Supercritical Carbon Dioxide Extraction of Selected Herbal Leaves: An Overview

Oral Bioavailability, Tissue Distribution, Metabolism, and Excretion of Panduratin A from Boesenbergia rotunda Extract in Healthy Rats

Background

Our previous studies in vitro and in vivo have shown anti-severe acute respiratory syndrome coronavirus 2 activity of fingerroot extract (Boesenbergia rotunda) and its phytochemical panduratin A.

Aim of Study

Therefore, the objective of this study was to determine the pharmacokinetic profiles of panduratin A, as a pure compound and in fingerroot extract, in rats.

Materials and Methods

Male rats were randomly divided into four groups. Rats underwent intravenous administration of 4.5 mg/kg panduratin A, a single oral administration of 45 mg/kg panduratin A, or a multiple oral administration of 45 mg/kg panduratin A-consisted fingerroot extract for 7 consecutive days. The concentrations of panduratin A in plasma, tissues, and excreta were measured by using LCMS with a validated method.

Results

The rats showed no change in health status after receiving all test preparations. The absolute oral bioavailability of panduratin A administered as pure panduratin A and fingerroot extract were approximately 9% and 6%, respectively. The peak concentrations for the single oral doses of 45 mg/kg panduratin A and fingerroot extract, were 4833 ± 659 and 3269 ± 819 µg/L, respectively. Panduratin A was mostly distributed in gastrointestinal organs, with the highest tissue-to-plasma ratio in the stomach. Approximately 20-30% of unchanged panduratin A from the administered dose was detected in feces while a negligible amount was found in urine. The major metabolites of administered panduratin A were identified in feces as oxidation and dioxidation products.

Conclusion

Panduratin A from fingerroot extract showed low oral bioavailability, good tissue distribution, and partially biotransformed before excretion via feces. These findings will assist in developing fingerroot extract as a phytopharmaceutical product for COVID-19 treatment.

Compositional Analysis and Potent Insecticidal Activity of Supercritical CO2 Fluid Extracts of Alcea nudiflora L. Leaves

To mitigate potentially severe food shortages due to the exponential growth of the global population, it is of paramount importance to improve the yield and quality of globally harvested food crops. As pest control contributes to both these aspects, the development of safe and effective pesticides is one of the main strategies pursued in this direction in the context of agricultural chemistry. During our investigation of natural pesticides, a supercritical CO₂ fluid extract of Alcea nudiflora L. was found to exert extremely potent insecticidal activity against aphids (Macrosiphum euphorbiae) and cowpea seed beetles (Callosobruchus maculatus) with LC₅₀ values of 0.03 mg/mL (24 h exposure, contact method). The facts that their insecticidal activity is in the most potent class among the essential oils known to date, and that the extract did not show any toxicity toward beneficial insects such as ladybugs (Coccinella magnifica) and European honeybees (Apis mellifera Linnaeus), indicate that this extract could be a good, natural, and safe new pesticide candidate. A compositional analysis of this extract was carried out using GC/MS.

Extraction of Galphimines from Galphimia glauca with Supercritical Carbon Dioxide

The anti-depressive and anxiolytic effect of galphimine B (isolated from Galphimia glauca) has been demonstrated by researchers. Therefore, it is necessary to explore extraction techniques that produce materials with adequate quality for pharmaceutical applications. In this work, supercritical extractions of galphimines from Galphimia glauca were performed in the presence of carbon dioxide. Pressure, temperature, particle diameter, and flow rate effects were examined to explore the conditions with the highest yield and the concentration profile of galphimines in the studied interval. The identification of the nor-seco triterpenoids and galphimine B and E was carried out by HPLC analyses. The mathematical modeling of the extraction curves was attained by the approaches proposed by Sovová and Papamichail et al. According to results, the highest yield 2.22% was obtained at 323.15 K, 326 μm, 3 L/min, and 33.75 MPa. Meanwhile, the content of galphimine B in the extract was, on average, 19.5 mg·g⁻¹.