Marginaols G-M, anti-inflammatory isopimarane diterpenoids, from the rhizomes of Kaempferia marginata

Marginaols G-M, a series of undescribed isopimarane diterpenoids, together with four known analogs were isolated from the rhizomes of Kaempferia marginata. The structures of these isolated compounds were characterized using high-resolution mass spectrometry and extensive 1D- and 2D-nuclear magnetic resonance (NMR) analyses. In addition, the absolute configurations of marginaol G and H were determined by X-ray crystallographic analysis and comparison with the literature values. When compared to the standard drug dexamethasone (IC₅₀ 4.7 μM), marginaol G, H, and 6β-acetoxysandaracopimaradien-1α,9α-diol had an intriguing anti-inflammatory effect on NO inhibition in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages, with IC₅₀ values ranging from 4.5 to 7.3 μM and being less cytotoxic to the cells. The anti-inflammatory action of these isopimarane diterpenoids from K. marginata supports the use of Thai traditional medicine for inflammation treatment.

Wound healing properties of pharmaceutical gel containing isopimarane diterpene isolated from Kaempferia galanga L

ETHNOPHARMACOLOGICAL RELEVANCE

Kaempferia galanga L. rhizomes have been widely used in Thailand as medicine for treating inflammation and wound. A number of bioactive compounds have been isolated from the rhizomes of K. galanga and these compounds exhibited various pharmacological activities.

AIM OF THE STUDY

The objective of this study is to investigate the wound healing properties of gel containing 6β-acetoxysandaracopimaradiene-1α, 9α-diol (KG6), a compound from K. galanga.

MATERIALS AND METHODS

KG6 gel formulations were prepared using 1.0% carbopol 940 as gelling agent. Three KG6 gel formulations (0.10, 0.25, 0.50% w/w) were subjected to heating-cooling test to determine their physical, chemical and biological stabilities. The wound healing properties of KG6 gel formulations were performed using RAW264.7 cells for anti-inflammatory effect, while their impact on cell proliferation and migration, collagen content and H₂O₂-induced oxidative stress was examined using human dermal fibroblasts (HDF).

RESULTS

The pH, viscosity and general appearance after the heating-cooling test of the three prepared gels were stable in the acceptable range of gel formulation for skin. Gel containing 0.25% KG6 showed better chemical stability than other formulations. The 0.25% KG6 gel significantly increased cell viability (102.8%) and produced the highest HDF cell migration (91.9%) which was greater than that of Aloe vera gel (96.2, 78.4%, respectively). This gel exhibited anti-inflammatory activity via suppressing nitric oxide release and improved the viability of HDF cells against H₂O₂-induced oxidative stress. The 0.25% KG6 gels also increased collagen content in HDF cells.

CONCLUSION

The gel formulation consisting of 0.25% KG6 with 1.0% of carbopol 940 was found to be a promising pharmaceutical gel for wound treatments due to marked wound healing properties.