https://nova.newcastle.edu.au/vital/access/ /manager/Index ${session.getAttribute("locale")} 5 https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:36554 Catharanthus roseus (L.) G. Don (C. roseus) stem. C. roseus stem was powdered and extracted with methanol using ultrasound-assisted extraction to obtain the crude extract. The crude extract was further fractioned using liquid-liquid extraction technique to obtain extracts of increasing polarity including n-butanol and residual aqueous fractions. The crude extract and its derived fractions were then subjected to phytochemical screening and assayed for antioxidant, antimicrobial and cytotoxic activities. Results showed that the n-butanol fraction contained the highest levels of saponins and phenolics (3037.54 mg ESE/g and 77.87 mg GAE/g, respectively) and possessed the strongest antioxidant capacity amongst the tested extracts. HPLC analysis revealed that this n-butanol fraction had high levels of apigenin and kaempferol, whereas the aqueous fraction contained a high level of gallic acid. The n-butanol fraction was found to effectively inhibit the activity of Escherichia coli and Staphylococccus lugdunensis. The n-butanol fraction also possessed strong cytotoxic activity in vitro against a wide range of cancer cell lines including A2780 (ovarian), H460 (lung), A431 (skin), MIA PaCa-2 (pancreas), Du145 (prostate), HT29 (colon), MCF-7 (breast), BE2-C (neuroblastoma), SJ-G2, U87 and SMA (glioblastoma) at low doses (GI50 values of 5.2−21.0 µg/mL). These results indicate that the n-butanol fraction prepared from C. roseus stem is a rich source of bioactive compounds which can be isolated for further evaluation as potential antimicrobial drugs or antitumor therapeutic agents.]]> Wed 09 Mar 2022 16:00:04 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:50021 Tue 27 Jun 2023 15:37:42 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:36553 Catharanthus roseus (L.) G. Don (C. roseus) is a well-known medicinal plant for its source of alkaloids solely found in the leaves. Other parts including the root are usually discarded after the alkaloid extraction. This study sought to investigate phytochemical profiles, antioxidant, antimicrobial and cytotoxic properties of the C. roseus root extract (RE) and its two sub-fractions including saponin-enriched (SE) and aqueous (AQ) fractions. The results showed that the RE was a rich source of saponins (1744.44 mg ESE/g) and phenolics (51.27 mg GAE/g), which comprised of gallic acid (25.74 mg/g), apigenin (1.45 mg/g) and kaempferol (1.58 mg/g). The SE fraction was enriched with 31% of saponins and 63% of phenolics higher than those of the RE; whereas the concentrations of saponins and phenolics of the AQ fraction were lower than those of the RE by 40% and 74%, respectively. The content of gallic acid in the SE fraction was 1.4-fold and 1.5-fold higher than those of the RE or AQ fraction, respectively. The SE fraction demonstrated potent antioxidant capacity, which was significantly higher than the RE or AQ fraction, and also exhibited strong anti-proliferative activity against 11 cancer cell lines including A2780 (ovarian), H460 (lung), A431 (skin), MIA PaCa-2 (pancreas), Du145 (prostate), HT29 (colon), MCF-7 (breast), BE2-C (neuroblastoma), SJ-G2, U87 and SMA (glioblastoma) with low GI₅₀ values (≤ 2.00 µg/mL). The SE fraction was also shown to effectively inhibit the growth of both bacteria (Escherichia coli, Enterobacter aerogenes and Staphylococccus lugdunensis) and fungi (Candida albicans and Aspergillus niger). These findings warrant further investigation to isolate major compounds from the SE fraction and further test their antioxidant, anticancer and antimicrobial activities.]]> Thu 17 Feb 2022 09:27:14 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:34478 Catharanthus roseus (L.) G. Don (C. roseus) is well known as an important medicinal plant, with compounds such as the vinca alkaloids isolated for their anticancer activity. As such, it is important to determine the effective solvent for bioactive compound extraction from this plant and the suitable drying methods for preparation of starting material. The aims of this study were to determine the effect of extraction solvents and drying methods on bioactive compounds and antioxidant properties of C. roseus. Water was found to be the optimal solvent for phenolic and flavonoid extraction; whereas, methanol was the best solvent for saponin and proanthocyanidin extraction. The data also revealed that vacuum drying at 50°C was suitable for drying the leaf and the flower which contained high levels of phenolics and flavonoids, while infrared drying at 35°C was recommended for drying the stem and the root which had high saponin content. Practical applications: This study suggested that different parts of C. roseus had different suitable thermal drying methods. For the leaf and the flower, vacuum drying at 50°C was the optimal drying method, whereas infrared drying at 35°C was suitable for drying the stem and the root. These drying conditions can be easily applied for preparation of dried plant parts with high levels of bioactive compounds in the large scale. Importantly, the data indicated that the stem and the root of C. roseus which were considered as waste when the leaf was used for exploiting alkaloids, possessed great content of saponins. Therefore, these parts can be further used for isolation and purification of saponins.]]> Fri 03 Dec 2021 10:35:25 AEDT ]]>