Anti‐HIV‐1 Integrase Activity and Molecular Docking Study of Compounds from Caesalpinia sappan L.

Caesalpinia sappan L. (Caesalpiniaceae) has been traditionally used as blood tonic, expectorant, and astringent by boiling with water. Searching for HIV‐1 integrase (IN) inhibitors from this plant is a promising approach. The EtOH extract of C. sappan and its isolated compounds were tested for their anti‐HIV‐1 IN effect using the multiplate integration assay, and the active compounds were determined for their mechanisms by molecular docking technique. Extraction from the heartwoods and roots of C. sappan led to the isolation of nine compounds. Among the compounds tested, sappanchalcone (2) displayed the strongest effect against HIV‐1 IN with an IC₅₀ value of 2.3 μM followed by protosappanin A (9, IC₅₀ = 12.6 μM). Structure‐activity relationships of compounds from C. sappan were found, in which the vicinal hydroxyl moiety were essential for anti‐HIV‐1 IN effect of compounds 2 and 9 by binding with the amino acid residues Gln148 and Thr66 in the core domain of the HIV‐ 1 IN enzyme, respectively. Copyright © 2015 John Wiley & Sons, Ltd.     

A Comparative Study on the Inhibitory Effects of Different Parts and Chemical Constituents of Pomegranate on α‐Amylase and α‐Glucosidase

Pomegranate has been documented for the management of diabetes in Unani and Chinese medicine. This study compared the effects of the extracts of different pomegranate parts, including juice, peels, seeds and flowers, on carbohydrate digestive enzymes (α‐amylase and α‐glucosidase) in vitro. The methanolic flower extract inhibited α‐amylase and α‐glucosidase, while the methanolic peel extract inhibited α‐glucosidase selectively. The most active flower extract was subjected to water‐ethyl acetate partition. The ethyl acetate fraction was more potent than the water fraction in inhibiting both enzymes. Gallic acid and ellagic acid also showed selective inhibition against α‐glucosidase, and their presence in the ethyl acetate fraction was confirmed by HPLC‐DAD and HPLC‐HESI‐MS. Our findings suggest that the inhibition of carbohydrate digestive enzymes and their phenolic content may contribute to the anti‐hyperglycaemic effects of pomegranate flower and peel, and support their claims in diabetes. Copyright © 2012 John Wiley & Sons, Ltd.     

Inhibitory Effects of (2′R)‐2′,3′‐dihydro‐2′‐(1‐hydroxy‐1‐methylethyl)‐2,6′‐bibenzofuran‐6,4′‐diol on Mushroom Tyrosinase and Melanogenesis in B16‐F10 Melanoma Cells

(2′R)‐2′,3′‐Dihydro‐2′‐(1‐hydroxy‐1‐methylethyl)‐2,6′‐bibenzofuran‐6,4′‐diol (DHMB) is a natural compound extracted from Morus notabilis. It was found that DHMB acts as a competitive inhibitor against mushroom tyrosinase with a Ki value of 14.77 μM. Docking results further indicated that it could form strong interactions with one copper ion with a distance of 2.7 Å, suggesting the mechanism of inhibition might be due to chelating copper ions in the active site. Furthermore, melanin production in B16‐F10 murine melanoma cells was significantly inhibited by DHMB in a concentration‐dependent manner without cytotoxicity. The results of western blotting also showed that DHMB decreased 3‐isobuty‐1‐methxlzanthine‐induced mature tyrosinase expression. Taken together, these findings indicated that DHMB may be a new promising pigmentation‐altering agent for agriculture, cosmetic, and therapeutic applications. Copyright © 2015 John Wiley & Sons, Ltd.     

