Phytochemical screening and evaluation of in vitro antioxidant and antimicrobial activities of the indigenous medicinal plant Albizia odoratissima

Context: Albizia odoratissima (L. f.) Benth has been used in Indian folk medicine to treat numerous inflammatory pathologies, such as leprosy, ulcers, burns and asthma.

Objective: To evaluate the antioxidant and antimicrobial properties of A. odoratissima.

Materials and methods: Dried leaves of A. odoratissima were extracted in organic solvents (hexane, chloroform, ethyl acetate, and methanol). The total phenolic content (TPC) and total flavonoid content (TFC) were determined using the Folin-Ciocalteu and aluminum chloride colorimetric methods, respectively. The antioxidant activity was examined using 2,2-diphenyl-1-picrylhydrazyl (DPPH), hydrogen peroxide (H₂O₂), 2,2′-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS), and ferric reducing antioxidant power (FRAP) assays. The antibacterial activity was examined using minimum inhibitory concentration (MIC) and the minimum bacterial concentration (MBC), determined by broth microdilution method against Gram-negative bacteria (Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa, and Proteus vulgaris) and Gram-positive bacterium (Staphylococcus aureus).

Results: The TPC ranged from 4.40?±?1.06 to 1166.66?±?31.85?mg GAE/g of dry weight (DW), and the TFC ranged from 48.35?±?3.62 to 109.74?±?1.84?mg QE/g of DW. The IC₅₀ values of the ethyl acetate extract for DPPH, ABTS, and H₂O₂ were 10.96?±?0.40, 4.35?±?0.07, and 163.82?±?1.52?μg/mL, respectively. Both methanol and ethyl acetate extracts demonstrated effective antibacterial activity with MICs and MBCs values ranging 136–546?μg/mL and 273–1093?μg/mL, respectively, against the tested pathogenic species.

Conclusions: The leaves of A. odoratissima showed potent free radical scavenging property and antimicrobial activity.     

Antioxidant,anti-collagenase and anti-elastase activities of Phyllanthus emblica,Manilkara zapota and silymarin: an in vitro comparative study for anti-aging applications

Context Phyllanthus emblica L. (Euphorbiaceae) (amla), Manilkara zapota L.P. Royen (Sapotaceae) (sapota) and silymarin are reported to contain antioxidant effects. However, information on other biological activities relating to the anti-aging properties is limited.

Objective To compare in vitro antioxidants, anti-collagenase (MMP-1 and MMP-2) and anti-elastase properties as well as the phenolic and flavonoid contents of amla, sapota and silymarin as potential anti-aging ingredients.

Materials and methods The ethanol amla and sapota fruit extracts were prepared by three cycles of maceration with 24 h duration each. The total phenolic (TPC) and flavonoid (TFC) contents were determined. The antioxidant capacity was evaluated by DPPH and ABTS assays. The effects of MMP-1, MMP-2 and elastase inhibitions were determined by using the EnzChek® assay kits (Molecular-Probes, Eugene, OR).

Results Amla exhibited the highest in TPC (362.43?±?11.2?mg GAE/g) while silymarin showed the highest in TFC (21.04?±?0.67?mg QE/g). Results of antioxidant activity by DPPH and ABTS methods showed that amla possessed the most potent capacity with IC₅₀ values of 1.70?±?0.07 and 4.45?±?0.10?μg/mL, respectively. Highest inhibitions against MMP-1, MMP-2 and elastase were detected for sapota with IC₅₀ values of 89.61?±?0.96, 86.47?±?3.04 and 35.73?±?0.61?μg/mL, respectively.

Discussion and conclusion Test extracts offered anti-aging properties in different mechanisms. Amla showed the highest phenolic content and antioxidant property with moderate anti-collagenase. Silymarin exhibited measurable flavonoid content with anti-elastase effect. Sapota showed the highest collagenase and elastase inhibitions with moderate antioxidant effect. Thus, extracts might be added as a mixture to gain the overall anti-aging effects.     

Antioxidant activity of phenolic extracts from different cultivars of Italian onion (Allium cepa) and relative human immune cell proliferative induction

Context: The total antioxidant activity (TAC) may vary considerably between onion cultivars. Immunological effects of onion phenolic compounds are still underestimated.

Objective: The objective of this study is to determine the total phenol content (TPC) and the relative TAC of three Allium cepa L. (Liliaceae) onion cultivars cultivated in Cannara (Italy): Rossa di Toscana, Borettana di Rovato, and Dorata di Parma, and to evaluate the phenol extracts ability to induce human immune cell proliferation.

