In vitro assessment of selected Korean plants for antioxidant and antiacetylcholinesterase activities

Context: Antiacetylcholinesterase (AChE) drugs have been a main therapeutic treatment for Alzheimer’s disease because increased AChE levels play a key role in reducing neurotransmission.

Objectives: Extracts from 35 Korean plants were selected and screened for antioxidant and anti-cholinesterase activity to explore new sources derived from Korean natural resources that could be used as AD therapeutic agents.

Materials and methods: The antioxidant effect of extracts from 35 selected Korean plants was determined using two most common free radical scavenging assays using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2′-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS). Additionally, the effect of extracts, identified as antioxidants, on acetylcholinesterase inhibition was assessed by an acetylcholinesterase assay kit.

Results: Out of 36 extracts of 35 plants tested, Oenothera biennis L. (9.09?μg/mL), Saururus chinensis (Lour.) Baill. (9.52?μg/mL) and Betula platyphylla var. japonica (9.85?μg/mL) showed strong DPPH scavenging activity. Twelve other extracts also exerted moderate free radical scavenging activities with IC₅₀ values ranging from 10 to 50?μg/mL. Antioxidant capacity detected by ABTS assay was only significant in O. biennis (23.40?μg/mL), while the other extracts were weak or unable to reduce the production of ABTS. Based on the antioxidant activities of these plant extracts, 19 extracts with IC₅₀ values less than 100?μg/mL in DPPH assay were selected for further AChE inhibition assay. Among the extracts tested, the IC₅₀ value for Prunella vulgaris var. lilacina NAKAI (18.83?μg/mL) in AChE inhibitory activity was the lowest, followed by O. biennis (20.09?μg/mL) and Pharbitis nil Chosy (22.79?μg/mL).

Conclusions: Considering complex multifactorial etiology of AD, the extracts of P. vulgaris var. lilacina (aerial part), O. biennis (seed) and P. nil (seed) may be safe and ideal candidates for future AD modifying therapies.     

Antimicrobial,anticancer, and antioxidant compounds from Premna resinosa growing in Saudi Arabia

Context: Premna resinosa (Hochst.) Schauer (Lamiaceae) is used in many places to treat bronchitis, respiratory illness and convulsions of the rib cage.

Objective: This study evaluates the anticancer, antimicrobial and antioxidant activities of P. resinosa, and isolates some responsible constituents.

Materials and methods: The methanol extract of P. resinosa aerial parts and its fractions (n-hexane, dichloromethane, ethyl acetate and n-butanol) were tested. Antimicrobial activity was tested using microdilution method against three Gram-positive and four Gram-negative bacteria. The tested concentrations ranged from 4000 to 7.8?μg/mL and MIC values were determined after 24?h incubation. Anticancer activity was evaluated against three human cancer cell lines (Daoy, HepG2 and SK-MEL28) using MTT assay. Antioxidant activity was investigated by DPPH scavenging method and β-carotene-linoleic acid assay.

Results: The greatest antimicrobial activity was exhibited by n-hexane fraction (MIC 10?μg/mL) against Staphylococcus aureus, Enterococcus faecalis, and Shigella flexneri. The n-hexane fraction induced the greatest cytotoxic activity against Daoy, HepG2, and SK-MEL28 cell lines with IC₅₀ values of 9.0, 8.5 and 13.2, respectively. Moreover, the dichloromethane and ethyl acetate fractions showed the highest antioxidant potential. A bioassay-guided fractionation led to the isolation and characterization of seven compounds for the first time, namely, quercetin (1), 3-methoxy quercetin (2), kaempferol (3), 3-methoxy kaempferol (4), myricetin 3,7,3′-trimethyl ether (5), lupeol (6), and stigmasterol (7).

Conclusion: Our results indicate that P. resinosa is a source for antimicrobial and cytotoxic compounds. However, further work is required to isolate other active principles and to determine the mechanism of action.     

Anti-acetylcholinesterase activity and antioxidant properties of extracts and fractions of Carpolobia lutea

Context: There is an unmet need to discover new treatments for Alzheimer’s disease. This study determined the anti-acetylcholinesterase (AChE) activity, DPPH free radical scavenging and antioxidant properties of Carpolobia lutea G. Don (Polygalaceae).

Objective: The objective of this study is to quantify C. lutea anti-AChE, DPPH free radical scavenging, and antioxidant activities and cell cytotoxicity.

Materials and methods: Plant stem, leaves and roots were subjected to sequential solvent extractions, and screened for anti-AChE activity across a concentration range of 0.02–200?μg/mL. Plant DPPH radical scavenging activity, reducing power, and total phenolic and flavonoid contents were determined, and cytotoxicity evaluated using human hepatocytes.

