Diterpenoid alkaloids isolated from Delphinium trichophorum alleviate pulmonary fibrosis via the TGF-ß/Smad pathway in 3T6 and HFL-1 cells.

Delphinium trichophorum Franch (DTF), a species endemic to China, has been widely used for centuries in Tibet as an indigenous medicine for treating cough, pneumonia, and pulmonary fibrosis. Hetisine-type C20-diterpenoid alkaloids have been reported to be characteristic and active ingredients. Herein, five ones with relatively high contents in D. trichophorum, including 2α,11α,13ß-triacetylhetisine (DTF1), trichodelphinine A (DTF2), trichodelphinine D (DTF3), 2α-acetyl-11α,13ß-dihydroxyhetisine (DTF4), and trichodelphinine C (DTF5), were investigated for anti-fibrosis effects using fibroblasts induced by TGF-ß1 or LPS for the first time. The results showed that all five tested compounds decreased hydroxyproline (HYP) levels and inhibited the abnormal proliferation of 3T6 and HFL-1 cells induced by either TGF-ß1 or LPS. Moreover, DTF1 and DTF2 attenuated the production of collagen (Col-1 and Col-3) at relatively low doses, suggesting their higher efficiency among the five alkaloids. Based on large-scale ligand-based pharmacophore modeling, TGFBR1 was screened as a potential target for these tested alkaloids. The molecular docking results also exhibited high-affinity interactions between TGFBR1 and five alkaloids, especially DTF1 and DTF2. Further experiments revealed that DTF1 and DTF2 could inhibit the expression of TGF-ß1 and α-SMA and the phosphorylation of Smad3 and Smad4 while restoring the expression of Smad7 protein. Overall, DTF1 and DTF2 may reduce collagen generation and delay the development of pulmonary fibrosis by inhibiting the activation of the TGF-ß/Smad signaling pathway. Our results provide experimental and theoretical evidence for DTF1 and DTF2 as superior candidates for further development of anti-fibrotic drugs.

Plant toxins that affect nicotinic acetylcholine receptors: a review.

Plants produce a wide variety of chemical compounds termed secondary metabolites that are not involved in basic metabolism, photosynthesis, or reproduction. These compounds are used as flavors, fragrances, insecticides, dyes, hallucinogens, nutritional supplements, poisons, and pharmaceutical agents. However, in some cases these secondary metabolites found in poisonous plants perturb biological systems. Ingestion of toxins from poisonous plants by grazing livestock often results in large economic losses to the livestock industry. The chemical structures of these compounds are diverse and range from simple, low molecular weight toxins such as oxalate in halogeton to the highly complex norditerpene alkaloids in larkspurs. While the negative effects of plant toxins on people and the impact of plant toxins on livestock producers have been widely publicized, the diversity of these toxins and their potential as new pharmaceutical agents for the treatment of diseases in people and animals has also received widespread interest. Scientists are actively screening plants from all regions of the world for bioactivity and potential pharmaceuticals for the treatment or prevention of many diseases. In this review, we focus the discussion to those plant toxins extensively studied at the USDA Poisonous Plant Research Laboratory that affect the nicotinic acetylcholine receptors including species of Delphinium (Larkspurs), Lupinus (Lupines), Conium (poison hemlock), and Nicotiana (tobaccos).