APOPTOTIC AND CYTOTOXIC ACTIVITIES OF STROBILANTHES VIRENDRAKUMARANA VENU AND P. DANIEL IN ALLIUM CEPA AND HUMAN RED BLOOD CELLS

Objective: The present study was aimed to explore the cytotoxicity of the aqueous shoot extract of Strobilanthes virendrakumarana Venu and P. Daniel in Allium cepa and human erythrocytes. It also focuses on the efficacy of the extract to induce apoptosis in the root primordia of A. cepa. Methods: The aqueous extract of the shade-dried shoot was prepared. The cytotoxicity was evaluated both in A. cepa and human red blood cells (RBC) using standard protocols. The apoptotic and metabolic/mitochondrial activity evaluated with the help of Evans blue staining and 2,3,5-Triphenyl tetrazolium chloride (TTC) staining methods, respectively. Results: Cytotoxic assay unveiled different types of aberrations which were dose-dependent. RBC assay revealed the capacity of phytocompounds in the extract to interact with the osmotic balance of RBC membrane and thereby modify it. Apoptosis induction was detected in A. cepa roots treated with various concentrations of the plant extract. The gradation in stain uptake indicates the apoptotic activity of the plant extract. The amount of generated formazon in TTC staining is an indirect evaluation of the metabolic/mitochondrial activity of the cell. Conclusions: These results may be attributed to the presence of bioactive compounds in the plant extract. The staining techniques reveal the qualitative and quantitative evaluation of the potentiality of the extract. Thus, the present study opens a new avenue for further exploration of the plant for its bioactivities

Pomegranate-mediated chemoprevention of experimental hepatocarcinogenesis involves Nrf2-regulated antioxidant mechanisms

Hepatocellular carcinoma (HCC), one of the most prevalent and lethal cancers, has shown an alarming rise in the USA. Without effective therapy for HCC, novel chemopreventive strategies may effectively circumvent the current morbidity and mortality. Oxidative stress predisposes to hepatocarcinogenesis and is the major driving force of HCC. Pomegranate, an ancient fruit, is gaining tremendous attention due to its powerful antioxidant properties. Here, we examined mechanism-based chemopreventive potential of a pomegranate emulsion (PE) against dietary carcinogen diethylnitrosamine (DENA)-induced rat hepatocarcinogenesis that mimics human HCC. PE treatment (1 or 10 g/kg), started 4 weeks prior to the DENA challenge and continued for 18 weeks thereafter, showed striking chemopreventive activity demonstrated by reduced incidence, number, multiplicity, size and volume of hepatic nodules, precursors of HCC. Both doses of PE significantly attenuated the number and area of γ-glutamyl transpeptidase-positive hepatic foci compared with the DENA control. PE also attenuated DENA-induced hepatic lipid peroxidation and protein oxidation. Mechanistic studies revealed that PE elevated gene expression of an array of hepatic antioxidant and carcinogen detoxifying enzymes in DENA-exposed animals. PE elevated protein and messenger RNA expression of the hepatic nuclear factor E2-related factor 2 (Nrf2). Our results provide substantial evidence, for the first time, that pomegranate constituents afford chemoprevention of hepatocarcinogenesis possibly through potent antioxidant activity achieved by upregulation of several housekeeping genes under the control of Nrf2 without toxicity. The outcome of this study strongly supports the development of pomegranate-derived products in the prevention and treatment of human HCC, which remains a devastating disease