Results: Carpolobia lutea exhibited concentration-dependent anti-AChE activity. The most potent inhibitory activity for the stem was the crude ethanol extract and hexane stem fraction oil (IC₅₀?=?140?μg/mL); for the leaves, the chloroform leaf fraction (IC₅₀?=?60?μg/mL); and for roots, the methanol, ethyl acetate and aqueous root fractions (IC₅₀?=?0.3–3?μg/mL). Dose-dependent free radical scavenging activity and reducing power were observed with increasing stem, leaf or root concentration. Total phenolic contents were the highest in the stem: ～632?mg gallic acid equivalents/g for a hexane stem fraction oil. Total flavonoid content was the highest in the leaves: ～297?mg quercetin equivalents/g for a chloroform leaf fraction. At 1?μg/mL, only the crude ethanol extract oil was significantly cytotoxic to hepatocytes.

Discussion and conclusions: Carpolobia lutea possesses anti-AChE activity and beneficial antioxidant capacity indicative of its potential development as a treatment of Alzheimer’s and other diseases characterized by a cholinergic deficit.     

Phenolic metabolites,biological activities,and isolated compounds of Terminalia muelleri extract

Context: Terminalia muelleri Benth. (Combretaceae), is rich with phenolics that have antioxidant and cytotoxic activities. No screening studies were published before on T. muelleri.

Objective: The study focused on isolation and identification of secondary metabolites from aqueous methanol leaf extract of T. muelleri and evaluation of its biological activities.

Materials and methods: The n-butanol extract was chromatographed on polyamide 6, and eluted with H₂O/MeOH mixtures of decreasing polarity, then separated by different chromatographic tools that yielded 10 phenolic compounds. The antioxidant activity of the extract was evaluated by investigating its total phenolic and flavonoid content and DPPH scavenging effectiveness. The extract and the two acylated flavones were evaluated for their anticancer activity towards MCF-7 and PC3 cancer cell lines. Molecular docking study of the acylated flavones was performed against topoisomerase enzyme.

Results and discussion: Two acylated flavonoids, apigenin-8-C-(2″-O-galloyl) glucoside 1 and luteolin-8-C-(2″-O-galloyl) glucoside 2, were isolated and identified for the second time in nature, with eight tannins (3–10), from the leaves of T. muelleri. The extract and compound 10 showed the most significant antioxidant activity (IC₅₀?=?3.55 and 6.34?μg/mL), respectively. The total extract and compound 2 demonstrated cytotoxic effect against MCF-7 with IC₅₀?=?29.7 and 45.2?μg/mL respectively, while compound 1 showed cytotoxic effect against PC3 (IC₅₀?=?40.8?μg/mL). The docking study of compounds 1 and 2 confirmed unique binding mode in the active site of human DNA topoisomerase enzyme.

Conclusions: Terminalia muelleri is a promising medicinal plant as it possesses high antioxidant activity and moderate cytotoxic activity against MCF-7.     

Potential anti-inflammatory,antioxidant and antimicrobial activities of Sambucus australis

Context: Sambucus australis Cham. &; Schltdl. (Adoxaceae) is used in Brazilian folk medicine to treat inflammatory disorders.

Objective: To evaluate the in vitro anti-inflammatory, antioxidant and antimicrobial properties of S. australis.

Materials and methods: The anti-in?ammatory activity of ethanol extracts of the leaf and bark of S. australis (1–100?μg/mL) were studied in lipopolysaccharide/interferon γ stimulated murine macrophages RAW 264.7 cells (24?h incubation) by investigating the release of nitric oxide (NO) and tumour necrosis factor-alpha (TNF-α) and in the TNF-α-induced nuclear factor kappa (NF-κB) assay. Minimum inhibitory concentration (MIC) was determined by the microdilution test (24?h incubation). Antioxidant activity was determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH), ferric reducing antioxidant power (FRAP) and the NO scavenging assays. Chemical composition was assessed by LC-MS/MS.

Results: Antioxidant activities in the DPPH (IC₅₀ 43.5 and 66.2?μg/mL), FRAP (IC₅₀ 312.6 and 568.3?μg/mL) and NO radical scavenging assays (IC₅₀ 285.0 and 972.6?μg/mL) were observed in the leaf and bark ethanol extracts, respectively. Solely the leaf extract showed significant inhibition of NO and TNF-α production in RAW264.7 cells at concentrations of 2 and 100?μg/mL, respectively, and suppression of TNF-α inhibition of NF-κB by 12.8 and 20.4% at concentrations of 50 and 100?μg/mL, respectively. The extract also exhibited antibacterial activity against Salmonella typhimurium (MIC 250?μg/mL) and Klebsiella pneumoniae (MIC 250?μg/mL). LC-MS/MS revealed the presence of chlorogenic acid and rutin as major compounds.

Discussion and conclusion: The results indicate that the ethanol leaf extract of S. australis exhibit prominent anti-in?ammatory effects.     

