Contribution of aroma compounds to the antioxidant properties of roasted white yam (Dioscorea rotundata)

Integrated comparative metabolite profiling via NMR and GC-MS analyses for tongkat ali (Eurycoma longifolia) fingerprinting and quality control analysis

Tongkat ali commonly known as Malaysian Ginseng (Eurycoma longifolia) is a herbal root worldwide available in nutraceuticals, either as a crude powder or capsules blended with other herbal products. Herein, a multiplexed metabolomics approach based on nuclear magnetic resonance (NMR) and solid-phase microextraction combined with gas chromatography-mass spectrometry (SPME-GC-MS) was applied for authentic tongkat ali extract vs some commercial products quality control analysis. NMR metabolite fingerprinting identified 15 major metabolites mostly ascribed to sugars, organic and fatty acids in addition to quassinoids and cinnamates. Following that, multivariate analysis as the non-supervised principal component analysis (PCA) and supervised orthogonal partial least squares-discriminant analysis (OPLS-DA) were applied revealing that differences were related to fatty acids and 13,21-dihydroeurycomanone being more enriched in authentic root. SPME-GC-MS aroma profiling led to the identification of 59 volatiles belonging mainly to alcohols, aldehydes/furans and sesquiterpene hydrocarbons. Results revealed that aroma of commercial products showed relatively different profiles being rich in vanillin, maltol, and methyl octanoate. Whereas E-cinnamaldehyde, endo-borneol, terpinen-4-ol, and benzaldehyde were more associated to the authentic product. The present study shed the light for the potential of metabolomics in authentication and standardization of tongkat ali and identification of its true flavor composition.

Effects of musk volatile compounds on attenuated nerve injury and improving post-cerebral ischemic exercise functions

BACKGROUND

Reperfusion Injury Acute ischemic stroke is increasing in people recently and Musk, as a commonly used Traditional Chinese Medicine (TCM), has been suggested as a potential agent against acute ischemic stroke, but the efficacies and underlying mechanisms of it remain unknown.

OBJECTIVE

This study was aimed to tested the hypotheses that volatile compounds of musk could attenuate nerve injury and identify the bioactive compounds and potential mechanisms of Musk.

METHOD

Transient middle cerebral artery occlusion (MCAO) model in vivo in Sprague-Dawley rats (SD rats) was used to test this hypothesis. Collecting ingredients of Musk and their related targets were discerned from the Gas chromatography-olfactory mass spectrometry (GC-O-MS) experiment. Then the potential mechanisms and targets of the compounds were searched by network pharmacology techniques. Finally, the pathway was verified by Western Bolt (WB).

RESULTS

First, Musk treatment significantly up-regulated the relative levels of AKT1, PI3KA, and VEGFA in the hippocampus, and improved the sport functions in the post-MCAO ischemic rats in vivo. Next, twenty potential flavor active compounds were recognized by GC-O-MS. A total of 89 key targets including HIF-1, PIK3CA, TNF signaling pathway, and VEGF were identified. AKT1, HIF1A, PIK3CA, and VEGFA were viewed as the most important genes, which were validated by molecular docking simulation.

CONCLUSION

The Volatile compounds of musk can attenuate nerve injury and improving post-cerebral ischemic exercise functions by HIF1A pathways, and the combined data provide novel insight for Musk volatile compounds developed as new drug for improving reperfusion injury in acute ischemic stroke.

Dioscorea spp.: Comprehensive Review of Antioxidant Properties and Their Relation to Phytochemicals and Health Benefits

Dioscorea, consisting of over 600 species, is the most important genus in the Dioscoreaceae family; however, the practically used plants, which are commonly called yam, are restricted to a remarkably smaller number of species. Numerous studies have reported the high nutritional value of yam, particularly as an alternative source of starch and some important micronutrients. Several Dioscorea species are widely used for various medicinal purposes as well. In many studies, the bioactivities and health benefits of Dioscorea extracts and other preparations have been related to the presence of phytochemicals, which possess antioxidant properties; they are related mainly to radical-scavenging capacity in chemical assays and positive effects on the endogenous antioxidant system in cell-based and in vivo assays. Considering the increasing number of publications on this topic and the absence of comprehensive and focused review papers on antioxidant potential, this article summarizes the results of studies on the antioxidant properties of Dioscorea spp. and their relation to phytochemicals and health benefits. A comprehensive survey of the published articles has revealed that the majority of studies have been performed with plant tubers (rhizomes, roots), while reports on leaves are rather scarce. In general, leaf extracts demonstrated stronger antioxidant potential than tuber preparations. This may be related to the differences in phytochemical composition: saponins, phenanthrenes and, for some pigment-rich species (purple yams), anthocyanins are important constituents in tubers, while phenolic acids and flavonoids are characteristic phytochemicals in the leaves. The review may assist in explaining ethnopharmacological knowledge on the health benefits of Dioscorea plants and their preparations; moreover, it may foster further studies of poorly investigated species, as well as their wider application in developing new functional foods and nutraceuticals.

Combination effects of rice extract and five aromatic compounds against α-glucosidase, α-amylase and tyrosinase

Rice is a source of bioactive compounds related to human health and has been used for both consumption and traditional medicine. The authors investigated the synergistic and additive effect of rice extract (RE) combined with five aromatic compounds against three enzymes: α-glucosidase, α-amylase and tyrosinase. RE was purified by thin-layer chromatography (TLC) and preparative TLC (PTLC) with different solvent systems. RE had higher α-glucosidase and α-amylase inhibitory activity than the five aromatic compounds, while the five aromatic compounds had higher tyrosinase inhibitory activity than RE. The combination of RE/acarbose produced synergic inhibition of α-glucosidase and α-amylase, whereas RE showed additive inhibition of both enzymes when combined with aromatic compounds. The five aromatic compounds showed additive inhibition of tyrosinase when combined with RE. The combination of 2-methoxy-4-vinylphenol/vanillin/guaiacol produced synergistic inhibition of α-amylase while showing antagonism of α-glucosidase and tyrosinase. Interestingly, the RE produced additive inhibition of α-glucosidase, α-amylase and tyrosinase when combined with the 2-methoxy-4-vinylphenol/vanillin/guaiacol combination. RE had rich bioactive compounds related to α-glucosidase, α-amylase and tyrosinase inhibitory activity. Volatile compounds, including 2-methoxy-4-vinylphenol, vanillin and guaiacol, enhanced the inhibitory activity of RE against α-glucosidase, α-amylase and tyrosinase activities.