Effect of vitamin A on methotrexate cytotoxicity in L1210 murine leukemia cells in culture

Effect of vitamin A as a neoadjuvant agent in chemotherapy and photodynamic therapy of Rhabdomyosarcoma cells

Combinational therapy is among the most used treatment modality's to increase cancer treatment efficacy. It may also reduce side effects, treatment time, and development of drug resistance. The effects of different analogues of vitamin A (VA) as neoadjuvant agent were observed in this study with chemotherapeutic drugs (doxorubicin and methotrexate) and photodynamic therapy (PDT) using 5-ALA and Photogem as photosensitizers in RD cells. The uptake time of photosensitizer was optimized by means of spectrophotometric measurements. Diode laser (λ = 635 nm ± 1 nm) was used as an illumination source for PDT. Responses of administered drugs were assessed by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. VA and its analogues exert prophylactic and therapeutic effects. Protective or antagonistic effects (CI > 1) were observed in each of the case. These results propose that the use of VA as a neoadjuvant agent in combinational therapeutic modalities may reduce the efficacy of cancer treatment protocols as well as the existing side effects. Thus, VA is not the successful drug for combinational therapies and under treatment cancer patients should try to avoid its use with oxidative stress induction therapies (e.g. PDT, Radiotherapy, chemotherapy).

Protective Effect of Vitamin A on ARA-C Induced Intestinal Damage in Mice

Background

Cytarabine (ARA-C) has been used for many years in the treatment of patients with leukemia and lymphoma. Gastrointestinal ulceration and mucositis are two of the well-known side effects of ARA-C. We set out to investigate whether vitamin A (VA) can help prevent ARA-C-induced mucosal lesions in mice.

Materials and methods

Mice were divided into 5 groups. Group I (control group) received only saline; group II received ARA-C plus saline; group III received ARA-C plus VA; group IV received ARA-C plus a lipid solution, and group V received VA alone. VA (5000 IU/kg) was administered orally to the mice once daily for 7 days. ARA-C (3.6 mg) was administered intraperitoneally for 5 days to groups II, III and IV, starting on the third day of VA treatment. Intestinal segments from the proximal end of the jejunum of treated mice were isolated.

Results

There was improved mucosal integrity, less necrosis and increased villus length with advanced mucosal proliferation in crypts in the VA plus ARA-C group when compared to the ARA-C groups without VA.

Conclusion

We conclude that VA has a protective effect against ARA-C-induced mucosal damage in mice.

Systematic review of natural agents for the management of oral mucositis in cancer patients

PURPOSE

The aim of this study was to review the available literature and define clinical practice guidelines for the use of natural agents for the prevention and treatment of oral mucositis.

METHODS

A systematic review was conducted by the Mucositis Study Group of the Multinational Association of Supportive Care in Cancer/International Society for Oral Oncology. The body of evidence for each intervention, in each cancer treatment setting, was assigned an evidence level. Based on the evidence level, one of the following three guideline determinations was possible: recommendation, suggestion, and no guideline possible.

RESULTS

A total of 49 papers across 15 interventions were examined. A new suggestion was developed in favor of systemic zinc supplements administered orally in the prevention of oral mucositis in oral cancer patients receiving radiation therapy or chemoradiation (Level III evidence). A recommendation was made against the use of intravenous glutamine for the prevention of oral mucositis in patients receiving high-dose chemotherapy prior to hematopoietic stem cell transplant (Level II evidence). No guideline was possible for any other agent, due to inadequate and/or conflicting evidence.

CONCLUSIONS

Of the various natural agents reviewed here, the available evidence supported a guideline only for two agents: a suggestion in favor of zinc and a recommendation against glutamine, in the treatment settings listed above. Well-designed studies of other natural agents are warranted.

Does vitamin A prevent high-dose-methotrexate-induced D-xylose malabsorption in children with cancer?

PURPOSE

Our aim was to explore whether vitamin A has protective effect on high-dose-methotrexate (HDMTX)-induced intestinal D-xylose malabsorption in children with leukemia and lymphoma.

PATIENTS AND METHODS

We performed a prospective randomized un-blinded study of vitamin A in 35 children with leukemia and lymphoma who were planned to receive HDMTX 3 g/m(2) and 5 g/m(2), respectively. Twenty-two patients (group 1) received a single dose of 180,000 IU a day before HDMTX was given, and 13 (group 2) received only HDMTX. The vitamin A group received the vitamin only once. Oral D-xylose absorption tests before and 7 days after HDMTX were carried out to evaluate intestinal absorption. Retinol-binding protein (RBP) levels prior to therapy were also measured for vitamin A status.

RESULTS

Although we observed no difference of HDMTX-induced toxicity, including hematological, dermatological, systemic, and other toxicities, between groups, the D-xylose absorption test was significantly better in-group 1 ( p=0.030). Absorption was decreased in five of 22 patients (23%) who received vitamin A comparing to eight of 13 (62%) who received only HDMTX ( p=0.033). RBP levels were lower than normal in 13 of 22 patients in-group 1 and nine of 13 in group 2. In patients whose RBP levels were lower than normal, HDMTX-induced toxicity was lower in the group 1 than group 2 but not statistically significant. No sign of vitamin A toxicity was observed throughout the study.

CONCLUSION

The administration of vitamin A before HDMTX may protect against drug-induced D-xylose malabsorption in children with cancer. Further studies are apparently needed to clarify the full benefits of vitamin A in preventing HDMTX-induced mucosal damage.

Docosahexaenoic acid exhibits a potent protection of small intestine from methotrexate-induced damage in mice

Oral administration of methotrexate (MTX) to mice causes the damage of small intestine. The permeability of poorly absorbable compound fluorescein isothiocyanate (FITC)-labeled dextran (average molecular weight, 4,400) through the small intestine was studied in vitro using everted segments of the small intestine. The permeability of FITC-dextran increased remarkably in the MTX-treated mice and oral administration of docosahexaenoic acid ethyl ester (DHA) protected the small intestine from the increase in the small intestinal permeability induced by the MTX treatment. The MTX treatment decreased retinol concentration in plasma of mice and the coadministration of DHA maintained its concentration to the level of control mice. The present study showed that DHA protected the small intestine of mice from the MTX-induced damage.