Suttijit Sriwatcharakul’s research while affiliated with King Mongkut's Institute of Technology Ladkrabang and other places

This research aim to study bioactivity of seed extract compare with fruit extract of Indian gooseberry; Phyllanthus emblica that use as medicinal plant widely in Thailand. Analyzed the efficacy of free radical scavenging by using DPPH radical scavenging assay reveal that the highest antioxidant activity found in the highest concentration, 10 mg/ml and both fruit and seed extracts had non-significant percentage of reduction as α-tocopherol. The determination of phytochemical exhibited that seed extract had the higher contents of tannin and flavonoid than fruit extract as 126.71 mg TAE/g extract and 1016.25 mg QE/g extract, respectively. Cytotoxicity studied of extracts against human breast adenocarcinoma cell line by MTT assay at the maximum concentration 10000 μg/ml found that seed extract had more toxicity than fruit extract at 68.98% and 35.57%. According to the bioactivities results, the seed of Phyllanthus emblica has potential to replace the fruit for medical aspects to add value of this plant.

This research is to study bioactivity of Delonix regia flower and leaf extracts collected in Thailand. We analyzed for efficacy of free radical scavenging and found that flower and leaf extracts from Samut Prakan showed the strongest percentage of reduction with IC50 50.21 and 105.0 mg/ml, respectively. The result of evaluated phytochemicals revealed that Chon Buri’s flower extract had the highest of total phenolic and tannin contents at 200 mg GAE/g extract and 32 mg TAE/g extract, respectively. Furthermore, Samut Prakan’s flower extract had the highest flavonoid compounds at 328.5 mg QE/g extract. To examine cytotoxicity on breast cancer cell lines, we found that Samut Prakan’s flower extract had the most cytotoxicity CC50 value, 5000 µg/ml. In conclusion, we found that the flower of Delonix regia is the promising part for the further study because the antioxidant activity and cytotoxicity strongly enhances when flower extract concentration is increased.

To evaluate the influences of seasonal changes and plant cultivars on estrogenic activity of the phytoestrogen-rich plant, Pueraria mirifica. Three cultivars of P. mirifica; PM-I, PM-II and PM-V, were grown in the same field trial for 3 years and random tubers collected during the summer, rainy season and winter seasons. Female Wistar rats were ovariectomized, kept for 14 days, randomly segregated into groups and treated with one of DW, 200microg/100g BW 17beta-estradiol (E2) or tuberous powder of PM-I, PM-II and PM-V at dosages of 100, or 1000mg/kg BW for the next 14 days. For the last 7 days of post-treatment period, rats received only DW. The vaginal cornification was recorded during the treatment and post-treatment period. The uterine tissues of the treated rats at the treatment and post-treatment periods were analyzed for uterine gland number and for the surface area of the myometrium, endometrium and lumen. In addition, ethanol tuberous extracts of PM-I, PM-II and PM-V was submitted to DPPH analysis. Vaginal cornification exhibited a dose-dependent response with plant samples collected during the winter and summer being more active than those collected in the rainy season. All plant samples-induced uterotrophic effects in the analysis at the treatment and post-treatment periods in a dose-dependent manner. The P. mirifica treated rats exhibited increasing uterine gland numbers and thickness of the endometrium and myometrium but a decreasing size of lumen, in comparison to the negative control. The results were more prominent in PM-I than other plants and also in plant samples collected during the winter and summer seasons than in the rainy season. DPPH assay of the ethanol tuberous extracts revealed variance in antioxidant activity. The results of uterotrophic and vaginal cornification assays reveal that P. mirifica exhibits a dose-dependent estrogenic activity under the influence of both seasonal changes and plant cultivars, which is confirmed by DPPH assay.

There is evidence that metabolic activation can increase the estrogenic activity of the phytoestrogen-rich herb in tests with HepG2 cells. Variation in both plant genetics and harvest season may also influence estrogenic activity of the plant materials. We evaluated the influence of in vitro metabolic activation by S9 mixture on the estrogenic activity of tuberous samples of different cultivars of the phytoestrogen-rich herb, Pueraria mirifica, harvested in different seasons. Plant extracts were derived from the tubers of five plant cultivars collected during summer, rainy season and winter and administered to MCF-7 cultures, an ERalpha-positive human mammary adenocarcinoma cell line for 3 days at dosages of 0.1, 1, 10, 100 and 1000microg/ml. These data were compared with the major plant isoflavonoids puerarin, daidzin, genistin, daidzein and genistein and with 17beta-estradiol, at concentrations of 10(-12) to 10(-6)M. The test system was done in the absence and presence of the S9 mixture. The major plant isoflavonoids and the plant extracts exhibited variable degrees of estrogenic activities as evaluated by altered proliferation of the MCF-7 cell line which were significantly enhanced in the presence of the S9 mixture. Metabolic activation of plant isoflavonoids at least in vitro by S9 mixture plays a significant role in amplification of the estrogenic activity of the phytoestrogen-rich plant. In addition, the estrogenic activities of the plant samples were potentially influenced by both seasonal changes and plant genetics.

