The general immunopharmacology of levamisole

Potentiation of interleukin-2 activity by levamisole and imidazole

Levamisole, a known antihelminthic drug, was able to affect IL-2 dependent proliferation of several T lymphocyte clones. Although levamisole did not replace IL-2 and had no effect at saturating IL-2 concentrations, it reduced by 2- to 4-fold the dose of IL-2 required to give 50% of the maximal DNA synthesis, the optimal concentration of levamisole being between 1 to 3 X 10(-4) M. This effect of levamisole was not due to an alteration of the kinetics of thymidine incorporation. Imidazole and other imidazole ring containing compounds, but not thiol-containing compounds, had similar effects to those of levamisole, suggesting a role of the imidazole ring in the potentiation of IL-2 activity.

Levamisole therapy in chronic type B hepatitis. Results of a double-blind randomized trial

A double-blind, randomized, controlled trial has been undertaken to evaluate treatment of chronic hepatitis type B with levamisole. Ten patients received levamisole (150 mg/day, 3 days/wk) and 10 received placebo until seroconversion to antibody to hepatitis B e antigen eventually occurred, or for a maximum of 18 mo. Final evaluation at 24 mo after starting treatment revealed that 60% of the patients in the levamisole group had become hepatitis B e antigen negative, 90% were hepatitis B virus-deoxyribonucleic acid negative in serum, and 8 of 9 (89%) patients had cleared hepatitis B core antigen from the liver. On the other hand, in the placebo group only 4 of the 10 subjects (40%) were hepatitis B e antigen and hepatitis B virus-deoxyribonucleic acid negative in serum and 3 of 8 (37.5%) of them became hepatitis B core antigen free in the liver. Moreover, in 8 patients of the treated group and in 4 of the control cases aminotransferase activities fell into the normal range. A liver biopsy specimen was obtained after treatment in 17 patients and 7 of 9 levamisole recipients showed marked improvement in hepatic histology, compared with 3 of 8 placebo recipients. These data show that patients treated with long-term levamisole therapy have a tendency toward normalization of aminotransferase activities and suppression of hepatitis B virus replication, suggesting that the drug may be of benefit in chronic hepatitis B e antigen-positive hepatitis.

Potentiation by levamisole, methisoprinol, and adenine or adenosine of the inhibitory activity of human interferon against encephalomyocarditis virus

The antiviral action of different human interferons against encephalomyocarditis virus in HeLa cell cultures was analyzed. Cell treatment with levamisole (200 micrograms/ml), methisoprinol (1 mg/ml), or adenine or adenosine (33 or 100 micrograms/ml, respectively) potentiated the anti-encephalomyocarditis virus activity of human interferon by 8- to 32-fold. A higher level of potentiation (256-fold) was achieved either by combined treatments with levamisole plus methisoprinol or by treatment with one of these compounds plus adenine or adenosine.

Effects of levamisole on primary cultures of adult rat hepatocytes

Levamisole represents one of several new compounds that exhibit immunomodulating activity. Pharmacological data have documented a relationship between liver drug metabolism of levamisole and its subsequent immunomodulating activity. To directly investigate this relationship in a controlled manner, primary cultures of adult rat hepatocytes were treated with levamisole, and ultrastructural and biochemical effects were analyzed. Ultrastructurally, levamisole did not disrupt the cellular architecture of the hepatocytes. Biochemically, levamisole stimulated alkaline phosphatase activity and elevated microsomal cytochrome P-450 content after a 48-hr incubation. High pressure liquid chromatographic analysis of levamisole metabolites produced by cultured hepatocytes suggested the formation of a hepatocyte-specific metabolite(s) that may be associated with its immunological mode of action.

Effect of levamisole on bone resorption in cultured mouse calvaria

The effects of levamisole (LT), dexamisole (DT), levo-p-bromotetramisole (LBT) and dextro-p-bromotetramisole (DBT) on bone were examined in an organ culture system using calvarial bones from newborn mice. LBT and DBT at concentrations 30 microM and greater and LT and DT at concentrations 100 microM and greater caused a dose-dependent, reversible inhibitory effect on mineral mobilization and matrix degradation. LBT, DBT (100 and 300 microM) as well as LT and DT (greater than or equal to 100 microM) reduced the spontaneous release of beta-glucuronidase without having any marked effect on the release of lactate dehydrogenase (LDH). LT and DT did not influence protein synthesis but LBT and LBT were inhibitory in concentrations at and above 100 microM. Mitotic activity, as assessed by incorporation of [3H]thymidine, was inhibited by LBT and DBT (0.1, 1 mM). LT and LBT caused a stereospecific inhibition of GPase, PPiase and ATPase. It is concluded that tetramisoles are potent, non-stereospecific inhibitors of bone resorption in vitro.

