Amira Mira

Comparative biological study of roots, stems, leaves, and seeds of Angelica shikokiana Makino

ETHNOPHARMACOLOGICAL RELEVANCE Angelica shikokiana has been used as a health food for its anticancer, anti-inflammatory, antibacterial, antiallergic, and blood vessel dilating effects in Japan. It can also be used to prevent and treat hepatitis, diabetes, hyperlipidemia, and arteriosclerosis. AIM OF THE STUDY The present study was designed to compare the biological activities such as melanin synthesis inhibitory, anti-allergy, anti-lipase, anti-bacterial, anti-oxidant, and neuroprotective activities of different parts of the plant that may justify the use of this plant in folk medicine. MATERIAL AND METHODS The roots, stems, leaves and, seeds of Angelica shikokiana were separately extracted with water and ethanol. Each extract was examined for melanin synthesis inhibitory and anti-allergy activity on B16-melanoma and RBL-2H3 cells using IgE and A23187 as a stimulant for β-hexosaminidase release, respectively. We also evaluated the inhibition of two enzymes, lipase and acetylcholine esterase, and of the bacterial growth of two species, Escherichia coli and Staphylococcus aureaus. The anti-oxidant activity was determined using oxygen radical anti-oxidant capacity, ORAC assay and its relation to the phenolic content was estimated using the Folin-Ciocalteu method. Besides, the protective effect of the extracts against H2O2-induced oxidative stress in mouse neuroblastoma, Neuro-2A cells was investigated. RESULTS The most active extract exhibiting melanin synthesis inhibition (63%) and at the same time with low cytotoxicity (15%) was the ethanol extract of roots at 20 µg/ml, followed by the ethanol extract of stems (57% inhibition, 5% cytotoxicity). On the other hand, the highest inhibitions of β-hexosaminidase release were recorded for the ethanol extract of leaves with IC50 value of 6.89 µg/ml followed by the water extract of the seeds and leaves with IC50 value of 78.32 and 88.44 µg/ml, respectively. For anti-lipase assay, ethanol extracts of the stems and roots showed the strongest inhibition with IC50 values of 204.06 and 216.24 µg/ml, respectively. None of the examined extracts showed any activity against Escherichia coli. while the ethanol extract of the roots and stems showed moderate inhibition for Staphylococcus aureus with minimum inhibitory concentration of 400 µg/ml. Ethanol extract of the roots showed only 30% inhibition of acetylcholine esterase enzyme. The results of anti-oxidant, phenolic content and protective effect against H2O2-induced cytotoxicity assays showed highly correlated data. Ethanol extract of the stems (ORAC value of 1.08 µmol Trolox/mg and phenolic content 44.25 μg GAE/mg) increased the cell viability of H2O2-treated Neuro-2A cells by 28%.

In vitro neuroprotective activities of compounds from Angelica shikokiana Makino

Angelica shikokiana is widely marketed in Japan as a dietary food supplement. With a focus on neurodegenerative conditions such as Alzheimer’s disease, the aerial part was extracted and through bio-guided fractionation, fifteen compounds [α-glutinol, β-amyrin, kaempferol, luteolin, quercetin, kaempferol-3-O-glucoside, kaempferol-3-O-rutinoside, methyl chlorogenate, chlorogenic acid, hyuganin E, 5-(hydroxymethyl)-2-furaldehyde, β-sitosterol-3-O-glucoside, adenosine (isolated for the first time from A. shikokiana), isoepoxypteryxin and isopteryxin] were isolated. Isolated compounds were evaluated for in vitro neuroprotection using acetylcholine esterase inhibitory, protection against hydrogen peroxide and amyloid β peptide (Aβ25-35)-induced neurotoxicity in neuro-2A cells, scavenging of hydroxyl radicals and intracellular reactive oxygen species and thioflavin T assays. Quercetin showed the strongest AChE inhibition (IC50 value = 35.5 µM) through binding to His-440 and Tyr-70 residues at the catalytic and anionic sites of acetylcholine esterase, respectively. Chlorogenic acid, its methyl ester, quercetin and luteolin could significantly protect neuro-2A cells against H2O2-induced neurotoxicity and scavenge hydroxyl radical and intracellular reactive oxygen species. Kaempferol-3-O-rutinoiside, hyuganin E and isoepoxypteryxin significantly decreased Aβ25-35-induced neurotoxicity and Th-T fluorescence. To the best of our knowledge, this is the first report about neuroprotection of hyuganin E and isoepoxypteryxin against Aβ25-35-induced neurotoxicity.

