Stability Study of Alpinia galanga Constituents and Investigation of Their Membrane Permeability by ChemGPS-NP and the Parallel Artificial Membrane Permeability Assay

Abstract

Alpinia galanga Willd., greater galangal, has been used for thousands of years as a spice as well as in traditional medicine. Its central nervous system (CNS) stimulant activity and neuroprotective effects have been proved both in animal models and human trials. However, the compounds responsible for these effects have not been identified yet. Therefore, the main constituents (p-OH-benzaldehyde (1), trans-p-coumaryl-alcohol (2), p-coumaryl-aldehyde (4), galanganol A (5), galanganol B (6), trans-p-acetoxycinnamyl alcohol (7), 1′S-1′-acetoxychavicol acetate (ACA, 9), and 1′S-1′-acetoxyeugenol acetate (AEA, 10) were isolated to investigate their aqueous stability and passive diffusion across the gastro-intestinal tract (GIT) membrane and the blood–brain barrier (BBB) by the parallel artificial membrane permeability assay (PAMPA). Our positive results for compounds 1, 2, 4, 7, 9, and 10 suggest good permeability, thus potential contribution to the effects of greater galangal in the CNS. The results of the PAMPA-BBB were corroborated by in silico chemography-based ChemGPS-NP framework experiments. In addition, examination of the chemical space position of galangal compounds in relation to known psychostimulants revealed that all the molecules in proximity are NET/SERT inhibitors. As ACA and AEA did not show much proximity to either compound, the importance of further investigation of their degradation products becomes more pronounced.

Characterization and Evaluation of Rapamycin-Loaded Nano-Micelle Ophthalmic Solution

“…The PAMPA experiment is widely used as an in vitro model for evaluating membrane permeability and transcellular permeation [ 26 , 27 , 28 , 29 , 30 ]. As shown in Figure 5 , compared with the free RAPA solution, the RAPA-NM exhibited a strong permeability potential.…”

“…This membrane permeation has also indicated the potential of improved in vivo corneal permeation [ 26 , 27 ]. The PAMPA experiment was performed as previously reported [ 28 , 29 , 30 ]. Briefly, free RAPA was dissolved in DMSO and further diluted with an artificial tears solution to obtain a RAPA concentration of 5 mg/mL.…”

An Overview of the Spices Used for the Prevention and Potential Treatment of Gastric Cancer

“…It has its uses in cooking, traditional medicine, and cosmetics. Two varieties are most commonly described in the medical literature: Alpinia galanga and Alpinia officinarum [174][175][176][177]. Galangal is rich in phenolic compounds (acids and flavonoids), of which galangin is predominant.…”

“…No reliable studies on the bioavailability of galangin have been identified. It is suggested that further experiments are needed, and studies are being conducted to obtain extracts that are well absorbed from the gastrointestinal tract [176]. The use of galangin in clinical settings may be hampered by its characteristic chemical properties (as a 3hydroxyflavone, it has low solubility in water) [31].…”

Phytochemical and pharmacological properties of the genus Alpinia from 2016 to 2023

“…As neuroprotective effects of A. galanga have been reported in several studies, the aqueous stability and gastro-intestinal/ blood-brain barrier (GI/BBB) permeability of the main compounds in the extract were investigated. 31 The phenolics (340, 342, 346, 351, 352, and 355) showed good permeability, which contributes to the neuroprotective effects of A. galanga. Four compounds with neuroprotective activity in A. oxyphylla were tested for BBB permeability, 2 and the order of permeability was 341, 147, 279, and 280.…”