Phenolics, Antioxidant and Antibacterial Activities of Immature and Mature Blumea balsamifera Leaf Extracts Eluted with Different Solvents

An Investigation into the Phytochemical Content and Antioxidant, Antidiabetic, and Wound-Healing Activities of Curculigo latifolia Found in Brunei Darussalam

This present study aimed to investigate the phytochemical content and antioxidant and antidiabetic activities of Curculigo latifolia leaves (CL) and C. latifolia roots (CR) found in Brunei Darussalam. Phytochemical screening showed that CL and CR extracts contain saponins, tannins, glycosides, and terpenoids. CR showed higher total phenolic content (TPC), but lower total flavonoid content (TFC) when compared to CL. The high TPC in CR contributed to its potent radical scavenging activity (RSA) against 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals and strong ferric reducing antioxidant power (FRAP). Additionally, CR exerted significant inhibition of ∝-glucosidase and ∝-amylase, suggesting a potential link between the chemical compounds and its antioxidant and antidiabetic effects. In the animal study of antihyperglycemic activity, treatment with 250 mg/kg body weight (b.w.) of the CL extract normalised the blood glucose levels and improved body weight gain of alloxan-induced diabetic rats within 14 weeks. Furthermore, our investigation into the wound-healing effects of young C. latifolia leaves (YCL) and matured C. latifolia leaves (MCL) showed a significant reduction in wound size on Day 3, 5, and 7 of the experimental study, indicating its wound-healing potential. Based on our findings, C. latifolia can be consumed as part of a balanced diet due to its antioxidant and antidiabetic properties.

Transcriptome analysis revealed the role of moderate exogenous methyl jasmonate treatments in enhancing the metabolic pathway of L-borneol in the Blumea balsamifera

Introduction

Blumea balsamifera L. (Ainaxiang) DC. is a perennial herb of the compositae family. It is also the primary source of natural borneol. Endo-borneol, the principal medical active element in B. balsamifera, is anti-inflammatory, antioxidant, and analgesic; enhances medicine absorption; refreshes; and is used as a spice and in cosmetic. Industrialization of B. balsamifera is limited by its low L-borneol concentration. Thus, understanding the accumulation pattern of the secondary metabolite endo-borneol and its synthesis process in secondary metabolism is critical for increasing B. balsamifera active ingredient content and cultivation efficiency.

Methods

In this work, B. balsamifera was treated with varying concentrations (1.00 and 10.00 mmol/L) of methyl jasmonate (MeJA) as an exogenous foliar activator. The physiological parameters and L-borneol concentration were then assessed. Transcriptome sequencing of B. balsamifera-induced leaves was used to identify key genes for monoterpene synthesis.

Results

The treatment effect of 1 mmol/L MeJA was the best, and the leaves of all three leaf positions accumulated the highest L-borneol after 120 h, correspondingly 3.043 mg·g-1 FW, 3.346 mg·g-1 FW, and 2.044 mg·g-1 FW, with significant differences from the control. The main assembly produced 509,285 transcripts with min and max lengths of 201 and 23,172, respectively. DEG analysis employing volcano blots revealed 593, 224, 612, 2,405, 1,353, and 921 upregulated genes and 4, 123, 573, 1,745, 766, and 763 downregulated genes in the treatments D1_1vsCK, D1_10vsCK, D2_1vsCK, D2_10vsCK, D5_1vsCK, and D5_10vsCK. Interestingly, when exposed to MeJA treatments, the MEP pathway's unigenes express themselves more than those of the MVA route. Finally, when treated with 1 mmol/L, the genes DXR, DXS, and GPS showed increased expression over time. At the same time, a 10 mmol/L therapy resulted in elevated levels of ispH and GGPS.

Discussion

Our preliminary research indicates that exogenous phytohormones can raise the level of L borneol in B. balsamifera (L.) DC when given in the appropriate amounts. The most significant discovery made while analyzing the effects of different hormones and concentrations on B. balsamifera (L.) DC was the effect of 1 mmol/L MeJA treatment.