Acetylcholine esterase inhibitors and melanin synthesis inhibitors from Salvia officinalis.

BACKGROUND Salvia officinalis is a traditionally used herb with a wide range of medicinal applications. Many phytoconstituents have been isolated from S. officinalis, mainly phenolic diterpenes, which possess many biological activities. PURPOSE This study aimed to evaluate the ability of the phenolic diterpenes of S. officinalis to inhibit acetylcholine esterase (AChE) as well as their ability to inhibit melanin biosynthesis in B16 melanoma cells. METHODS The phenolic diterpenes isolated from the aerial parts of S. officinalis were tested for their effect on melanin biosynthesis in B16 melanoma cell lines. They were also tested for their ability to inhibit AChE using Ellmans method. Moreover, a molecular docking experiment was used to investigate the binding affinity of the isolated phenolic diterpenes to the amino acid residues at the active sites of AChE. RESULTS Seven phenolic diterpenes-sageone, 12-methylcarnosol, carnosol, 7b-methoxyrosmanol, 7a-methoxyrosmanol, isorosmanol and epirosmanol-were isolated from the methanolic extract of the aerial parts of S. officinalis. Isorosmanol showed a melanin-inhibiting activity as potent as that of arbutin. Compounds 7a-methoxyrosmanol and isorosmanol inhibited AChE activity by 50% and 65%, respectively, at a concentration of 500 µM. CONCLUSIONS The results suggest that isorosmanol is a promising natural compound for further studies on development of new medications which might be useful in ageing disorders such as the declining of cognitive functions and hyperpigmentation.

Anti-choline esterase activity of ceramides from the Red Sea marine sponge Mycale euplectellioides

The isolation and structure elucidation of new phytoceramides from a methanolic extract of the Red Sea sponge Mycale euplectellioides was exclusively studied. Structure elucidation was achieved using spectroscopic techniques, including 1D and 2D NMR and HRMS. The anti-choline esterase activity of the isolated ceramides was evaluated in vitro using a microplate-based Ellman’s assay. Bioassay guided isolation led to the isolation of a MEC-1 phytoceramide molecular species; further purification of MEC-1 afforded three pure phytoceramides: MEC-1-4, MEC-1-7 and MEC-1-8. Molecular modeling studies using glide docking showed tight binding of the ceramides to acetylcholine esterase (AChE). The ceramides showed a better docking score and glide Emodel value when compared to known AChE inhibitors. The ceramides interacted with an aromatic residue of the peripheral anionic site and penetrated deeply into the catalytic triad residues of the active site. Overall, the ceramides obtained using the approaches described here could be considered as promising lead compounds for the discovery and design of potent anti-choline esterase drug candidates, which would be used for Alzheimer’s eradication.

In vitro Cytotoxic Activities and Molecular Mechanisms of Angelica shikokiana Extract and its Isolated Compounds

