α-Amylase and α-glucosidase inhibitors from the aerial parts of Chamaecrista pumila (Lam.) K. Larsen.

One new compound, 4,7-dihydroxy-2-hydroxymethyl-5,6-dimethoxyanthraquinone (1), along with eight known compounds (2-9) were isolated from the methanol extracts of the aerial parts of Chamaecrista pumila (Lam.) K. Larsen. Their chemical structure was determined based on spectroscopic data interpretation and comparison with the reported data. The inhibitory effects of them on α-amylase and α-glucosidase were performed. The results showed that compounds 4, 6, 8, and 9 against potent α-glucosidase with the inhibition values of 98.14 ± 0.05, 98.19 ± 0.04, 97.01 ± 0.49, 84.43 ± 0.6% at 50 µM, respectively. Compounds 4 and 6 displayed significance against α-amylase at 200 µM with inhibition values of 22.35 ± 1.10 and 60.47 ± 0.91%.

Inhibitory actions of borneol on the substantia gelatinosa neurons of the trigeminal subnucleus caudalis in mice.

The substantia gelatinosa (SG) of the trigeminal subnucleus caudalis (Vc) is the first relay site for the orofacial nociceptive inputs via the thin myelinated Aδ and unmyelinated C primary afferent fibers. Borneol, one of the valuable timehonored herbal ingredients in traditional Chinese medicine, is a popular treatment for anxiety, anesthesia, and antinociception. However, to date, little is known as to how borneol acts on the SG neurons of the Vc. To close this gap, the whole-cell patch-clamp technique was applied to elucidate the antinociceptive mechanism responding for the actions of borneol on the SG neurons of the Vc in mice. In the voltage-clamp mode, holding at -60 mV, the borneol-induced non-desensitizing inward currents were not affected by tetrodotoxin, a voltage-gated Na+ channel blocker, 6-cyano-7-nitro-quinoxaline-2,3-dione, a non-N-methyl-D-aspartate (NMDA) glutamate receptor antagonist and DL-2-amino-5-phosphonopentanoic acid, an NMDA receptor antagonist. However, borneol-induced inward currents were partially decreased in the presence of picrotoxin, a γ-aminobutyric acid (GABA)A receptor antagonist, or strychnine, a glycine receptor antagonist, and was almost suppressed in the presence of picrotoxin and strychnine. Though borneol did not show any effect on the glycine-induced inward currents, borneol enhanced GABA-mediated responses. Beside, borneol enhanced the GABA-induced hyperpolarization under the current-clamp mode. Altogether, we suggest that borneol contributes in part toward mediating the inhibitory GABA and glycine transmission on the SG neurons of the Vc and may serve as an herbal therapeutic for orofacial pain ailments.

New dammarane-type triterpenoid glycosides from Gynostemma burmanicum.

The chemical composition of Gynostemma burmanicum King ex Chakrav. was investigated for the first time in this study. Nine dammarane glycosides (1‒9) were isolated from the EtOH extract of the aerial parts of G. burmanicum. Their structures were elucidated by 1D and 2D NMR spectroscopic interpretation as well as by chemical studies. The new compounds were 3ß,20S-dihydroxydammar-24-ene-3-O-ß-D-glucopyranosyl-20-O-[ß-D-xylopyranosyl-(1→6)-ß-D-glucopyranoside] (1), 3ß,12ß,20S-trihydroxydammar-24-ene-3-O-ß-D-xylopyranosyl-20-O-[ß-D-xylopyranosyl-(1→6)-ß-D-glucopyranoside] (2), and 12-oxo-3ß,20S-dihydroxydammar-24-ene-3-O-[ß-D-glucopyranosyl(1→2)-ß-D-glucopyranosyl]-20-O-[ß-D-xylopyranosyl-(1→6)-ß-D-glucopyranoside] (3).

Anti-inflammatory constituents from Psychotria prainii H. Lév.

One new and three known compounds were isolated from the ethanol extract of Psychotria prainii aerial parts. By means of spectroscopic methods, their structures were elucidated to be deacetylasperulosidic acid 6-ethyl ether (1), asperulosidic acid (2), asperuloside (3) and obtucarbamates C (4). The isolated compounds were evaluated for their inhibitory effect on NO production in LPS-stimulated RAW264.7 cells. Among them, compounds 2 and 4 exhibited strong effect with the IC50 values of 5.75 ± 0.85 and 6.92 ± 0.43 µM, respectively. This is the first report for the chemical composition and biological activity of P. prainii.

Anti-osteoporotic and Antioxidant Activities by Rhizomes of Kaempferia parviflora Wall. ex Baker

In this report, we investigated the antioxidant (peroxyl radical-scavenging and reducing capacities) and anti-osteoporotic activities of extracts and isolated constituents (1 - 16) from the rhizomes of Kaempferia parviflora Wall. ex Baker on pre-osteoclastic RAW 264.7 cells. Compound 5 exhibited significant peroxyl radical-scavenging capacity, with TE value of 8.47 ± 0.52 µM, while compound 13 showed significant reducing capacity, with CUPRAC value of 5.66 ± 0.26 µM, at 10.0 µM. In addition, flavonoid compounds 2, 4, 6, 8, 10, 12, and terpene compound 15 showed significant inhibition of tartrate-resistant acid phosphatase (TRAP) in NF-κB ligand-induced osteoclastic RAW 264.7 cells, with values ranging from 16.97 ± 1.02 to 64.67 ± 2.76%. These results indicated that K. parviflora could be excellent sources for the antioxidant and anti-osteoporotic traditional medicinal plants.

In vitro evaluation of the antioxidant and cytotoxic activities of constituents of the mangrove Lumnitzera racemosa Willd.

This study performed phytochemical and bioactive assessments of the mangrove Lumnitzera racemosa Willd. leaves. Bioassay-guided fractionation of the methanolic extracts led to the identification of thirty-six compounds (1-36), their structures were elucidated using detailed NMR spectroscopic and MS analysis. The extracts, fractions, and the isolated compounds were screened for potential antioxidant and cytotoxic activities. Antioxidant assays were performed using peroxyl radical-scavenging and reducing assays, whereas cytotoxicity was measured using MTT assays in HL-60 and Hel-299 cell lines. The methanolic extract, CH2Cl2 and n-BuOH fractions (10.0 µg/mL) exhibited potent antioxidant activity, with Trolox equivalent (TE) values of 24.94 ± 0.59, 28.34 ± 0.20, and 27.09 ± 0.37 (µM), respectively. In addition, the isolated compounds exerted cytotoxic effects in a dose-dependent manner; compounds 1 and 14 exhibited the most potent cytotoxicity in HL-60 cells, with IC50 values of 0.15 ± 0.29 and 0.60 ± 0.16 µM, respectively. To clarify the mechanism(s) behind these cytotoxic effects, we measured the time-dependent changes in apoptotic markers including the condensation and fragmentation of nuclear chromatin, and the downregulation of p-ERK1/2, p-AKT, and c-Myc levels.

Two new C-glucosyl benzoic acids and flavonoids from Mallotus nanus and their antioxidant activity.

Two new 2-C-beta-D-glucopyranosyl benzoic acid derivatives named mallonanosides A (1) and B (2) were isolated from the methanolic extract of the leaves of Mallotus nanus along with five known flavonoids, kaempferin (3), juglanin (4), quercitrin (5), myricitrin (6), and rhoifolin (7). Their structures were established on the basis of spectral and chemical evidence. Their antioxidant activities were shown to depend on the number of hydroxyl groups, and the location and species of sugar moiety.