Antioxidant and Anti‐α‐glucosidase Compounds from the Rhizome of Peltiphyllum peltatum (Torr.) Engl

The antioxidant, anti‐α‐glucosidase and anticholinesterase effects of the alcohol extract of fresh underground rhizomes of Peltiphyllum peltatum were studied. A potent antioxidant activity accompanied by a selective α‐glucosidase effect was observed for the crude extract. Further activity‐guided fractionation (petroleum ether, chloroform, ethyl acetate, n‐butanol and water) resulted in the identification of the ethyl acetate fraction with the highest antioxidant effect. Gallic acid, methyl‐3‐O‐methyl gallate, catechin, gallocatechin, bergenin and 11‐O‐galloylbergenin were isolated from the ethyl acetate fraction. While all the isolated compounds did show a variable degree of radical scavenging effect, 11‐O‐galloylbergenin was identified as the selective α‐glucosidase inhibitor. The isolation, structural elucidation and biological effects of these compounds are discussed. Copyright © 2012 John Wiley & Sons, Ltd.     

In Vitro and In Silico Evaluation of NF‐κB Targeted Costunolide Action on Estrogen Receptor‐Negative Breast Cancer Cells—A Comparison with Normal Breast Cells

Costunolide, a sesquiterpene lactone is a plant‐derived secondary metabolite found to be present in most of the pharmacologically active herbs, being the cause for their medicinal values. The present study aims to evaluate the cytotoxic effect of costunolide isolated from Costus speciosus rhizome extract on MDA‐MB‐231 cells and explore its targeted action in comparison with its action on the normal breast cells (MCF 10A). The effect of costunolide on cell viability of the cells was assessed by 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide viability assay. The targeted action of the compound was analyzed comparing the effectiveness of the compound to alter the protein expression levels of NF‐κB subunits in the normal and the cancer cells using western blotting analysis. In silico studies were performed to predict the targeted interaction of costunolide with the NF‐κB subunit proteins. Costunolide inhibited the cell viability of MDA‐MB‐231 cells in a dose‐dependent manner leaving no significant change in the viability of the normal breast cells. The over expressed NF‐κB subunits – p65, 52 and 100 in the cancer cells were found to be downregulated when treated with costunolide at an effective dose of 20 and 40 μM costunolide. In silico results provided stable interactions between costunolide and the target proteins, supporting the in vitro results in addition. Thus, costunolide derived from C. speciosus plant source elevates a fresh conviction for its use in breast cancer therapy for its cytotoxic efficacy and non‐toxic nature. Copyright © 2014 John Wiley & Sons, Ltd.     

Protective effect of Morinda citrifolia fruits on β‐amyloid (25–35) induced cognitive dysfunction in mice: An experimental and biochemical study

The neuroprotective effect of an ethyl acetate extract of Morinda citrifolia (Rubiaceae) Linn. fruits (EMC, ethyl acetate extract of Morinda citrifolia) at doses of 200 and 400 mg/kg, p.o. was studied on β‐amyloid (25–35) peptide induced cognitive dysfunction in mice. In the step‐down inhibitory avoidance, EMC exhibited a significant increase in short‐term memory and long‐term memory (p < 0.05). A significant decrease (p < 0.01) in escape latency was noticed in the animals in the water maze. A significant increase (p < 0.01) in alteration of behavior was exhibited upon administration of EMC 200 and 400 mg/kg on the Y maze. Exploratory parameters such as line crossings, head dipping and rearing were increased significantly in EMC treated groups in a dose‐dependent manner (p < 0.05 and p < 0.01). A significant reduction (p < 0.05) in acetyl cholinesterase activity was noticed in the EMC 200 and 400 mg/kg treated groups. The level of monoamine oxidase‐A was decreased by the administration of EMC 200 and 400 mg/kg (p < 0.05 and p < 0.01, respectively). EMC at a dose of 400 mg/kg exhibited a significant increase (p < 0.01) in the levels of serotonin and dopamine. Antioxidant enzymes such as superoxide dismutase, glutathione reductase, glutathione peroxidase and ascorbic acid were decreased significantly in the b‐amyloid peptide injected group, whose levels were restored significantly (p < 0.01) by the administration of EMC (400 mg/kg). Copyright © 2009 John Wiley & Sons, Ltd.     

