Editorial

Insights into the management of diabetic neuropath

Phytochemical constituents of Cassia fistula

Since the advent of modern drug treatments, traditional medicine has greatly receded in occidental societies. Moreover, only a limited number of medicinal plants have received detailed scientific scrutiny thereby prompting the World Health Organisation to recommend that this area be comprehensively investigated. Cassia fistula Linn is used extensively in various parts of the world against a wide range of ailments, the synergistic action of its metabolite production being most probably responsible for theplant’s beneficial effects. This paper reviews the primary and secondary metabolite composition of vegetative and reproductive plant parts and cell cultures thereby derived, with emphasis on potent phenolic antioxidants such as anthraquinones, flavonoids and flavan-3-ol derivatives. This paper also appraises the antioxidant and free radical propensities of plant parts and cell culture extracts. The data so far generated clearly sets the basis for a clearer understanding of the phytochemistry of the plant and derived cultures and opens the possibility of the potential utilization of the phenolic rich extracts from medicinal plants in food system or as prophylactics in nutritional/food supplement programs. Thus traditional medicinal plant- derived antioxidants may protect against a number of diseases and reduceoxidation processes in food systems. In order to establish this, it is imperative to measure the markers of baseline oxidative stress particularly in human health and disease and examine how they are affectedby supplementation with pure compounds or complex plant extracts from the traditional medicinal plants

Alterations in the antioxidant status of patients suffering from diabetes mellitus and associated cardiovascular complications

In view of the high prevalence of type 2 diabetes mellitus, this study aimed at determining the total plasma antioxidant capacity of type 2 diabetic patients with and without macrovascular complications. The erythrocyte catalase level was also evaluated because of the implication of catalase as a risk factor in diabetes. 90 age-­‐, gender-­‐ and body mass index-­‐matched subjects were used for this study and divided into healthy subjects (Group I, n=30), diabetic patients (Group II, n=30) and diabetic patients with cardiovascular complications (Group III, n=30). Blood samples collected from 90 eligible subjects were analyzed for glucose, HbA1c, urea, creatinine, total cholesterol, triglyceride, HDL and  LDL cholesterol levels. Blood antioxidant activity and erythrocyte catalase levels were assessed. The mean antioxidant status values of Groups II and III were found to be significantly lower than that of Group I (p < 0.05). A significant decrease was also observed in the mean catalase level of Groups II and III as compared to Group I (p < 0.05) while a significant increase in fasting blood glucose level, glycated hemoglobin, triglycerides and urea was observed in Groups II and III compared to Group I. These data suggest that the in vivo antioxidant defense was highly compromised in patients with diabetes and associated cardiovascular complications although they were on medication, thereby suggesting the potential contributory beneficial effects of exogenous antioxidants. Furthermore, a reduction in catalase level may suggest the role of increasing hydrogen peroxide concentration in the disease progression.KEY WORDS: Antioxidant; Erythrocyte catalase; Cardiovascular complications; Type 2 diabetes mellitu

Terminalia bentzoë, a Mascarene Endemic Plant, Inhibits Human Hepatocellular Carcinoma Cells Growth In Vitro via G0/G1 Phase Cell Cycle Arrest

Tropical forests constitute a prolific sanctuary of unique floral diversity and potential medicinal sources, however, many of them remain unexplored. The scarcity of rigorous scientific data on the surviving Mascarene endemic taxa renders bioprospecting of this untapped resource of utmost importance. Thus, in view of valorizing the native resource, this study has as its objective to investigate the bioactivities of endemic leaf extracts. Herein, seven Mascarene endemic plants leaves were extracted and evaluated for their in vitro antioxidant properties and antiproliferative effects on a panel of cancer cell lines, using methyl thiazolyl diphenyl-tetrazolium bromide (MTT) and clonogenic cell survival assays. Flow cytometry and comet assay were used to investigate the cell cycle and DNA damaging effects, respectively. Bioassay guided-fractionation coupled with liquid chromatography mass spectrometry (MS), gas chromatography-MS, and nuclear magnetic resonance spectroscopic analysis were used to identify the bioactive compounds. Among the seven plants tested, Terminaliabentzoë was comparatively the most potent antioxidant extract, with significantly (p < 0.05) higher cytotoxic activities. T. bentzoë extract further selectively suppressed the growth of human hepatocellular carcinoma cells and significantly halted the cell cycle progression in the G0/G1 phase, decreased the cells’ replicative potential and induced significant DNA damage. In total, 10 phenolic compounds, including punicalagin and ellagic acid, were identified and likely contributed to the extract’s potent antioxidant and cytotoxic activities. These results established a promising basis for further in-depth investigations into the potential use of T. bentzoë as a supportive therapy in cancer management