GC-MS profile of antimicrobial and antioxidant fractions from Cordia rothii roots

Context: An ethnobotanical survey of Cordia rothii Roem. & Schult. (Boraginaceae) reveals it as a medicinal plant.

Objective: Antimicrobial and antioxidant potential evaluation and identification of chemical constituents via GC-MS of C. rothii roots fractions. To the best of our knowledge, this is the first systematic investigation of the roots exploiting GC-MS.

Materials and methods: Extraction and fractionation of C. rothii roots furnished various fractions using solvents of varying polarity, i.e., n-hexane, chloroform, ethyl acetate, acetone and methanol. In vitro antimicrobial and antioxidant screening was performed using disk diffusion and DPPH methods, respectively. MIC of active fractions was also determined using disk diffusion method. GC-MS was used to identify constituents which may be responsible for these activities.

Results: Among various fractions from C. rothii roots, fraction KA-C showed strong antibacterial activity against 17 microorganisms tested, with MIC ranging from 250–31.25?μg/mL. Fractions KA-A, KM and KM-A exhibited significant antioxidant potential with EC₅₀ 46.875?μg/mL, while fractions KEA-PE, KM-PE and KM-M were good with EC₅₀ 93.750?μg/mL. Forty-five phytochemicals were identified in GC-MS studies including eight hydrocarbons, six free fatty acids, 11 fatty acids esters, two phenylpropanoids, four aromatics, four terpenoid quinones/hydroquinones, three triterpenes, four phytosterols, two hexose metabolites and a DNA base. Of these, 32 constituents have been reported for the first time from C. rothii, 24 from genus Cordia and 15 from Boraginaceae.

Discussion and conclusion: Strong antibacterial and antioxidant potential of C. rothii roots may be due to the contribution of phytoconstituents identified through GC-MS studies.     

Anti-inflammatory,free radical scavenging and alpha-glucosidase inhibitory activities of Hamelia patens and its chemical constituents

Context Hamelia patens Jacq. (Rubiaceae) is traditionally used to treat wounds, inflammation and diabetes. However, there is still a lack of scientific evidence to support these applications.

Objective The objective of this study is to evaluate the anti-inflammatory, antioxidant and antidiabetic activities of Hamelia patens, and identify its bioactive compounds.

Materials and methods Four extracts were obtained by maceration and liquid–liquid extraction: HEX, DCM–EtOAc, MeOH–EtOAc and MeOH–Aq. The anti-inflammatory effect was evaluated orally on rat paw carrageenan-induced oedema over 6?h (50, 200 and 500?mg/kg), and topically in mouse ear oedema induced by 12-tetradecanoylphorbol-13-acetate (TPA) after 4?h (0.5 and 1?mg/ear). We also evaluated myeloperoxidase levels in ear tissue, 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging ability, and in vitro α-glucosidase inhibition. The chemical compounds were separated by column chromatography and identified by spectroscopic analysis.

Results We found that the oral administration of the HEX extract at 500 and 200?mg/kg significantly decreased the carrageenan-induced inflammation after 1 and 3?h, respectively. The MeOH–EtOAc extract significantly inhibited myeloperoxidase activity (83.5%), followed by the DCM–EtOAc extract (76%), β-sitosterol/stigmasterol (72.7%) and the HEX extract (55%), which significantly decreased oedema induced by TPA at both doses, giving a similar effect to indomethacin. We also found that the MeOH–EtOAc, MeOH–Aq and DCM–EtOAc extracts showed good DPPH scavenging activity (IC₅₀ values of 18.6, 93.9 and 158.2?μg/mL, respectively). The HEX extract showed the lowest α-glucosidase inhibition (an IC₅₀ value of 26.07?μg/mL), followed by the MeOH–EtOAc extract (an IC₅₀ value of 30.18?μg/mL), β-sitosterol/stigmasterol (IC₅₀ 34.6?μg/mL) and compound A ((6E,10E,14E,18E)-2,6,10,14,18,23-hexamethyl-2,6,10,14,18,22-tetracosahexaene, an IC₅₀ value of 114.6?μg/mL), which were isolated for the first time from Hamelia patens.

Discussion and conclusion Hamelia patens possesses anti-inflammatory, antioxidant and α-glucosidase inhibitory activities, which support its traditional use. These effects can be attributed to the identified compounds.     

Unlocking the in vitro anti-inflammatory and antidiabetic potential of Polygonum maritimum

Context: Several Polygonum species (Polygonaceae) are used in traditional medicine in Asia, Europe and Africa to treat inflammation and diabetes.

Objective: Evaluate the in vitro antioxidant, anti-inflammatory and antidiabetic potential of methanol and dichloromethane extracts of leaves and roots of the halophyte Polygonum maritimum L.

