Xiaosong Zhu

S‐Allylmercaptocysteine Attenuates Cisplatin‐Induced Nephrotoxicity through Suppression of Apoptosis, Oxidative Stress, and Inflammation

Cisplatin is a potent chemotherapeutic agent, but its clinical usage is limited by nephrotoxicity. S-allylmercaptocysteine (SAMC), one of the water-soluble organosulfur garlic derivatives, has antioxidant and anti-inflammatory properties and plays an important role in protecting cells from apoptosis. This study aims to examine the protective effects of SAMC on cisplatin nephrotoxicity and to explore the mechanism of its renoprotection. Rats were treated with cisplatin with or without pre-treatment with SAMC. Renal function, histological change, oxidative stress markers and antioxidant enzyme activities were investigated. Apoptotic marker, nuclearfactor (NF)-κB activity, expression of nuclear factor erythroid 2-related factor 2 (Nrf2), NAD(P)H:quinone oxidoreductase 1 (NQO1) and inflammatory cytokines were also examined. The effect of SAMC on cell viability and apoptosis was examined in cultured human kidney (HK-2) cells. SAMC was confirmed to significantly attenuate cisplatin-induced renal damage by using histological pathology and molecular biological method. Pre-treatment with SAMC reduced NF-κB activity, up-regulated Nrf2 and NQO1 expression and down-regulated inflammatory cytokine levels after cisplatin administration. Cisplatin-induced apoptosis in HK-2 cells was significantly attenuated by SAMC. Thus our results suggest that SAMC could be a potential therapeutic agent in the treatment of the cisplatin-induced nephrotoxicity through its anti-apoptotic, anti-oxidant and anti-inflammatory effects.

Diallyl trisulfide suppresses tumor growth through the attenuation of Nrf2/Akt and activation of p38/JNK and potentiates cisplatin efficacy in gastric cancer treatment

Diallyl trisulfide (DATS), a garlic organosulfide, has shown excellent chemopreventive potential. Cisplatin (DDP) is widely used to treat solid malignant tumors, but causing serious side effects. In the current study, we attempted to elucidate the chemopreventive mechanisms of DATS in human gastric cancer BGC-823 cells in vitro, and to investigate whether DATS could enhance the anti-tumor efficacy of DDP and improve quality of life in BGC-823 xenograft mice in vivo. Treatment with DATS (25–400 μmol/L) dose-dependently inhibited the viability of BGC-823 cells in vitro with an IC50 of 115.2±4.3 μmol/L after 24 h drug exposure. DATS (50–200 μmol/L) induced cell cycle arrest at G2/M phase in BGC-823 cells, which correlated with significant accumulation of cyclin A2 and B1. DATS also induced BGC-823 cell apoptosis, which was accompanied by the modulation of Bcl-2 family members and caspase cascade activation. In BGC-823 xenograft mice, administration of DATS (20–40 mg·kg−1·d−1, ip) dose-dependently inhibited tumor growth and markedly reduced the number of Ki-67 positive cells in tumors. Interestingly, combined administration of DATS (30 mg·kg−1·d−1, ip) with DDP (5 mg/kg, every 5 d, ip) exhibited enhanced anti-tumor activity with fewer side effects. We showed that treatment of BGC-823 cells with DATS in vitro and in vivo significantly activated kinases such as p38 and JNK/MAPK and attenuated the Nrf2/Akt pathway. This study provides evidence that DATS exerts anticancer effects and enhances the antitumor efficacy of DDP, making it a novel candidate for adjuvant therapy for gastric cancer.

Diallyl trisulfide inhibits naphthalene-induced oxidative injury and the production of inflammatory responses in A549 cells and mice.

Diallyl trisulfide (DATS) is a garlic organosulfide that may have a therapeutic potential in the treatment of some diseases. We sought to determine whether DATS could inhibit naphthalene-induced oxidative injury and the production of inflammatory responses in vitro and in vivo. A549 cells were either pre-treated (PreTx, prevention) or concurrently treated (CoTx, treatment) with 20μM naphthalene and either 5 or 10μM DATS. PreTx and CoTx showed the prevention and the treatment potential of DATS to inhibit the generation of naphthalene-induced reactive oxygen species (ROS) in the A549 cells. DATS showed antioxidative activity by elevating the SOD activities in the low dose groups. The mechanistic study showed that the DATS-mediated inhibition of naphthalene-induced oxidative injury and the production of inflammatory responses (i.e., TNF-α, IL-6, and IL-8) were attributed to inhibiting the activity of nuclear factor-kappa B (NF-κB). In addition, DATS inhibited the production of serum nitric oxide NO and myeloperoxidase (MPO) in the lungs of Kunming mice. The histological analysis results indicate that DATS inhibited the naphthalene-induced lung damage, which is consistent with the in vitro study results. The in vivo and in vitro results suggest that DATS may be an effective attenuator of naphthalene-induced lung damage.

