Supap Saenphet

Molecular analysis of echinostome metacercariae from their second intermediate host found in a localised geographic region reveals genetic heterogeneity and possible cryptic speciation.

Echinostome metacercariae are the infective stage for humans and animals. The identification of echinostomes has been based until recently on morphology but molecular techniques using sequences of ribosomal RNA and mitochondrial DNA have indicated major clades within the group. In this study we have used the ITS2 region of ribosomal RNA and the ND1 region of mitochondrial DNA to identify metacercariae from snails collected from eight well-separated sites from an area of 4000 km2 in Lamphun Province, Thailand. The derived sequences have been compared to those collected from elsewhere and have been deposited in the nucleotide databases. There were two aims of this study; firstly, to determine the species of echinostome present in an endemic area, and secondly, to assess the intra-specific genetic diversity, as this may be informative with regard to the potential for the development of anthelmintic resistance and with regard to the spread of infection by the definitive hosts. Our results indicate that the most prevalent species are most closely related to E. revolutum, E. trivolvis, E. robustum, E. malayanum and Euparyphium albuferensis. Some sites harbour several species and within a site there could be considerable intra-species genetic diversity. There is no significant geographical structuring within this area. Although the molecular techniques used in this study allowed the assignment of the samples to clades within defined species, however, within these groupings there were significant differences indicating that cryptic speciation may have occurred. The degree of genetic diversity present would suggest the use of targeted regimes designed to minimise the selection of anthelmintic resistance. The apparent lack of geographic structuring is consistent with the transmission of the parasites by the avian hosts.

Antiproliferative effect of Moringa oleifera Lam. and Pseuderanthemum palatiferum (Nees) Radlk extracts on the colon cancer cells

Consumption of Moringa oleifera and Pseuderanthemum palatiferum for cancer therapy is becoming popular in Thailand. The aim of this study was therefore to investigate the inhibitory effect of the aqueous and ethanol extracts from M. oleifera and P. palatiferum leaves on colon cancer cell proliferation. Prior to the antiproliferative test, primarily safety test of the extracts was conducted by Ames test and the two extracts were clarified for their non-mutagenic activity. Test of antiproliferative effect on 3 types of colon cancer cell lines; HCT15, SW48 and SW480, using the extracts at the concentrations of 100, 250, 500 and 1,000 μg/ml for 24, 48 and 72 h, respectively by 3′-(4, 5 dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide (MTT) assay showed that both extracts were toxic to all types of tested cell lines with increasing concentrations and time. It was also found that M. oleifera extract was more effective than that of P. palatiferum. Moreover, the ethanol extract of M. oleifera tended to give better antiproliferative results on all tested cell lines than the aqueous extract and SW48 was found to be the most sensitive cell line type. It has been shown from our results that these two plants might be new choices of naturally therapeutic products against colon cancer.

Haplorchis taichui: Worm recovery rate and immune responses in infected rats (Rattus norvegicus)

Worm recovery rate, mucosal mast cells (MMCs), eosinophils and serum IgE concentration in rats were investigated after orally feeding 300 Haplorchis taichui metacercariae to male rats. The duodenal, jejunal and ileal tissue sections were stained with 1% alcian blue and 0.5% safranin-O for MMC count. Eosinophil count and the serum IgE concentration assay were measured from cardiac puncture blood. The average worm recovery rates were 20.00%, 13.00%, 0.67%, 1.67% and 0.00% on day 3, 7, 14, 21 and 28 post-infection (PI), respectively. The number of MMCs in the infected rats were significantly higher than in the controls (P<0.01), reaching a peak on day 21 PI. They decreased thereafter, with the decline in worm recovery. Eosinophil count and Serum IgE concentration were also increased but not significantly higher than the controls. However, they showed a positive relationship to worm recovery. It could be concluded from the results that MMCs, eosinophils and IgE may play an important role in the expulsion of H. taichui from rat intestine. However, the mechanism by which the MMC result in the helminth expulsion still need to be understood, and it is recommended that other cells such as goblet cells be studied further.

