Inhibitory Effect of Isopanduratin A on Adipogenesis: A Study of Possible Mechanisms.

The root of Boesenbergia rotunda, a culinary plant commonly known as fingerroot, has previously been reported to possess anti-obesity activity, with four flavonoids identified as active principles, including pinostrobin, panduratin A, cardamonin, and isopanduratin A. However, the molecular mechanisms underlying the antiadipogenic potential of isopanduratin A remain unknown. In this study, isopanduratin A at non-cytotoxic concentrations (1-10 µM) significantly suppressed lipid accumulation in murine (3T3-L1) and human (PCS-210-010) adipocytes in a dose-dependent manner. Downregulation of adipogenic effectors (FAS, PLIN1, LPL, and adiponectin) and adipogenic transcription factors (SREBP-1c, PPARγ, and C/EBPα) occurred in differentiated 3T3-L1 cells treated with varying concentrations of isopanduratin A. The compound deactivated the upstream regulatory signals of AKT/GSK3ß and MAPKs (ERK, JNK, and p38) but stimulated the AMPK-ACC pathway. The inhibitory trend of isopanduratin A was also observed with the proliferation of 3T3-L1 cells. The compound also paused the passage of 3T3-L1 cells by inducing cell cycle arrest at the G0/G1 phase, supported by altered levels of cyclins D1 and D3 and CDK2. Impaired p-ERK/ERK signaling might be responsible for the delay in mitotic clonal expansion. These findings revealed that isopanduratin A is a strong adipogenic suppressor with multi-target mechanisms and contributes significantly to anti-obesogenic activity. These results suggest the potential of fingerroot as a functional food for weight control and obesity prevention.

Pinostrobin: An Adipogenic Suppressor from Fingerroot (Boesenbergia rotunda) and Its Possible Mechanisms.

Obesity is a critical factor for chronic metabolic syndromes. The culinary plant fingerroot (Boesenbergia rotunda) has been reported for its anti-obesity activity. The anti-adipogenic effects of pandurantin A, a main component of fingerroot cultivated in Indonesia, have been studied. Nevertheless, the suppressive effect and related mechanisms of pinostrobin, a major constituent of Thai fingerroot, on adipogenesis have never been thoroughly investigated. This study aimed to evaluate the potential of pinostrobin to inhibit adipocyte differentiation. Culturing pre-adipocytes from both mouse (3T3-L1) and human (PCS-210-010) with pinostrobin at non-toxic concentrations (5-20 µM) for 48 h obviously hindered their differentiation into mature adipocyte as evidenced by reduced cellular lipid droplets. The lower levels of lipid metabolism-mediating proteins, namely C/EBPα, PPARγ, and SREBP-1c, as well as cellular triglyceride content were demonstrated in pinostrobin-treated 3T3-L1 cells when compared to the untreated control group. Additionally, pinostrobin modulated the signals of MAPK (p38 and JNK) and Akt (Akt/GSK3ß, Akt/AMPKα-ACC). These findings suggest the benefit of fingerroot as a source of phytopharmaceuticals for obesity prevention and management, with pinostrobin as the active principle.

Four Novel Phenanthrene Derivatives with α-Glucosidase Inhibitory Activity from Gastrochilus bellinus.

Four new phenanthrene derivatives, gastrobellinols A-D (1-4), were isolated from the methanolic extract of Gastrochilus bellinus (Rchb.f.) Kuntze, along with eleven known phenolic compounds including agrostophyllin (5), agrostophyllidin (6), coniferyl aldehyde (7), 4-hydroxybenzaldehyde (8), agrostophyllone (9), gigantol (10), 4-(methoxylmethyl)phenol (11), syringaldehyde (12), 1-(4'-hydroxybenzyl)-imbricartin (13), 6-methoxycoelonin (14), and imbricatin (15). Their structures were determined by spectroscopic methods. Each isolate was evaluated for α-glucosidase inhibitory activity. Compounds 1, 2, 3, 7, 9, 13, and 15 showed higher activity than the drug acarbose. Gastrobellinol C (3) exhibited the strongest α-glucosidase inhibition with an IC50 value of 45.92 µM. A kinetic study of 3 showed competitive inhibition on the α-glucosidase enzyme. This is the first report on the phytochemical constituents and α-glucosidase inhibitory activity of G. bellinus.

Constituents of Huberantha jenkinsii and Their Biological Activities.

The phytochemical investigation of Huberantha jenkinsii resulted in the isolation of two new and five known compounds. The new compounds were characterized as undescribed 8-oxoprotoberberine alkaloids and named huberanthines A and B, whereas the known compounds were identified as allantoin, oxylopinine, N-trans-feruloyl tyramine, N-trans-p-coumaroyl tyramine, and mangiferin. The structure determination was accomplished by spectroscopic methods. To evaluate therapeutic potential in diabetes and Parkinson's disease, the isolates were subjected to assays for their α-glucosidase inhibitory activity, cellular glucose uptake stimulatory activity, and protective activity against neurotoxicity induced by 6-hydroxydopamine (6-OHDA). The results suggested that mangiferin was the most promising lead compound, demonstrating significant activity in all the test systems.