubilization in vitro. All fractions except FRL-70 contained flavonoids including (+) catechin, (−) epicatechin, (+) gallocatechin, (−) epigallocatechin, and their -4-phloroglucinol adducts. The fractions FRL-50 and FRL-DW significantly (p < 0.05) inhibited the activity of ruminal glutamic oxaloacetic transaminase and glutamic pyruvic transaminase. All fractions inhibited glutamate dehydrogenase activity (p < 0.05) with increasing concentration, while protease activity decreased 15−18% with increasing concentrations. Fractions FRL-50 and FRL-DW completely inhibited the activity of cellulase enzymes. Solubilization of Rubisco was higher in F. religiosa (22.36 ± 1.24%) and F. racemosa (17.26 ± 0.61%) than that of wheat straw (WS) (8.95 ± 0.95%) and berseem hay (BH) (3.04 ± 0.08%). A significant (p < 0.05) increase in protein solubilization was observed when WS and BH were supplemented with FR and FRL leaves at different proportions. The efficiency of microbial protein was significantly (p < 0.05) greater in diets consisting of WS and BH with supplementation of F. racemosa leaves in comparison to those supplemented with F. religiosa leaves. The overall conclusion is that the fractions extracted from F. religiosa showed greater inhibitory effects on rumen enzymes and recorded higher protein solubilization in comparison to the F. racemosa. Thus, PAs from F. religiosa are potential candidates to manipulate rumen enzymes activities for efficient utilization of protein and fiber in ruminants.

Metabolomic profile of medicinal plants with anti-RVFV activity

Twenty medicinal plants with previously established anti-viral activity against a wild-type RVFV were further investigated using bio-chemometric and analytical techniques. The aim being to identify compounds common in plants with anti-RVFV activity, potentially being the major contributors to the anti-viral effect. Proton nuclear magnetic resonance (¹H NMR) spectroscopy coupled with multivariate data analysis (MVDA) was applied to characterize metabolite profiles of twenty antiviral medicinal plants. Discrimination and prediction of metabolome data of active anti-RVFV from the less-active samples was assessed using the multivariate statistical models by constructing a robust principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA) regression model. Annotation of metabolites in the samples with higher activity were performed by Chenomx software and the compounds confirmed using Ultra-High-Performance Liquid Chromatography-Quadrupole Time-of-Flight Mass Spectrometry (UHPLC-qTOF-MS). Both the PCA and OPLS-DA score plots showed clustering of samples; however, the OPLS-DA plot indicated a clear separation among active and less-active samples. Metabolic biomarkers were screened by p-value < 0.05 and variable importance in the projection (VIP) value >1 and S-plot. Among active samples, the most prominent metabolites putatively identified by NMR include trigonelline, vanillic acid, fumarate, chlorogenic acid, ferulate, and formate. The presence of the compounds were confirmed by UHPLC-qTOF-MS, and two hydroxylated fatty acids were additionally detected indicated by peaks at m/z 293.2116 and m/z 295.2274 13S-Hydroxy-9Z,11E,15Z-octadecatrienoic acid and 13-Hydroxy-9Z,11E-octadecadienoic acid were annotated for the first time in all the antiviral active samples and are considered potential metabolites responsible for the antiviral activity. The study provides a metabolomic profile of anti-RVFV plant extracts and report for the first time the presence of hydroxylated fatty acids 13S-Hydroxy-9Z,11E,15Z-octadecatrienoic acid and 13-Hydroxy-9Z,11E-octadecadienoic acid, present in all the tested medicinal plants with high anti-RVFV activity and is a potential target for the future development of antiviral therapeutic agents.

