Immunotoxicity activity of natural furocoumarins from milky sap of Ficus carica L. against Aedes aegypti L.

Ficus carica L., its fruits are delicious and can be eaten by human. Its leaves are commonly used to cure hemorrhoid and clear away heart ache. The milky sap of F. carica have a significant toxic effect against early fourth-stage larvae of Aedes aegypti L with an lethal concentration (LC(50)) value of 10.2 µg/ml and an LC(90) value of 42.3 µg/ml. Two natural furocoumarins, 5-methoxypsoralen and 8-methoxypsoralen were isolated from the milky sap of F. carica. The LC(50) value of 5-methoxypsoralen and 8-methoxypsoralen were 9.4 and 56.3 µg/ml, respectively. The above indicates that major compounds may play a more important role in the toxicity of the milky sap of F. carica.

Nucleic acid-8-methoxypsoralen crosslinks bind monoclonal anti-Z-DNA antibody.

Native calf thymus DNA and poly(dA-dT).poly(dA-dT) were photo-adducted with 8-methoxypsoralen and characterized by thermal denaturation (Tm) and hydroxyapatite column chromatography. The data demonstrated the formation of interstrand photo-crosslinks. It has been shown by competition ELISA and band shift assays that crosslinked species of DNA-8-MOP and poly(dA-dT)-8-MOP photoadducts recognize previously defined monoclonal anti-Z-DNA antibody (Z22). The results indicate the possible presence of Z- or Z-like epitopes on nucleic acid-8-MOP crosslinks as Z22 antibody does not recognize other nucleic acid conformations. These studies also point out that conformational changes in DNA arising from the photo-addition could induce antibodies to DNA or could cause autoimmune disease.

Antigenicity of poly(dA-dT) . poly(dA-dT) photocrosslinked with 8-methoxypsoralen.

We report the formation of photocrosslink (diad-duct) between duplex poly(dA-dT) and 8-methoxypsoralen inferred on the basis of UV and fluorescence characteristics, Tm, nuclease S1 digestibility, and hydroxyapatite column chromatography. The photocrosslink was highly immunogenic inducing high titer antibodies in goat. The affinity constant of antigen-antibody interaction quantitated by precipitin titration was found to be 2.71 x 10(9) M-1, calculated by Langmuir isotherm plot. These antibodies were highly specific showing recognition of almost exclusively of nucleic acid-furocoumarin photoadducts and could be used as a probe to detect and quantitate DNA modified with furocoumarins in health and disease. Antibodies against poly(dA-dT)-furocoumarin photocrosslink might be a better probe because of repeated A-T sequences on the immunogen.

Antigen binding specificity of antibodies against 8-methoxypsoralen photoadducted DNA.

The photoadduct between native DNA and 8-methoxypsoralen was characterized on the basis of UV and fluorescence characteristics, Tm, nuclease S 1 digestibility and hydroxyapatite column chromatography. Approximately 80% of photoadduct has at least one diadduct (crosslink) per DNA molecule and only thymine was modified to the extent of 69%. The photo-crosslink was highly immunogenic inducing antibodies having apparent association constant of 1.3 x 10(-9)M. The immune IgG was highly specific towards nucleic acid-furocoumarin crosslink site without appreciable recognition of B-conformation or nucleic acid bases. The antibodies could be used as probe to detect and quantitate nucleic acid modified with furocoumarins in health and disease.

Use of extracorporeal photochemotherapy in heart transplant recipients during acute rejection: a case study.

Despite the growing availability of improved immunosuppressive agents, acute and chronic rejection episodes remain a major complication in heart transplant recipients. The rejection of allografts is a normal part of the body's response to foreign antigens. The key to controlling this response is to administer a regimen of multiple immunosuppressive drugs. Evidence indicates that by adding extracorporeal photochemotherapy to a standard immunomodulatory regimen, the rejection process can be reversed without significantly increasing patient risk. In this case study we examine extracorporeal photochemotherapy and the care of patients receiving this therapy.

Immune serum against anti-DNA-8-methoxypsoralen photoadduct.

Specific immune serum against photo-damaged DNA with the photoadducts of 8-methoxypsoralen (8-MOP) was obtained. The antigenic determinant is a polynucleotide chain with a mono-photoadduct: a coumarin moiety of psoralen linked through a cyclobutane ring to the 5,6-bond of thymine. The specific rabbit antiserum was used in the immunofluorescence method, for the detection of photodamaged DNA in the kinetoplasts and nuclei of unicellular organisms Crithidia luciliae, in the nuclei of snap-frozen tissue of mammals, and in human blood lymphocytes. Detection by the immunofluorescence method was limited by psoralen availability in situ; the psoralen concentration should be in the range 0.05-0.2 microgram/cm2 on specimens submitted to a topical application or about 1 microgram/ml in cell suspension. The long-wave ultraviolet light (UV-A) exposure dose applied to the nuclei should exceed 1 J/cm2.