The leaf, stem and root extracts of Chromolaena odorata were evaluated for their effect on platelet-activating factor (PAF) receptor binding on rabbit platelets using 3H-PAF as a ligand. The leaf extract demonstrated high PAF receptor binding inhibitory activity of 79.2±2.1% at 18.2 μg/ml. A total of eleven flavonoids were subsequently isolated from the active leaf extract and evaluated for their effects on PAF receptor binding. Eight of the flavonoids exhibited >50% inhibition on the binding activity at 18.2 μg/ml. These flavonoids were identified as eriodictyol 7,4′-dimethyl ether, quercetin 7,4′-methyl ether, naringenin 4′-methyl ether, kaempferol 4′-methyl ether, kaempferol 3-O-rutinoside, taxifolin 4′-methyl ether, taxifolin 7-methyl ether and quercetin 4′-methyl ether. Their IC50 values ranged from 19.5 to 62.1 μM.

An alkaloid compound from the hairy root culture of Eurycoma longifolia has been isolated and characterised as 9-methoxycanthin-6-one. The aims of these studies were to investigate the in vitro anti-cancer activities of 9-methoxycanthin-6-one against ovarian cancer (A2780, SKOV-3), breast cancer (MCF-7), colorectal cancer (HT29), skin cancer (A375) and cervical cancer (HeLa) cell lines by using a Sulphorhodamine B assay, and to evaluate the mechanisms of action of 9-methoxycanthin-6-one via the Hoechst 33342 assay and proteomics approach. The results had shown that 9-methoxycanthin-6-one gave IC₅₀ values of 4.04 ± 0.36 µM, 5.80 ± 0.40 µM, 15.09 ± 0.99 µM, 3.79 ± 0.069 µM, 5.71 ± 0.20 µM and 4.30 ± 0.27 µM when tested in A2780, SKOV-3, MCF-7, HT-29, A375 and HeLa cell lines, respectively. It was found that 9-methoxycanthin-6-one induced apoptosis in a concentration dependent manner when analysed via the Hoechst 33342 assay. 9-methoxycanthine-6-one were found to affect the expressions of apoptotic-related proteins, that were proteins pyruvate kinase (PKM), annexin A2 (ANXA2), galectin 3 (LGAL3), heterogeneous nuclear ribonucleoprotein A1 (HNRNP1A1), peroxiredoxin 3 (PRDX3), and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) from the differential analysis of 2-DE profiles between treated and non-treated 9-methoxycanthine-6-one. Proteins such as acetyl-CoA acyltransferase 2 (ACAA2), aldehyde dehydrogenase 1 (ALDH1A1), capping protein (CAPG), eukaryotic translation elongation factor 1 (EEF1A1), malate dehydrogenase 2 (MDH2), purine nucleoside phosphorylase (PNP), and triosephosphate isomerase 1 (TPI1) were also identified to be associated with A2780 cell death induced by 9-methoxycanthine-6-one. These findings may provide a new insight on the mechanisms of action of 9-methoxycanthin-6-one in exerting its anti-cancer effects in vitro.

This is the first report to identify the presence of 3-O-caffeoyl quinic acid (1), 4-O-caffeoyl quinic acid (2), 5-O-caffeoyl quinic acid (3), epi-catechin (4), and procyanidin B2 (5) in the young propagules of Rhizophora mucronata. Compounds 2–5 were purified and then treated against breast, colorectal, and ovarian cancer cell lines for 72 h and the results of the Sulphorhodomine-B (SRB) assay were evaluated for percent cell viability and IC₅₀ values. Epi-catechin, 4-O-caffeoyl quinic acid, 5-O-caffeoyl quinic acid and procyanidin B2 showed strong to moderate inhibitory effects when treated on breast (T47D), colorectal (HT29), and ovarian (A2780, SKOV3) cancer cell lines with IC₅₀ values ranging from 16.77 ± 0.58 to 28.28 ± 0.89 μg/mL. In silico evaluation was performed to evaluate the drug-likeness and toxicological effects of these compounds using Molinspiration calculation and OSIRIS program. It was found that compounds 2, 3, and 4 have the potential to be orally active and have a low risk in exerting the mutagenic, tumorigenic, irritant, and reproductive effects.

Medicinal plants are a vital source of new bioactive compounds due to their ecological biodiversity and varied chemical properties of each species. Phenotypic selection coupled with the evaluation of genotypes based on the chemical profile can be used for the development of a high-yielding variety. However, most of the raw material that has been used for commercial production of herbal products is mainly derived from wild sources, with little knowledge of the quality of genetic materials. Thus, three medicinal species, Chromolaena odorata (Siam weed), Andrographis paniculata (Creat), and Baeckea frutescens (False ru), were chosen based on their significant benefits to human health. These medicinal species have been traditionally used to treat various illnesses, and have been shown to possess anti-inflammatory, antimicrobial, anticancer, and antioxidant properties. This paper highlights the harvesting method and collection of accessions from natural habitats for the selection of superior genotypes. Individual plants having superior phenotypic characteristics and bioactive compounds were identified. We successfully developed appropriate propagation techniques for each species for the mass production of high-yielding planting material. The establishment of breeding activities for these medicinal plants will provide quality raw materials to support the herbal industry in increasing the value of pharmaceutical products. These efforts will also ensure the sustainable production of high-quality planting materials for the establishment of herbal plantations.