Bioactivity-guided fractionation led to the successful isolation of antiosteoporotic components, i.e. physicion (1), rubiadin-1-methyl ether (2), 2-hydroxy-1-methoxy- anthraquinone (3), 1,2-dihydroxy-3-methylanthraquinone (4), 1,3,8-trihydroxy-2-methoxy- anthraquinone (5), 2-hydroxymethyl-3-hydroxyanthraquinone (6), 2-methoxyanthraquinone (7) and scopoletin (8) from an ethanolic extract of the roots of Morinda officinalis. Compounds 4-8 are isolated for the first time from M. officinalis. Among them, compounds 2 and 3 promoted osteoblast proliferation, while compounds 4, 5 increased osteoblast ALP activity. All of the isolated compounds inhibited osteoclast TRAP activity and bone resorption, and the inhibitory effects on osteoclastic bone resorption of compounds 1 and 5 were stronger than that of other compounds. Taken together, antiosteoporotic activity of M. officinalis and its anthraquinones suggest therapeutic potential against osteoporosis.

Eclipta prostrata, an aromatic plant, is known in Chinese herbal medicine for the treatment of various kidney diseases. In the present study, the volatile components were isolated from the aerial parts of this plant by hydrodistillation and analysed by GC–MS. A total of 55 compounds, which were the major part (91.7%) of the volatiles, were identified by matching mass spectra with a mass spectrum library (NIST 05.L). The main components were as follows: heptadecane (14.78%), 6,10,14-trimethyl-2-pentadecanone (12.80%), n-hexadecanoic acid (8.98%), pentadecane (8.68%), eudesma-4(14),11-diene (5.86%), phytol (3.77%), octadec-9-enoic acid (3.35%), 1,2-benzenedicarboxylic acid diisooctyl ester (2.74%), (Z,Z)-9,12-octadecadienoic acid (2.36%), (Z)-7,11-dimethyl-3-methylene-1,6,10-dodecatriene (2.08%) and (Z,Z,Z)-1,5,9,9-tetramethyl-1,4,7-cycloundecatriene (2.07%). The effects of volatile components and ethanolic extract from the aerial parts of this plant on the proliferation and differentiation of primary osteoblasts were evaluated by the MTT method and measuring the activity of alkaline phosphatase (ALP activity). Both volatile components and ethanolic extract (1 μg/mL to 100 μg/mL) significantly (p < 0.01) stimulated the proliferation and increased the ALP activity of primary osteoblasts. These results propose that E. prostrata can play an important role in osteoblastic bone formation, and may possibly lead to the development of bone-forming drugs.

The antioxidant activities of ethanolic crude extract (ECE) and its four different solvent sub-fractions (namely, petroleum ether fraction (PEF), ethyl acetate fraction (EAF), n-butanol fraction (BF) and the aqueous fraction (AF) from the receptacles of Nelumbo nucifera Gaertn. (Receptaculum Nelumbinis) were investigated using two in vitro antioxidant assays. BF showed the highest total phenolic content (607.6 mg/g gallic acid equivalents), total flavonoid content (862.7 mg/g rutin equivalents) and total proanthocyanidin content (331.0 mg/g catechin equivalents), accompanied with the highest antioxidant activity compared to other fractions through 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azino-bis-(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) radical scavenging assays. Five flavonol glycosides, namely hyperoside (1), isoquercitrin (2), quercetin-3-O-β-D-glucuronide (3), isorhamnetin-3-O-β-D-galactoside (4) and syringetin-3-O-β-D-glucoside (5) were isolated from the Receptaculum Nelumbinis. Compounds 2–5 were isolated for the first time from the Receptaculum Nelumbinis. The five isolated flavone glycosides, particularly compounds 1–3, demonstrated significant DPPH and ABTS radical scavenging activity, with IC₅₀ values of 8.9 ± 0.2, 5.2 ± 0.2, 7.5 ± 0.1 for DPPH and 114.2 ± 1.7, 112.8 ± 0.8, 172.5 ± 0.7 µg/mL for ABTS, respectively. These results suggest that Receptaculum Nelumbinis has strong antioxidant potential and may be potentially used as a safe and inexpensive bioactive source of natural antioxidants.

A simple and reliable method of high-performance liquid chromatography with photodiode array detection (HPLC-DAD) was developed to evaluate the quality of Receptaculum Nelumbinis (dried receptacle of Nelumbo nucifera) through establishing chromatographic fingerprint and simultaneous determination of five flavonol glycosides, including hyperoside, isoquercitrin, quercetin-3-O-β-d-glucuronide, isorhamnetin-3-O-β-d-galactoside and syringetin-3-O-β-d-glucoside. In quantitative analysis, the five components showed good regression (R > 0.9998) within linear ranges, and their recoveries were in the range of 98.31%–100.32%. In the chromatographic fingerprint, twelve peaks were selected as the characteristic peaks to assess the similarities of different samples collected from different origins in China according to the State Food and Drug Administration (SFDA) requirements. Furthermore, hierarchical cluster analysis (HCA) was also applied to evaluate the variation of chemical components among different sources of Receptaculum Nelumbinis in China. This study indicated that the combination of quantitative and chromatographic fingerprint analysis can be readily utilized as a quality control method for Receptaculum Nelumbinis and its related traditional Chinese medicinal preparations.