Alocasia sakonakhonensis (Araceae), a new species from northeastern Thailand.

Alocasia sakonakhonensis Chatan & Promprom (Araceae), a new species from northeastern Thailand, is described and illustrated. It is clearly different from other previously known species by leaves, spathe, ovary, sterile interstice, synandria, and appendix. Color illustrations, and a distribution map are provided, as well as comparative morphological characters about its similar species. The preliminary conservation status assessment of the new species was presented.

Evaluation of Antidiabetic and Antioxidant Activities of Fruit Pulp Extracts of Cucurbita moschata Duchesne and Cucurbita maxima Duchesne.

Objective: To evaluate and compare the antidiabetic and antioxidant activities of fruit pulp extracts from Cucurbita moschata (PCMOS) and Cucurbita maxima (PCMAX). Methods: The antidiabetic activity was carried out in vivo by orally and daily giving the extracts at a dose of 500 mg/kg·b.w. to the streptozotocin-induced diabetic male albino Wistar rats for six weeks. After the period of administration, blood glucose levels, body weight, serum insulin, morphology of islets of Langerhans, biochemical parameters, and haematological values of the rats were determined. Meanwhile, the antioxidant activity was carried out in vitro by determination of total phenolic and flavonoid contents, DPPH radical scavenging activity, and ferric reducing antioxidant power. Results: PCMAX significantly (p < 0.05) reduced blood glucose levels but increased the body weight, serum insulin levels, size and number of islets of Langerhans, and ß-cell number of the treated diabetic rats more than PCMOS did. However, they did not alter biochemical parameters and haematological values of the treated diabetic rats. PCMAX possessed total phenolic and flavonoid contents and showed DPPH scavenging and FRAP reducing antioxidant power more significantly (p < 0.05) than PCMOS. Conclusions: According to the obtained results, it is indicated that PCMOS and PCMAX possess antidiabetic and antioxidant activities. PCMAX possesses more potent antidiabetic and antioxidant activities than PCMOS. These are probably due to PCMAX providing polysaccharide and total phenolic and flavonoid contents more than PCMOS.

A new species of Amorphophallus (Araceae) from northeastern Thailand.

Amorphophallussakonnakhonensis Chatan & Promprom, a new species from northeastern Thailand, is described and illustrated. The new species is most similar to A.harmandii Engl. & Gehrm. and A.linearis Gagnep., but it is distinguished by the combination of characters as follows: clear differences with A.harmandii are shorter style; disc-like, slightly smooth surface, concave centre, ca. 0.2 × 0.1 mm stigma; slightly cylindrical, slightly narrower upper part of staminate flower zone; slightly cylindrical to elongate-fusiform, erect or slightly erect, creamy white appendix. The clearly distinct morphology with A.linearis are disc-like, slightly smooth surface, concave centre, ca. 0.2 × 0.1 mm stigma; elliptic or obovate leaflet; 1-3 cm long, creamy white appendix. The preliminary conservation status was assessed, and the distinct characteristics of similar species were discussed.

A new species of Dischidia (Apocynaceae, Asclepiadoideae) from North-eastern Thailand.

Dischidia phuphanensis Chatan & Promprom, a new species from north-eastern Thailand, is described and illustrated. The new species is similar to D. tonkinensis Costantin, but is distinguished by the shape of its leaves, the apices of the staminal corona lobes, the colour of the corolla and the absence of a corolline corona. The distinguishing characters of similar species are discussed. A key for the identification of those species in Thailand without pitcher-like leaves is provided.

Sindora stipitata (Detarioideae, Leguminosae), a new species from Thailand.

Sindora stipitata, a new species in the subfamily Detarioideae (Leguminosae), collected from Nakhon Phanom Province, Thailand, is described and illustrated. The new species is morphologically similar to S. leiocarpa but differs in its smaller stature (3-5 m high), 6-foliolate paripinnate leaves, falcate persistent stipules, presence of a petal auricle, absence of a petal claw, stipitate ovary and capitate stigma. A key to the Thailand and Malesia species of Sindora is provided.

Finding new agents in medicinal plants to act on the myometrium.

This report summarizes work investigating the effects of some medicinal plants on uterine contraction. As there is a clinical need to find better drugs to help control uterine activity, and novel compounds are sought, the mechanisms whereby the medicinal plants exert their effects, as well as their major compounds, are discussed. By identifying the plants, major constituents and mechanisms, this review also illustrates the potential for development of new drugs, so that better ways to treat uterine disorders will be available to women worldwide.

The effects of pomegranate seed extract and beta-sitosterol on rat uterine contractions.

The aim of this study was to investigate the effects of pomegranate (Punica granatum L., Punicaceae) seed extract on uterine contractility. Pomegranate seeds were methanolic extracted and their constituents analyzed using gas chromatography and mass spectrometry. Isometric force was measured in strips of longitudinal rat myometrium and the effects of pomegranate seed extract studied. We found beta-sitosterol to be the main constituent of the extract (16%) and its effects were also investigated. Pomegranate seed extract and beta-sitosterol increased spontaneous contractions in a concentration-dependent manner with a maximum effect at 250 mg/100 mL and 1 mg/100 mL, respectively. The amplitude and frequency of the phasic contraction were significantly increased along with basal tension. The effects of pomegranate seed extract were very similar to those of beta-sitosterol. Force produced in the presence of pomegranate seed extract was abolished by the inhibition of L-type calcium channels or myosin light chain kinase (MLCK). Contractions were not potentiated by pomegranate extract following the inhibition of K channels or inhibition of the sarcoplasmic reticulum calcium ATPase (SERCA). The actions of beta-sitosterol and the extract were not blocked by the estrogen receptor blocker, fulvestrant. We conclude that pomegranate seed extract is a potent stimulator of phasic activity in rat uterus. Our data suggest that the uterotonic effect is due to nonestrogenic effects of beta-sitosterol acting to inhibit K channels and SERCA and thereby increasing contraction via calcium entry on L-type calcium channels and MLCK. We suggest that pomegranate extract and beta-sitosterol may be a useful uterine stimulant.