Materials and methods: TPC was determined by the Folin–Ciocalteu method, TAC with FRAP, TEAC/ABTS, and DPPH methods. Peripheral blood mononuclear cells from healthy human donors were incubated for 24?h at 37?°C with 1?ng/mL of phenolic extract in PBS, immunostained, and then analyzed by 4-color flow cytometry for the phenotypic characterization of T helper cells (CD4+ cells), cytotoxic T lymphocytes (CD8+ cells), T regulatory cells (CD25high CD4+ cells), and natural killer cells/monocytes (CD16+ cells).

Results: Rossa di Toscana displayed the highest TPC (6.61?±?0.87?mg GA equivalents/g onion bulb DW) and the highest TAC with the experienced methods: FRAP, 9.19?±?2.54 μmol Trolox equivalents/g onion bulb DW; TEAC/ABTS, 21.31?±?0.41 μmol Trolox equivalents/g onion bulb DW; DPPH, 22.90?±?0.01 μmol Trolox equivalents/g onion bulb DW. Incubation with Rossa di Toscana extract determined an increase in the frequency of the antitumor/anti-infection NK CD16+ immune cells (23.0?±?0.4%).

Discussion and conclusions: Content of health-promoting phenols and the deriving antioxidant and immunostimulating activity vary considerably among the investigated cultivars. Rossa di Toscana can be considered as a potential functional food.     

Antioxidant and antimicrobial activities of ethanol and aqueous extracts from Urtica urens

Context: Urtica urens L. (Urticaceae) is an important and commonly used plant for its medicinal and pharmacological properties.

Objective: We analyzed the antioxidant and antimicrobial activities of the leaves of Urtica urens in ethanol (EtOH) and water (WA) solvents, employing standard analytical methods.

Materials and methods: Polyphenol, flavonoid and tannin content of Urtica urens leaves were determined, after their extraction, using EtOH (70%) and WA extracts as well as the antioxidant (DPPH, ABTS, β-carotene and FRAP) and the antibacterial (via the method of dilution tests) activities of EtOH and WA extracts.

Results: The 70% EtOH of Urtica urens showed the highest values of total phenolic (31.41?mg GAE/g DW), flavonoids (6.81?mg quercetin/g DW), tannin (8.29?mg GAE/g DW) and TEAC (560?mmol Trolox/g DW), compared to the WA. The results of DPPH for EtOH (95.56%) were higher than that of WA (64.56%) at a concentration of 40?mg/L. The extracts displayed a FRAP 106.23 for EtOH and 30.55?μmol Fe(II)/g DW for WA. The results clearly indicated that EtOH was the strongest radical scavenger (IC_50?=_?245.65?±?10.2?μg/mL). Ethanol was the most effective with minimum inhibitory concentration (MIC)?Discussion and conclusion: The results indicate that leaves of Urtica urens could be used as natural antioxidant and antimicrobial agents.     

Comparative pharmacokinetics of chlorogenic acid in beagles after oral administrations of single compound,the extracts of Lonicera japanica,and the mixture of chlorogenic acid,baicalin, and Forsythia suspense

Context: Chlorogenic acid (ChA) is the major compound in Shuang-Huang-Lian (SHL), which is mainly composed of ChA, baicalin, and Forsythia suspense Thunb Vahl.

Objective: The effects of co-existing compounds in SHL and Lonicera japanica Thunb on the absorption of ChA was investigated.

Materials and methods: According to 3?×?3 Latin-square test, ChA alone, the extracts of Lonicera japanica, or the mixture of ChA, baicalin and Forsythia suspense (ChA effective doses is 60?mg/kg) was separately given to six beagles for seven days. The oral pharmacokinetic parameters of ChA in plasma, urine and faeces were quantified by HPLC/UV and analyzed.

Results: The pharmacokinetic parameters of ChA alone, the extracts of Lonicera japanica, and the mixture of ChA, baicalin, and Forsythia suspense were as followed: C_max (2.350?±?0.483, 1.655?±?0.576, 2.332?±?0.606?μg/mL), AUC_0-∞ (6.324?±?1.853, 4.216?±?1.886, 6.074?±?1.473?μg·h/mL), t_1/2 (0.911?±?0.187, 1.204?±?0.309, 1.094?±?0.193?h), and T_max (1.861?±?0.499, 1.000?±?0.459, 1.833?±?0.279?h). Accumulative fraction excretion of ChA in urine were 0.73?±?0.55, 1.25?±?1.23, 1.05?±?0.96%, while that in faeces were 0.68?±?0.94, 0.19?±?0.40, and 1.76?±?3.57%.

