Phytochemical Composition, Antioxidant, Antibacterial, and Enzyme Inhibitory Activities of Various Organic Extracts from Apocynum hendersonii (Hook.f.) Woodson

Abstract

Apocynum hendersonii is a traditional medicinal plant used primarily as tea. It has a potential health benefit from its rich bioactive substances. This study investigated the reactivity of solvents of different polarities (ethanol, ethyl acetate, n-hexane, methanol, and water) extracts of the A. hendersonii leaf. The phytochemical composition of the extracts was evaluated using a Fourier Transform Infrared spectrophotometer (FT-IR), Gas Chromatography-Mass Spectrometry (GC-MS), UHPLC-MS, and Higher Performance Liquid Chromatography (HPLC). The result revealed the presence of medicinally important bioactive constituents, including phenols, flavonoids, and polysaccharides. Methanol extracts exhibited the highest flavonoid contents (20.11 ± 0.85 mg QE/g DW) and the second-highest in terms of phenolic (9.25 ± 0.03 mg GAE/g DW) and polysaccharide (119.66 ± 2.65 mg GE/g DW). It also had the highest antioxidant capacity with 60.30 ± 0.52% and 4.60 ± 0.02 µmol Fe2+ per g DW based on a 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay and ferric reducing antioxidant power (FRAP), respectively. Ethanol extract displayed the maximum antibacterial action against Gram-negative and Gram-positive bacteria and the highest inhibition activity against the enzymes tyrosinase and acetylcholinesterase, followed by methanol extract. The principal component analysis revealed a positive correlation between the constituents, bioactivities, and extracts. The overall result showed A. hendersonii as a rich natural source of antimicrobial and antioxidant bioactive compounds and may be used for future applications in pharmaceuticals and food industries.

Total Flavonoids Extracts of Apocynum L. from the Ili River Valley Region at Different Harvesting Periods and Bioactivity Analysis

“…The total flavonoid content of A. venetum and A. hendersonii leaves was determined at the four different harvesting stages. In previous studies, A. venetum and A. hendersonii contained significant amounts of flavonoids, and methanol was shown to be more effective in recovering flavonoids from the Apocynum [ 22 ]. Therefore, methanol was used as the extraction solvent, and the result of the total flavonoid content in the two species is shown in Figure 1 B.…”

“…Conversely, the better antioxidant activity displayed by A. venetum might have been due to its relatively higher flavonols content. Flavonols such as quercetin and its derivatives are used in many pharmaceutical products as antioxidants [ 22 ]. Myricetin is shown to possess antitumor, anti-obesity, anti-inflammatory, and protection against cardiovascular and neurological ailments [ 36 ].…”

“…A modified approach [ 22 ] was adopted for the extraction. Apocynum L. leaf powder (5 g) was extracted with 100 mL methanol at 80 °C for 2 h. The supernatant was filtered with Whatman No.1 filter paper and dried with a rotary evaporator to obtain the dried extract powder, which was stored at 4 °C in the dark.…”

“…According to the method [ 22 ] with slight modification, the content of flavonoids was determined quantitatively by a spectrophotometer. In brief, 0.3 mL of 5% NaNO 2 and 0.3 mL of 10% AlCl 3 were added to 2 mL of the extract solutions and mixed, followed by 6 min incubation and the addition of 4 mL of 4% NaOH.…”

Integrated multiomic study on the evolution and natural variation of flavonoid biosynthesis in Apocynum venetum and Apocynum hendersonii

“…Apocynum species (A. venetum and A. hendersonii ) are perennial herbaceous plants with medicinal significance and excellent ecological adaptability (Abubakar, Huang, et al , 2022;Abubakar et al , 2021;Gao et al , 2021). The paucity of gene sequence resources has limited in-depth molecular research onApocynum species (Li et al , 2019).…”