Background: Angelica shikokiana is a Japanese medicinal herb that is included among food and drug preparations protecting against cancer; however, there is no previous report about the cytotoxicity of A. shikokiana or its bioactive compounds. Objective: This study was designed to investigate the cytotoxic activities of A. shikokiana methanol extract (AME) and its isolated compounds and to identify the molecular mechanisms of the cytotoxicity. Materials and Methods: Cytotoxicity and selectivity was investigated by measuring the IC50 values on five cancer cell lines; human hepatocellular carcinoma, rhabdomyosarcoma (RD), colorectal carcinoma, human epithelioma and human breast adenocarcinoma and one normal cell line; human lung fibroblasts. The effects on tubulin polymerization and histone deacetylase 8 (HDAC8), were examined to determine the mechanism of cytotoxicity. Docking study was designed to examine the binding affinity to the target molecules. Results: Methanol extract and some of its isolated coumarins and flavonoids showed potent, selective cytotoxicity against cancer cell lines. AME and all isolated compounds inhibited tubulin polymerization. Angelicin and kaempferol-3-O-rutinoside were the most active compounds. Phenolic compounds and furanocoumarins showed binding affinity to colchicine binding site rather than the vinblastine binding site of tubulin microtubules. On the other side, quercetin, kaempferol, luteolin, chlorogenic acid, and methyl chlorogenate exhibited the strongest activity against HDAC8 and the highest affinity to trichostatin A binding site. Conclusion: These findings provide the first scientific evidence of the cytotoxicity of AME through inhibition of tubulin polymerization and HDAC8 activity through its coumarin and flavonoid content. SUMMARY The present study provides for the first time a clue for the cytotoxic activities of the AME. Our results indicate that the cytotoxic activities are partially related to the ability of AME to inhibit tubulin polymerization and HDAC8 activity. Isolated compounds; Angelicin and kaempferol-3-O-rutinoside showed the strongest inhibition of tubulin polymerization through binding to colchicine binding domain of tubulin microtubules. Phenolic compounds; quercetin, luteolin, kaempferol, chlorogenic acid and methyl chlorogenate exhibited a strong inhibition of HDAC8 through binding to TSA binding site. This, however, further detailed pharmacological and in vivo studies should be the next step in evaluating the cytotoxic activities of AME and its active compounds that are currently ongoing. Abbreviations used: AME: Methanol extract of the aerial part of A. shikokiana, HDACs: Histone deacetylases,HDAC8: Histone deacetylase 8

Antiplatelet and Anticoagulant Activities of Angelica shikokiana Extract and Its Isolated Compounds

Angelica shikokiana is a Japanese medicinal plant that is used traditionally in several ailments of cardiovascular diseases. However, there is no report regarding its anticoagulant or antiplatelet activities. So this study was designed to screen for such activities (anticoagulant by prothrombin time [PT], activated partial thromboplastin time, and thrombin time assays and antiplatelet activities against adenosine 5′-diphosphate [ADP] and arachidonic acid-induced platelet aggregations) for the methanol extract of the aerial part (Angelica methanol extract [AME]), its isolated coumarins, flavonoids, and flavonoid metabolites. The AME had potent anticoagulant and antiplatelet activities, and the flavonoid compounds were evidenced to be responsible for such activities. Among coumarins compounds, hyuganin C showed significant prolongation of only PT, while other coumarins were inactive. Similarly, hyuganin C and bergapten were the only active coumarins against ADP-induced platelet aggregation. Compared to the parent compounds, colonic metabolites of the flavonoids had similar anticoagulant and antiplatelet activities, while glucuronides showed sharp decreases in all studied activities. This is the first report showing that the medicinal plant A shikokiana has potent antiplatelet and anticoagulant activities.

Biological Activities of Oleanolic Acid Derivatives from Calendula officinalis Seeds

Phytochemical examination of butanol fraction of Calendula officinalis seeds led to the isolation of two compounds identified as 28‐O‐β‐D‐glucopyranosyl‐oleanolic acid 3‐O‐β‐D–glucopyranosyl (1→3)‐β‐D‐glucopyranosiduronic acid (CS1) and oleanolic acid 3‐O‐β‐D–glucopyranosyl (1→3)‐β‐D‐glucopyranosiduronic acid (CS2). Biological evaluation was carried out for these two compounds such as melanin biosynthesis inhibitory, hyaluronic acid production activities, anti obesity using lipase inhibition and adipocyte differentiation as well as evaluation of the protective effect against hydrogen peroxide induced neurotoxicity in neuro‐2A cells. The results showed that, compound CS2 has a melanin biosynthesis stimulatory activity; however, compound CS1 has a potent stimulatory effect for the production of hyaluronic acid on normal human dermal fibroblast from adult (NHDF‐Ad). Both compounds did not show any inhibitory effect on both lipase and adipocyte differentiation. Compound CS2 could protect neuro‐2A cells and increased cell viability against H2O2. These activities (melanin biosynthesis stimulatory and protective effect against H2O2 of CS2 and hyaluronic acid productive activities of these triterpene derivatives) have been reported for the first time. Copyright