Discussion and conclusion: Co-existing compounds in SHL have no effect on the absorption of ChA, while the concomitant compounds in Lonicera japanica could decrease that of ChA. ChA in Beagles might have high biological transformation.     

Phytoextract of Indian mustard seeds acts by suppressing the generation of ROS against acetaminophen-induced hepatotoxicity in HepG2 cells

Abstract

Context: Indian mustard [Brassica juncea (L.) Czern. & Coss. (Brassicaceae)] is reported to possess diverse pharmacological properties. However, limited information is available concerning its hepatoprotective activity and mechanism of action.

Objective: To study the protective mechanism of mustard seed extract against acetaminophen (APAP) toxicity in a hepatocellular carcinoma (HepG2) cell line.

Materials and methods: Hepatotoxicity models were established using APAP (2.5–22.5?mM) based on the cytotoxicity profile. An antioxidant-rich fraction from mustard seeds was extracted and evaluated for its hepatoprotective potential. The mechanism of action was elucidated using various in vitro antioxidant assays, the detection of intracellular generation of reactive oxygen species (ROS), and cell cycle analysis. The phytoconstituents isolated via HPLC-DAD were also evaluated for hepatoprotective activity.

Results: Hydromethanolic seed extract exhibited hepatoprotective activity in post- and pre-treatment models of 20?mM APAP toxicity and restored the elevated levels of liver indices to normal values (p?<?0.05). Post-treatment suppressed the generation of ROS by 58.37% and pre-treatment effectively prevented the generation of ROS by 90.5%. The mechanism of ROS suppression was further supported by antioxidant activity (IC₅₀) data from DPPH (103.37?±?4.2?µg AAE/mg), FRAP (83.26?±?1.1?µg AAE/mg), ORAC (1115?µM GAE/ml), ABTS (83.05?µg GAE/ml), and superoxide (345.22?±?5.15?µg AAE/mg) scavenging assays and by the restoration of cell cycle alterations. HPLC-DAD analysis revealed the presence quercetin, vitamin E, and catechin, which exhibited hepatoprotective activity.

Discussion and conclusions: A phytoextract of mustard seeds acts by suppressing the generation of ROS in response to APAP toxicity.     

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.     

Phytochemical investigation and radical scavenging activities of Melia azedarach and its DNA protective effect in cultured lymphocytes

Abstract

Context: Melia azedarach Linn (Meliaceae) is an Ayurvedic medicinal plant which is native to India. It is traditionally used for the treatment of leprosy, inflammation, scrofula, anthelmintic, antilithic, diuretic, deobstruent and cardiac disorders.

Objective: To evaluate the phytochemical constituents and antioxidant activities of the ethanol leaf extract of Melia azedarach (MA) and its protective effect against H₂O₂-induced cellular damage in cultured lymphocytes.

Materials and methods: The dose-dependent study of MA (20, 40, 60, 80, 100?µg/ml) was used to study in vitro radical scavenging assays. The effective dose of MA (60?µg/ml) was further used to study the H₂O₂-induced DNA damage (comet assay and DNA fragmentation assay) in cultured lymphocytes.

Results: The ethanol extract of MA (20, 40, 60, 80, 100?µg/ml) exhibited a significant dose-dependent inhibition of in vitro radical scavenging assays and their corresponding IC₅₀ values as follows: hydroxyl radical (26.50?±?0.26?µg/ml), superoxide anion (30.00?±?0.32?µg/ml), nitric oxide radical (48.00?±?0.48?µg/ml), DPPH radical (30.55?±?0.32?µg/ml) and reducing power (22.00?±?0.22?µg/ml). The increase in the severity of DNA damage and TBARS was increased significantly (p?<?0.05) at 500?µM H₂O₂-treated cultured lymphocytes and RBC cellular membranes. The phytochemical screening studies identified 13 chemical constituents present in the leaf extract of MA.

Discussion and conclusion: The results of this study demonstrate that MA offers protection against H₂O₂-induced cellular damage and it can be developed as an effective antioxidant during oxidative stress.     

In vitro antioxidant and cytotoxic properties of ethanol extract of Alpinia oxyphylla fruits

Abstract

Context. Alpinia oxyphylla Miquel (Zingiberaceae) is a traditional Chinese herbal medicine widely used for the treatment of intestinal disorders, urosis and diuresis. However, information about antioxidant and cytotoxic properties of its fruits remains to be elucidated.

