Xiaolan Cheng

Sulforaphane protects against rotenone-induced neurotoxicity in vivo : Involvement of the mTOR, Nrf2, and autophagy pathways

Sulforaphane, a naturally occurring compound found in cruciferous vegetables, has been shown to be neuroprotective in several neurological disorders. In this study, we sought to investigate the potential protective effects and associated molecular mechanisms of sulforaphane in an in vivo Parkinson’s disease (PD) model, based on rotenone-mediated neurotoxicity. Our results showed that sulforaphane inhibited rotenone-induced locomotor activity deficiency and dopaminergic neuronal loss. Additionally, sulforaphane treatment inhibited the rotenone-induced reactive oxygen species production, malondialdehyde (MDA) accumulation, and resulted in an increased level of total glutathione and reduced glutathione (GSH): oxidized glutathione (GSSG) in the brain. Western blot analysis illustrated that sulforaphane increased the expression of nuclear factor (erythroid-derived 2)-like 2 (Nrf2), heme oxygenase-1 (HO-1), and NAD(P)H quinone oxidoreductase (NQO1), the latter two of which are anti-oxidative enzymes. Moreover, sulforaphane treatment significantly attenuated rotenone-inhibited mTOR-mediated p70S6K and 4E-BP1 signalling pathway, as well as neuronal apoptosis. In addition, sulforaphane rescued rotenone-inhibited autophagy, as detected by LC3-II. Collectively, these findings demonstrated that sulforaphane exert neuroprotective effect involving Nrf2-dependent reductions in oxidative stress, mTOR-dependent inhibition of neuronal apoptosis, and the restoration of normal autophagy. Sulforaphane appears to be a promising compound with neuroprotective properties that may play an important role in preventing PD.

Banxia xiexin decoction protects against dextran sulfate sodium-induced chronic ulcerative colitis in mice

ETHNOPHARMACOLOGICAL RELEVANCE Banxia Xiexin decoction (BXD), one of a traditional Chinese medicine chronicled in Shang Han Lun, is commonly used to treat gastroenteritis, ulcerative colitis and diarrhea. In our study, we used current biomedical approaches to investigate the therapeutic efficacy of BXD and possible protective mechanism involved in inhibiting dextran sulfate sodium (DSS)-induced chronic ulcerative colitis model. MATERIALS AND METHODS Chronic DSS colitis was induced in C57BL/6 male mice by three cycles of 5 days of 2% DSS in drinking water, alternating with 5 days of normal water, totaling 30 days. In BXD group, the mice were administered at a dose of 8.7g/kg BXD for 5 days before and during DSS treatment via oral gavage per day. Mice in vehicle group and DSS group were given orally the same volume of drinking water, instead. Body weight, stool characters and hematochezia were observed everyday. The colorectal tissues were used to detect levels of TNF-α, IL-4, IL-10, IL-1β, IL-17, IL-23 and MPO by ELISA or qRT-PCR. The expression of COX-2, 8-Oxoguanine and Nrf2 were examined by IHC, and p-p65 was examined by western blotting. ThOD and the content of MDA were measured according to kits respectively. RESULTS BXD significantly protected against DSS-induced chronic ulcerative colitis by amelioration of body weight loss, DAI and histology score. The level of TNF-α, IL-1β, IL-17, IL-23, COX-2 and p-p65 were decreased significantly, while the level of IL-10 improved with the treatment of BXD. MDA, MPO and 8-Oxoguanine were decreased, meanwhile SOD activity and Nrf2 expression were elevated significantly by BXD. CONCLUSIONS BXD possesses the potential of anti-inflammation and anti-oxidation to treat colitis. The protective mechanism of BXD may involve in inhibition of NF-κBp65 activation and increasement of Nrf2 expression in colorectums of mice.