Diallyl Trisulfide Inhibits Growth of NCI-H460 in Vitro and in Vivo, and Ameliorates Cisplatin-Induced Oxidative Injury in the Treatment of Lung Carcinoma in Xenograft Mice

Diallyl trisulfide (DATS), an organosulfuric component of garlic oil, exhibits potential anticancer and chemopreventive effects. Cisplatin (DDP), a common chemotherapeutic agent, has provided great therapeutic contributions to treating solid tumors, but with serious side effects. Here, we verified the anti-tumor properties of DATS on lung cancer in vitro and in vivo, and evaluated synergistic effects of DATS combined with DDP on the NCI-H460 xenograft model. Significantly decreased cell viabilities, cell cycle G1 arrest, and apoptosis induction were observed in DATS treated NCI-H460 cells (p<0.05). And injection of DATS (30 or 40 mg/kg) to female Balb/c mice significantly inhibited the growth of human NCI-H460 cell tumor xenograft (p<0.001). Moreover, DATS in combination with DDP exhibited enhanced anti-tumor activity via induction of apoptosis. Apoptosis pathways were confirmed by modulation of p53, Bcl-2 family members; induction of active caspase-3/8/9 and activation of JNK- and p38-MAPK pathways. Interestedly, DATS+DDP administration exerted fewer side effects, such as suppressing the weight loss and ameliorating DDP-induced oxidative injury, especially in renal parenchyma. In addition, increased E-cadherin and decreased MMP-9 expression levels were observed in DATS-treated tumor tissues. These studies provide supports that DATS might be a potential candidate for combination with DDP in cancer treatment.

Characterization and protective effect of Polygonatum sibiricum polysaccharide against cyclophosphamide-induced immunosuppression in Balb/c mice

In this study, the polysaccharide from Polygonatum sibiricum (PSP) was evaluated for the immunomodulatory activity by the cyclophosphamide (Cy)-induced immunosuppressed-model in vivo. The PSP has been analyzed in order to identify a variety of chemical properties such as monosaccharide compositions and structural confirmation. The results show that the main components of PSP were galactose and rhamnose. The PSP could significantly stimulate neutral red phagocytosis of RAW264.7 macrophages. Compared with the cyclophosphamide group, PSP accelerated recovery of spleen and thymus indexes, and enhanced T cell and B cell proliferation responses as well as peritoneal macrophage phagocytosis. In addition, PSP treatment restored the levels of IL-2, TNF-α, IL-8 and IL-10 in the serum of the Cy-treated mice in a dose-dependent manner. Therefore, PSP played an important role in the protection against immunosuppression in the Cy-treated mice and could be used as a potential immunostimulant agent.

Inhibitory effects of S-allylmercaptocysteine against benzo(a)pyrene-induced precancerous carcinogenesis in human lung cells

The anti-cancer effects of oil-soluble organosulfur compounds in garlic in the initiation phase of carcinogenesis are known. However, there are few experimental studies investigating S-allylmercaptocysteine (SAMC), a water-soluble derivative of garlic. This study investigated whether SAMC prevented the carcinogen benzo(a)pyrene (B(a)P) from inducing precancerous activity in human lung cells (A549 cell line). A549 cells were either pre-treated (PreTM) or concurrently treated (CoTM) with 1μM B(a)P and either 10 or 50 μM SAMC. The 50 μM PreTM group inhibited B(a)P-induced cell proliferation by approximately 100%. The 50 μM SAMC PreTM and CoTM inhibited the B(a)P-induced G2/M phase shift by 100% and 97%, respectively. Furthermore, the PreTM and CoTM groups exhibited the potential to reduce the generation of reactive oxygen species (ROS) relative to the B(a)P group by at least 78%. The SAMC PreTM elevated superoxide dismutase (SOD) by approximately 100%. In this study, we revealed the mechanisms involved in SAMC inhibition of B(a)P-induced carcinogenesis, including suppression of cell proliferation, cell cycle regulation, attenuation of ROS formation, inhibition of DNA damage, increase of SOD activity and inhibition of nuclear factor-kappa B (NF-κB) activity. SAMC appears to be a novel therapeutic candidate for the prevention and treatment of B(a)P-induced human lung cancer.

Pharmacological Investigation of the Anti-Inflammation and Anti-Oxidation Activities of Diallyl Disulfide in a Rat Emphysema Model Induced by Cigarette Smoke Extract

Diallyl disulfide (DADS) is the main organosulfur ingredient in garlic, with known antioxidant and anti-inflammatory activities. The aim of the present study was to investigate the effect of DADS on reducing the inflammation and redox imbalance in a rat emphysema model that was induced by intraperitoneal injection of cigarette smoke extract (CSE). Briefly, DADS exerted an anti-inflammation effect on emphysema rats through decreasing cell influx in the bronchoalveolar lavage fluid (BALF) and suppressing pro-inflammation cytokine production including tumor necrosis factor alpha (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6) via inhibiting the NF-κB pathway. In addition, levels of oxidative stress markers including malondialdehyde (MDA) and myeloperoxidase (MPO) were reduced, while the activities of glutathione (GSH), glutathione peroxidase (GSH-PX), superoxide dismutase (SOD) and total antioxidant capacity (T-AOC) were markedly enhanced by DADS. Moreover, MMP-9 and TIMP-1 expression were down-regulated by DADS. Furthermore, the regulation effects of DADS on CD4+ and CD8+ T cells were observed. In conclusion, these encouraging findings suggest that DADS could be considered as a promising anti-inflammation and antioxidative agent for the treatment of emphysema.

