In vitro inhibitory effects of SardinianPistacia lentiscusL. andPistacia terebinthusL. on metabolic enzymes: Pancreatic lipase, α-amylase, and α-glucosidase

Pistacia lentiscus: Phytochemistry and Antidiabetic Properties

Pistacia lentiscus L. (P. lentiscus) is an evergreen shrub (Anacardiaceae family) primarily found in the Mediterranean region. The plant has been thoroughly characterized, resulting in a high concentration of bioactive compounds as flavonoids and phenolics. Moreover, P. lentiscus was revealed to possess a great nutritional and industrial importance because of its variety of biological activities, including antibacterial, anti-inflammatory, anti-atherogenic and antioxidant properties. Many of its beneficial health properties and applications date back to antiquity, and the European Medicines Agency officially acknowledged it as an herbal medicinal product. Indeed, it is widely employed in conventional medicine to treat several diseases, including type 2 diabetes (T2D). On this basis, this review aims to summarize and describe the chemical composition of different parts of the plant and highlight the potential of P. lentiscus, focusing on its antidiabetic activities. The plant kingdom is drawing increasing attention because of its complexity of natural molecules in the research of novel bioactive compounds for drug development. In this context, P. lentiscus demonstrated several in vitro and in vivo antidiabetic effects, acting upon many therapeutic T2D targets. Therefore, the information available in this review highlighted the multitarget effects of P. lentiscus and its great potential in T2D treatment.

The Phenolic Content of Pistacia lentiscus Leaf Extract and Its Antioxidant and Antidiabetic Properties

The aims of this study were to determine the polyphenolic profile, to estimate the total phenolic and flavonoid contents, and to evaluate the antioxidant and antidiabetic activities of the extract of Pistacia lentiscus leaves, and the hydroacetonic mixture was employed as an alternative for common solvents in the extraction process. In order to explain the antidiabetic activity, molecular docking has been performed on the main constituents of the leaf extract. The characterization of the extract has been performed by high-performance liquid chromatography (HPLC) leading to the detection of 20 compounds of which gallic acid, ellagic acid, catechin, kaempferol, and quercetin 3-glucoside were identified using authentic standards. The total phenolic and flavonoid contents, assessed using the Folin-Ciocalteu and quercetin methods, were 394.5 ± 0.08 mg gallic acid equivalent/g dry extract (mg GAE/g DE) and 101.2 ± 0.095 mg quercetin equivalent/g dry extract (mg QE/g DE), respectively. On the other hand, the antioxidant activity of leaf extract, quantified by determining the ability to neutralize the free radical DPPH and β-carotene/linoleate model system, reached the values of 0.0027 ± 0.002 mg/mL and 0.128 ± 0.04 mg/mL, respectively. Regarding the antidiabetic activity, based on the inhibition of pancreatic α-amylase activity, a significant inhibition of about 68.20% with an IC50 value of 0.266 mg/mL had been observed. This finding is consistent with the molecular docking study of the main phenolic compounds of the extracts, where a remarkable binding affinity against α-amylase was observed, with values of -7.631 (kcal/mol), -6.818 (kcal/mol), and -5.517 (kcal/mol) for the major compounds catechin, quercetin-3-glucoside, and gallic acid, respectively.

Analysis of the Chemical Composition and Evaluation of the Antioxidant, Antimicrobial, Anticoagulant, and Antidiabetic Properties of Pistacia lentiscus from Boulemane as a Natural Nutraceutical Preservative