Neuroprotective effects of Triticum aestivum L. against β‐Amyloid‐induced cell death and memory impairments

β‐Amyloid (Aβ) is a key component of senile plaques, neuropathological hallmarks of Alzheimer's disease (AD) and has been reported to induce cell death via oxidative stress. This study investigated the protective effects of Triticum aestivum L. (TAL) on Aβ‐induced apoptosis in SH‐SY5Y cells and cognitive dysfunctions in Sprague‐Dawley (SD) rats. Cells treated with Aβ exhibited decreased viability and apoptotic features, such as DNA fragmentation, alterations in mitochondria and an increased Bax/Bcl‐2 ratio, which were attenuated by TAL extract (TALE) pretreatment. To elucidate the neuroprotective mechanisms of TALE, the study examined Aβ‐induced oxidative stress and cellular defense. TALE pretreatment suppressed Aβ‐increased intracellular accumulation of reactive oxygen species (ROS) via up‐regulation of glutathione, an essential endogenous antioxidant. To further verify the effect of TALE on memory impairments, Aβ or scopolamine was injected in SD rats and a water maze task conducted as a spatial memory test. Aβ or scopolamine treatment increased the time taken to find the platform during training trials, which was decreased by TALE pretreatment. Furthermore, one of the active components of TALE, total dietary fiber also effectively inhibited Aβ‐induced cytotoxicity and scopolamine‐caused memory deficits. These results suggest that TALE may have preventive and/or therapeutic potential in the management of AD. Copyright © 2009 John Wiley & Sons, Ltd.     

Houttuynia cordata Thunb. Volatile Oil Exhibited Anti‐inflammatory Effects In Vivo and Inhibited Nitric Oxide and Tumor Necrosis Factor‐α Production in LPS‐stimulated Mouse Peritoneal Macrophages In Vitro

Houttuynia cordata Thunb. (HC) is a medicinal herb that generally used in traditional Chinese medicine for treating allergic inflammation. The present study investigated the inhibitory effect of the volatile oil from HC Thunb. on animal models of inflammation and the production of inflammatory mediators in vivo and in vitro. In vivo, xylene‐induced mouse ear edema, formaldehyde‐induced paw edema and carrageenan‐induced mice paw edema were significantly decreased by HC volatile oil. HC volatile oil showed pronounced inhibition of prostaglandin (PG) E₂ and malondialdehyde production in the edematous exudates. In vitro exposure of mouse resident peritoneal macrophages to 1, 10, 100 and 1000 µg/mL of HC volatile oil significantly suppressed lipopolysaccharide (LPS)‐stimulated production of NO and tumor necrosis factor‐α (TNF‐α) in a dose‐dependent manner. Exposure to HC volatile oil had no effect on cell viability and systemic toxicity. Furthermore, HC volatile oil inhibited the production of NO and TNF‐α by down‐regulating LPS‐stimulated iNOS and TNF‐α mRNA expression. Western blot analysis showed that HC volatile oil attenuated LPS‐stimulated synthesis of iNOS and TNF‐α protein in the macrophages, in parallel. These findings add a novel aspect to the biological profile of HC and clarify its anti‐inflammatory mechanism. Copyright © 2012 John Wiley & Sons, Ltd.     

Inhibitory Effect of Ethanol Extract of Magnolia officinalis on Memory Impairment and Amyloidogenesis in a Transgenic Mouse Model of Alzheimer's Disease via Regulating β‐Secretase Activity

Alzheimer's disease (AD) is the most common form of dementia and is characterized by deposition of amyloid beta (Aβ) in the brain. The components of the herb Magnolia officinalis are known to have antiinflammatory, antioxidative and neuroprotective activities. In this study we investigated the effects of ethanol extract of M. officinalis on memory dysfunction and amyloidogenesis in a transgenic mouse model of AD. Oral pretreatment of ethanol extract of M. officinalis (10 mg/kg in 0.05% ethanol) into drinking water for 3 months inhibited memory impairment and Aβ deposition in the brain of Tg2576 mice. Ethanol extract of M. officinalis also decreased activity of β‐secretase, cleaving Aβ from amyloid precursor protein (APP), and expression of β‐site APP cleaving enzyme 1 (BACE1), APP and its product, C99. Our results showed that ethanol extract of M. officinalis effectively prevented memory impairment via down‐regulating β‐secretase activity. Copyright © 2012 John Wiley & Sons, Ltd.     

