Differential cytoprotective effect of copper- and iron-containing chlorophyllins against oxidative stress-mediated cell death

Relationship between lifespan and somatic mutation in D. melanogaster after treatment with chlorophyllin

Sodium copper chlorophyllin (SCC) has a genetic damage inhibitory capacity due to its antioxidant action. For this reason, it was considered to investigate its role in the life span of Drosophila melanogaster and its relationship with the frequency of somatic mutation induced by gamma rays. Results indicated that SCC alone prolonged the lifespan only in females, but in combination with 20 Gy of gamma rays, the aging delay in both sexes was significant. In addition to confirming that the porphyrin reduces the frequency of mutation, the individuals with the highest mutation load are the individuals who die more quickly, and once they are eliminated, the survivor individuals treated with 20 Gy or with SCC + 20 Gy, died at the same rate. The results together indicate that SCC not only inhibits induced genetic damage, but it also has beneficial effects that probably cause an aging delay of the treated population that need to be investigated.

Light-Activated Biomedical Applications of Chlorophyll Derivatives

Tetrapyrroles are the basis of essential physiological functions in most living organisms. These compounds represent the basic scaffold of porphyrins, chlorophylls, and bacteriochlorophylls, among others. Chlorophyll derivatives, obtained by the natural or artificial degradation of chlorophylls, present unique properties, holding great potential in the scientific and medical fields. Indeed, they can act as cancer-preventing agents, antimutagens, apoptosis inducers, efficient antioxidants, as well as antimicrobial and immunomodulatory molecules. Moreover, thanks to their peculiar optical properties, they can be exploited as photosensitizers for photodynamic therapy and as vision enhancers. Most of these molecules, however, are highly hydrophobic and poorly soluble in biological fluids, and may display undesired toxicity due to accumulation in healthy tissues. The advent of nanomedicine has prompted the development of nanoparticles acting as carriers for chlorophyll derivatives, facilitating their targeted administration with demonstrated applicability in diagnosis and therapy. In this review, the chemical and physical properties of chlorophyll derivatives that justify their usage in the biomedical field, with particular regard to light-activated dynamics are described. Their role as antioxidants and photoactive agents are discussed, introducing the most recent nanomedical applications and focusing on inorganic and organic nanocarriers exploited in vitro and in vivo.

Shengxuening Extracted from Silkworm Excrement Mitigates Myelosuppression via SCF-Mediated JAK2/STAT3 Signaling

Shengxuening (SXN) is a Chinese patent medicine with main ingredients (including chlorophyll derivatives and sodium iron chlorophyllin) extracted from silkworm excrement. SXN exhibited efficacy in clinical trials of renal anemia and iron deficiency anemia; however, the specific mechanisms remain unclear. This study found that SXN increased the number of peripheral blood cells and improved the bone marrow morphology in myelosuppressed mouse model, reversed the reduction in body weight and spleen indices, and increased the serum levels of erythropoietin and granulocyte-macrophage colony-stimulating factor. Quantitative real-time PCR array and Western blot analysis showed the enhanced expression of stem cell factor (SCF), JAK2, and STAT3 in the liver. These results suggested that SXN promoted the recovery of hemopoietic function in myelosuppressed models by increasing the secretion of hematopoietic factors and activating the JAK2/STAT3 pathway. Therefore, this medicine may be applied as therapeutic pharmaceutical drug to mitigate myelosuppression.

Efficacy of SXN in the Treatment of Iron Deficiency Anemia: A Phase IV Clinical Trial

Shengxuening (SXN) tablet is extracted from the excrement of the silkworm and has effects on hematopoiesis. The main components of SXN are chlorophyll derivatives and sodium iron chlorophyllin (SIC). The present study aims to investigate the efficiency and safety of SXN on iron deficiency anemia. This phase IV, multicenter, open-label, randomized clinical trial was conducted in 31 hospitals in China from June 2001 to April 2002. Adults and children were randomly divided into low-dose (L-SXN), medium-dose (M-SXN), and high-dose (H-SXN) groups, respectively. The course of treatment was 1 month. Peripheral hemogram levels and iron status were examined before and after treatment. Adults in all three dose groups demonstrated a significant increase in hemoglobin (HGB) concentration. Children who received SXN treatment in medium and high doses also demonstrated increased HGB concentration. Reticulocyte counts increased at the end of treatment in the M-SXN and H-SXN adult groups and in the M-SXN child group. For both children and adults, SXN in the three dose groups was found to significantly elevate red blood cell level, mean corpuscular volume, mean corpuscular hemoglobin, and mean corpuscular hemoglobin concentration. The total effective rate in the SXN-treated group reached 84.8%. The incidence of adverse events was 4.07%. The most common side effects were nausea (2.83%), diarrhea (0.74%), and rash (0.25%). SXN was proved to be efficient and safe for adults and children with iron deficiency anemia.