Objective: The ethanol crude extract (CE) and its fractions [petroleum ether fraction (PF), ethyl acetate fraction (EF), n-butanol fraction (BF) and water fraction (WF) extracted by petroleum ether, ethyl acetate, n-butanol and water, respectively] of A. oxyphylla fruits were investigated for their antioxidant activity and cytotoxicity.

Materials and methods: The total phenolic content (TPC) and antioxidant activity of the extracts were determined by Folin–Ciocalteu reagent, 1,1-diphenyl-2-picrylhydrazyl (DPPH^?), Trolox equivalent antioxidant capacity and reducing power assay. Cytotoxicity of the extracts (0–200?μg/mL) was tested on six human cancer cell lines (breast cancer cell line, cervix carcinoma cell line, lung adenocarcinoma cell line, liver carcinoma cell line, gastric cancer cell line and colon cancer cell line) using the sulforhodamine B assay.

Results: The TPC of extracts varied from 8.2 to 20.3?mg gallic acid equivalents/g dry weight. DPPH radical scavenging effect of extracts decreased in the order of EF?>?BF?>?CE?>?PF?>?WF, with IC₅₀ values ranging from 74.7 to 680.8?μg/mL. 2,2-azo-bis(3-Ethylbenzothiazoline-6-sulfoic acid) diammonium salt scavenging activity ranged from 0.118 to 0.236?mmol Trolox equivalence/mg extract. The extracts exhibited concentration-dependent reducing power, and EF showed the highest reducing ability. A satisfactory correlation (R²?>?0.826) between TPC and antioxidant activity was observed. In addition, EF, PF and CE exhibited potent anticancer effects on six cancer cell lines with IC₅₀ values ranging from 40.1 to 166.3?μg/mL.

Discussion and conclusion: The ethanol extract of A. oxyphylla fruit, especially the EF, was found to possess potent antioxidant and anticancer activities, and thus a great potential for the application in food and drug products.     

Quantitative analysis of rutin,quercetin, naringenin,and gallic acid by validated RP- and NP-HPTLC methods for quality control of anti-HBV active extract of Guiera senegalensis

Context: Guiera senegalensis J.F. Gmel (Combretaceae) is a folk medicinal plant used in various metabolic and infectious diseases. In addition to its antiviral activities against herpes and fowlpox, the anti-HBV efficacy is very recently reported.

Objective: To develop and validate simple, sensitive RP-/NP-HPTLC methods for quantitative determination of biomarkers rutin, quercetin, naringenin, and gallic acid in the anti-HBV active G. senegalensis leaves ethanol-extract.

Materials and methods: RP-HPTLC (rutin &; quercetin; phase- acetonitrile:water, 4:6) and NP-HPTLC (naringenin &; gallic acid; phase- toluene:ethyl acetate:formic acid, 6:4:0.8) were performed on glass-backed silica gel plates 60F₂₅₄-RP18 and 60F₂₅₄, respectively. The methods were validated according to the ICH guidelines.

Results: Well-separated and compact spots (R_f) of rutin (0.52?±?0.006), quercetin (0.23?±?0.005), naringenin (0.56?±?0.009) and gallic acid (0.28?±?0.006) were detected. The regression equations (Y) were 12.434x?+?443.49, 10.08x?+?216.85, 11.253x?+?973.52 and 11.082x?+?446.41 whereas the coefficient correlations (r²) were 0.997?±?0.0004, 0.9982?±?0.0001, 0.9974?±?0.0004 and 0.9981?±?0.0001, respectively. The linearity ranges (ng/spot) were 200–1400 (RP-HPTLC) and 100–1200 (NP-HPTLC). The LOD/LOQ (ng/band) were 33.03/100.1 (rutin), 9.67/29.31 (quercetin), 35.574/107.8 (naringenin), and 12.32/37.35 (gallic acid). Gallic acid (7.01?μg/mg) was the most abundant biomarker compared to rutin (2.42?μg/mg), quercetin (1.53?μg/mg) and naringenin (0.14?μg/mg) in the extract.

Conclusion: The validated NP-/RP-HPTLC methods were simple, accurate, and sensitive for separating and quantifying antiviral biomarkers in G. senegalensis, and endorsed its anti-HBV activity. The developed methods could be further employed in the standardization and quality-control of herbal formulations.     

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.     