Material and methods: Antioxidant activity was determined (up to 1?mg/mL) as radical-scavenging activity (RSA) of 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), copper (CCA) and iron (ICA) chelating activities and iron reducing power (FRAP). NO production was measured in lipopolysaccharide (LPS)-stimulated macrophages for 24?h at concentrations up to 100?μg/mL and antidiabetic potential was assessed by α-amylase and α-glucosidase inhibition (up to 10?mg/mL) assays. The phytochemical composition of the extracts was determined by gas chromatography-mass spectrometry (GC-MS).

Results: The methanol leaf extract had the highest activity against DPPH? (IC₅₀ =?26?μg/mL) and ABTS⁺? (IC₅₀ =?140?μg/mL), FRAP (IC₅₀ =?48?μg/mL) and CCA (IC₅₀ =?770?μg/mL). Only the dichloromethane leaf extract (LDCM) showed anti-inflammatory activity (IC₅₀ =?48?μg/mL). The methanol root (IC₅₀ =?19?μg/mL) and leaf (IC₅₀ =?29?μg/mL) extracts strongly inhibited baker’s yeast α-glucosidase, but LDCM had higher rat’s α-glucosidase inhibition (IC₅₀ =?2527?μg/mL) than acarbose (IC₅₀ =?4638?μg/mL). GC-MS analysis identified β-sitosterol, stigmasterol, 1-octacosanol and linolenic acid as possible molecules responsible for the observed bioactivities.

Conclusions: Our findings suggest P. maritimum as a source of high-value health promoting commodities for alleviating symptoms associated with oxidative and inflammatory diseases, including diabetes.     

Further insight into the bioactivity of the freshwater sponge Ochridaspongia rotunda

Context: Bioprospection has become a dynamic scientific field that explores novel possibilities for the implementation of natural products in medicine and pharmacy. Compared to marine species from all kingdoms, freshwater species have been highly neglected.

Objective: This work focuses on the screening of acetylcholinesterase inhibitory (AChE) and mutagenic activities of the acetone extract (obtained by maceration) of the freshwater sponge Ochridaspongia rotunda Arndt (Malawispongiidae) in vitro.

Materials and methods: AChE inhibitory activity was evaluated both in liquid (five different concentrations of the extract, from 1 to 100?μg/mL) and in solid (seven different concentrations of the extract, from 0.5 to 10.0?μg) by methods well described in literature, while mutagenicity was estimated using the Ames test (four different concentrations of the extract, from 0.106 to 1.328?mg/plate).

Results: Ochridaspongia rotunda acetone extract exhibited promising AChE inhibitory activity in a dose-dependent manner both in liquid (IC₅₀ 23.07?μg/mL) and in solid (1.50?μg). Furthermore, the Ames test revealed no sign of mutagenicity at any concentration tested. Its FTIR spectrum coupled with the positive Liebermann?Burchard, Salkowski and Zak color reactions (tests) indicated the presence of sterol compounds.

Discussion and conclusion: The screened extract may inspire a search for novel anticholinesterase therapeutic agent(s) potentially used in the treatment of Alzheimer's disease. Further research will be directed toward its detailed chemical analysis along with addressing the issue of a real producer of the natural product(s) responsible for the AChE activity observed.     

Antioxidant and anti-inflammatory activities of Aerva pseudotomentosa leaves

Context: Aerva pseudotomentosa Blatt. &; Hallb. (Amaranthaceae), commonly called ‘Bui’, is a medicinal plant of the arid region. It is used for the treatment of inflammatory disorders, such as rheumatic pain, and healing of wounds, which are associated with oxidative stress.

Objective: The present study evaluated the antioxidant potential of Aerva pseudotomentosa leaves by in vitro models and its anti-inflammatory effect in rats.

Material and methods: The aqueous extract (APAE) was analyzed by HPTLC and HPLC. The antioxidant effect of APAE was evaluated by various in vitro methods [DPPH (1, 1-diphenyl-2-picryl-hydrazil) and hydrogen peroxide free radical scavenging, reducing power, and anti-lipid peroxidation assays]. Anti-inflammatory effect was studied in carrageenan and formalin-induced paw oedema models in rats. APAE (200 and 400?mg/kg) and standard drug, indomethacin (10?mg/kg), were administered orally 1?h before carrageenan/formalin administration and inflammation was noted up to 5?h.

Results: HPLC analysis of APAE revealed the presence of rutin. APAE showed significant scavenging effect on DPPH (IC₅₀ 49.37?μg/mL) and peroxide (IC₅₀ 288.2?μg/mL) radicals. The extract exhibited reducing potential and inhibition of lipid peroxidation. APAE treatment significantly attenuated mean increase in paw volume and exhibited inhibition of paw oedema in both in vivo models with inhibition of 45.11% and 49.42%, respectively at 5?h.

Discussion and conclusion: APAE exhibited in vitro antioxidant and anti-inflammatory activities. Anti-inflammatory effect of APAE may be attributed to its antioxidant potential, due to the presence of rutin and other phenolics. This study substantiates folk use of leaves in inflammatory disorders.     

