Cytotoxic and larvicidal activities of Stemona alkaloids from the aerial parts and roots of Stemona curtisii Hook.f.

A new Stemona alkaloid glycoside derivative, 6-hydroxy-5,6-seco-stemocurtisinoside (4), was isolated from the ethanolic extract of the aerial parts of Stemona curtisii Hook.f., together with stemocurtisine (1), (11Z)-1',2'-didehydrostemofoline (2) and 6-hydroxy-5,6-seco-stemocurtisine (3). Whereas, stemocurtisine (1), stemocurtisinol (5) and oxyprotostemonine (6) were isolated from the roots. Their structures were elucidated using 1D and 2D NMR spectroscopy as well as MS experiments. The extract and the pure isolated compounds were evaluated for their cytotoxicities and their larvicidal activities against the dengue vector, Aedes aegypti. The alkaloid 2 showed the strongest larvicidal activity with a LC50 value of 2.44 µM. While the alkaloid 3 exhibited cytotoxicity against MCF-7 and KB cells (IC50 values of 62.52 and 18.82 µM, respectively) and showed no significant cytotoxicity against Vero cells. Additionally, quantitative analysis of the most active compounds; 2 and 3 in the crude extracts was also performed by HPLC.

Kaempferia parviflora Extract Inhibits STAT3 Activation and Interleukin-6 Production in HeLa Cervical Cancer Cells.

Kaempferia parviflora (KP) has been reported to have anti-cancer activities. We previously reported its effects against cervical cancer cells and continued to elucidate the effects of KP on inhibiting the production and secretion of interleukin (IL)-6, as well as its relevant signaling pathways involved in cervical tumorigenesis. We discovered that KP suppressed epidermal growth factor (EGF)-induced IL-6 secretion in HeLa cells, and it was associated with a reduced level of Glycoprotein 130 (GP130), phosphorylated signal transducers and activators of transcription 3 (STAT3), and Mcl-1. Our data clearly showed that KP has no effect on nuclear factor kappa B (NF-κB) localization status. However, we found that KP inhibited EGF-stimulated phosphorylation of tyrosine 1045 and tyrosine 1068 of EGF receptor (EGFR) without affecting its expression level. The inhibition of EGFR activation was verified by the observation that KP significantly suppressed a major downstream MAP kinase, ERK1/2. Consistently, KP reduced the expression of Ki-67 protein, which is a cellular marker for proliferation. Moreover, KP potently inhibited phosphorylation of STAT3, Akt, and the expression of Mcl-1 in response to exogenous IL-6 stimulation. These data suggest that KP suppresses EGF-induced production of IL-6 and inhibits its autocrine IL-6/STAT3 signaling critical for maintaining cancer cell progression. We believe that KP may be a potential alternative anti-cancer agent for suppressing cervical tumorigenesis.

Chemical diversity and anti-acne inducing bacterial potentials of essential oils from selected Elsholtzia species.

Essential oils from the aerial parts of four Elsholtzia species; Elsholtzia stachyodes, Elsholtzia communis, Elsholtzia griffithii and Elsholtzia beddomei were obtained by steam distillation and their chemical components were analysed by gas chromatography-mass spectrometry (GC-MS). Principle Component Analysis was used to identify the chemical variations in the essential oils from these plants, which could be categorised into two groups according to their main chemical components which are acylfuran derivatives and oxygenated monoterpenes. Additionally, the anti-acne inducing bacterial activity against Staphylococcus aureus and Staphylococcus epidermidis were evaluated. The oil from E. stachyodes was the most efficacious against the growth of S. aureus and S. epidermidis having MIC values of 0.78 and 1.56 µL/mL, respectively, and exhibited five times more effective than erythromycin (standard antibiotic).