Chemical composition and biological activities of Helicteres vegae and Heliopsis sinaloensis

Context: Helicteres vegae Cristóbal (Sterculiaceae) (Hv) and Heliopsis sinaloensis B.L. Turner (Asteraceae) (Hs) are endangered and poorly studied plant species; related plants have been used against chronic-degenerative and infectious diseases. Therefore, Hv and Hs could be sources of bioactive compounds against these illnesses.

Objective: To determine the chemical composition and biological activities (antioxidant, antimutagenic and antimicrobial) of Hv and Hs leaves (L) and stems (S).

Materials and methods: Methanol extracts (ME) of each plant/tissue were evaluated for their phytochemicals; phenolics (HPLC-DAD-ESI-MS); antioxidant activity (AA) (0.125–4?mg/mL) (DPPH, ABTS, ORAC and β-carotene discoloration); antimutagenicity (0.5 and 1?mg/plate) (Ames assay, tester strain Salmonella enterica serovar Typhimurium YG1024, 1-nitropyrene as mutagen); activity against human pathogens (1?mg/mL); and toxicity (0.01–2?mg/mL) (Artemia salina assay).

Results: All ME showed flavonoids and triterpenes/steroids. The ME-SHv had the highest content of total phenolics (TP) (2245.82?±?21.45?mg GAE/100?g d.w.) and condensed tannins (603.71?±?1.115?mg CE/100?g d.w.). The compounds identified were flavonoids (kaempferol 7-O-coumaroylhexoside, and two kaempferol 7-O-rhamnosylhexosides) and phenolics [rosmarinic acid, and 3′-O-(8″-Z-caffeoyl) rosmarinic acid]. The ME-LHs showed the highest content of flavonoids (357.88?mg RE/g d.w.) and phenolic acids (238.58?mg CAE/g d.w.) by HPLC. The ME-SHv showed the highest AA. All ME were strong antimutagens (63.3-85.7%). Only the Hs extracts were toxic (ME-LHs, LC₅₀?=?94.9?±?1.7?μg/mL; ME-SHs, LC₅₀?=?89.03?±?4.42?μg/mL).

Discussion and conclusions: Both Hv and Hs are potential sources of preventive and therapeutic agents against chronic-degenerative diseases.     

Effects of berberine on the pharmacokinetics of losartan and its metabolite EXP3174 in rats and its mechanism

Context: Losartan and berberine (BBR) are often simultaneously used for the treatment of senile diabetic nephropathy in clinics. However, the potential herb–drug interaction between losartan and BBR is unknown.

Objective: This study investigates the influence of BBR on the pharmacokinetics of losartan and EXP3174, and investigates the effects of BBR on the metabolic stability of losartan.

Materials and methods: The pharmacokinetic profiles losartan and EXP3174 of orally administered losartan (10?mg/kg) with and without pretreatment with BBR (20?mg/kg) within 24?h were determined in Sprague-Dawley rats. The inhibitory effects of BBR on the metabolic stability of losartan were investigated using rat liver microsomes.

Results: The C_max (1.26?±?0.37 versus 1.96?±?0.45?mg/L) and the AUC_(0–t) (8.25?±?0.89 versus 12.70?±?1.42?mg h/L) of losartan were significantly (p?<?0.05) increased by BBR compared to the control, while the C_max (0.97?±?0.15 versus 0.77?±?0.06?mg/L) of EXP3174 was significantly decreased compared to the control (p?<?0.05). The T_max of losartan was prolonged from 0.41?±?0.12 to 0.52?±?0.18?h, but the difference was not significant. However, the T_max of EXP3174 was decreased significantly (p?<?0.05) from 8.14?±?0.36 to 3.33?±?0.28?h. The metabolic stability of losartan was increased from 37.4 to 59.6?min.

Discussion and conclusion: We infer that BBR might increase the plasma concentration of losartan and decrease the concentration of EXP3174 through inhibiting the activity of CYP3A4 or CYP2C9.     

An evaluation of the anti-inflammatory,antipyretic and analgesic effects of hydroethanol leaf extract of Albizia zygia in animal models

Context: The leaves of Albizia zygia (DC.) J.F. Macbr. (Leguminosae-Mimosoideae) are used in Ghanaian traditional medicine for the treatment of pain, inflammatory disorders and fever (including malaria).

Objectives: The present study evaluated the anti-inflammatory, antipyretic and analgesic effects of the hydroethanol leaf extract of Albizia zygia (AZE) in animal models.

Materials and methods: The anti-inflammatory and antipyretic effects of AZE were examined in the carrageenan-induced foot oedema model and the baker’s yeast-induced pyrexia test respectively. The analgesic effect and possible mechanisms of action were also assessed in the formalin test.