Multi-response optimal hot pressurized liquid recovery of extractable polyphenols from leaves of maqui (Aristotelia chilensis [Mol.] Stuntz)

Multi-response optimization of hot pressurized liquid extraction (HPLE) was applied for the first time to obtain maqui (Aristotelia chilensis [Mol.] Stuntz) leaf extracts. The total polyphenol content (TPC), the antioxidant capacity (AC) as well as the total polyphenol purity of the maqui leaf extracts were accurately predicted (RSD < 8%) at the evaluated extraction scales. The optimum HPLE conditions that prioritized TPC and AC equally (OPT1) recovered ~3 times more TPC (205.14 mg GAE/g leaves) than maqui leaf extracts obtained by maceration, while the extract that prioritized purity over TPC and AC presented the highest purity (36.29%) and an EC50 ~3 times lower than currently reported values. It was found by multi-response optimization that maqui leaves and HPLE are among the best natural sources and extraction techniques, respectively, to recover protocatechuic acid, quercetin, and catechin.

In Vitro Evaluation of Anti-Rift Valley Fever Virus, Antioxidant and Anti-Inflammatory Activity of South African Medicinal Plant Extracts

Rift valley fever virus (RVFV) is a mosquito-borne virus endemic to sub-Saharan African countries, and the first sporadic outbreaks outside Africa were reported in the Asia-Pacific region. There are no approved therapeutic agents available for RVFV; however, finding an effective antiviral agent against RVFV is important. This study aimed to evaluate the antiviral, antioxidant and anti-inflammatory activity of medicinal plant extracts. Twenty medicinal plants were screened for their anti-RVFV activity using the cytopathic effect (CPE) reduction method. The cytotoxicity assessment of the extracts was done before antiviral screening using the MTT assay. Antioxidant and reactive oxygen/nitrogen species' (ROS/RNS) inhibitory activity by the extracts was investigated using non-cell-based and cell-based assays. Out of twenty plant extracts tested, eight showed significant potency against RVFV indicated by a decrease in tissue culture infectious dose (TCID50) < 105. The cytotoxicity of extracts showed inhibitory concentrations values (IC50) > 200 µg/mL for most of the extracts. The antioxidant activity and anti-inflammatory results revealed that extracts scavenged free radicals exhibiting an IC50 range of 4.12-20.41 µg/mL and suppressed the production of pro-inflammatory mediators by 60-80% in Vero cells. This study demonstrated the ability of the extracts to lower RVFV viral load and their potency to reduce free radicals.

Composition and Antibacterial Activity of Aronia melanocarpa (Michx.) Elliot, Cornus mas L. and Chaenomeles superba Lindl. Leaf Extracts

The purpose of this study was to investigate the composition of leaf extracts from Aronia melanocarpa, Chaenomeles superba, and Cornus mas, and their antimicrobial activity against typical spoilage-causing and pathogenic bacteria found in meat and meat products. The highest total phenolic content (TPC) was detected in C. superba extract, followed by C. mas and A. melanocarpa extracts. The antioxidant capacity of the extracts was measured by DPPH and ABTS assays. The lowest IC₅₀ values were found for C. superba extract, followed by C. mas and A. melanocarpa extracts. LC-MS and HPLC analysis revealed that A. melanocarpa and C. superba extracts contained hydroxycinnamic acid derivatives and flavonoids (mainly flavonols). Hydroxycinnamic acid derivatives were detected in the C. mas extract, as well as flavonols, ellagitannins, and iridoids. The antibacterial activity of the plant extracts was tested against Gram-negative bacteria (Moraxella osloensis, Pseudomonas fragi, Acinetobacter baumanii, Escherichia coli, Enterobacter aerogenes, Salmonella enterica) and Gram-positive bacteria (Enterococcus faecium, Staphylococcus aureus, Brochothrix thermosphacta, Lactobacillus sakei, Listeria monocytogenes) using the microculture method. The extracts acted as bacteriostatic agents, decreasing the growth rate (µ_max) and extending the lag phase (t_lag). C. mas showed most potent antibacterial activity, as confirmed by principal component analysis (PCA).

