Chemopreventive aspects, investigational anticancer applications and current perspectives on allyl isothiocyanate (AITC): a review

Allyl isothiocyanates (AITC) have gained recognition in recent years as effective chemotherapeutic and epigenetic modulators. The chemopreventive properties and toxicological perspectives of AITCs from the last few decades were taken into account by a number of investigations. Their active therapeutic relevance was hindered by a number of factors, including instability under typical physiological conditions and low bioavailability due to low aqueous solubility. In this review, we highlighted the chemopreventive attributes of AITC in relation to its molecular mechanisms and metabolic fate for cancer. Moreover, we emphasized on investigational anticancer activities and various strategies for delivery of AITC in different types of cancer. Considering cellular interactions, we shed light on the toxicological properties of AITCs to address further issues regarding their assessment in therapeutic development. This review identifies knowledge gaps with various contemporary approaches involving most recent studies and may pave the way for a better understanding for the development of novel AITC therapeutics.

A combination of Tropaeolum majus herb and Armoracia rusticana root for the treatment of acute bronchitis

BACKGROUND

Tropaeolum majus herb (nasturtium) and Armoracia rusticana root (horseradish) produce three different isothiocyanates as secondary metabolites, which exert antibacterial, anti-inflammatory, and immune-modulatory functions in humans.

PURPOSE

Combined in the medicinal product ANGOCIN® Anti-Infekt N, the two natural components demonstrated promising effects against acute bronchitis.

STUDY DESIGN

A randomized, two-armed, placebo-controlled, double-blind, phase IV study revealed the healing fostering effect of the two herbal plant components METHODS: This study included 384 patients, with 195 in the treatment and 189 in the placebo group. The 'bronchitis severity score' (BSS) was utilized as primary endpoint. This score sums the ratings for five significant bronchitis symptoms, which are established at the patient's visits to the clinic.

RESULTS

Compared to placebo intake, the group of patients treated with the phytomedicine showed statistically significant accelerated healing of bronchitis symptoms after three days of treatment, with reductions in coughing, mucous production, and chest pain. This beneficial effect persisted for the entire duration of treatment until day ten.

CONCLUSION

In conclusion, a combination of Tropaeolum majus herb and Armoracia rusticana root promotes an elevated improvement of bronchitis symptomatology.

Differentiated Effects of Allyl Isothiocyanate in Diabetic Rats: From Toxic to Beneficial Action

Allyl isothiocyanate (AITC), a constituent of Brassica family plants, has been reported to possess a high bioactivity in animal and human cells, showing ambiguous properties from adverse to beneficial ones. It was reported its genotoxic, carcinogenic, goitrogenic effects. On the other side, AITC has shown anti-cancer, cardioprotective, neuroprotective, and lately anti-obesity abilities. So far, its anti-diabetic effects are poorly explored. We tried to assess AITC action on carbohydrate, lipid and hormonal disorders in high fat diet-fed/streptozotocin diabetic rats. In this report, diabetic rats were treated intragastrically at doses 2.5, 5 and 25 mg/kg b.w./day of AITC for 2 weeks. Irrespectively of doses, AITC considerably lowered thyroid hormones (fT4, fT3), increased liver TG content, and also caused robust LDL-cholesterol and direct bilirubin concentration enhancement. Moreover, AITC at the highest dose caused pancreatic amylase and lipase drops and thyroid gland hypertrophy. AITC at 2.5 and 5 mg significantly reduced blood glucose levels along with robust beta-hydroxybutyric acid drop. Additionally, AITC at 5 mg improved insulin sensitivity (HOMA-IR index) in spite of reduced blood insulin. To conclude, despite amelioration of diabetic hyperglycemia by AITC, the adverse lipids and hormonal effects may exclude its use as a health-promoting compound in terms of anti-diabetic properties.

Mechanisms of the Anticancer Effects of Isothiocyanates

Cancer results from aberrant signaling pathways that result in uncontrolled cellular proliferation. The epidemiological studies have shown a strong inverse correlation between dietary consumption of cruciferous vegetables and incidences of cancer. Isothiocyanates (ITCs) are present in cruciferous vegetables like broccoli, cabbage, watercress, etc. and are identified as the major active constituents. Several mechanistic studies have demonstrated chemopreventive and chemotherapeutic activity of ITCs against various tumor types. ITCs exert anticancer activity by suppressing various critical hallmarks of cancer like cellular proliferation, angiogenesis, apoptosis, metastasis, etc., in vitro as well as in preclinical animal model. ITCs also generate reactive oxygen species to induce apoptosis in cancer cells. Due to promising preclinical results, few ITCs have also advanced to clinical trials. This chapter provides a candid review on the chemopreventive and chemotherapeutic activity of various major ITCs.

