Hypolipidaemic and antiplatelet activity of phenoxyacetic acid derivatives related to α-asarone

Ethno-pharmacology of Asaroon (Asarum europaeum L.) with special reference to Unani System of Medicine

Asaroon is the rhizome of Asarum europaeum L. and is commonly used in Unani medicines for its various pharmacological actions. It is an evergreen plant with glossy foliage. It belongs to the family of Aristolochiaceae and is native to Europe and the United State of America. Some species of Asaroon have been found in the Eastern Himalayan region. Asaroon has actions like Muharrik-i-A'sab (nervine stimulant), Mudirr-i-Bawl (diuretics), Mudirr-i-Hayd (emmenagogue), Musakkin-i-Alam (analgesic), Mufattit-i-sudad (remove obstructions) and Muqawwī-i-Jigar (hepatotonic), etc. It is used in the management of Hummā (fevers), Waja 'al-Mafasil (polyarthritis), Sara (epilepsy), Falij (paralysis), Ihtibās al-Tamth (amenorrhea) and Niqris (gout), etc. as per the Unani system of medicine (USM). It is used as a single herb as well as with a combination of other drugs to manage many diseases. The A. europaeum L. contains volatile oils and flavonoids along with other secondary metabolites. In the Indian market, Valeriana wallichii DC has been sold as Tagar but in some cases, it is sold as Asaroon. It is a clear case of adulteration by replacement of costly foreign drugs with a similar-looking indigenous drug. In this manuscript, we have discussed the Ethno-pharmacology of the A. europaeum L. with special reference to USM and basic differences with V. wallichii DC to show that both drugs are different and their actions and uses are also different from each other.

α-asarone induces cardiac defects and QT prolongation through mitochondrial apoptosis pathway in zebrafish

α-asarone is a natural phenylpropene found in several plants, which are widely used for flavoring foods and treating diseases. Previous studies have demonstrated that α-asarone has many pharmacological functions, while some reports indicated its toxicity. However, little is known about its cardiovascular effects. This study investigated developmental toxicity of α-asarone in zebrafish, especially the cardiotoxicity. Zebrafish embryos were exposed to different concentrations of α-asarone (1, 3, 5, 10, and 30 μM). Developmental toxicity assessments revealed that α-asarone did not markedly affect mortality and hatching rate. In contrast, there was a concentration-dependent increase in malformation rate of zebrafish treated with α-asarone. The most representative cardiac defects were increased heart malformation rate, pericardial edema areas, sinus venosus-bulbus arteriosus distance, and decreased heart rate. Notably, we found that α-asarone impaired the cardiac function of zebrafish by prolonging the mean QTc duration and causing T-wave abnormalities. The expressions of cardiac development-related key transcriptional regulators tbx5, nkx2.5, hand2, and gata5 were all changed under α-asarone exposure. Further investigation addressing the mechanism indicated that α-asarone triggered apoptosis mainly in the heart region of zebrafish. Moreover, the elevated expression of puma, cyto C, afap1, caspase 3, and caspase 9 in treated zebrafish suggested that mitochondrial apoptosis is likely to be the main reason for α-asarone induced cardiotoxicity. These findings revealed the cardiac developmental toxicity of α-asarone, expanding our knowledge about the toxic effect of α-asarone on living organisms.

Pharmacology and toxicology of α- and β-Asarone: A review of preclinical evidence

BACKGROUND

Asarone is one of the most researched phytochemicals and is mainly present in the Acorus species and Guatteria gaumeri Greenman. In preclinical studies, both α- and β-asarone have been reported to have numerous pharmacological activities and at the same time, many studies have also revealed the toxicity of α- and β-asarone.

PURPOSE

The purpose of this comprehensive review is to compile and analyze the information related to the pharmacokinetic, pharmacological, and toxicological studies reported on α- and β-asarone using preclinical in vitro and in vivo models. Besides, the molecular targets and mechanism(s) involved in the biological activities of α- and β-asarone were discussed.

METHODS

Databases including PubMed, ScienceDirect and Google scholar were searched and the literature from the year 1960 to January 2017 was retrieved using keywords such as α-asarone, β-asarone, pharmacokinetics, toxicology, pharmacological activities (e.g. depression, anxiety).

RESULTS

Based on the data obtained from the literature search, the pharmacokinetic studies of α- and β-asarone revealed that their oral bioavailability in rodents is poor with a short plasma half-life. Moreover, the metabolism of α- and β-asarone occurs mainly through cytochrome-P450 pathways. Besides, both α- and/or β-asarone possess a wide range of pharmacological activities such as antidepressant, antianxiety, anti-Alzheimer's, anti-Parkinson's, antiepileptic, anticancer, antihyperlipidemic, antithrombotic, anticholestatic and radioprotective activities through its interaction with multiple molecular targets. Importantly, the toxicological studies revealed that both α- and β-asarone can cause hepatomas and might possess mutagenicity, genotoxicity, and teratogenicity.