Lethal and sublethal effects of a methomyl-based insecticide in Hoplobatrachus rugulosus

The aim of this study was to investigate the lethal and sublethal toxicity of a methomyl-based insecticide in Hoplobatrachus rugulosus, as methomyl-based insecticides are applied in massive amounts and agrochemicals have effects on the decline in amphibian populations. To evaluate the toxic effects of methomyl from agricultural application, a methomyl-based insecticide containing 40% methomyl was selected. The median lethal concentration of 96 hours of methomyl exposure was 8.69 ppm for H. rugulosus tadpoles. The lethal concentration also produced severe histological damage in the livers and kidneys of the exposed tadpoles. The sublethal concentration used for methomyl was 144 ppb during the metamorphosis period. It was found that the sublethal concentration of the methomyl compound could decrease growth, metamorphosis time, and size, disturb biochemical parameters, and produce histological damage. In livers, methomyl effects increased oxidative stress and dramatically decreased the glycogen level of the treated froglets. Mononuclear infiltration, blood congestion, amorphous substances, and hepatocytes vacuolization were observed throughout liver tissue. The methomyl-based insecticide also increased oxidative stress and decreased nitric oxide levels in the kidneys of the exposed froglets. Renal tissue damage including blood congestion, amorphous substances, and Bowman’s capsule spaces reduction were found in the methomyl exposure group. The methomyl compound also produced vacuoles in various stages of oocytes, but no histological damage was found in testicular tissue. Our results indicated strong toxic effects of the methomyl-based insecticide on H. rugulosus, a broadly tolerant anuran.

Uvaria rufa Blume attenuates benign prostatic hyperplasia via inhibiting 5α-reductase and enhancing antioxidant status

ETHNOPHARMACOLOGICAL RELEVANCE Traditional medicine has used Uvaria rufa Blume as an ethnomedicinal plant for treating fever, skin allergies, intestinal ulcers and prostate disorders including BPH. However, no scientific evidence supports the traditional use. AIM OF THE STUDY This study aimed to evaluate the therapeutic potential of U. rufa on BPH using in vitro and in vivo models. MATERIALS AND METHODS In vitro studies screened the efficacy of a 5α-reductase (5αR) inhibition and antioxidant activity of petroleum ether, ethyl acetate, ethanol and aqueous extracts from the stem of U. rufa. Phytochemical screening was performed to determine the active compound using high-performance liquid chromatography (HPLC). Ethyl acetate extract (UR-EtOAc) of U. rufa was used to evaluate the therapeutic efficacy in vivo models. BPH was induced by subcutaneous injection of testosterone propionate (3mg/kg) to male rats for 30 days. After 30 days of oral administration of UR-EtOAc at doses of 10 and 20mg/kg and finasteride at a dose of 1mg/kg, the prostate weight, prostate index (PI), testosterone and androgen receptor (AR) levels, and histopathological alteration of prostate gland were determined. Also, oxidative status and toxicity indices were assessed. RESULTS UR-EtOAc exhibited the highest potency of inhibition of 5αR and possessed potent antioxidants rich in phenolics and flavonoids contents. The active compound analyzed by HPLC was β-sitosterol. In vivo results show a significant reduction in prostate weight, PI, and AR in all treated groups when compared to the BPH model group (P<0.001). Also, the UR-EtOAc and finasteride treated groups had increased prostatic and serum testosterone levels when compared to the BPH model group. A histopathological investigation of the prostate glands supported the above results. UR-EtOAc elevated the antioxidant enzymes and reduced the malondialdehyde level in BPH-induced rats. Moreover, treatment of UR-EtOAc at all doses had no toxic effects on the vital organs and serum biochemical indices. CONCLUSIONS UR-EtOAc from the stem of Uvaria rufa Blume appears to have the potential as a phytotherapeutic agent in the management of BPH, which provides the scientific evidence for traditional use.

Evaluation of biochemical, hematological and histopathological parameters of albino rats treated with Stemona aphylla Craib. extract

In order to measure the safety of Stemona aphylla Craib., an effective insecticidal plant, on mammals, the effects of the ethanolic extracts from the root of S. aphylla on blood biochemical, hematological and histopathological indices of albino rats have been evaluated. Male rats were given extracts orally at the doses of 300 and 500 mg/kg body weight/day for 45 consecutive days. These were compared to control rats which received only distilled water. The results of this study showed no significant differences in aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, blood urea nitrogen and creatinine of all treated groups when compared to those of the control groups (P > 0.05). Nevertheless, an increase in lymphocytes count was observed in all treated groups. The alterations in liver and kidney tissues of all treated groups showed leukocyte infiltration and haemorrhage in hepatic sinusoids. Moreover, the contracted glomerulus, dilated renal tubules and leukocyte infiltration were found in kidney tissues. The significant injury of tissues observed in this study is a sign of the toxicity of S. aphylla to mammalian species. The use of S. aphylla as bioinsecticide active ingredient should be, therefore, thoroughly considered.