Results: AZE (30–300?mg/kg, p.o.), either preemptively or curatively, significantly inhibited carrageenan-induced foot edema in 7-day-old chicks (ED₅₀ values; preemptive: 232.9?±?53.33?mg/kg; curative: 539.2?±?138.28?mg/kg). Similarly, the NSAID diclofenac (10–100?mg/kg, i.p.) significantly reduced the oedema in both preemptive (ED₅₀: 21.16?±?4.07?mg/kg) and curative (ED₅₀: 44.28?±?5.75?mg/kg) treatments. The extract (30–300?mg/kg, p.o.) as well as paracetamol (150?mg/kg, p.o.) also showed significant antipyretic activity in the baker’s yeast-induced pyrexia test (ED₅₀ of AZE: 282.5?±?96.55?mg/kg). AZE and morphine (1–10?mg/kg, i.p.; positive control), exhibited significant analgesic activity in the formalin test. The analgesic effect was partly or wholly reversed by the systemic administration of naloxone, theophylline and atropine.

Conclusion: The results suggest that AZE possesses anti-inflammatory, antipyretic and analgesic properties, which justifies its traditional use. Also, the results show the involvement of the opioidergic, adenosinergic and the muscarinic cholinergic pathways in the analgesic effects of AZE.     

In vitro anti-aging activities of extracts from leaves of Ma Kiang (Cleistocalyx nervosum var. paniala)

Abstract

Context: Cleistocalyx nervosum (DC.) Kosterm. var. paniala (Roxb.) J. Parn. & Chantaran. (Myrtaceae) or Ma Kiang contains high amounts of phenolic compounds. Antioxidant activity of its fruit and seed has been investigated. However, limited available information concerning the biological activities of its leaves has been reported.

Objective: To investigate the in vitro anti-aging potential of young and old leaves of Ma Kiang.

Materials and methods: Ma Kiang leaves were extracted using water, methanol, and chloroform as the solvents by cold (sonication) and hot (boiling) processes. The extracts were determined for total phenolic and flavonoid contents. The extracts (at 0.001–10?mg/ml) were tested for antioxidative and tyrosinase inhibition activities using a colorimetric method. The cytotoxicity of extracts (at 0.0001–1?mg/ml) was determined with human skin fibroblasts. Also, the extracts at 0.001, 0.01, and 0.1?mg/ml which showed no toxicity were tested for MMP-2 inhibition.

Results: The cold methanol extract of the old leaves showed the highest total phenolic and flavonoid contents of 511.44?±?18.23?μg GAE/mg and 262.96?±?2.98?μg QE/mg, respectively. This extract also gave high free radical scavenging, lipid peroxidation inhibition, and tyrosinase inhibition activities with SC₅₀, IPC₅₀, and IC₅₀ values of 0.02?±?0.004, 0.23?±?0.13, and 0.02?±?0.006?mg/ml, respectively. The extract at 0.1?mg/ml exhibited the highest MMP-2 inhibition of 91.14?±?1.67%.

Discussion and conclusion: The anti-aging potential of the cold methanol extract from old leaves of Ma Kiang can be further developed as an anti-aging agent.     

Antioxidant,antimicrobial and wound healing properties of Struthanthus vulgaris

Context: Struthanthus vulgaris (Vell.) Mart. (Loranthaceae) has been widely used in traditional medicine in Brazil to bathe wounds.

Objective: The objective of this study is to investigate the in vitro wound healing effects, together with the antioxidant and antimicrobial activities of S. vulgaris leaf and branch extracts.

Material and methods: Ethanol leaf and branch extracts of S. vulgaris were investigated at 1–100?µg/ml concentrations in the scratch assay after 14?h. Antioxidant activity was investigated using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging assay, and the antibacterial activity was tested at concentrations up to 1000?µg/ml against Gram-positive and Gram-negative bacteria by the microdilution test after 24?h. The total phenolic and flavonoid contents were determined by colorimetric methods.

Results: Struthanthus vulgaris leaf and branch extracts at 100?µg/ml concentration stimulated migration and proliferation of fibroblasts and enhanced cell numbers by 56.2% and 18.6%, respectively. Antioxidant activity exhibited IC₅₀ values of 24.3 and 18.9?µg/ml for the leaf and branch extracts, respectively. The ethanol leaf extract showed antimicrobial activity against the Gram-positive Staphylococcus mutans and Staphylococcus aureus bacteria, exhibiting minimum inhibitory concentration values of 125 and 500?µg/ml, respectively. An appreciable total phenolic content in the leaves (813.6?±?2.7?mg/g) and branches (462.8?±?9.6?mg/g), and relatively low concentration of flavonoids in the leaves (13.3?±?4.3?mg/g) and branches (1.9?±?0.2?mg/g), was detected.

