Diet-Induced High Serum Levels of Trimethylamine-N-oxide Enhance the Cellular Inflammatory Response without Exacerbating Acute Intracerebral Hemorrhage Injury in Mice.

Trimethylamine-N-oxide (TMAO), an intestinal flora metabolite of choline, may aggravate atherosclerosis by inducing a chronic inflammatory response and thereby promoting the occurrence of cerebrovascular diseases. Knowledge about the influence of TMAO-related inflammatory response on the pathological process of acute stroke is limited. This study was designed to explore the effects of TMAO on neuroinflammation, brain injury severity, and long-term neurologic function in mice with acute intracerebral hemorrhage (ICH). We fed mice with either a regular chow diet or a chow diet supplemented with 1.2% choline pre- and post-ICH. In this study, we measured serum levels of TMAO with ultrahigh-performance liquid chromatography-tandem mass spectrometry at 24 h and 72 h post-ICH. The expression level of P38-mitogen-protein kinase (P38-MAPK), myeloid differentiation factor 88 (MyD88), high-mobility group box1 protein (HMGB1), and interleukin-1ß (IL-1ß) around hematoma was examined by western blotting at 24 h. Microglial and astrocyte activation and neutrophil infiltration were examined at 72 h. The lesion was examined on days 3 and 28. Neurologic deficits were examined for 28 days. A long-term choline diet significantly increased serum levels of TMAO compared with a regular diet at 24 h and 72 h after sham operation or ICH. Choline diet-induced high serum levels of TMAO did not enhance the expression of P38-MAPK, MyD88, HMGB1, or IL-1ß at 24 h. However, it did increase the number of activated microglia and astrocytes around the hematoma at 72 h. Contrary to our expectations, it did not aggravate acute or long-term histologic damage or neurologic deficits after ICH. In summary, choline diet-induced high serum levels of TMAO increased the cellular inflammatory response probably by activating microglia and astrocytes. However, it did not aggravate brain injury or worsen long-term neurologic deficits. Although TMAO might be a potential risk factor for cerebrovascular diseases, this exploratory study did not support that TMAO is a promising target for ICH therapy.

Neferine promotes the apoptosis of HNSCC through the accumulation of p62/SQSTM1 caused by autophagic flux inhibition.

Head and neck squamous cell carcinoma (HNSCC), one of the most common malignancies worldwide, often has a poor prognosis due to the associated metastasis and chemoresistance. Hence, the development of more effective chemotherapeutics is critical. Neferine, a bisbenzylisoquinoline alkaloid isolated from the seed embryo of Nelumbo nucifera (common name: Lotus), exerts antitumor effects by regulating apoptosis and autophagy pathways, making it a potential therapeutic option for HNSCC. In our study, it was revealed that neferine inhibited the growth and induced the apoptosis of HNSCC cells both in vitro and in vivo. Furthermore, the results revealed that neferine activated the ASK1/JNK pathway by increasing reactive oxygen species production, resulting in the subsequent induction of apoptosis and the regulation of canonical autophagy in HNSCC cells. Moreover, a novel pro­apoptotic mechanism was described for neferine via the activation of caspase­8 following the accumulation of p62, which was caused by autophagic flux inhibition. These findings provided insights into the mechanisms responsible for the anticancer effect of neferine, specifically highlighting the crosstalk that occured between apoptosis and autophagy, which was mediated by p62 in HNSCC. Hence, the neferine­induced inhibition of autophagic flux may serve as the basis for a potential adjuvant therapy for HNSCC.

Neferine induces autophagy of human ovarian cancer cells via p38 MAPK/ JNK activation.

Ovarian cancer is the most lethal gynecological malignancy. Patients usually have poor prognosis because of late diagnosis, relapse, and chemoresistance. It is pressing to seek novel agent for the treatment of ovarian cancer. Neferine is a bisbenzylisoquinoline alkaloid isolated from the embryos of lotus (Nelumbo nucifera). In this study, we investigated the antitumor effect of neferine on ovarian cancer cells. We found that neferine exhibited growth-inhibitory effect on human ovarian cancer cells, whereas showing less cytotoxic to non-malignant fallopian tube epithelial cells. Furthermore, we demonstrated that neferine induced autophagy and inactivated the mTOR pathway. Finally, we found that both p38 MAPK and JNK signaling pathways were activated by neferine treatment and contributed to the induction of autophagy in ovarian cancer cells. In conclusion, our findings showed that neferine induced autophagy of human ovarian cancer cells via p38 MAPK/JNK activation. Neferine may be explored as a promising antitumoral agent in ovarian cancer.