Garlic-derived organosulfur compound exerts antitumor efficacy via activation of MAPK pathway and modulation of cytokines in SGC-7901 tumor-bearing mice

Abstract Diallyl trisulfide (DATS), a natural agent derived from garlic, has been tested for its antigastric cancer activities in various preliminary studies. However, more systematic pharmacodymatic (PD) and mechanistic evaluations are clearly needed. The aim of this study was to investigate the antitumor effects of DATS in the treatment of human gastric cancer cell SGC‐7901 both in vitro and in vivo using widely recommended study procedures. DATS suppressed cancer cells proliferation and induced cell cycle arrest accompanied by an increase in the expressions of cyclin A2 and cyclin B1 in SGC‐7901 cancer cells. DATS also caused an increase in apoptotic cell death, which involved in accumulations of bax, p53, and cytochrome C and reduction of Bcl‐2 expressions. Besides, activation of JNK, ERK and p38 phosphorylation in DATS‐treated cells suggested that mitogen‐activated protein kinase (MAPKs) pathways were involved in DATS‐induced apoptosis. Meanwhile, DATS significantly inhibited tumor growth and promoted tumor apoptosis in a xenograft model of gastric cancer cell SGC‐7901. DATS inhibited tumor migration and invasion by modulating MMP9 and E‐cadherin protein expressions. In addition, DATS treatment evidently increased the cytokine secretions of IL‐12, TNF‐&agr; and IFN‐&ggr; (p < 0.05). Biochemical serum analysis and histopathological examination indicated no obvious side effects in major mouse organs. Therefore, our findings provide a framework for further exploration of DATS as a novel chemotherapeutic for human gastric cancer. HighlightsThe efficacy and mechanisms of DATS are evaluated on the tumors from human gastric cancer cell SGC‐7901 using widely accepted protocols.DATS possesses the ability of activation of MAPK pathway and modulation of cytokines in SGC‐7901 tumor‐bearing mice.DATS is found to be less cytotoxic and exerts the immunomotherapeutic effect on the tumor reduction.

Metabolism and pharmacokinetics studies of allyl methyl disulfide in rats

Abstract 1. Allyl methyl disulfide (AMDS) is one of the main compounds in garlic, whereas its metabolism has not been studied yet. 2. In this work, we first identified the metabolites of AMDS in rat erythrocytes and rats using GC–MS. The transformation mechanism study among different metabolites was then conducted. The apparent kinetics of AMDS in rat erythrocytes and pharmacokinetics of AMDS by oral administration in rats were also studied. 3. The metabolic pathway study showed that AMDS was mainly metabolized in rats to allyl methyl sulfoxide (AMSO) and allyl methyl sulfone (AMSO2) through mechanisms of reduction, methylation and oxidation. The transformation mechanism study indicated that AMDS was firstly reduced to allyl mercaptan (AM) in rat erythrocytes, and then methylated to allyl methyl sulfide (AMS) by S-adenosylmethionine (SAM) and S-adenosylhomocysteine (SAH), and finally oxidized to AMSO and AMSO2 by liver microsomes. The half-life of AMDS in rat erythrocytes was 6.285 ± 0.014 min while the half-lives of its active metabolites AMSO and AMSO2 in vivo were 18.17 and 17.50 h, respectively. Also, the large AUCs of the two active metabolites were observed, indicating potential applications of AMDS for certain pharmacological effects.

L-Menthol alleviates cigarette smoke extract induced lung injury in rats by inhibiting oxidative stress and inflammation via nuclear factor kappa B, p38 MAPK and Nrf2 signalling pathways

L-Menthol is the main ingredient of peppermint which affects various pharmacological effects such as anti-inflammation and anti-oxidative activity. In this study, we aimed to evaluate the potential effects of L-menthol on cigarette smoke extract (CSE) induced lung injury in rats. Morphology assessment results revealed that administration with L-menthol (5, 10 or 20 mg kg−1 d−1) significantly alleviated CSE-induced lung injury. Besides, L-menthol significantly reduced the inflammatory response by suppressing the production of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and interleukin-6 (IL-6) via downregulating nuclear factor kappa B (NF-κB) and p38 MAPK pathways. Meanwhile, L-menthol decreased the levels of oxidative stress markers including malondialdehyde (MDA) and myeloperoxidase (MPO) whereas it increased the amount of glutathione (GSH), glutathione peroxidase (GSH-Px), superoxide dismutase (SOD) and total antioxidant capacity (T-AOC) through activation of the Nrf2 pathway. Furthermore, the expression of MMP-9 and TIMP-1 in lungs was reduced after treatment with L-menthol, and this indicated that L-menthol might have a potential effect on airway remodeling. Moreover, immunohistochemistry analyses indicated that L-menthol could suppress the infiltration of CD4+ and CD8+ T cells in lung tissues and this was probably due to the immune regulation activity of L-menthol. Taken together, our findings support that L-menthol might be a potential candidate for the treatment of CSE-induced lung injury in rats.