Discussion and conclusion: The antioxidant and antibacterial activities, together with the strong ability to stimulate proliferation and migration of fibroblasts, provide some support for the traditional use of S. vulgaris.     

Anti-proliferative and matrix metalloproteinase-2 inhibition of Longkong (Lansium domesticum) extracts on human mouth epidermal carcinoma

Abstract

Context: Longkong [Lansium domesticum Corr. (Meliaceae)] is a popular tropical plant producing economic edible fruits found mainly in Southeast Asia. However, limited information is available concerning anticancer activity of Longkong.

Objective: To investigate anticancer activities in human mouth epidermal carcinoma (KB) of Longkong extracts.

Materials and methods: Various parts of Longkong which was collected from Northern and Eastern of Thailand were extracted by the hot and cold processes using water, chloroform, and methanol. The extracts were tested for anti-oxidative activities and anti-proliferation as well as matrix metalloproteinase inhibition on KB cells.

Results: The hot water extract of seeds from Northern region (NSEWH), the cold water extract of old leaves from Northern region (NOLWC), and the hot chloroform extract of young leaves from Eastern region (EYLCH) showed the highest free radical scavenging, metal ion chelating, and lipid peroxidation inhibition with SC₅₀, MC₅₀ and IPC₅₀ values of 0.34?±?0.03, 0.47?±?1.60 and 0.86?±?0.31?mg/ml, respectively. The hot and cold chloroform extract of young fruits from Northern region (NYFCH and NYFCC) exhibited anti-proliferation effect against KB cells with IC₅₀ values of 603.45?±?55.35 and 765.06?±?46.19?mg/ml, respectively. NYFCC exhibited the highest pro- and active MMP-2 inhibition at 53.03?±?2.65 and 31.30?±?0.43%, more than all tested standard anticancer drugs except cisplatin.

Discussion and conclusion: The cold chloroform extract of young fruits from Northern region appeared to contain anticancer active compounds against KB cells because of its high anti-proliferation and MMP-2 inhibition activities.     

Vasorelaxant properties of Vernonia amygdalina ethanol extract and its possible mechanism

Context: Vernonia amygdalina Del. (VA) (Asteraceae) is commonly used to treat hypertension in Malaysia.

Objective: This study investigates the vasorelaxant mechanism of VA ethanol extract (VAE) and analyzes its tri-step FTIR spectroscopy fingerprint.

Materials and methods: Dried VA leaves were extracted with ethanol through maceration and concentrated using rotary evaporator before freeze-dried. The vasorelaxant activity and the underlying mechanisms of VAE using the cumulative concentration (0.01–2.55?mg/mL at 20-min intervals) were evaluated on aortic rings isolated from Sprague Dawley rats in the presence of antagonists.

Results: The tri-step FTIR spectroscopy showed that VAE contains alkaloids, flavonoids, and saponins. VAE caused the relaxation of pre-contracted aortic rings in the presence and absence of endothelium with EC₅₀ of 0.057?±?0.006 and 0.430?±?0.196?mg/mL, respectively. In the presence of Nω-nitro-l-arginine methyl ester (EC₅₀ 0.971?±?0.459?mg/mL), methylene blue (EC₅₀ 1.203?±?0.426?mg/mL), indomethacin (EC₅₀ 2.128?±?1.218?mg/mL), atropine (EC₅₀ 0.470?±?0.325?mg/mL), and propranolol (EC₅₀ 0.314?±?0.032?mg/mL), relaxation stimulated by VAE was significantly reduced. VAE acted on potassium channels, with its vasorelaxation effects significantly reduced by tetraethylammonium, 4-aminopyridine, barium chloride, and glibenclamide (EC₅₀ 0.548?±?0.184, 0.158?±?0.012, 0.847?±?0.342, and 0.304?±?0.075?mg/mL, respectively). VAE was also found to be active in reducing Ca²⁺ released from the sarcoplasmic reticulum and blocking calcium channels.

Conclusions: The vasorelaxation effect of VAE involves upregulation of NO/cGMP and PGI₂ signalling pathways, and modulation of calcium/potassium channels, and muscarinic and β₂-adrenergic receptor levels.     