Pistacia lentiscus L. has traditionally been employed as a diuretic and stimulant in the treatment of hypertension. Our interest centered on analyzing the chemical profile of the plant's leaves and its in vitro, in vivo, and in silico antioxidant, antimicrobial, anticoagulant, and antidiabetic effects in order to valorize this species and prepare new high-value products that can be used in the agro-food and pharmaceutical industries. When this species' essential oil was hydrodistilled and subjected to GC-MS analysis, the results showed that the principal components were germacrene D (17.54%), spathulenol (17.38%), bicyclogermacrene (12.52%), and terpinen-4-ol (9.95%). The extraction of phenolic compounds was carried out by decoction and Soxhlet. The determination of total polyphenols, flavonoids, and tannins of aqueous and organic extracts by spectrophotometric methods demonstrated the richness of this species in phenolic compounds. Chromatographic analysis by HPLC/UV-ESI-MS of the aqueous extract of P. lentiscus revealed the presence of 3,5-di-O-galloyl quinic acid, gallic acid, and 3,4,5-tri-O-galloyl quinic acid specific to this species. The study of antioxidant activity by three methods (DPPH, FRAP, and Total Antioxidant Capacity) revealed that P. lentiscus is a very promising source of natural antioxidants. The antimicrobial activity of the essential oil and aqueous extract (E0) was studied by microdilution on the microplate. The results revealed the effectiveness of the aqueous extract compared to the essential oil against Gram-negative bacteria (K. pneumoniae, A. baumannii, E. aerogenes, E. cloacae, P. fluorescence, Salmonella sp., Shigella sp., and Y. enterolitica) and candidoses (C. krusei and C. albicans). The measurements of prothrombin time (PT) and activated partial thromboplastin time (aPTT) of the aqueous extract (E0) can significantly prolong these tests from concentrations of 2.875 and 5.750 mg/mL, respectively. The antihyperglycemic effect of the aqueous extract (E0) showed a strong in vitro inhibitory activity of α-amylase and α-glucosidase compared to acarbose. Thus, it significantly inhibited postprandial hyperglycemia in Wistar albino rats. The in-silico study of the major compounds of the essential oil and extract (E0) carried out using PASS, SwissADME, pkCSM, and molecular docking tools confirmed our in vitro and in vivo results. The studied compounds showed a strong ability to be absorbed by the gastrointestinal tract and to passively diffuse through the blood-brain barrier, a similarity to drugs, and water solubility. Molecular docking experiments deduced the probable mode of action of the identified compounds on their respective target proteins, such as NADPH oxidase, thrombin, α-amylase, and α-glucosidase. Furthermore, given the demonstrated antioxidant, antimicrobial, anticoagulant, and antidiabetic effects, we can affirm the richness of P. lentiscus in bioactive molecules and its use in traditional medicine as a source of preservative agent.

Metabolomics-Based Profiling via a Chemometric Approach to Investigate the Antidiabetic Property of Different Parts and Origins of Pistacia lentiscus L

Pistacia lentiscus L. is a medicinal plant that grows spontaneously throughout the Mediterranean basin and is traditionally used to treat diseases, including diabetes. The aim of this work consists of the evaluation of the α-glucosidase inhibitory effect (i.e., antidiabetic activity in vitro) of different extracts from the leaves, stem barks and fruits of P. lentiscus harvested on mountains and the littoral of Tizi-Ouzou in Algeria. Metabolomic profiling combined with a chemometric approach highlighted the variation of the antidiabetic properties of P. lentiscus according to the plant's part and origin. A multiblock OPLS analysis showed that the metabolites most involved in α-glucosidase inhibition activity were mainly found in the stem bark extracts. The highest inhibitory activity was found for the stem bark extracts, with averaged inhibition percentage values of 84.7% and 69.9% for the harvested samples from the littoral and mountain, respectively. On the other hand, the fruit extracts showed a lower effect (13.6%) at both locations. The UHPLC-ESI-HRMS characterization of the metabolites most likely responsible for the α-glucosidase-inhibitory activity allowed the identification of six compounds: epigallocatechin(4a>8)epigallocatechin (two isomers), (epi)gallocatechin-3'-O-galloyl-(epi)gallocatechin (two isomers), 3,5-O-digalloylquinic acid and dihydroxy benzoic acid pentoside.

A Review of Pistacia lentiscus Polyphenols: Chemical Diversity and Pharmacological Activities

