Evaluation of Pharmacological and Phytochemical Profiles of Piptadeniastrum africanum (Hook.f.) Brenan Stem Bark Extracts

Abstract

The stem bark (SB) of Piptadeniastrum africanum (PA) has been extensively used in African traditional medicinal systems. However, there is a dearth of scientific information regarding its possible activity in the management of type II diabetes, Alzheimer’s disease, and skin hyperpigmentation disorders. This study therefore attempted to elucidate the in vitro inhibitory action of ethyl acetate, methanol, and water extracts of P. africanum stem bark (PA-SB) on α-amylase, α-glucosidase, acetylcholinesterase, butyrylcholinesterase, and tyrosinase. Cell viability, catecholamine, and 3-hydroxykynurenine levels of hypothalamic HypoE22 cells exposed to PA-SB extracts were also investigated. The phytochemical profiles of the extracts were determined by high performance liquid chromatography (HPLC) and antioxidant properties were investigated. Saponin (867.42 mg quillaja equivalent/g) and tannin (33.81 mg catechin equivalent/g) contents were higher in the methanol extract. Multiple dihydroxy-trimethoxy(iso)flavone isomers, loliolide, eriodictyol, naringenin, luteolin, chrysoeriol, apigenin, and liquiritigenin, were characterized from PA-SB extracts using HPLC. The methanol extract of PA-SB showed highest inhibitory activity against acetylcholinesterase (4.88 mg galantamine equivalent (GALAE)/g extract), butyrylcholinesterase (5.37 mg GALAE/g extract), and tyrosinase (154.86 mg kojic acid equivalent/g extract) while α-glucosidase was effectively inhibited by the ethyl acetate extract (15.22 mmol acarbose equivalent/g extract). The methanol extract of PA-SB also showed potent antioxidant properties (493.87, 818.12, 953.07, and 732.19 mg Trolox equivalent/g extract, for 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS), cupric reducing antioxidant capacity (CUPRAC), and ferric reducing antioxidant power (FRAP) assays, respectively). PA-SB extracts exhibited antioxidant activity and promising inhibition against key enzymes related to type II diabetes, Alzheimer’s disease, and skin hyperpigmentation disorders. Additionally, all extracts were able to contrast hydrogen peroxide-induced oxidative stress, in HypoE22 cells, thus restoring basal catecholamine and 3-hydroxykinurenine levels, whereas only methanol and water extracts stimulated basal dopamine release. Overall, data from the present study contribute to the biological assessment of P. africanum that appears to be a promising source of natural compounds with protective and neuromodulatory effects.

A comparative study of nutrient composition, bioactive properties and phytochemical characteristics of Stauntonia obovatifoliola flesh and pericarp

“…For SOP, its AChE inhibitory was strongly correlated to TFC and TPC (r = −0.86 and −0.85, p < 0.01), DPPH radical scavenging activity (r = −0.75, p < 0.01), and α-glucosidase inhibitory (r = 0.83, p < 0.01), while SOF was relatively low correlated to these indicators, and was clearly distinct from SOP. The correlation analyses above were consistent with the above conclusion of αglucosidase inhibitory, that the active ingredients in SOP and SOF are not consistent, resulting in differences in their activities such as α-glucosidase and AChE inhibitory abilities (41).…”

Unravelling the Phytochemical Composition and the Pharmacological Properties of an Optimized Extract from the Fruit from Prunus mahaleb L.: From Traditional Liqueur Market to the Pharmacy Shelf

“…Further bioinformatics analyses were conducted for predicting the pharmacokinetic properties of these phytochemicals, especially the capability to cross the blood brain barrier that was considered as a cornerstone for supporting the reported evaluation of the extract protective effects in hypothalamic HypoE22 cells challenged with hydrogen peroxide and added to a cell medium as a pro-oxidant stimulus. In this context, the capability of P. mahaleb water extract in contrasting the hydrogen peroxide-induced turnover of dopamine [ 19 ] was evaluated. Considering the potential application of P. mahaleb in ulcerative colitis, we also investigated the protective effects of the water extract of P. mahaleb on isolated mouse colon specimens challenged with lipopolysaccharide (LPS) to simulate in this ex vivo model the burden of oxidative stress and inflammation occurring in ulcerative colitis [ 20 ].…”

Evaluation of Antioxidant, Antimicrobial and Tyrosinase Inhibitory Activities of Extracts from Tricholosporum goniospermum, an Edible Wild Mushroom

“…For the evaluation of the in vitro antioxidant activity, different assays were employed, namely DPPH, CUPRAC and FRAP. The detailed procedures regarding each method are described in previous works [ 35 ]. Briefly, in the DPPH assay, the methanolic DPPH solution (0.004%) was mixed with mushroom extract solution, after which the absorbances were recorded at 517 nm after a 30 min incubation.…”