Acetylcholinesterase Inhibitory and Antioxidant Activity of the Compounds Isolated from Vanda roxburghii

Abstract

Vanda roxburghii has been used in traditional medicine to treat nervous system disorders including Alzheimer’s disease (AD). We reported earlier a high acetylcholinesterase inhibitory and antioxidant activity in the chloroform fraction of this plant. Therefore, this study was designed to explore the compounds with acetylcholinesterase inhibitory and antioxidant activities from the chloroform fraction of Vanda roxburghii. Phytochemical investigation led to the isolation for the first time of a fatty acid ester: methyl linoleate (1), and three phenolics: syringaldehyde (2), vanillin (3), and dihydroconiferyl dihydro-p-coumarate (4) along with the previously reported compound gigantol (5). Among the isolates, vanillin (3) and dihydroconiferyl dihydro-p-coumarate (4) were found to significantly inhibit the activity of acetylcholinesterase, scavenge the free radicals, exhibit the reducing power and total antioxidant activity, and effectively reduce the peroxidation of lipid. Gigantol (5) and syringaldehyde (2), despite lacking the activity against acetylcholinesterase, exhibited antioxidant activity. Among the compounds, gigantol (5) appeared to be the most potent antioxidant. These findings revealed that V. roxburghii contained compounds with potential acetylcholinesterase inhibitory and antioxidant activity, which support its traditional use in the treatment of AD.

Acetylcholinesterase and butyrylcholinesterase inhibitory activities of antioxidant peptides obtained from enzymatic pea protein hydrolysates and their ultrafiltration peptide fractions

“…Literature is replete with information about in vivo and in vitro antioxidant and anti‐cholinesterase inhibition activities of components derived from plant sources. A few examples include powdered Psoralea corylifolia fruits (Gauresh et al, 2015), flower extracts from Nymphaea pubescens (Acharya et al, 2018), Anthocleista vogelii leaf extracts (Ajayi et al, 2019), essential oils from Lippia thymoides (Silva et al, 2019), and roots from Vanda roxburghii (Ahammed et al, 2021). Natural peptides from plant sources have been shown to display antioxidant and neurodegenerative modulating properties with a positive impact in terms of preventive and therapeutic measures (Prasasty et al, 2018).…”

Anti-inflammatory Activity of the Phenolic Compounds from Vanda roxburghii R. Br.

“…Vanillin and syringaldehyde are two common phenolic compounds found in nature. The compounds have shown earlier the antioxidant and anti-inflammatory activity in different in vitro model (Ahammed et al, 2021;Salau et al, 2020;Shahzad et al, 2018). Using the carrageenan-induced hind paw edema model we report here that these two compounds have similar anti-inflammatory activity.…”

“…The therapeutic uses of this plant have been documented in Unani and Ayurvedic systems of medicines. We reported earlier that the plant has high phenolic content and antioxidant activity, and possesses cholinesterase inhibitory potential Ahammed et al, 2021). In a preliminary study, we observed the antiinflammatory activity in the crude extract of the plant and the activity was high in the chloroform fraction among other fractions examined .…”

“…The crude methanol extract and its chloroform fraction was prepared by the method as described earlier (Ahammed et al, 2021). In summary, the dried coarse powder of the plant root (1 kg) was soaked in methanol (5 litres) and kept at room temperature with gentle shaking for 5 days.…”

“…The isolated compounds were identified as syringaldehyde (1), vanillin (2), dihydroxyconiferyl dihydro-p-coumarate (3) and gigantol (4) by comparing their R f values with the authentic samples (Uddin et al, 2015a;Ahammed et al, 2021).…”