Pistacia lentiscus (lentisk) is a plant species of the Anacardiaceae family. It is a medicinal plant that grows wild in the Mediterranean region. This review aims to update the existing knowledge regarding P. lentiscus polyphenols by consulting references dated from 1996 to 2022. The data are organized and analyzed as follows: (i) to show the chemical diversity of phenolic products from P. lentiscus; (ii) to summarize the variability in phenolic composition and quantity; this could be attributed to plant origin, environmental conditions, phenological stage, and the polarity of the extraction solvents; (iii) to present the pharmacological properties in agreement with the traditional uses of this plant; and (iv) to demonstrate the correlation between the chemical profile and the pharmacological effect. Various compositions were observed, including phenolic acids, flavonoid glycosides, anthocyanins, catechins, and their derivatives. The biological and therapeutic potentials of lentisk extracts have been evaluated in terms of antioxidant, antimicrobial, and anti-inflammatory activities. Most of these activities are related to the phenolic composition of this plant. The content of this review will undoubtedly contribute to the choice of techniques for isolating the different bioactive molecules contained in the P. lentiscus. It is also of significance for the potential development of a micro-industrial sector based on the valorization of lentisk polyphenols.

Effect of the main constituents of Pistacia lentiscus leaves against the DPPH radical and xanthine oxidase: experimental and theoretical study

The aim of this work is to study the content of phenolic compounds in P lentiscus leaves and their antioxidant effect. After extracting the phenolic compounds, fractionation by liquid/liquid partition with increasing polarity gives five extracts. Three of them (ButF, AqF and ButA) were found to have good antioxidant activity. Their IC_50s for the inhibition of the free radical formation of DPPH are 1.76 µg/mL, 1.307 µg/ml, and 1.77 µg/mL, respectively. These values are very interesting, considering the effect of the powerful flavonoid quercetin, whose IC₅₀ against DPPH is 1.53 µg/mL. These extracts are also active against xanthine oxidase (XO). The IC_50s measured are 0.14 mg/mL, 0.186 mg/mL and 0.33 mg/mL for ButF, Aq F and ButAq F extract respectively, in comparison with allopurinol (0.44 mg/mL). A phytochemical analysis by LC/ESI-MS-MS was performed to explain the observed activities. The results show 22 peaks representing: flavanols, namely catechin, d-Gallocatechin, and gallocatechin gallate. The only flavone detected in the studied extracts was luteolin glucuronide and was found to be in higher amounts in butanolic extract (2,71mg/mL). The phenolic acids and derivatives were also identified in the extracts. A theoretical study was performed to deduce the specificity of the binding between the major compounds identified in the P. lentiscus extract and the xanthine oxidase enzyme using Schrödinger software. The docking procedure was validated using the extraction of ligands from the binding site. Their re-anchoring to the xanthine oxidase structure using quercetin and allopurinol was considered reference molecules. After docking, post-docking minimization was performed to achieve the best scoring poses with the MM-GBSA approach. The dGBind energy of MM-GBSA representing the binding energy of the receptor and the ligand was calculated based on molecular mechanics. Results reveal that β-Glucogallin compounds such as Digalloylquinic acid, Gallocatechin, and Myricetin-3-O rhamnoside are more active than allopurinol, with stronger Docking score (Gscore) and MM-GBSA dGBind.Communicated by Ramaswamy H. Sarma.

Investigation of Enzyme Inhibitory Activities, Antioxidant Activities, and Chemical Properties of Pistacia vera Leaves Using LC-QTOF-MS and RP-HPLC

Since the leaves of some Pistacia species are used in traditional folk medicine for diabetes, this study investigated the in vitro antidiabetic effect (α-glucosidase and α-amylase) of Pistacia vera leaves. Additionally, the current study investigated the antihypercholesterolemic (cholesterol esterase), antiobesity (pancreatic lipase), and antioxidant activities (i.e., total antioxidant capacity, DPPH (2,2-Diphenyl-1-picrylhydrazyl) radical scavenging activity, metal chelating activity, and ferric-reducing antioxidant power) of P. vera leaves. The aqueous-alcoholic leaf extract inhibited α-amylase, α-glucosidase, and pancreatic lipase with the half-maximal inhibitory concentration values of 7.74 ± 0.72, 11.08 ± 3.96, and 168.43 ± 26.10 µg/mL, respectively. It was determined that the crude extract had high DPPH radical scavenging activity, ferric-reducing power, and moderate metal chelating activity. The ethyl acetate (EtOAc) subextract obtained by the liquid-liquid fractionation of the crude extract showed potent α-amylase and α-glucosidase inhibitory activities. The EtOAc subextract (5.794 ± 0.027 g/100 g subextract) was standardized by reversed-phase high-performance liquid chromatography based on β-pentagalloyl glucose, which showed inhibitory effects on both amylase and glucosidase enzymes. Fifteen compounds, seven of which are organic acid derivatives and eight of which are flavonoids, were identified by liquid chromatography quadrupole time-of-flight mass spectrometry (LC-QTOF-MS) analysis in the crude extract of P. vera leaves. Seven of the fifteen phenolic compounds detected in the crude extract by LC-QTOF-MS have both glucosidase and amylase inhibitory effects. As a result, P. vera leaves can be a potential source for compounds with high antioxidant effects that show inhibitory effects on enzymes involved in carbohydrate digestion in the prevention and treatment of diabetes or can be evaluated as a standardized extract.

