Oxidative Stress and DNA Damage Effect of Dioscorea hispida Dennst. on Placental Tissues of Rats.

Dioscorea hispida Dennst. locally known as "ubi gadung" has been used as a traditional remedy and source of carbohydrate among Malaysians. To assess the effect of Dioscorea hispida aqueous extract (DHAE) on the production of reactive oxygen species (ROS) and their effects on DNA damage in Sprague Dawley rat's placental tissues, pregnant rats were randomly divided into four groups. The animals were orally treated with distilled water (negative control) and three different concentrations of DHAE (250, 500 and 1000 mg/kg body weight (BW)) from gestation day 6 until 20. The oxidative stress in placental tissues was evaluated at day 21 by measuring the level of ROS, superoxide dismutase (SOD) and lipid peroxidation biomarker, malondialdehyde (MDA) while comet assay was used for DNA damage. There was no significant production of ROS and SOD activities in all groups. Significant changes were observed in the MDA level at 1000 mg/kg BW DHAE. Comet assay revealed a significant increase (p < 0.05) of DNA damage on animals treated with 250 and 500 mg/kg BW DHAE but not at the highest concentration. It was postulated that the placental cells could have undergone necrosis which destroys all components including DNA. This occurrence simultaneously reduces the levels of DNA damage which can be represented by lower level of tail moments. This finding correlates with our histopathological examination where necrotic cells of spongiotrophoblast were observed in the basal zone of placental tissue. The high amount of hydrogen cyanide and other compounds in 1000 mg/kg BW DHAE could elevate the lipid peroxidation and directly induce cell necrosis which requires further investigation.

Herbal-Based Formulation Containing Eurycoma longifolia and Labisia pumila Aqueous Extracts: Safe for Consumption?

A combined polyherbal formulation containing tongkat ali (Eurycoma longifolia) and kacip fatimah (Labisia pumila) aqueous extracts was evaluated for its safety aspect. A repeated dose 28-day toxicity study using Wistar rats was conducted where the polyherbal formulation was administered at doses 125, 500 and 2000 mg/kg body weight to male and female treatment groups daily via oral gavage, with rats receiving only water as the control group. In-life parameters measured include monitoring of food and water consumption and clinical and functional observations. On day 29, blood was collected for haematological and biochemical analysis. The rats were necropsied and the organs were collected for histopathological examination. This study showed that the combined formulation did not induce any significant toxicity effect at any dose level in terms of morbidity, mortality, behaviour, functional observation, body weight, food and water consumption, whole blood haematology and serum biochemistry. However, there were some microscopic changes in the histopathological examinations of some organs given 2000 mg/kg body weight, which may suggest an early response to the polyherbal formulation. From this study, the no observed adverse effect level is estimated to be more than 500 mg/kg body weight but not exceeding 2000 mg/kg body weight. The observed effects at the highest dose indicate the need for further study of longer dosing duration.

Histopathological changes in placenta and liver of pregnant rats administered with aqueous extract of Dioscorea hispida var. daemona (Roxb) Prain & Burkill.

Dioscorea hispida var. daemona (Roxb) Prain & Burkill (DH), also known a tropical yam or intoxicating yam is a bitter wild tuber which is consumed as a staple food and traditionally used as a remedy in Malaysia. However, DH is also notorious for its intoxicating effects and there is currently a dearth of study of possible effects of DH on liver and placental tissues and hence its safe consumption warrants in-depth investigation. This study was therefore designed to investigate into the effect of DH on liver and placenta of pregnant rat via histopathological examination. Thirty pregnant Sprague-Dawley rats were randomly divided into five groups consisting of a control (distilled water) and four DH aqueous extract groups (250, 500, 1000 and 2000 mg/kg body weight). The extracts were administered via oral gavage daily throughout the study and animals were sacrificed on day 21. Paraffin-embedded, hematoxylin and eosin stained sections of placenta and liver were examined. Significant changes (p < 0.05) were observed on relative liver and placental weights of animals treated with 2000 mg/kg body weight DH extract. The placental numbers were decreased with the increased of DH extract concentration. Liver histological examination in all treated groups showed that tissues underwent degeneration characterized by hepatocyte swelling, cytoplasmic vacuolation, cytolysis, margination and clumping of nucleus chromatin. Changes of the basal and labyrinth zone were observed in placental tissues in all treated groups. Glycogen cells were reduced with fibrin deposition in the basal zone, while irregular vessel formation was demonstrated in the labyrinth zone. UHPLC-ESI-MS analysis showed the presence four steroidal saponins DH. In conclusion, DH aqueous extract exert hepatotoxicity and adverse effects on the placenta of rats. However, the underlying mechanism and phytochemicals inducing the observed toxicity require further investigation.

Screening factors influencing the production of astaxanthin from freshwater and marine microalgae.

Astaxanthin, a carotenoid pigment found in several aquatic organisms, is responsible for the red colour of salmon, trout and crustaceans. In this study, astaxanthin production from freshwater microalga Chlorella sorokiniana and marine microalga Tetraselmis sp. was investigated. Cell growth and astaxanthin production were determined spectrophotometrically at 620 and 480 nm, respectively. Astaxanthin was extracted using acetone and measured subsequent to biomass removal. Aerated conditions favoured astaxanthin production in C. sorokiniana, whereas Tetraselmis sp. was best cultured under unaerated conditions. C. sorokiniana produced more astaxanthin with the highest yield reached at 7.83 mg/l in 6.0 mM in nitrate containing medium compared to Tetraselmis sp. which recorded the highest yield of only 1.96 mg/l in 1.5 mM nitrate containing medium. Production in C. sorokiniana started at the early exponential phase, indicating that astaxanthin may be a growth-associated product in this microalga. Further optimization of astaxanthin production was performed using C. sorokiniana through a 2(3) full factorial experimental design, and a yield of 8.39 mg/l was achieved. Overall, the study has shown that both microalgae are capable of producing astaxanthin. Additionally, this research has highlighted C. sorokiniana as a potential astaxanthin producer that could serve as a natural astaxanthin source in the current market.