Extraction of Galphimines from Galphimia glauca with Supercritical Carbon Dioxide

Rhododendron luteum Sweet Flower Supercritical CO2 Extracts: Terpenes Composition, Pro-Inflammatory Enzymes Inhibition and Antioxidant Activity

Terpenes are plant secondary metabolites known for their anti-inflammatory and antioxidant activities. According to ethnobotanical knowledge, Rhododendron luteum Sweet was used in traditional medicine against inflammation. The present study was conducted to determine the triterpene profile and antioxidant and anti-inflammatory activity of supercritical CO2 (SC-CO2) extracts of Rhododendron luteum Sweet flower (RLF). An LC-APCI-MS/MS analysis showed the presence of eight pentacyclic triterpenes and one phytosterol in the extracts obtained with pure CO2 as well as CO2 with the addition of aqueous ethanol as a co-solvent. Among the compounds detected, oleanolic/ursolic acid, β-sitosterol and 3β-taraxerol were the most abundant. The extract obtained with pure SC-CO2 was additionally subjected to HS-SPME-GC-FID-MS, which revealed more than 100 volatiles, mainly eugenol, β-phenylethanol, dodecane, β-caryophyllene, estragole and (Z)- and (E)-cinnamyl alcohol, followed by δ-cadinene. The extracts demonstrated significant hyaluronidase inhibition and exhibited varying modes of lipoxygenase and xanthine oxidase inhibitory activities. The studies of RLF have shown that their SC-CO2 extracts can be a rich source of triterpenes with anti-inflammatory potential.

Triterpenes G-A and G-E from Galphimia glauca with anti-inflammatory and anti-arthritic activity in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Galphimia glauca is a medicinal plant that treats inflammatory and anti-rheumatic problems. Its anti-inflammatory capacity has been reported pharmacologically, attributed to the triterpenes G-A and G-E.

AIM

The objective of the present work was to measure the anti-inflammatory and immunomodulatory effect of the methanolic extract (GgMeOH) of Galphimia glauca and the isolated galphimines G-A and G-E, first in an acute test of plantar edema with carrageenan, and later in the model of experimental-induced arthritis with CFA. The effect was measured by quantifying joint inflammation, the concentration of pro- (TNF-α, IL-6, IL-17) and anti-inflammatory (IL-10, and IL-4) cytokines, and the ADA enzyme in joints, kidneys, and spleen from mice with experimental arthritis.

METHOD

The extract and the active triterpenes were obtained according to established methods using different chromatographic techniques. Female ICR strain mice were subjected to intraplantar administration with carrageenan and treated with different doses of GgMeOH, G-A, and G-E; edema was monitored at different times. Subsequently, the concentration of TNF-a and IL-10 in the spleen and swollen paw was quantified. Meloxicam (MEL) was used as an anti-inflammatory control drug. The most effective doses of each treatment were analyzed using a complete Freunds adjuvant (CFA)-induced experimental arthritis model. Joint inflammation was followed throughout the experiment. Ultimately, the concentration of inflammation markers, oxidant stress, and ADA activity was quantified. In this experimental stage, methotrexate (MTX) was used as an antiarthritic drug.

RESULTS

Treatments derived from G. glauca, GgMeOH (DE50 = 158 mg/kg), G-A (DE50 = 2 mg/kg), and G-E (DE50 = 1.5 mg/kg) caused an anti-inflammatory effect in the plantar edema test with carrageenan. In the CFA model, joint inflammation decreased with all natural treatments; GgMeOH and G-A inhibited the ADA enzyme in all organs analyzed (joints, serum, spleen, left and right kidneys), while G-E inhibited the enzyme in joints, serum, and left kidney. CFA caused an increase in the weight index of the organs, an effect that was counteracted by the administration of G. glauca treatments, which also modulate the response to the cytokines analyzed in the different organs (IL-4, IL-10, IL-17, IL-6, and TNF- α).

CONCLUSION

It is shown, for the first time, that the GgMeOH extract and the triterpenes G-A and G-E of Galphimia glauca have an anti-arthritic effect (anti-inflammatory, immunomodulatory, antioxidant, and ADA inhibitor), using an experimental arthritis model with CFA. Therefore, knowledge of the plant as a possible therapeutic agent for this rheumatic condition is expanding.

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