Valorisation of baobab (Adansonia digitata) seeds by ultrasound assisted extraction of polyphenolics. Optimisation and comparison with conventional methods

In this study, ultrasound-assisted extraction (UAE) of phenolic compounds in baobab (Adansonia digitata) seeds was optimised using RSM. Based on the single factor experiment results, the effect of four parameters, extraction time (10-20 min), temperature (40-60 °C), % amplitude (30-50) and solvent to solid ratio (20-30, mL/g) on Total Flavonoids Content (TFC) were investigated and optimised using a central composite design (CCD). The predicted optimal conditions with the highest desirably (0.874) were: 20 min, 30% amplitude, 60 °C temperature and 30 mL/g solvent to solid ratio. Under these conditions, the experimental TFC value (1633.84 ± 10.75 mg RE/100 g DW) was highly correlated with the predicted value (1631.77 mg RE/100 g DW). Moreover, a comparative study confirmed that the recovery of TFC, TPC and antioxidant activity (DPPH and FRAP) was significantly higher in UAE than maceration and Heat Assisted Extraction (HAE) extraction methods in addition to a shorter extraction time. HPLC analysis of the UAE optimised sample extract revealed the presence of 10 phenolic compounds with the highest concentration of D-(+) catechin (87.18 ± 14.57 µg/g). This study is the first attempt to optimise UAE parameters for the extraction of phenolic compounds in baobab seeds.

Gallic acid targets acute myeloid leukemia via Akt/mTOR-dependent mitochondrial respiration inhibition

Gallic acid is one of the many phenolic acids that can be found in dietary substances and traditional medicine herbs. The anti-cancer activities of gallic acid have been shown in various cancers but its underlying molecular mechanisms are not well understood. In this study, we show Akt/mammalian target of rapamycin (mTOR)-dependent inhibition of mitochondrial respiration as a mechanism of gallic acid's action in acute myeloid leukemia (AML). Gallic acid significantly induces apoptosis of AML cell lines, primary mononuclear cells (MNC) and CD34 stem/progenitors isolated form AML patients via caspase-dependent pathway. It also significantly enhances two standard AML chemotherapeutic agents' efficacy in vitro cell culture system and in vivo xenograft model. Gallic acid inhibits dose- and time-dependent mitochondrial respiration, leading to decreased ATP production and oxidative stress. Overexpression of constitutively active Akt restores gallic acid-mediated inhibition of mTOR signaling, mitochondrial dysfunction, energy crisis and apoptosis. Our results demonstrate that mitochondrial respiration inhibition by gallic acid is a consequence of Akt/mTOR signaling suppression. Our findings suggest that combination therapy with gallic acid may enhance antileukemic efficacy of standard chemotherapeutic agents in AML.

Baccaurea angulata fruit juice ameliorates altered hematological and biochemical biomarkers in diet-induced hypercholesterolemic rabbits

Hypercholesterolemia is an important risk factor linked to the alteration of blood hematology and clinical chemistry associated with the development and progression of atherosclerosis. Previous studies have demonstrated the safety and potential health benefits of Baccaurea angulata (BA) fruit. We hypothesized that the oral administration of BA fruit juice could ameliorate the alteration in the hematological and biochemical biomarkers of diet-induced hypercholesterolemic rabbits. The aim of this study was to investigate the effects of different doses of BA juice on the hematological and biochemical biomarkers in normo- and hypercholesterolemic rabbits. Thirty-five healthy adult New Zealand White rabbits were assigned to seven different groups for 90days of diet intervention. Four atherogenic groups were fed a 1% cholesterol diet and 0, 0.5, 1.0, and 1.5mL of BA juice per kg of rabbit daily. The other three normal groups were fed a commercial rabbit pellet diet and 0, 0.5, and 1.0mL of BA juice per kg of rabbit daily. Baseline and final blood samples after 90days of repeated administration BA juice were analyzed for hematological parameters while serum, aortic and hepatic lysates were analyzed for lipid profiles and other biochemical biomarkers. The alteration of the hemopoietic system, physiological changes in serum and tissues lipid profiles and other biochemicals resulting from the consumption of a high-cholesterol diet were significantly (P<.05) ameliorated by the administration of BA juice. Improvements of the biomarkers in rabbits were dose-dependent, markedly enhanced at the highest dose of juice (1.5mL/kg/day). The results suggest potential health benefits of the antioxidant-rich BA fruit juice against hypercholesterolemia-associated hematological and biochemical alterations in the rabbit.