Therapeutic potential of digitoflavone on diabetic nephropathy: nuclear factor erythroid 2-related factor 2-dependent anti-oxidant and anti-inflammatory effect

Nuclear factor erythroid 2-related factor 2 (Nrf2) has emerged as a therapeutic target in many diseases, because it can induce antioxidant enzymes and other cytoprotective enzymes. Moreover, some Nrf2 activators have strong anti-inflammatory activities. Oxidative stress and inflammation are major components involved in the pathology of diabetic nephropathy. In the present study, we evaluated the Nrf2-dependent anti-oxidative and anti-inflammatory effects of digitoflavone in streptozotocin-induced diabetic nephropathy. The molecular mechanisms of digitoflavone were investigated in vitro using SV40-transformed mouse mesangial cells (SV40-Mes13). For the in vivo experiment, diabetes was induced in Nrf2+/+ and Nrf2−/− mice by STZ injection, and digitoflavone was administered 2 weeks after the STZ injection. Digitoflavone induced Nrf2 activation and decreased oxidative damage, inflammation, TGF-β1 expression, extracellular matrix protein expression, and mesangial cell hyperplasia in SV40-Mes13 cells. Digitoflavone-treated Nrf2+/+ mice, but not Nrf2−/− mice, showed attenuated common metabolic disorder symptoms, improved renal performance, minimized pathological alterations, and decreased oxidative damage, inflammatory gene expression, inflammatory cell infiltration, TGF-β1 expression, and extracellular matrix protein expression. Our results show that the anti-oxidative and anti-inflammatory effects of digitoflavone are mediated by Nrf2 activation and that digitoflavone can be used therapeutically to improve metabolic disorders and relieve renal damage induced by diabetes.

The Natural Diterpenoid Isoforretin A Inhibits Thioredoxin-1 and Triggers Potent ROS-Mediated Antitumor Effects

Aberrant expression of thioredoxin 1 (Trx1) plays an important role in cancer initiation and progression and has gained attention as an anticancer drug target. Here we report that the recently discovered natural diterpenoid isoforretin A (IsoA) significantly inhibits Trx1 activity and mediates anticancer effects in multiple preclinical settings. The inhibitory effect of IsoA was antagonized by free radical scavengers polyethylene glycol-catalase, polyethylene glycol superoxide dismutase, thiol-based antioxidants N-acetylcysteine and glutathione. Mass spectrometry analysis revealed that the mechanism of action was based on direct conjugation of IsoA to the Cys32/Cys35 residues of Trx1. This conjugation event attenuated reversible thiol reduction of Trx1, leading to ROS accumulation and a broader degradation of thiol redox homeostasis in cancer cells. Extending these in vitro findings, we documented that IsoA administration inhibited the growth of HepG2 tumors in a murine xenograft model of hepatocellular carcinoma. Taken together, our findings highlight IsoA as a potent bioactive inhibitor of Trx1 and a candidate anticancer natural product. Cancer Res; 77(4); 926-36. ©2016 AACR.

Ancient Chinese Formula Qiong-Yu-Gao Protects Against Cisplatin-Induced Nephrotoxicity Without Reducing Anti-tumor Activity.

Cisplatin is a highly effective anti-cancer chemotherapeutic agent; however, its clinical use is severely limited by serious side effects, of which nephrotoxicity is the most important. In this study, we investigated whether Qiong-Yu-Gao (QYG), a popular traditional Chinese medicinal formula described 840 years ago, exhibits protective effects against cisplatin-induced renal toxicity. Using a mouse model of cisplatin-induced renal dysfunction, we observed that pretreatment with QYG attenuated cisplatin-induced elevations in blood urea nitrogen and creatinine levels, ameliorated renal tubular lesions, reduced apoptosis, and accelerated tubular cell regeneration. Cisplatin-mediated elevations in tumor necrosis factor alpha (TNF-α) mRNA, interleukin-1 beta (IL-1β) mRNA, and cyclooxygenase-2 (COX-2) protein in the kidney were also significantly suppressed by QYG treatment. Furthermore, QYG reduced platinum accumulation in the kidney by decreasing the expression of copper transporter 1 and organic cation transporter 2. An in vivo study using implanted Lewis lung cancer cells revealed that concurrent administration of QYG and cisplatin did not alter the anti-tumor activity of cisplatin. Our findings suggest that the traditional Chinese medicinal formula QYG inhibits cisplatin toxicity by several mechanisms that act simultaneously, without compromising its therapeutic efficacy. Therefore, QYG may be useful in the clinic as a protective agent to prevent cisplatin-induced nephrotoxicity.