Molecular targets of isothiocyanates in cancer: recent advances

Cancer is a multistep process resulting in uncontrolled cell division. It results from aberrant signaling pathways that lead to uninhibited cell division and growth. Various recent epidemiological studies have indicated that consumption of cruciferous vegetables, such as garden cress, broccoli, etc., reduces the risk of cancer. Isothiocyanates (ITCs) have been identified as major active constituents of cruciferous vegetables. ITCs occur in plants as glucosinolate and can readily be derived by hydrolysis. Numerous mechanistic studies have demonstrated the anticancer effects of ITCs in various cancer types. ITCs suppress tumor growth by generating reactive oxygen species or by inducing cycle arrest leading to apoptosis. Based on the exciting outcomes of preclinical studies, few ITCs have advanced to the clinical phase. Available data from preclinical as well as available clinical studies suggest ITCs to be one of the promising anticancer agents available from natural sources. This is an up-to-date exhaustive review on the preventive and therapeutic effects of ITCs in cancer.

Single administration effects of ethanol on the distribution of white blood cells in rats

Acute single administration effects of ethanol on the distribution of total white blood cells (WBCs), neutrophil, basophil, eosinophil, monocyte and lymphocytes were studied in rats. Acute single administration effects of ethanol on the number of red blood cells (RBCs), hemoglobin concentration and hematocrit were also examined. Male 8-week-old Sprague Dawley rats were randomly divided into the ethanol-administered (ETA) group and the control (CON) group. Two parts of an experiment, 1) 1st experiment : (ethanol dose : 1.0 g/kg body weight), and 2) 2nd experiment : (ethanol dose : 2.0 g/kg body weight) were carried out in rats. The rats were starved to 19:00, and deprived of diet for 12 hr and water for 1 hr before the single administration of ethanol. 1.0 or 2.0 g/kg body weight of ethanol (in 20% (w/w) ethanol) was orally administered to ETA group rats via a stainless stomach tube. In the CON group rats, 0.9% NaCl solution was orally given with the solution volume being equal, in the same manner. Single administration of 1.0 or 2.0 g/kg body weight of ethanol did not change the number of RBCs, hemoglobin concentration and hematocrit. Single administration of 1.0 g/kg body weight of ethanol did not also change the number of WBCs. However, administration of 2.0 g/kg body weight of ethanol increased significantly the number of neutrophil, basophil, monocyte and total WBCs without changing the number of eosinophil and lymphocytes. These results suggest that single administration of 2.0 g/kg body weight of ethanol to rats increased markedly the number of the natural immunity cells without changing the number of acquired cells.

Capsaicinoids-induced changes of plasma glucose, free fatty acid and glycerol concentrations in rats

Red peppers are used as a spice for enhancing the palatability of foods. Two major capsaicinoids, dihydrocapsaicin (DHC) and capsaicin (CAP) are responsible for up to 90% of the total pungency of pepper fruits. These capsaicinoids are known to enhance energy metabolism and thermogenesis. However, there is a little information on the effects of capsaicinoids on the lipolysis and carbohydrate metabolism. We studied the effects of DHC and CAP on plasma glucose, free fatty acid (FFA) and glycerol concentrations in rats. Male six-week-old Sprague Dawley rats were divided into the DHC, CAP and control groups. Each capsaicinoid (dose = 3 mg/kg BW/day) was subcutaneously administered to rats for 10 days. DHC increased markedly plasma glucose, FFA and glycerol concentrations on day 1-10 by 14-35%, 61-103% and 108-174%, respectively, as compared with those of the control group. CAP increased relatively plasma glucose concentrations on day 1-3 by 15-17%, as compared with the control group. However, there were no significant differences in plasma glucose concentrations on day 7-10 among three groups. On the contrary, CAP did not change plasma FFA and glycerol concentrations on day 1-3. However, CAP increased markedly plasma FFA and glycerol concentrations on day 7-10 by 54-89% and 92-98%, respectively, as compared with the control group. DHC and CAP did not change the weights of white (perirenal and periepididymal) and brown (interscapular) adipose tissues. In conclusion, the effects of capsaicinoids on plasma glucose, FFA and glycerol concentrations were relatively higher in the DHC than in the CAP, and capsaicinoids did not change the weight of white and brown adipose tissues.