Controlled therapeutic trial of levamisole and sulphasalazine in acute ulcerative colitis

Forty five patients with acute ulcerative colitis were randomly allocated to receive (a) sulphasalazine, (b) levamisole, or (c) a combination of sulphasalazine and levamisole. Each group contained 15 patients. The ulcerative colitis activity index (UCAI), the remission and relapse rates were compared at three monthly intervals for one year. The UCAI fell in each group. Detailed analysis of all clinical and biochemical parameters used for estimation of UCAI showed that the only difference was in patients receiving combined therapy who continued to have a raised ESR and platelet count. Fewer patients, however, went into remission on levamisole therapy (46.6%) compared with the other two groups (66.6%). The cumulative relapse rate was 20% for those receiving levamisole compared with 6.6% in the other groups. Side effects were observed in 20% of patients receiving levamisole, 26% receiving sulphasalazine, and 40% in those having combined therapy. The results indicate that levamisole is unlikely to have a major role in the management of patients with ulcerative colitis.

The effect of levamisole on gastric ulcers induced in the rat by anti-inflammatory and necrotizing agents

Levamisole, in doses similar to those required to observe immunostimulation in animals, antagonized dose-dependently, in rats, gastric ulcers produced by necrotizing agents (HCl and ethanol) and NSAIDs (indomethacin and piroxicam) without affecting the anti-inflammatory properties of these latter drugs.

Inhibiting effect of levamisole on superoxide production from rat mast cells

The aim of the present study was to test whether levamisole acts as a superoxide scavenger. The drug was incubated at four different concentrations (range 1, 5, 10, 20 micrograms/ml) with purified rat mast cells which were then induced to generate superoxide ions, by challenge with compound 48/80 (1 microgram/ml). Ten minutes preincubation with the drug completely abolished superoxide ions production. Addition of levamisole to the cell suspension simultaneously with the releaser caused full inhibition of O2(-) generation at the lowest dose, while higher doses failed to suppress 48/80 induced O2(-) generation. In a cell-free superoxide-generating system, like xanthine-xanthine oxidase, levamisole did not act as a superoxide scavenger at any of the doses tested.

Evaluation of levamisole as an adjuvant to chemotherapy for treatment of ANLL

Levamisole is a synthetic, orally administered, relatively nontoxic compound with immunorestorative ability. Levamisole was tested in this study of 60 adults with acute nonlymphocytic leukemia (ANLL) to determine if augmentation of response rate or duration, or survival over that obtained with a standard chemotherapy regimen alone would result. The chemotherapy regimens for all patients consisted of daunorubicin and cytosine arabinoside for induction and consolidation, methotrexate with citrovorum factor reversal in a cytoreductive phase, and late intensification with thioguanine and cytosine arabinoside. The first 30 patients received chemotherapy alone; a second group of 30 patients were scheduled to receive levamisole in addition to chemotherapy. Levamisole, 45 mg/m2, was administered orally twice daily for three consecutive days each week beginning one week after the initiation of induction chemotherapy and continuing until relapse. No significant difference emerged between the two groups with respect to remission rate, time to achieve remission, postrelapse survival, or total survival. However, a trend towards improved postcomplete remission survival (P = 0.072) was noted in the levamisole group, and patients who received levamisole had a significantly greater reinduction rate after relapse (P = 0.019).

Sodium diethyldithiocarbamate (imuthiol) and cancer

Sodium diethyldithiocarbamate (imuthiol), a nonantigenic, nontoxic and noncarcinogenic compound, evinces distinctive properties in recruitment and activation of T cells, and no direct influences on B cells or macrophages. The biological attributes of imuthiol (destruction of neoplastic cells, bacteria, fungi and parasites; a detoxifying influence against carcinogens or agents toxic for the liver) could strengthen its activity as a biological response modifier. Preliminary clinic testings show that imuthiol restores T cell activities and regulates the ratio among T cell subsets in cancer patients, without untoward side effects.