An investigation of the effects of curcumin on iron overload,hepcidin level,and liver function in β‐thalassemia major patients: A double‐blind randomized controlled clinical trial

This study investigated the effects of curcumin, the active polyphenol in turmeric, on iron overload, hepcidin level, and liver function in β‐thalassemia major patients. This double‐blind randomized controlled clinical trial was conducted on 68 β‐thalassemia major patients. The subjects were randomly divided into 2 groups to receive either 500 mg curcumin capsules (total: 1,000 mg) twice daily or placebo for 12 weeks. Dietary intakes and biochemical variables including hemoglobin, transferrin saturation, total iron binding capacity, nontransferrin bound iron (NTBI), ferritin, hepcidin, alanine aminotransferase (ALT), and aspartate aminotransferase (AST) were assessed at the beginning and end of the trial. Curcumin significantly reduced serum levels of NTBI (2.83 ± 1.08 compared with 2.22 ± 0.97 μmol/L, p = .001), ALT (42.86 ± 11.15 compared with 40.60 ± 9.89 U/L, p = .018), and AST (49.45 ± 12.39 compared with 46.30 ± 10.85 U/L, p = .002) at the end of the study. Based on analysis of covariance, a significant decrease was also observed in levels of NTBI (2.22 ± 0.97 vs. 2.55 ± 0.94 μmol/L, p = .026), ALT (40.60 ± 9.89 vs. 45.01 ± 10.42 U/L, p = .004), and AST (46.30 ± 10.85 vs. 50.99 ± 9.36 U/L, p = .009) in curcumin group in comparison with placebo group. There were no significant changes in hepcidin and other variables in any of the 2 groups. Curcumin administration alleviated iron burden and liver dysfunction by reducing NTBI, ALT, and AST levels in patients with β‐thalassemia major.

     

Therapeutic Effect of Rhizoma Dioscoreae Nipponicae on Gouty Arthritis Based on the SDF‐1/CXCR 4 and p38 MAPK Pathway: An In Vivo and In Vitro Study

Rhizoma Dioscoreae Nipponicae (RDN) is a widely used traditional Chinese herb, which is used to treat arthroncus, arthrodynia and arthritis. As is known to us, inflammatory mechanisms have played an important role in the occurrence, course and prognosis of gouty arthritis (GA). The aim of this study was to determine the characteristic expressed proteins of synovium in GA rat and synovial cell. The rat model of GA was induced by monosodium urate (MSU) crystal. Tissue samples were assayed by immunohistochemical method. The effects of RDN on Stromal cell‐derived factor 1 (SDF‐1), CXCR 4 and p38 mitogen‐activated protein kinase (MAPK) were investigated in MSU crystal‐induced rat. The levels of SDF‐1 and mitogen‐activated kinase kinase (MKK) 3/6 were measured by Western Blot in interleukin‐1β (IL‐1β) incubated fibroblast‐like synoviocytes (FLS). A significant increase in the levels of SDF‐1, CXCR 4 and p38 MAPK were observed in MSU crystal‐induced rat. The increased SDF‐1 and MKK 3/6 levels were observed in IL‐1β incubated FLS. With the treatment of RDN, the above changes were reverted back to near normal levels. RDN might have some therapeutic effects on GA through SDF‐1/CXCR 4 and p38 MAPK pathway, and dioscin may be the active compound in RDN to exert therapeutic effect on GA. Copyright © 2013 John Wiley & Sons, Ltd.