Derivatization, molecular docking and in vitro acetylcholinesterase inhibitory activity of glycyrrhizin as a selective anti-Alzheimer agent

Abstract Acetylcholinesterase inhibitors (AChE-Is) increase both level and duration of action of acetylcholine (ACh); thus, alleviate symptoms of Alzheimer’s disease (AD). Glycyrrhizin, is the main active compound in liquorice root. Its aglycone, glycyrrhetinic acid, has shown several beneficial pharmacological activities. This study reports the synthesis and screening of a series of glycyrrhetinic acid analogs as AChE-Is. Fourteen derivatives were prepared, of which five derivatives are recorded as new viz., 3-phenyl-carbamoyl-18β-glycyrrhetinic acid (J9), 3-acetyl-18β-glycyrrhetinic-30-anilinamide (J10), 3-acetyl-18β-glycyrrhetinic-30-ethanolamide (J11), 3-acetyl-18β-glycyrrhetinic-30-n-butylamide (J12) and 18β-glycyrrhetinic acid-30-prenyl ester (J14), in addition to nine known derivatives (J1-J8 & J13). Compounds J12, J11, J0 and J3 showed remarkable AChE-I activity with IC50 values of 3.43, 5.39, 6.27 and 8.68 μM, respectively. These results are in full agreement with the docking study. The active compounds were non-cytotoxic to normal cells (WI-38).

An update on antitumor activity of Angelica species

Genus Angelica (Family: Apiaceae) comprises more than 60 species of medicinal plants. Many of these species have long been used in ancient traditional medicine systems, especially in the Eastern countries. For many years, several species of Angelica, e.g., A. archangelica, A. dahurica, A. keiskei, A. gigas, A. pubescens, A. sinensis, A. shikokiana have been used traditionally as anti-inflammatory, diuretic, expectorant, and diaphoretic. Also, these have been used as remedies for hepatitis, arthritis, indigestion, coughs, chronic bronchitis, pleurisy, fever, rheumatism, bacterial and fungal infections, and diseases of the urinary organs. Several classes of compounds such as coumarins, acetylenic compounds, chalcones, sesquiterpenes, and polysaccharides have been reported from these plants. This chapter outlines the results of various scientific studies on Angelica species that were reported to have anticancer and antitumor activities.

Improved Biological Activities of Isoepoxypteryxin by Biotransformation

Isoepoxypteryxin is the major coumarin of a Japanese medicinal plant Angelica shikokiana. This research was designed to study the effect of structural changes through fungal biotransformation on the reported biological activities of isoepoxypteryxin. Among the tested microorganisms, only Cordyceps sinensis had enzymes that could catalyze the ester hydrolysis and the reductive cleavage of the epoxide ring of isoepoxypteryxin, separately, to give two more polar metabolites (+)‐cis‐khellactone (P1) and a new coumarin derivative (+)‐cis‐3′‐[(2‐methyl‐3‐hydroxybutanoyl)oxy]‐4′‐acetoxy‐3′,4′‐dihydroseselin (P2), respectively. The polar metabolite P2 showed stronger cytotoxicity and higher selectivity than isoepoxypteryxin. On the molecular level, P2 showed more in vitro inhibition of both tubulin polymerization and histone deacetylase 8 (HDAC8). Similarly, P2 showed more neuroprotection against amyloid beta fragment 1 – 42 (Aβ1 – 42)‐induced neurotoxicity in human neuroblastoma cells (SH‐SY5Y) and exhibited more inhibition of the in vitro aggregation of Aβ1 – 42. Both metabolites showed stronger antiplatelet aggregation by increased inhibition of thromboxane‐A2 synthase (TXS) activity and thromboxane‐A2 (TXA2) production. This study is the first to describe the improved cytotoxic, neuroprotective, and antiplatelet aggregation activities of isoepoxypteryxin through its biotransformation by C. sinensis.