Effects of Danshen tablets on pharmacokinetics of atorvastatin calcium in rats and its potential mechanism

Context: Danshen tablets (DST), an effective traditional Chinese multi-herbal formula, are often combined with atorvastatin calcium (AC) for treating coronary heart disease in the clinic.

Objective: This study investigated the effects of DST on the pharmacokinetics of AC and the potential mechanism.

Materials and methods: The pharmacokinetics of AC (1?mg/kg) with or without pretreatment of DST (100?mg/kg) were investigated using LC-MS/MS. The effects of DST (50?μg/mL) on the metabolic stability of AC were also investigated using rat liver microsome incubation systems.

Results: The results indicated that C_max (23.87?±?4.27 vs. 38.94?±?5.32?ng/mL), AUC_(0–t) (41.01?±?11.32 vs. 77.28?±?12.92?ng h/mL), and t_1/2 (1.91?±?0.18 vs. 2.74?±?0.23?h) decreased significantly (p?t_1/2) of AC was also decreased (25.7?±?5.2 vs. 42.5?±?6.1) with the pretreatment of DST.

Discussion and conclusions: This study indicated that the main components in DST could accelerate the metabolism of AC in rat liver microsomes and change the pharmacokinetic behaviors of AC. So these results showed that the herb-drug interaction between DST and AC might occur when they were co-administered. Therefore, the clinical dose of AC should be adjusted when DST and AC are co-administered.     

Role of GABAB receptors and p38MAPK/NF-κB pathway in paclitaxel-induced apoptosis of hippocampal neurons

Context: The effects of the anticancer drug paclitaxel on learning and memory are rarely studied.

Objective: This study investigated changes in GABA_B receptor expression during paclitaxel-induced apoptosis of hippocampal neurons and the role of the p38MAPK/NF-κB pathway in this process.

Materials and methods: Hippocampal neurons isolated from neonatal Sprague–Dawley rats were divided into six groups: Control (C), SB (10?µL of 10-µmol/L SB203580), SN (53?µg/mL SN50), N (1?µmol/L paclitaxel), SB?+?N (10?µmol/L SB203580?+?1?µmol/L paclitaxel) and SN?+?N (53?µg/mL SN50?+?1?µmol/L paclitaxel). Cells in different groups were treated with corresponding agents for 24?h at 37?°C. The apoptosis rate and protein levels of GABA_B1 receptors and NF-κB p65 were evaluated. Rat models of neuropathic pain was induced by paclitaxel and were divided into four groups such as N, B?+?N, SN?+?N and SN?+?B?+?N groups. Rats in the N group received intrathecal injections of normal saline solution. Rats in the B?+?N group received intrathecal injections of 10?μL baclofen (0.05?μg/μL). Rats in the SN?+?N and SN?+?B?+?N groups received intrathecal injections of SN50 and SN50 plus baclofen, respectively. Spatial learning and memory were evaluated in rat models based on the escape latency and the number of crossings over the platform and protein levels of GABA_B1 receptors, NF-κB, IL-1β and TNFα were measured by immunohistochemistry assay and western blot.

Results: The neuronal apoptosis rate was significantly increased in N (49.16?±?3.12)%, SB?+?N (31.18?±?3.02)% and SN?+?N (28.47?±?3.75)% groups, accompanied by increased levels of GABA_B1 receptors and NF-κB p65 (p?p?B1:9.0?±?1.6, NF-κB p65:29.6?±?2.4, IL-1β: 30.4?±?3.4, TNFα: 31.0?±?3.4), B?+?N, SN?+?N and SN?+?B?+?N groups evidently increased levels of GABA_B1 receptor (B?+?N:SN?+?N:SN?+?B?+?N?=?19.4?±?2.1:20.8?±?1.9:28.0?±?1.9) but significantly decreased levels of NF-κB p65 (B?+?N:SN?+?N:SN?+?B?+?N?=?21.2?±?1.5:18.6?±?2.1:12.6?±?1.5), IL-1β (B?+?N:SN?+?N:SN?+?B?+?N?=?22.0?±?1.0:19.6?±?1.8:14.6?±?1.5) and TNF α (B?+?N:SN?+?N:SN?+?B?+?N?=?23.0?±?1.6:22.2?±?0.8:16.6?±?1.7). Similar findings were found in western blot analysis.

Discussions and conclusions: Paclitaxel may reduce cognitive function in rats through the p38MAPK/NF-κB pathway and GABA_B1 receptors.