Secondary Metabolites in the Dendrobium heterocarpum Methanolic Extract and Their Impacts on Viability and Lipid Storage of 3T3-L1 Pre-Adipocytes

Abstract

Although many natural products have proven their potential to regulate obesity through the modulation of adipocyte biology, none of them has yet been approved for clinical use in obesity therapy. This work aims to isolate valuable secondary metabolites from an orchid species (Dendrobium heterocarpum) and evaluate their possible roles in the growth and differentiation of 3T3-L1 pre-adipocytes. Six compounds were isolated from the orchid’s methanolic extracts and identified as amoenylin (1), methyl 3-(4-hydroxyphenyl) propionate (2), 3,4-dihydroxy-5,4’-dimethoxybibenzyl (3), dendrocandin B (4), dendrofalconerol A (5), and syringaresinol (6). Among these phytochemicals, compounds 2, 3, and 6 exhibited lower effects on the viability of 3T3-L1 cells, offering non-cytotoxic concentrations of ≲10 µM. Compared to others tested, compound 3 was responsible for the maximum reduction of lipid storage in 3T3-L1 adipocytes (IC50 = 6.30 ± 0.10 µM). A set of protein expression studies unveiled that compound 3 at non-cytotoxic doses could suppress the expression of some key transcription factors in adipocyte differentiation (i.e., PPARγ and C/EBPα). Furthermore, this compound could deactivate some proteins involved in the MAPK pathways (i.e., JNK, ERK, and p38). Our findings prove that D. heterocarpum is a promising source to explore bioactive molecules capable of modulating adipocytic growth and development, which can potentially be assessed and innovated further as pharmaceutical products to defeat obesity.

Identification, Biological Function Profiling and Biosynthesis of Secondary Metabolites in Medicinal Orchids

“…However, it has been reported that the methanol extract of D. heterocarpum has the potential to regulate obesity by reducing the lipid storage capacity of 3T3-L1 pre-adipocytes, inhibiting the expression of key differentiation factors and ultimately affecting lipid storage and the differentiation of preadipocytes. The main substance responsible for this effect was identified as 3,4-dihydroxy-5,4′-dimethoxybibenzyl [ 76 ]. Interestingly, the efficacy of extract activity is also influenced by the type of solvent used.…”

Compounds with anti-neuroinflammatory activity from aerides falcata

“…This positioning was supported by the NOESY correlation of AF8 (Figure79) which showed a correlation between H-2 to proton MeO-3 and H-6 to proton MeO-5.From the above data NMR spectra identified that AF8 was syringaresinol. This compound was previously isolated from Magnolia thailandica(60) and in several Dendrobium such as D. nobile, D. scundum, and D. heterocarpum(53,61,62) Syringaresinol[39]…”