Total alkaloid fraction of Leonurus japonicus Houtt. Promotes angiogenesis and wound healing through SRC/MEK/ERK signaling pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Leonurus japonicus Houtt., also known as motherwort, is a traditional Chinese medicine that was first identified in Shennong Bencao Jing, the first and essential pharmacy monograph in China. L. japonicus has been regarded as a good gynecological medicine since ancient times. It has been widely used in clinical settings for treatment of gynecological diseases and postnatal rehabilitation with good efficacy and low adverse effects. AIM OF THE STUDY: The main purpose of this study was to determine the angiogenic and wound healing effects of total alkaloid fraction from L. japonicus Houtt. (TALH) in vivo and in vitro. In addition, the main bioactive components of total alkaloids were to be identified and analyzed in this study. MATERIALS AND METHODS: First, the UHPLC/Q-TOF-MS method was used to identify and quantify the major components in the TALH extract. The wound healing activity was evaluated in vivo using a rat full-thickness cutaneous wound model. Histological study of wound healing in rat model was performed via immunohistochemistry and immunofluorescence. Cell proliferation was determined by MTT assay. Wound healing and transwell assays were used for detection of cell migration. The effect on tube formation was determined by tube formation assay in HUVECs. Western blot and RT-PCR were used to detect the expressions of relative proteins and genes respectively. Knock-down of SRC by siRNA was done to verify the crucial role of SRC in promotion of angiogenesis induced by TALH. RESULTS: Seven characteristic peaks were recognized in the UHPLC/Q-TOF-MS spectrum, while four of the main components were quantified. The wound model in rats showed that treatment of TALH promoted wound healing by stimulating cellular proliferation and collagen deposition. In vitro experiments showed that co-treatment of TALH and VEGF increased cell proliferation, migration and tube formation in HUVECs. Mechanistic studies suggested that the co-treatment increased gene expressions of SRC, MEK1/2 and ERK1/2, as well as the phosphorylation levels of these proteins. Furthermore, the effect of co-treatment was attenuated after SRC knockdown, suggesting that SRC plays an important role in angiogenesis and wound healing induced by TALH and VEGF co-treatment. CONCLUSION: Our results showed that TALH was one of the main active components of L. japonicus that promoted angiogenesis and wound healing by regulating the SRC/MEK/ERK pathway. Our study provided scientific basis for better clinical application of L. japonicas.

Functional preserving carbon dots-based fluorescent probe for mercury (II) ions sensing in herbal medicines via coordination and electron transfer.

Mercury ions (Hg2+) are one of the compulsory items in the quality control of herbal medicines for its serious toxicity to human health. Highly selective and sensitive Hg2+ detection, especially in complex real samples, is still challenging. In this work, Fluorescent (FL) carbon dots (CDs) with a core-shell structures composed of the crystalline core of stacked sp2-hybridized carbon layers and the shell of functional groups on the periphery of carbon layers are facilely prepared through a one-step hydrothermal synthetic route. They can specifically interact with Hg2+ in aqueous medium to form aggregates, during which coordination of carboxyl functional groups on the surface of CDs with Hg2+ occurred, which facilitated electron transfer from the CDs to Hg2+. As a result, fluorescence of the CDs was quenched with a high efficiency, making the detection of Hg2+ highly sensitive with the limit of determination (LOD) of 2.2 nM (3σ). With that, detection of Hg2+ in the complex compound herbal medicines samples with highly reproducible results has been successfully realized by using the as-prepared CDs, showing that fluorescent CDs-based probe may have great potential in the quality controls of heavy metals for pharmaceutical analysis.