CONCLUSIONS

Taken together, further preclinical studies are required to confirm the pharmacological properties of α-asarone against depression, anxiety, Parkinson's disease, psychosis, drug dependence, pain, inflammation, cholestasis and thrombosis. Besides, the anticancer effect of β-asarone should be further studied in different types of cancers using in vivo models. Moreover, further dose-dependent in vivo studies are required to confirm the toxicity of α- and β-asarone. Overall, this extensive review provides a detailed information on the preclinical pharmacological and toxicological activities of α-and β-asarone and this could be very useful for researchers who wish to conduct further preclinical studies using α- and β-asarone.

2-Amino-5-bromopyridinium 2-phenoxyacetate

The phenoxyacetate anion of the title salt, C5H6BrN2+·C8H7O3−, is essentially planar, with a dihedral angle of 7.6 (5)° between the carboxylate group and the benzene ring. In the crystal, the cation and the anion are linkedviaN—H...O hydrogen bonds, forming a helical chain along a 21screw axis. In the chain, a π–π stacking interaction between the pyridinium and benzene rings, with a centroid–centroid distance of 3.854 (2) Å, and a C—H...O interaction are observed. The chains are further linked through another C—H...O hydrogen bond, forming a three-dimensional network.

Protection of Saururus Chinensis Extract against Liver Oxidative Stress in Rats of Triton WR-1339-induced Hyperlipidemia

Saururus chinensis has been reported to contain compounds such as lignans, alkaloids, diterpenes, flavonoids, tannins, steroids, and lipids. Fermentation is commonly used to break down certain undesirable compounds, to induce effective microbial conversion, and to improve the potential nutraceutical values. Previous studies have reported that the fermentation process could modify naturally occurring constituents, including isoflavons, saponins, phytosterols, and phenols, and could enhance biological activities, specifically antioxidant and antimicrobial properties. The probiotic strains used for fermentation exert beneficial effects and are safe. In this study, the antioxidative effects of the Bacillus subtilis fermentation of Saururus chinensis were investigated in a rat model with Triton WR-1339-induced hyperlipidemia by comparing the measured antioxidative biological parameters of fermented Saururus chinensis extract to those of nonfermented Saururus chinensis extract. Fermentation played a more excellent role than nonfermentation in ultimately protecting the body from oxidative stress in the liver of the experimental rats with Triton WR-1339-induced hyperlipidemia.

Separation of cis- and trans-Asarone from Acorus tatarinowii by Preparative Gas Chromatography

A preparative gas chromatography (pGC) method was developed for the separation of isomers (cis- and trans-asarone) from essential oil of Acorus tatarinowii. The oil was primarily fractionated by silica gel chromatography using different ratios of petroleum ether and ethyl acetate as gradient elution solvents. And then the fraction that contains mixture of the isomers was further separated by pGC. The compounds were separated on a stainless steel column packed with 10% OV-101 (3 m × 6 mm, i.d.), and then the effluent was split into two gas flows. One percent of the effluent passed to the flame ionization detector (FID) for detection and the remaining 99% was directed to the fraction collector. Two isomers were collected after 90 single injections (5 uL) with the yield of 178 mg and 82 mg, respectively. Furthermore, the structures of the obtained compounds were identified as cis- and trans-asarone by (1)H- and (13)C-NMR spectra, respectively.

Hypolipidaemic activity of orally administered diphenyl diselenide in Triton WR-1339-induced hyperlipidaemia in mice

Objectives

A significant association between the trace element selenium and hyper-cholesterolaemia has been reported. This study was designed to investigate a potential hypolipidaemic effect of diphenyl diselenide ((PhSe)2) in Triton WR-1339-induced hyperlipidaemia in mice.

Methods

Triton was administered intraperitoneally (400 mg/kg) to overnight-fasted mice to develop acute hyperlipidaemia. (PhSe)2 was administered orally (10 mg/kg) 30 min before Triton. At 24 h after Triton injection, blood samples were collected to measure plasma lipid levels. The hepatic thiobarbituric acid reactive substances and ascorbic acid levels as well as catalase and glutathione peroxidase activity were recorded.

Key findings

(PhSe)2 administration significantly lowered total cholesterol, non-high-density lipoprotein-cholesterol and triglycerides, whilst it increased high-density lipoprotein-cholesterol levels in plasma of hyperlipidaemic mice. Neither oxidative stress nor the antioxidant effect of (PhSe)2 was observed in the mouse liver in this experimental protocol.

Conclusions

These findings indicated that (PhSe)2 was able to lower plasma lipid concentrations. Further studies are needed to elucidate the exact mechanism by which (PhSe)2 exerted its hypolipidaemic effect in the management of hyperlipidaemia and atherosclerosis.