Gut microbiota drives the attenuation of dextran sulphate sodium-induced colitis by Huangqin decoction

The gut microbiota, including probiotics and pathogenic microorganisms, is involved in ulcerative colitis (UC) by regulating pathogenic microorganisms and the production of intestinal mucosal antibodies. Huangqin decoction (HQD), a traditional Chinese formula chronicled in the Shanghan lun, has been recognized as an effective drug for UC, owing to its anti-inflammatory and anti-oxidative properties. In the present study, we investigated whether HQD ameliorates dextran sulphate sodium (DSS)-induced colitis through alteration of the gut microbiota. We found that HQD significantly inhibited colitis, alleviating the loss of body weight, disease activity index, colon shortening, tissue injury, and inflammatory cytokine changes induced by DSS treatment. Principal component analysis and principal co-ordinate analysis showed an obvious difference among the groups, with increased diversity in the DSS and DSS+HQD groups. Linear discriminant analysis effect size was used to determine differences between the groups. The relative abundance of Lactococcus was higher in the DSS+HQD group than in the DSS group, whereas Desulfovibrio and Helicobacter were decreased. Furthermore, the protective effect of HQD was attenuated only in antibiotic-treated mice. In conclusion, our results suggest that HQD could ameliorate DSS-induced inflammation through alteration of the gut microbiota.

Protective effects of Huangqin Decoction against ulcerative colitis and associated cancer in mice

Individuals with ulcerative colitis (UC) are at a high risk for developing colorectal cancer (CRC). Huangqin Decoction (HQD), a traditional Chinese medicinal formula chronicled in the Shang Han Lun, is commonly used to treat gastrointestinal symptoms. However, experimental evidence for supporting the clinical practice is lacking. This study used modern biomedical approaches to investigate the protective/preventive effects of HQD in dextran sulfate sodium (DSS)-induced acute/chronic UC and azoxymethane (AOM)/DSS-induced CRC in mice. HQDs were prepared in 4 different ways: HQD-1 and HQD-2 were prepared in boiling water, whereas HQD-3 and HQD-4 were prepared in heated ethanol (70%). For HQD-1 and HQD-3, the 4 constituent herbs were processed together, whereas for HQD-2 and HQD4, these herbs were processed individually and then combined. The mice were administered 9.1 g/kg HQD via oral gavage daily. HQD-1 significantly inhibited DSS-induced acute UC, whereas HQD-3 and HQD-4 exhibited mild ameliorative effects; but HQD-2 had no protective effect and resulted in a higher mortality rate. This higher mortality rate may be due to the greater abundance of baicalein and wogonin in HQD-2 than HQD-1. Furthermore, HQD-1 protected against DSS-induced chronic UC and significantly inhibited AOM/DSS-induced CRC in mice. HQD-1 also inhibited the production of inflammatory cytokines and increased antioxidant capacity both in chronic DSS and AOM/DSS treated mice. Overall, HQD-1 inhibits the development of acute/chronic colitis and prevents colitis-associated CRC, possibly by inhibiting inflammation and preventing oxidative stress induced cellular damage.

Herbal Medicine AC591 Prevents Oxaliplatin-Induced Peripheral Neuropathy in Animal Model and Cancer Patients

Oxaliplatin is clinically compelling because of severe peripheral neuropathy. The side effect can result in dosage reductions or even cessation of chemotherapy, and no effective treatments are available. AC591 is a standardized extract of Huangqi Guizhi Wuwu decoction, an herbal formula recorded in “Synopsis of the Golden Chamber” for improving limb numbness and pain. In this study, we investigated whether AC591 could protect against oxaliplatin-induced peripheral neuropathy. To clarify it, a rat model of oxaliplatin-induced peripheral neuropathy was established, and neuroprotective effect of AC591 was studied. Our results showed that pretreatment with AC591 reduced oxaliplatin-induced cold hyperalgesia, mechanical allodynia as well as morphological damage of dorsal root ganglion. Microarray analysis indicated the neuroprotective action of AC591 depended on the modulation of multiple molecular targets and pathways involved in the downregulation of inflammation and immune response. Moreover, AC591 enhanced the antitumor activity of oxaliplatin to some extent in Balb/c mice bearing CT-26 carcinoma cells. The efficacy of AC591 is also investigated in 72 colorectal cancer patients. After four cycles of treatment, the percentage of grades 1–2 neurotoxicity in AC591-treated group (n = 36) was 25%, whereas in the control group the incidence was 55.55% (P < 0.01) (n = 36). No significant differences in the tumor response rate between the two groups were found. These evidences suggested that AC591 can prevent oxaliplatin-induced neuropathy without reducing its antitumor activity, and may be a promising adjuvant to alleviate sensory symptoms in clinical practice.