Antibacterial and antioxidant activities in various parts of Artocarpus lacucha Buch. Ham. ethanolic extract

Artocarpus lacucha is an endemic plant to North Sumatera, Indonesia. This plant has pharmacological activities, including acting as an antioxidant and antibacterial. The aim of the present study was to analyze the antibacterial and antioxidant activities, and determine the flavonoid compounds from four parts of A. lachuca, namely leaves, barks, twigs and fruits. Antioxidant activity was investigated using the 2,2-diphenyl 1-picrylhydrazyl (DPPH) and cupric reducing antioxidant capacity (CUPRAC) methods. Antibacterial activity was analyzed using disk diffusion and microdilution methods. Several flavonoids, such as luteolin-7-O-glucoside, rutin, quercetin, kaempferol and apigenin, were determined using high performance liquid chromatography. Based on the antioxidant activity test results using the DPPH method, the bark ethanolic extract provided the highest antioxidant capacity, while the CUPRAC method indicated that the twig ethanolic extract had the highest antioxidant capacity. The antibacterial activity test results demonstrated that at a low concentration of 750 µg/disk the bark ethanolic extract obtained the highest inhibition zone and minimum inhibitory concentration level against six of nine pathogenic bacteria. Therefore, A. lachuca bark ethanolic extract could be potentially developed as antioxidant and antibacterial agents.

Identification of Chemical Constituents in Blumea balsamifera Using UPLC-Q-Orbitrap HRMS and Evaluation of Their Antioxidant Activities

Blumea balsamifera (L.) DC., a perennial herb in the Asteraceae family native to China and Southeast Asia, has a notable history of medicinal use due to its pharmacological properties. Using UPLC-Q-Orbitrap HRMS techniques, we systematically investigated the chemical constituents of this plant. A total of 31 constituents were identified, of which 14 were flavonoid compounds. Significantly, 18 of these compounds were identified in B. balsamifera for the first time. Furthermore, the mass spectrometry fragmentation patterns of significant chemical constituents identified in B. balsamifera were analyzed, providing important insights into their structural characteristics. The in vitro antioxidative potential of the methanol extract of B. balsamifera was assessed using DPPH and ABTS free-radical-scavenging assays, total antioxidative capacity, and reducing power. The antioxidative activity exhibited a direct correlation with the mass concentration of the extract, with IC₅₀ values of 105.1 ± 0.503 μg/mL and 12.49 ± 0.341 μg/mL for DPPH and ABTS, respectively. For total antioxidant capacity, the absorbance was 0.454 ± 0.009 at 400 μg/mL. In addition, the reducing power was 1.099 ± 0.03 at 2000 μg/mL. This study affirms that UPLC-Q-Orbitrap HRMS can effectively discern the chemical constituents in B. balsamifera, primarily its flavonoid compounds, and substantiates its antioxidative properties. This underscores its potential utility as a natural antioxidant in the food, pharmaceutical, and cosmetics sectors. This research provides a valuable theoretical basis and reference value for the comprehensive development and utilization of B. balsamifera and expands our understanding of this medicinally valuable plant.

Synthesis, Structure Revision, and Anti-inflammatory Activity Investigation of Putative Blumeatin

Blumeatin, reported herein, bearing two hydroxyl groups at C3' and C5' of ring B, is isolated from the traditional Chinese medicine Blumea balsamifera. But the isolation procedure of blumeatin from plants has limitations of prolonged duration and high cost. A procedure featuring Lewis acid-catalyzed ring closure and chiral resolution via Schiff base intermediates is provided here to prepare optically pure blumeatin and its R-isomer efficiently. Furthermore, the structure revision of putative blumeatin based on a logically synthetic procedure and NMR spectroscopic analysis was conducted. The 1D and 2D NMR data analysis unambiguously confirmed our proposal that the reported blumeatin structure has been misassigned as it corresponds to sterubin, which contains two hydroxyl groups at C3' and C4' of ring B. Finally, the results of the ear-swelling test exhibited that synthetic (±)-blumeatin and (±)-sterubin had moderate anti-inflammatory activity which was less than that of (-)-sterubin.