An in vitro analysis of the rat C6 glioma cells to elucidate the linear alkylbenzene sulfonate induced oxidative stress and consequent G2/M phase cell cycle arrest and cellular apoptosis

Linear alkylbenzene Sulphonate (LAS) is the anionic surfactant component of globally consumed detergents. Exposure of sub-inhibitory fractions viz., 1/10th (T1), 1/5th (T2), and 1/2.5th (T3) of IC₅₀ for 48 h, of LAS (5 μM, 10 μM, and 20 μM, respectively) to viable C6 glioma cells of rat, besides imparting morphological alterations leads to gross cytotoxicity. Expression of the damaged DNA coupled with cleaved PARP (p < 0.05; p < 0.01 and p < 0.001) were recorded for T1, T2 and T3, respectively. Subsequently, the cell cycle at G2/M check point was significantly arrested (p < 0.05 for T1 and T2; p < 0.01 for T3). The flow cytometric analysis reveals the initiation of apoptosis in C6 cells as is evident by a significant increase (p < 0.01 for T1, p < 0.001 for T2, and T3) in the intake of annexin-V, the calcium dependent apoptotic phospholipid binding protein. Moreover, significantly increased reactive oxygen species (ROS) (p < 0.05; p < 0.01 and p < 0.001) after 6 h of exposure for all the three sets, registered a declining trend (P < 0.001) when T3 cells were co-treated with N-acetyl cysteine (NAC). Furthermore, the significant attenuation (p < 0.01) of expression of the cleaved PARP and a consequent decrease (p < 0.05) in the cell cycle arrest at G2/M phase after scavenging ROS induced oxidative stress by treating C6 cells with NAC clearly evinces that LAS induced apoptosis is mediated by intracellular ROS. Thus, these findings provide a tangible basis for further investigations including in vivo studies, to unravel the molecular mechanism involved in ROS mediated and LAS induced cytotoxic manifestations.

Chemopreventive potential of chlorophyllin: a review of the mechanisms of action and molecular targets

Chlorophyllin (CHL), a water soluble semisynthetic derivative of the ubiquitous plant pigment chlorophyll used as a food additive, is recognized to confer a wide range of health benefits. CHL has been shown to exhibit potent antigenotoxic, anti-oxidant, and anticancer effects. Numerous experimental and epidemiological studies have demonstrated that dietary supple-mentation of CHL lowers the risk of cancer. CHL inhibits cancer initiation and progression by targeting multiple molecules and pathways involved in the metabolism of carcinogens, cell cycle progression, apoptosis evasion, invasion, and angiogenesis. The modulatory effects of CHL on the hallmark capabilities of cancer appear to be mediated via abrogation of key oncogenic signal transduction pathways such as nuclear factor kappa B, Wnt/β-catenin, and phosphatidylinositol-3-kinase/Akt signaling. This review provides insights into the molecular mechanisms of the anticancer effects of dietary CHL.

A 13-week subchronic toxicity study of sodium iron chlorophyllin in F344 rats

Sodium iron chlorophyllin (SIC), a water-soluble chlorophyll derivative, has been used as a food additive for green coloration. In the present study, a subchronic toxicity study of SIC was performed in male and female F344 rats with oral administration in diet at concentrations of 0%, 0.2%, 1.0%, and 5.0% for 13 weeks. No mortalities, abnormal clinical signs, and hematological changes were observed in any of the groups during the experiment. Significant reduction of body weight gain was noted in 5.0% males. In serum biochemistry, serum transferrin levels were significantly increased in 5.0% males and females. Relative spleen weights of both sexes were markedly reduced with 5.0% SIC as compared to the controls, and absolute weights of spleen were also significantly decreased in males. On histopathological assessment, diffuse hypertrophy of acinar cells in the parotid gland was observed in all examined 5.0% males and females, but not in the other groups. Based on the histopathology of the parotid glands, the no-observed-adverse-effect level (NOAEL) of SIC in the present study was estimated to be 1.0% (609 mg/kg bw/day for males and 678 mg/kg bw/day for females).

Proteasome inhibitor MG-132 induces C6 glioma cell apoptosis via oxidative stress

AIM

Proteasome inhibitors have been found to suppress glioma cell proliferation and induce apoptosis, but the mechanisms are not fully elucidated. In this study we investigated the mechanisms underlying the apoptosis induced by the proteasome inhibitor MG-132 in glioma cells.

METHODS

C6 glioma cells were used. MTT assay was used to analyze cell proliferation. Proteasome activity was assayed using Succinyl-LLVY-AMC, and intracellular ROS level was evaluated with the redox-sensitive dye DCFH-DA. Apoptosis was detected using fluorescence and transmission electron microscopy as well as flow cytometry. The expression of apoptosis-related proteins was investigated using Western blot analysis.

RESULTS

MG-132 inhibited C6 glioma cell proliferation in a time- and dose-dependent manner (the IC(50) value at 24 h was 18.5 μmol/L). MG-132 (18.5 μmol/L) suppressed the proteasome activity by about 70% at 3 h. It induced apoptosis via down-regulation of antiapoptotic proteins Bcl-2 and XIAP, up-regulation of pro-apoptotic protein Bax and caspase-3, and production of cleaved C-terminal 85 kDa PARP). It also caused a more than 5-fold increase of reactive oxygen species. Tiron (1 mmol/L) effectively blocked oxidative stress induced by MG-132 (18.5 μmol/L), attenuated proliferation inhibition and apoptosis in C6 glioma cells, and reversed the expression pattern of apoptosis-related proteins.

CONCLUSION

MG-132 induced apoptosis of C6 glioma cells via the oxidative stress.