In Vitro and In Silico Study of the α-Glucosidase and Lipase Inhibitory Activities of Chemical Constituents from Piper cumanense (Piperaceae) and Synthetic Analogs

Digestive enzymes are currently considered important therapeutic targets for the treatment of obesity and some associated metabolic diseases, such as type 2 diabetes. Piper cumanense is a species characterized by the presence of bioactive constituents, particularly prenylated benzoic acid derivatives. In this study, the inhibitory potential of chemical constituents from P. cumanense and some synthesized compounds was determined on digestive enzymes (pancreatic lipase (PL) and α-glucosidase (AG)). The methodology included isolating and identifying secondary metabolites from P. cumanense, synthesizing some analogs, and a molecular docking study. The chemical study allowed the isolation of four prenylated benzoic acid derivatives (1–4). Four analogs (5–8) were synthesized. Seven compounds were found to significantly inhibit the catalytic activity of PL with IC₅₀ values between 28.32 and 55.8 µM. On the other hand, only two compounds (6 and 7) were active as inhibitors of AG with IC₅₀ values lower than 155 µM, standing out as the potential multitarget of these chromane compounds. Enzyme kinetics and molecular docking studies showed that the bioactive compounds mainly interact with amino acids other than those of the catalytic site in both PL and AG. This work constitutes the first report on the antidiabetic and antiobesity potential of substances derived from P. cumanense.

Profiling of Essential Oils from the Leaves of Pistacia lentiscus Collected in the Algerian Region of Tizi-Ouzou: Evidence of Chemical Variations Associated with Climatic Contrasts between Littoral and Mountain Samples

Leaves of Pistacia lentiscus were collected from two Algerian sites in the mountains and the littoral of the Tizi-Ouzou region. The harvest was conducted in four consecutive seasons on the same selected set of trees. Essential oils (EOs) were extracted by hydrodistillation; then, they were analyzed by gas chromatography coupled mass spectrometry (GC-MS). Forty-seven constituents could be detected and quantified, including α-pinene (2–13%), β-caryophyllene (8–25%), β-myrcene (0.3–19%), bornyl acetate (0.8–7%), δ-cadinene (3–8%), bisabolol (1–9%), β-pinene (0.9–7%), caryophyllene oxide (4–9%), and α-cadinol (3–11%). Antioxidant (AOx) activities of the EOs were assessed by ferric reducing antioxidant power (FRAP), 2,2-diphenyl-1-picrylhydrazyl (DPPH), and 2,2′-azino-bis (3-ethylbenzothiazoline)-6-sulfonic acid (ABTS) assays. Significant differences in EO composition and AOx activities appeared dependent on the season and the site. Variations of AOx activities were significant for the FRAP and ABTS tests but not for DPPH. Characterization of the leaf fatty acyl (FA) profiles was performed by GC-MS. Variability appeared according to season and altitude. Polyunsaturated fatty acids levels were high (27–55%) at the coldest date and place. The levels of linolenic acyl in the leaves were significantly correlated with bisabolol levels in the EOs (Spearman’s correlation coefficient: 0.818). Such results will be useful for the sustainable local valorization of wild P. lentiscus. These data also open new routes for further studies on terpenoid biosynthesis using correlation networks and fluxomic approaches.