Modulation of some markers of erectile dysfunction and malonaldehyde levels in isolated rat penile tissue with unripe and ripe plantain peels: identification of the constituents of the plants using HPLC

Context: Plantain fruit pulp has been used as a natural remedy to manage erectile dysfunction (ED) in traditional medicine. However, the potency of the peel has not been examined with respect to ED management.

Objective: This study investigated and compared the inhibitory potential of unripe (UPP) and ripe (RPP) plantain peels on some enzymes associated with ED and Fe²⁺-induced oxidative stress in albino rat penile homogenate in vitro.

Materials and method: Aqueous extract of the peels was prepared and the effect on phosphodiesterase-5 (PDE-5), arginase, acetylcholinesterase (AChE), angiotensin-I converting enzyme (ACE) and Fe²⁺-induced malonyladehyde in isolated albino rat penile homogenate were investigated. Phenolic constituents of the peels powder were characterized using high-performance liquid chromatography coupled with diode array detector (HPLC-DAD).

Result: Extract from UPP had higher PDE-5 (IC₅₀?=?3.10?μg/mL), arginase (IC₅₀?=?0.96?μg/mL), AChE (IC₅₀?=?6.30?μg/mL) and ACE (IC₅₀?=?0.41?μg/mL) inhibitory ability compared with RPP (PDE-5, IC₅₀?=?4.33?μg/mL; arginase, IC₅₀?=?1.34?μg/mL; AChE, IC₅₀?=?8.64?μg/mL; ACE, IC₅₀?=?0.63?μg/mL). The extract from UPP also had higher inhibition of Fe²⁺-induced lipid peroxidation. HPLC-DAD analysis revealed that gallic and caffeic acids, rutin, quercitrin and quercetin were abundant in UPP, while catechin, kaempferol, chlorogenic and ellagic acids were the dominant phenolic compounds in RPP.

Discussion and conclusion: Inhibition of enzymes associated with ED and lipid peroxidation could be linked with the phenolic compounds. However, UPP appeared to be more potent.     

Cytotoxic activity of physodic acid and acetone extract from Hypogymnia physodes against breast cancer cell lines

Context: Lichens produce specific secondary metabolites with different biological activity.

Objective: This study investigated the cytotoxic effects of physodic acid, in addition to the total phenolic content and cytotoxic and antioxidant activity of acetone extract from Hypogymnia physodes (L.) Nyl. (Parmeliaceae).

Materials and methods: Cytotoxicity of physodic acid (0.1–100?μM) was assessed in MDA-MB-231, MCF-7 and T-47D breast cancer cell lines and a nontumorigenic MCF-10A cell line using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, neutral red uptake and crystal violet assays during 72?h of incubation. An MTT assay was also used to assess the cytotoxic effects of the acetone extract (0.1–100?μg/mL) in the MDA-MB-231, MCF-7, T-47D breast cancer cell lines after 72?h. The total phenolic content of the acetone extract, expressed as the gallic acid equivalent, was investigated using Folin-Ciocalteu reagent. The antioxidant activity of the extract was assessed by 2,2-diphenyl-1-picrylhydrazyl and ferric-reducing antioxidant power assays.

Results: The cytotoxic activity of physodic acid appeared to be strong in the tumorigenic cell lines (IC₅₀ 46.0–93.9?μM). The compound was inactive against the nontumorigenic MCF-10A cell line (IC_50?>100?μM). The acetone extract showed cytotoxicity in the breast cancer cell lines (IC₅₀ 46.2–110.4?μg/mL). The acetone extract was characterized by a high content of polyphenols, and it had significant antioxidant activity.

Discussion and conclusion: Physodic acid and acetone extract from H. physodes displayed cytotoxic effects in the breast cancer cell lines. Furthermore, acetone extract from H. physodes possessed significant antioxidant properties.     

An unprecedented antioxidative isopimarane norditerpenoid from bivalve clam,Paphia malabarica with anti-cyclooxygenase and lipoxygenase potential

Context: The yellow-foot bivalve clam, Paphia malabarica Chemnitz (Veneridae) is distributed in the southwest coastal regions of India. The ethyl acetate-methanol extract of this species exhibited significant antioxidant and anti-inflammatory activities.

Objectives: To purify and characterize the bioactive compound from P. malabarica along with in vitro assays.

Materials and methods: The edible portion of P. malabarica was freeze dried (1.20?kg, yield 20.0%) and extracted with ethyl acetate and methanol (1:1 v/v, 500?mL ×3) by sonication (8?h). The antioxidant activity against DPPH/ABTS^+?and anti-inflammatory potential against cyclooxygenase-1,2 (COX-1, 2)/5-lipoxygenase (5-LOX) enzymes were carried out with varying concentrations (0.25–2.00?mg/mL) to determine the IC₅₀ values. The crude extract was chromatographically fractionated and the fraction showing greater potential was further fractionated to yield the pure compound, which was characterized by extensive NMR, IR and mass spectroscopic analyses.

