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 ( ) reduced blood glucose levels but increased the body weight, serum insulin levels, size and number of islets of Langerhans, and β-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 ( ) 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.

Amorphophallus sakonnakhonensis 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.

Aims: Leaves of B. nakhonphanomensis were extracted and the extract was used in gas chromatography-mass spectrometry (GC-MS) analysis to evaluate the total phenols, total flavonoids and antioxidant activity. Methods: The extract of B. nakhonphanomensis was analyzed by GC-MS. Quantitative analysis for total phenols was done by the Folin-Ciocatteu method and for total flavonoids by the aluminium chloride method. The antioxidant activity of the ethanolic extract was evaluated by the DPPH method. Results: GC-MS analysis revealed the presence of 19 phytochemical constituents. These compounds were identified by comparing their retention times and peak areas with those from the literature and by interpretation of the mass spectra. The major chemical constituents were inositol (48.55 %), alpha-tocopherol (12.21 %) and phenol (6.61 %). Total phenolic content was 48.69±0.56 mg/100 of Gallic acid equivalent (GE). The total flavonoid contentwas 10539± 6.14 mg/100 of quercetin equivalent (QE). Antioxidant activity was 17.07±0.24 µg/100 of ascorbic acid equivalent antioxidant capacity (AEAC).Conclusion: These findings are the first report and suggest that the rich phytochemical content of B. nakhonphanomensis has good antioxidant activity.

Colocasia sookchaloemiae (Araceae) is described from Phu Pha Yol National Park (northeastern Thailand). It is morphologically similar to C. fallax , from which it differs in having seasonal dormancy (vs. evergreen), broader and non-glaucous laminae (vs. narrower and slightly glaucous beneath), a speckled green ovary (vs. mostly green), a convex stigma with a depressed center (vs. 3-lobed), a sparsely hairy sterile interstice (vs. glabrous), and a thicker stipitate appendix (vs. slender, often sessile, or shortly stipitate). A comparative study of living plants, cultivated specimens, and herbarium material (including types) supports its recognition as a distinct species. The new taxon grows on rocky cliffs in dry dipterocarp and mixed deciduous forests at 350–400 m a.s.l., and it is currently known from Mukdahan and Sakon Nakhon provinces. A preliminary IUCN assessment indicates that the species is Data Deficient (DD).

A new subspecies, Ardisia crenata Sims subsp. mukdahanensis Chatan & Promprom (Primulaceae), is described from Mukdahan Province, Thailand. This discovery was made during field studies conducted from 2021 to 2023, during which the authors collected and analysed specimens, comparing them with relevant taxonomic literature and herbarium collections. A. crenata subsp. mukdahanensis is distinct from its closest relative, A. crenata subsp. crassinervosa by a combination of morphological traits, such as moderately dense minute hairs on young shoots, abaxial side of young lamina and calyx, peduncles and pedicels; larger flowers (7.0–7.5 mm) that are pure white or pinkish; larger fruits (7–8 mm) and absence of glandular punctation in organs such as lamina, calyx, corolla, anther and fruit. This new subspecies grows in slightly dense dry evergreen forests or open areas near streams and is preliminarily assigned to the Data Deficient (DD) category according to IUCN guidelines.

Background: The genus Vitex contains about 300 species distributed around the world. These genuses are used in the treatment of premenstrual syndrome. However, their estrogenic activity is not well understood. Objectives: To compare the estrogenic activity and lipid profile of ethanol extracts of leaves of Vitex pinnata L. with 17 β-estradiol in bilaterally ovariectomized (OVX) rats. Methods: Ethanol extracts were analyzed by gas chromatography-mass spectrometry (GC-MS). Bilaterally OVX rats were divided into five groups,(n = 6) receiving different treatments, consisting of a vehicle (1% Tween), ethanol extract of V. pinnata at three different doses (100, 500, 1000 mg/kg) and standard drug, 17 β-estradiol at a dose of 1 mg/kg. All groups were administered orally, daily for 14 days. Results: GC-MS data revealed that the major chemical constituents of the extract were 3, 7, 11, 15-Tetramethylhexadecen-2-en-1-ol, Gamma-Stigmasterol, 9,12,15-octadecatrienoic acid and n-hexadecanoic acid. V. pinnata extracts at 1000 mg/kg slightly increased uterine and vaginal weight and endometrial thickness. Doses of extract at 500 and 1000 mg/kg induced a significant (P < 0.05) decrease of triglycerides and total cholesterol in serum of OVX rats. Conclusion: V. pinnata leaf extract exhibits estrogenic activity and reduces levels of serum triglycerides and cholesterol. The understanding of such activity of V. pinnata leaf extract has benefits for postmenopausal women.