Optimization of a Green Ultrasound-Assisted Extraction of Different Polyphenols from Pistacia lentiscus L. Leaves Using a Response Surface Methodology

Pistacia lentiscus leaves are used in several applications, thanks to their polyphenolic abundance. Thiswork aimed to characterize the polyphenols and to optimize the extraction conditions to shorten the time, decrease the consumption of solvent, and to maximize the yield of different classes of phenolics, which have diverse industrial applications. The variables were optimized by applying a Box-Behnken design. Galloyl and myricetin derivatives were the most abundant compounds, and two new tetragalloyl derivatives were identified by LC-MS/MS. According to the models, the maximum yields of polyphenols (51.3 ± 1.8 mg g-1 DW) and tannins (40.2 ± 1.4 mg g-1 DW) were obtained using 0.12 L g-1 of 40% ethanol at 50 °C. The highest content of flavonoids (10.2 ± 0.8 mg g-1 DW) was obtained using 0.13 L g-1 of 50% ethanol at 50 °C, while 0.1 L g-1 of 30% ethanol at 30 °C resulted in higher amounts of myricitrin (2.6 ± 0.19 mg g-1 DW). Our optimized extraction decreased the ethanolic fraction by 25% and halved the time compared to other methods. These conditions can be applied differently to obtain P. lentiscus extracts richer in tannins or flavonoids, which might be employed for various purposes.

Antidiabetic and Anticholinesterase Properties of Extracts and Pure Metabolites of Fruit Stems of Pistachio (Pistacia vera L.)

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Five metabolites were isolated by chromatographic methods from the fruit stems of P. vera and their chemical structures were characterized as masticadienonic acid (1), tirucallol (2), masticadienolic acid (3), pistachionic acid (4) and inulobiose (5) via FT-IR, 1H-NMR, 13C-NMR, 1D-NMR and 2D-NMR. Pistachionic acid (4), a new shikimic acid derivative, was isolated from the ethanol extract for the first time. The hexane, chloroform, ethanol extracts and pure metabolites exhibited antidiabetic properties by inhibiting α- glycosidase and α-amylase enzymes at different rates. Their inhibitory effects against the α- glycosidase enzyme were also higher than that of the acarbose (IC50=10.30 mg/mL). Masticadienolic acid (3) (IC50=0.03 mg/mL), masticadienonic acid (1) (IC50=0.13 mg/mL) and hexane extract (IC50=0.09 mg/mL) with the lowest IC50 values were found to be most active substances. Nevertheless, the inhibitory effect of acarbose against the α-amylase enzyme was determined to be higher than the inhibition effects of the extracts and pure metabolites. According to the IC50 values, the best inhibitors against the α-amylase were ethanol extract (IC50=5.17 mg/mL), pistachionic acid (4) (IC50=7.35 mg/mL), tirucallol (2) (IC50=7.58 mg/mL) and masticadienolic acid (3) (IC50=8.22 mg/mL), respectively among the applications. In addition, anticholinesterase properties of the extracts and pure metabolites were investigated by testing the inhibitory properties against acetylcholine esterase (AChE) and butrylcholine esterase (BChE) enzymes activities. The results showed that the anticholinesterase properties of all extracts and pure metabolites were weaker than those of the commercial cholinesterase inhibitors, neostigmine and galantamine, and all applications reduced the activity of these enzymes at very high concentrations.

Chemometric discrimination of three Pistacia species via their metabolic profiling and their possible in vitro effects on memory functions

Alzheimer's disease (AD) is the most widespread neurodegenerative disease; there are around ten million new cases of Alzheimer yearly worldwide especially in middle or low-income countries. Pistacia is a genus of flowering plants including the well-known, economically important P. chinensis Bunge, P. lentiscus L. and P. khinjuk. In this study, the metabolic profiling of Pistacia leaves extracts was achieved via UHPLC-ESI-MS analysis and GC-MS analysis employing chemometric analysis for their discrimination. In addition, the methanolic extracts of different Pistacia species were assessed for their anti-cholinesterase and anti-inflammatory activities by various in vitro assays. 37 and 30 metabolites belonging to different classes were identified by UHPLC-ESI-MS and GC-MS analyses respectively. Chemometric analysis revealed that P. lentiscus and P. khinjuk were more closely related chemically to each other. All studied Pistacia leaves extracts showed apparent anti-cholinesterase and anti-inflammatory activities, which promotes their use in the prevention and management of AD.