Results and discussion: The fractionation of crude extract of P. malabarica was followed by structural characterization of the new rearranged isopimarane derivative, 18 (4 → 14), 19 (4 → 8)-bis-abeo C₁₉ norditerpenoid. The isopimarane derivative displayed comparable antioxidant activity with α-tocopherol (IC₅₀ DPPH scavenging activity ～0.6?mg/mL), whereas anti-inflammatory (anti-5-LOX) effect of the title compound was significantly greater (IC₅₀ 0.75?mg/mL) than ibuprofen (IC₅₀ 0.93?mg/mL). In addition, the greater selectivity index (anti-COX-1_IC50/anti-COX-2_IC50 0.85) explained the lesser side effects of the isopimarane norditerpenoid than the nonsteroidal anti-inflammatory drug-based therapies.

Conclusions: The isopimarane derivative isolated from P. malabrica can be a natural substitute to commercial drugs in future.     

Biological activity assessment and phenolic compounds characterization from the fruit pericarp of Litchi chinensis for cosmetic applications

Context: Litchi chinensis Sonn. (Spindaceae) is an important economic fruit of Thailand. Therapeutic effects of the fruits are contributed by anti-inflammatory phenolics.

Objective: To extract the litchi fruit pericarp in order to identify biologically actives substances with potential for cosmetic application.

Materials and methods: The litchi pericarp was macerated by 70% ethanol (EtOH) and partitioned using n-hexane and ethyl acetate (EtOAc). In vitro antioxidant activities were assessed by 1, 1-diphenyl-2-picrylhydrazyl (DPPH), ABTS and ferric reducing ability of plasma (FRAP) assays including tyrosinase inhibitory effect. Cellular radical scavenging capacity was monitored in a normal human fibroblast cell culture (NHF). Total phenolic content was determined and characterized by HPLC.

Results: The EtOAc fraction was a significant antioxidant, stronger than ascorbic acid (p < 0.01), as assessed by ABTS (IC₅₀ = 7.137 ± 0.021 μg/mL), DPPH (IC₅₀ = 2.288 ± 0.063 μg/mL) and FRAP (EC_1mMFeSO4 = 8013.183 ± 58.804 μg/mL) assays. It demonstrated an antityrosinase effect (IC₅₀ = 197.860 ± 1.230 μg/mL) and showed no cytotoxic activity toward Vero and NHF cells, at a maximum tested concentration (50 μg/mL), with cellular antioxidant activity. Total phenolic content was highest in the most potent antioxidant fraction. Quercetin, rosmarinic and gallic acids were found. Total phenolic content is highly related to FRAP, antityrosinase, and ABTS activities.

Discussion and conclusion: Pericarp from litchi fruit can be obtained abundantly from agricultural waste, and the strong antioxidant activity demonstrated in this report may have application in topical cosmetic products. This ecological antioxidant can be prepared using a feasible method resulting in less waste and increased agro-industrial profitability.     

HPTLC analysis,antioxidant, anti-inflammatory and antiproliferative activities of Arisaema tortuosum tuber extract

Context: Oxidative stress and inflammation are related to several chronic diseases including cancer and atherosclerosis. Arisaema tortuosum (Wall.) Schott (Araceae) is an Indian folk medicinal herb traditionally used for treatment of various diseases related to inflammation and stress.

Objective: This study was carried out for HPTLC analysis and evaluation of antioxidant, anti-inflammatory and antiproliferative activities of a methanol extract of A. tortuosum tuber.

Materials and methods: The antioxidant activities of methanol extract of A. tortuosum tuber (1?mg/mL) were evaluated by DPPH, ABTS and FRAP assays and anti-inflammatory effects by diene-conjugate and β-glucuronidase assays, with in vitro tumor growth inhibition on HeLa cancer cells. The results for antioxidant and anti-inflammatory effects were compared using Trolox and salicylic acid as reference compounds, respectively.

Results: The TLC and HPTLC analysis showed the presence of quercetin, rutin, luteolin and lectin (R_f values 0.97, 0.53, 0.59 and 1.58, respectively). The methanol fraction of tuber exhibit higher activity in each antioxidant system with a special attention for DPPH (IC₅₀?=?852?μg/mL), ABTS (IC₅₀?=?532?μg/mL), and FRAP (IC₅₀?=?458?μg/mL), as compared with Trolox as standard, with a remarkable amount of phenolics (86.2?mg/100?g) and flavonoids (175.5?mg/100?g), along with potent anti-inflammatory activity indicated by diene-conjugate (86.20%) and β-glucuronidase (92.92%) inhibition, as compared with salicylic acid as reference compound. The antiproliferative activity at 100?mg/mL was 88% inhibition with HeLa cells. The inhibition of HeLa cell proliferation was greatest (p?A. tortuosum tuber extract treatments and least with the 25?mg/mL dose.