Pueraria mirifica is a tuberous plant enriched with active phytoestrogens. There is no established information about the factors influencing isoflavonoid storage in the tubers. We investigated the tuberous storage of the major isoflavonoids of 1-year-old plants. Four cultivars of P. mirifica were cultivated in the same field trial during the same period to establish a unique plant age and differentiation under the same environment and soil conditions. The tubers collected from the 1-year-old plants in the summer, rainy season and winter were submitted to an HPLC analysis with a gradient system comprising 0.1% acetic acid and acetonitrile. Five major isoflavonoids, puerarin, daidzin, genistin, daidzein and genistein, were adopted as standards. P. mirifica tubers of different cultivars collected in the same season exhibited significant differences in individual and total isoflavonoid contents, showing chemovariety. P. mirifica tubers of the same cultivar collected from different seasons also exhibited significant differences in individual and total isoflavonoid contents, showing the influence of season. In conclusion, the tuberous storage of major isoflavonoids in 1-year-cultivated plants was greatly diverse and was strongly influenced by the season and plant genetics.

Thesis (M.Sc.)--Chulalongkorn University, 1998 In the search for bioactive substances from four weed species in compositae family; Eupatorium adenophorum Spreng., Eupatoruim odoratum Linn., Ageratum conyzoides Linn. and Sphaeranthus africanus Linn., the preliminary results revealed that the crude extract of the aerial part of E. adenophorum displayed the most attractive biological activities. Further solvent fractionation of E. adenophorum and biological tests exhibited that dichloromethane, ethyl acetate and butanol crude extracts showed rice growth inhibition activity 95.35%, 90.05% and 100% at concentration 0.1 g, respectively and displayed cytotoxicity against brine shrimp (Artemia salina Linn.) with LC50 value of 10.43, 12.56 and 10.02, respectively at 24 h. The separation of dichloromethane, ethanol, ethyl acetate and butanol crude extracts by means of chromatograph led to the isolation of 6 substances. They were found to be a mixture of long chain alcohols, stigmasterol, a mixture of long chain carboxylic acids, a mixture of long chain esters, protocatechuic acid and steroid glycoside. Protocatechuic acid displayed high bioactivity as plant growth inhibitor 92.30% at dose level 1000 ppm. ศึกษาฤทธิ์ทางชีวภาพเบื้องต้นของวัชพืชวงศ์ Compositate 4 ชนิด คือ สาบหมา (Eupatorium adenophorum Spreng), สาบเสือ (Eupatorium odoratum Linn), สาบแร้งสาบกา (Ageratum conyzoides Linn) และหญ้าค้อนกลอง (Sphaeranthus africanus Linn) พบว่า สิ่งสกัดจากส่วนเหนือดินของสาบหมาแสดงฤทธิ์ทางชีวภาพที่น่าสนใจ และเมื่อศึกษาการยังยั้งการเจริญเติบโตของพืชและความเป็นพิษต่อไรสีน้ำตาล พบว่า สิ่งสกัดไดคลอโรมีเทน, เอทิลแอซิเตต และบิวทานอล ของสาบหมา สามารถยับยั้งการเจริญเติบโตของต้นข้าว 95.35%, 90.05% และ 100% ที่ความเข้มข้น 0.1 g และแสดงความเป็นพิษต่อไรสีน้ำตาลโดยมีค่า LC50 10.43, 12.56 และ 10.02 ตามลำดับ เมื่อทำการแยกสิ่งสกัดทั้ง 3 ชนิด ด้วยวิธีทางโครมาโทกราฟี สามารถแยกสารได้ 6 ชนิด คือ ของผสมแอลกอฮอล์โซ่ตรง, stigmasterol, ของผสมกรดโซ่ตรง, ของผสมเอสเทอร์โซ่ตรง, protocatechuic acid และสเตียรอยด์ไกลโคโซด์ โดย protocatechuic acid แสดงฤทธิ์ในการยับยั้งการเจริญเติบโตของต้นข้าว 92.30% ที่ความเข้มข้น 1000 ppm