Isolation and pharmacological characterization of a new cytotoxic L-amino acid oxidase from Bungarus multicinctus snake venom

ETHNOPHARMACOLOGICAL RELEVANCE Bungarus multicinctus snake belongs to Elapidae family and is widely distributed in southern China. It is widely used in traditional Chinese medicine with the effect of dispelling wind and removing obstruction in the meridians. Moreover, it is also as a chief ingredient of many polyherbal formulations for the treatment of cancer. AIM OF THE STUDY To evaluate the antitumor activity of Bungarus multicinctus snake venom components and isolate, characterize the most effective anti-tumor component of Bungarus multicinctus snake venom. MATERIALS AND METHODS The in vitro antitumor activity of Bungarus multicinctus venom components was detected by cytotoxicity assay and cell apoptosis assay. A unique LAAO from Bungarus multicinctus venom named as BM-Apotxin was isolated and characterized by Sephadex G-75 gel filtration, Sephadex G-25 desalting, Q ion-exchange chromatography and subsequent amino acids sequence determination. The LAAO activity and enzyme kinetics of BM-Apotxin was detected by microplate assay. RESULTS BM-Apotxin, a 65KDa glycoprotein, which contributed to the most anti-tumor effects of Bungarus multicinctus venom. BM-Apotxin can selectively kill tumor cells, with less cytotoxicity to the normal cells. BM-Apotxin is an L-amino acid oxidase (LAAO) with high sequence identity to other snake venom LAAOs. Its anti-tumor activity is mainly due to the hydrogen peroxide produced from LAAO oxidation. But the catalase did not reverse its anti-tumor effect completely. Like other snake venom LAAOs, BM-Apotxin can oxidize many L amino acids, not D amino acids. The optimum substrate for BM-Apotxin is L-Phe. Moreover, BM-Apotxin deglycosylation can significantly reduce the LAAO activity and anti-tumor activity of BM-Apotxin. CONCLUSION This study will facilitate the study on anti-tumor mechanism of snake venom and drug development based on Bungarus multicinctus venom.

Nrf2 inhibits oxaliplatin-induced peripheral neuropathy via protection of mitochondrial function

ABSTRACT Oxaliplatin‐induced peripheral neuropathy (OIPN) is a severe, dose‐limiting toxicity associated with cancer chemotherapy. The efficacy of antioxidant administration in OIPN is debatable, as the promising preliminary results obtained with a number of antioxidants have not been confirmed in larger clinical trials. Besides its antioxidant activity, the transcription factor, nuclear factor‐erythroid 2 (NF‐E2) p45‐related factor 2 (Nrf2) plays a crucial role in the maintenance of mitochondrial homeostasis, and mitochondrial dysfunction is a key contributor to OIPN. Here, we have investigated the protective properties of Nrf2 in OIPN. Nrf2‐/‐ mice displayed severe mechanical allodynia and cold sensitivity and thus experienced increased peripheral nervous system injury compared to Nrf2+/+ mice. Furthermore, Nrf2 knockout aggravated oxaliplatin‐induced reactive oxygen species production, decreased the mitochondrial membrane potential, led to abnormal intracellular calcium levels, and induced cytochrome c‐related apoptosis and overexpression of the TRP protein family. Sulforaphane‐induced activation of the Nrf2 signaling pathway alleviated morphological alterations, mitochondrial dysfunction in dorsal root ganglion neurons, and nociceptive sensations in mice. Our findings reveal that Nrf2 may play a critical role in ameliorating OIPN, through protection of mitochondrial function by alleviating oxidative stress and inhibiting TRP protein family expression. This suggests that pharmacological or therapeutic activation of Nrf2 may be used to prevent or slow down the progression of OIPN. HIGHLIGHTSOxaliplatin (OHP) caused severe mechanical and cold sensitivities in Nrf2‐/‐ mice.Nrf2 knockout aggravated OHP‐induced ROS production and mitochondrial damage.Nrf2 reduced OHP‐induced peripheral neuropathy by protecting mitochondrial function.Nrf2 reversed OHP‐induced TRP family overexpression in DRG neurons.Nrf2 may be a therapeutic candidate for OHP‐induced peripheral neuropathy.