Discussion and conclusion: Our results suggested that A. tortuosum tuber might be used as a promising and potent antioxidant, anti-inflammatory, and antiproliferative agent and might be used for standardization of potential drug after successful isolation and characterization of bioactive compounds.     

Antioxidant and cytotoxic activity of carotenes produced by Dunaliella salina under stress

Context Dunaliella salina Teodoresco (Dunaliellaceae) is one of the promising microalgae consumed as food and medicine for many years.

Objective Dunaliella salina was grown under different stress conditions for enhancing carotene production. The carotene enriched extract was evaluated for antioxidant and cytotoxic activity.

Materials and methods Carotene content was calculated under salinity, nitrogen and temperature stress conditions. Antioxidant activity was determined through DPPH assay by incubating the samples for 45?min with 250?μg/mL of extract and reducing power assay was performed with 50, 100, 150 and 200?μg/mL of extract. Cytotoxicity was determined by incubating ～2?×?10⁴ MCF-7 (breast cancer) cells with 250?μg of extract in each well for 72?h by MTT assay.

Result Carotene content was significantly increased to 9.8 (3.5 M NaCl), 13.9 (37?°C), 8.2 (250?mM KNO₃) and 10.6?μg/mL (nitrogen-depleted medium) as compared with 3.2?μg/mL in normal conditions (1.7 M NaCl, 0.75?mM KNO₃ and 28?°C). Free radical scavenging activity increased at 3.0 and 3.5 M NaCl (27.8 and 57.5%, respectively), 37?°C (31.4%) and in nitrogen-depleted medium (41.9%) compared with normal (15%) conditions. Carotene content and scavenging activity were positively correlated under salinity (r?=?0.97), temperature (r?=?0.85) and nitrogen (r?=?0.7) stress conditions. Cytotoxicity against MCF-7 cell lines increased due to increase in carotene content suggesting that cytotoxicity may be associated with carotene accumulation.

Discussion and conclusions Carotene content enhanced by D. salina under stress conditions increased the antioxidant and cytotoxic activity.     

Compounds from the pods of Astragalus armatus with antioxidant,anticholinesterase, antibacterial and phagocytic activities

Context: The phytochemical study and biological activities of Astragalus armatus Willd. subsp. numidicus (Fabaceae) pods, an endemic shrub of Maghreb, are reported.

Objective: This study isolates the secondary metabolites and determines the bioactivities of Astragalus armatus pods.

Materials and methods: The chloroform, ethyl acetate and n-butanol extracts of hydro-ethanolic extracts were studied. Antioxidant activity was investigated using DPPH and ABTS radical scavenging, CUPRAC and ferrous chelating assays at concentrations ranging from 3 to 200?μg/mL. Anticholinesterase activity was determined against acetylcholinesterase and butyrylcholinesterase enzymes at 50, 100 and 200?μg/mL. Antibacterial activity was performed according to minimum inhibitory concentration (MIC) method. Carbon clearance method in albino mice was used for the phagocytic activity at concentrations 50, 70 and 100?mg/kg body weight. Spectroscopic techniques were used to elucidate the compounds.

Results: Ethyl acetate extract afforded a flavonoid (1) while the n-butanol extract gave four flavonoids (2–5), a cyclitol (6) and a cycloartane-type saponin (7). The ethyl acetate extract exhibited highest antioxidant activity in DPPH (IC₅₀: 67.90?±?0.57?μg/mL), ABTS (IC₅₀: 11.30?±?0.09?μg/mL) and CUPRAC (A_0.50: 50.60?±?0.9?μg/mL) assays. The chloroform extract exhibited the best antibacterial activity against Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa, each with 80?μg/mL MIC values. The n-butanol extract enhanced phagocytic activity.

Discussion and conclusion: Isorhamnetin (1), isorhamnetin-3-O-α-l-rhamnopyranosyl-(1 → 6)-β-d-galactopyranoside (2), isorhamnetin-3-O-β-d-apiofuranosyl-(1 → 2)-[α-l-rhamnopyranosyl-(1 → 6)]-β-d-galactopyranoside (3), kaempferol-3-O-(2,6-di-O-α-l-rhamnopyranosyl)-β-d-galactopyranoside (4), kaempferol-3-O-(2,6-di-O-α-l-rhamnopyranosyl)-β-d-glucopyranoside (5), pinitol (6) and cyclomacroside D (7) were isolated whereas 1, 2, 6 and 7 are reported for the first time from A. armatus.     