Alpha-Tomatine Induces Apoptosis and Inhibits Nuclear Factor-Kappa B Activation on Human Prostatic Adenocarcinoma PC-3 Cells

BACKGROUND: Alpha-tomatine (α-tomatine) is the major saponin in tomato (Lycopersicon esculentum). This study investigates the chemopreventive potential of α-tomatine on androgen-independent human prostatic adenocarcinoma PC-3 cells. METHODOLOGY/PRINCIPAL FINDINGS: Treatment of highly aggressive human prostate cancer PC-3 cells with α-tomatine resulted in a concentration-dependent inhibition of cell growth with a half-maximal efficient concentration (EC(50)) value of 1.67±0.3 µM. It is also less cytotoxic to normal human liver WRL-68 cells and normal human prostate RWPE-1 cells. Assessment of real-time growth kinetics by cell impedance-based Real-Time Cell Analyzer (RTCA) showed that α-tomatine exhibited its cytotoxic effects against PC-3 cells as early as an hour after treatment. The inhibitory effect of α-tomatine on PC-3 cancer cell growth was mainly due to induction of apoptosis as evidenced by positive Annexin V staining and decreased in mitochondrial membrane potential but increased in nuclear condensation, polarization of F-actin, cell membrane permeability and cytochrome c expressions. Results also showed that α-tomatine induced activation of caspase-3, -8 and -9, suggesting that both intrinsic and extrinsic apoptosis pathways are involved. Furthermore, nuclear factor-kappa B (NF-κB) nuclear translocation was inhibited, which in turn resulted in significant decreased in NF-κB/p50 and NF-κB/p65 in the nuclear fraction of the treated cells compared to the control untreated cells. These results provide further insights into the molecular mechanism of the anti-proliferative actions of α-tomatine. CONCLUSION/SIGNIFICANCE: α-tomatine induces apoptosis and inhibits NF-κB activation on prostate cancer cells. These results suggest that α-tomatine may be beneficial for protection against prostate cancer development and progression

Methyl gallate – Rich fraction of Syzygium coriaceum leaf extract induced cancer cell cytotoxicity via oxidative stress

Whilst the pharmacological potential of Syzygium species is well reported in the literature, data on the Mauritian endemic Syzygium species is limited. Thus, the in vitro antioxidant and anti-proliferative properties of three endangered Syzygium species, endemic to Mauritius, were investigated. Leaves samples of the three species were exhaustively extracted with a hydro-methanolic solvent and the antioxidant activities of the derived extracts were evaluated using a battery of six in vitro models. The antiproliferative effect of S. coriaceum was evaluated against lung carcinoma (A549), liposarcoma (SW872) and hepatocellular carcinoma (HepG2) cell lines. Further, the effect of S. coriaceum on intracellular reactive oxygen species (ROS) generation, intrinsic antioxidant enzymes activities and DNA damage in HepG2 cells were studied. MTT guided-fractionation coupled with mass spectrometry, column chromatography and NMR spectroscopy analysis was employed to characterise the bioactive entities in S.coriaceum. S.coriaceum showed the most potent antioxidant activities in all six assay models and also induced a dose-dependent decrease in the cell viability. S. coriaceum treatment in HepG2 cells resulted in a dose-dependent increase in the level of ROS with a 4.4 fold increment at 100 µg/mL (p ≤ 0.0001). The surge in ROS level was corroborated by a parallel dose-dependent decrease in antioxidant enzyme activities. A significant 80.5% drop in glutathione peroxidase activity was observed at 40 µg/mL (p ≤ 0.0001). Spectroscopic analysis revealed gallic acid (1) and methyl gallate (2) as major bioactive components in S. coriaceum leaf extract along with quercitrin (3), quercetin 3-O-β-d-xylopyranosyl-(1→2)-α-l-rhamnopyranoside (4), tellimagrandin I (5), and 3,4,6-tri-O-galloyl-d-glucose (6). Analysis of HepG2 cells treated with commercially available gallic acid and methyl gallate showed a similar trend in activities as S. coriaceum leaf extract. Collectively, these results demonstrated that S. coriaceum and its major bioactive phenolics: gallic acid and methyl gallate, may effectively induce cell death in HepG2 cells via upregulation of ROS