Binding of bilirubin with albumin-coupled liposomes: implications in the treatment of jaundice

Therapeutic potential of salvigenin to combat atrazine induced liver toxicity in rats via regulating Nrf-2/Keap-1 and NF-κB pathway

Atrazine (ATR) is the second most extensively used herbicide which adversely affects the body organs including liver. Salvigenin (SGN) is a flavonoid which demonstrates a wide range of biological and pharmacological abilities. This study was planned to assess the protective ability of SGN to avert ATR induced liver damage in rats. Thirty-two rats (Rattus norvegicus) were divided into four groups including control, ATR (5 mg/kg), ATR (5 mg/kg) + SGN (10 mg/kg) and SGN (10 mg/kg) alone supplemented group. ATR exposure reduced the expression of Nrf-2 while instigating an upregulation in Keap-1 expression. Furthermore, the activities of catalase (CAT), glutathione peroxidase (GPx), superoxide dismutase (SOD), heme‑oxygenase-1 (HO-1) and glutathione reductase (GSR) contents were decreased while increasing reactive oxygen species (ROS) and malondialdehyde (MDA) levels after ATR treatment. Moreover, ATR poisoning increased the levels of ALT, AST, and ALP while reducing the levels of total proteins, and albumin in hepatic tissues of rats. Besides, ATR administration escalated the expressions of Bax and Caspase-3 while inducing a downregulation in the expressions of Bcl-2. Similarly, ATR intoxication increased the levels of Interleukin-6 (IL-6), Nuclear factor kappa-B (NF-κB), Interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), and the activity of cyclooxygenase-2 (COX-2). Furthermore, ATR disrupted the normal histology of hepatic tissues. However, SGN treatment remarkably protected the liver tissues via regulating antioxidant, anti, inflammatory, anti-apoptotic as well as histology parameters. Therefore, it is concluded that SGN can be used as therapeutic agent to combat ATR-induced hepatotoxicity.

Thymoquinone, an active constituent of Nigella sativa seeds, binds with bilirubin and protects mice from hyperbilirubinemia and cyclophosphamide-induced hepatotoxicity

Some reports indicate that thymoquinone (TQ), the main constituent of Nigella sativa seeds, is hepatoprotective. The aim of this study was to determine whether TQ is able to bind directly to bilirubin, and whether TQ or liposomal formulation of TQ (Lip-TQ) can reduce cyclophosphamide (CYP)-induced liver toxicity, serum bilirubin level in mice. The binding of TQ with bilirubin was studied by UV-VIS, fluorescence and Near-UV CD spectroscopy. Inhibition of binding of bilirubin to erythrocytes by TQ was also examined. To increase the in vivo efficacy, Lip-TQ was prepared and used against CYP-induced toxicity. The protective role of TQ or Lip-TQ against CYP-induced toxicity was assessed by determining the liver function parameters, the levels of superoxide dismutase (SOD) and catalase (CAT), and histological studies. It was found that TQ binds to bilirubin and significantly inhibits the binding of bilirubin to erythrocytes. Lip-TQ (10 mg/kg) significantly reduced the levels of aspartate transaminase (AST) from 254 ± 48 to 66 ± 18 IU/L (P < 0.001), alanine transaminase (ALT) from 142 ± 28 to 47.8 ± 16 IU/L (P < 0.05) and serum bilirubin from 2.8 ± 0.50 to 1.24 ± 0.30 mg/dl (P < 0.05). Treatment with Lip-TQ reduced the CYP-induced inflammation and hemorrhage in liver tissues. Moreover, treatment with free or Lip-TQ protected the activity of SOD and CAT in CYP-injected mice. Therefore, TQ can reduce the level of bilirubin in systemic circulation in disease conditions that lead to hyperbilirubinemia and liver toxicity and hence may be used as a supplement in the treatment of liver ailments.

PLGA-microsphere mediated clearance of bilirubin in temporarily hyperbilirubinemic rats: An alternate strategy for the treatment of experimental jaundice

In the present study, we have demonstrated the suitability of microspheres in removal of plasma bilirubin from systemic circulation of hyperbilirubinemic rats. Poly (lactide co-glycolide) microspheres (PLGA microspheres) have been shown to bind with bilirubin in both a concentration and time dependent manner. The binding affinity of bilirubin to microspheres was enhanced when rat serum albumin (RSA) was loaded into the microspheres. On evaluating the potential of microspheres in elimination of bilirubin from the systemic circulation, RSA bearing microspheres were found to be competent in both removing bilirubin from the systemic circulation and controlling elevated plasma levels of liver function enzymes in temporarily hyperbilirubinemic rats. On the basis of results of the present study, we suggest that microsphere-based delivery system may help in development of safe, effective and alternate strategy for the treatment of hyperbilirubinemic conditions in model animals.

Liposome‐Bilirubin Interaction: A Novel Strategy to Eliminate Bilirubin from Systemic Circulation

In the present study, we established the role of liposomes in removal of bilirubin from systemic circulation of the hyperbilirubinemic rats. Bilirubin has been demonstrated to possess inherent tendency to interact with liposomes through ionic as well as hydrophobic interactions. The size as well as lamellarity of the liposomes does not seem to affect their binding with bilirubin. However, the charge on the surface of liposomes plays an important role in bilirubin-liposome interaction, e.g., bilirubin binds more extensively with positively charged liposomes as compared to the neutral or negatively charged liposomes. The present study further demonstrates that liposomes were effective in reducing the increased plasma bilirubin level in hyperbilirubinemic model animals as well. The results of the study suggest that positively charged liposome-mediated selective homing of excess plasma bilirubin to the hepatocytes seems to offer an important strategy in management of hyperbilirubinemic conditions.