In vitro digestion,antioxidant and antiacetylcholinesterase activities of two species of Ruta: Ruta chalepensis and Ruta montana

Context: Ruta genus (Rutaceae) is abundantly used and described in the most ancient systematic records of medical practice of the Mediterranean world. In Tunisia, this genus is represented by two medicinal and aromatic shrubs: Ruta chalepensis L. and Ruta montana L.

Objective: This study investigates the antioxidant and acetylcholinesterase inhibition (AChE) activities before and after in vitro gastrointestinal metabolism of leaf decoction of R. chalepensis and R. montana.

Materials and methods: We study, in vitro, the effect of the gastrointestinal juices gastric (1.75?mL) or pancreatic (2.5?mL) juices, on the biological activity by the measurement of the antioxidant activity and AChE inhibition during 4?h of decoction extract obtained from the leaves of the two species of Ruta.

Results: The results showed that the ability to inhibit the AChE enzyme was similar; being the greatest inhibitory activity exhibited by the ethanol extract (IC_50?=_?12?±?1.1?μg/mL) obtained from leaves of R. chalepensis.

Conclusion: In conclusion, we showed that there was no appreciable degradation and that the activity was kept constant after gastric and pancreatic juice digestion.     

Chemical composition,antioxidant, antitumor,anticancer and cytotoxic effects of Psidium guajava leaf extracts

Context Psidium guajava L. (Myrtaceae) leaves are used in traditional medicines for the treatment of cancer, inflammation and other ailments.

Objective The current study explores scientific validation for this traditional medication.

Materials and methods We used ferric-reducing antioxidant power (FRAP) and 2,2-diphenyl-1-picryl hydrazil (DPPH) assays to estimate antioxidant activity of P. guajava leaf extracts (methanol, hexane and chloroform). Antitumour and in vivo cytotoxic activities were determined using potato disc assay (PDA) and brine shrimp lethality assay, respectively. Three human carcinoma cell lines (KBM5, SCC4 and U266) were incubated with different doses (10–100?μg/mL) of extracts and the anticancer activity was estimated by MTT assay. NF-κB suppressing activity was determined using electrophoretic mobility shift assay (EMSA). Chemical composition of the three extracts was identified by GC-MS. Total phenolic and flavonoid contents were measured by colorimetric assays.

Results and discussions The order of antioxidant activity of three extracts was methanol?>?chloroform?>?hexane. The IC₅₀ values ranged from 22.73 to 51.65?μg/mL for KBM5; 22.82 to 70.25?μg/mL for SCC4 and 20.97 to 89.55?μg/mL for U266 cells. The hexane extract exhibited potent antitumour (IC_50? value?=_?65.02?μg/mL) and cytotoxic (LC_50? value?=_?32.18?μg/mL) activities. This extract also completely inhibited the TNF-α induced NF-κB activation in KBM5 cells. GC-MS results showed that pyrogallol, palmitic acid and vitamin E were the major components of methanol, chloroform and hexane extracts. We observed significant (p?<?0.05) difference in total phenolic and flavonoid contents of different solvent extracts.

Conclusion The present study demonstrates that P. guajava leaf extracts play a substantial role against cancer and down-modulate inflammatory nuclear factor kB.     

Phenolic composition,antioxidant and anti-acetylcholinesterase activities of the Tunisian Scabiosa arenaria

Abstract

Context: There is a need for the discovery of novel natural antioxidants and acetylcholinesterase inhibitors (AChEIs) that are safe and effective at a global level. This is the first study on antioxidant and anti-acethylcholinesterase activity of Scabiosa arenaria Forssk (Dipsacaceae).

Objective: The antioxidant potential and anti-acetylcholinesterase (AChE) activity of S. arenaria were investigated.

Material and methods: The crude, ethyl acetate (EtOAc), butanol (n-BuOH) and water extracts prepared from flowers, fruits and stems and leaves of S. arenaria were tested to determine their total polyphenol content (TPC), total flavonoid content (TFC), total condensed tannin content (CTC) and their antioxidant activity by using 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS), reducing power and β-carotene bleaching inhibition activity. Anti-AChE activity was also determined.

Results: EtOAc and n-BuOH fractions of fruits had both the highest (TPC) (269.09?mg gallic acid equivalents/g dry weight). The crude extract of stems and leaves had the highest TFC (10.9?mg quercetin equivalent/g dry weight). The n-BuOH fraction of stems and leaves had the highest CTC (489.75?mg catechin equivalents/g dry weight). The EtOAc fraction of flowers exhibit a higher activity in each antioxidant system with a special attention for DPPH assay (IC₅₀?=?0.017?mg/mL) and reducing power (EC₅₀?=?0.02?mg/mL). The EtOAc and n-BuOH fractions of stems and leaves showed strong inhibition of AChE (IC₅₀?=?0.016 and 0.029?mg/mL, respectively).

Discussion and conclusions: These results suggest the potential of S. arenaria as a possible source of novel compounds and as an alternative antioxidant and AChEIs.