https://ogma.newcastle.edu.au/vital/access/ /manager/Index ${session.getAttribute("locale")} 5 https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:45055 Wed 26 Oct 2022 11:55:28 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:37074 Helicteres hirsuta Lour. (H. hirsuta) has been considered as a herbal medicine for the treatment of malaria and diabetes but limited studies have been conducted on its anticancer and antibacterial properties. In this study, the in vitro antibacterial and anticancer properties of the leaf and stem extracts and their two sub-fractions (aqueous and saponin-enriched butanol fractions) prepared from H. hirsuta were elucidated. MTT and CCK-8 assays were employed to assess their in vitro anticancer properties against various cancer cell lines. The antibacterial activity was assessed using the disc diffusion method and minimum inhibitory concentration (MIC) values were determined. The results revealed that the saponin-enriched fractions from H. hirsuta leaves and stems showed the highest antibacterial activity against E. coli (MIC values of 2.50 and 5.00 mg/mL, respectively) and S. lugdunensis (MIC values of 0.35 and 0.50 mg/mL, respectively). Importantly, these saponin-enriched fractions possessed strong anticancer activity in vitro towards a range of cancer cell lines including MIA PaCa-2 (pancreas); A2780 (ovarian); H460 (lung); A431 (skin); Du145 (prostate); HT29 (colon); MCF-7 (breast); SJ-G2, U87, SMA (glioblastoma) and BE2-C (neuroblastoma) at low doses (GI₅₀ values of 0.36–11.17 µg/mL). They especially revealed potent anti-pancreatic cancer activity in vitro against MIA PaCa-2, BxPC-3 and CFPAC-1 cells with IC50 values of 1.80–6.43 µg/mL. This finding provides scientific evidence of the cytotoxic activity of the extracts prepared from H. hirsuta leaves and stems, and suggests further studies to isolate active compounds for development of new anticancer agents from these plant extracts.]]> Wed 19 Jan 2022 15:15:13 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:31434 S. chinensis. Acetone (50% v/v) was found to be the optimal extraction solvent for extractable solids (12.2%), phenolic compounds (60 mg GAE/g DW), flavonoids (100 mg CE/g DW), proanthocyanidins (47.4 mg CE/g DW), and saponins (754 mg EE/g DW) as well as antioxidant capacity (ABTS 334 mM TE/g DW, DPPH 470 mM TE/g DW, FRAP 347 mM TE/g DW, and CUPRAC 310 mM TE/g DW). The extract prepared from 50% acetone had high levels of bioactive compounds (TPC 555 mg GAE/g CRE, flavonoids 819 mg CE/g CRE, proanthocyanidins 392 mg CE/g CRE, and saponins 1,880 mg EE/g CRE) as well as antioxidant capacity (ABTS 414 mM TE/g, DPPH 407 mM TE/g, FRAP 320 mg TE/g, and CUPRAC 623 mM TE/g), thus further confirming that 50% acetone is the solvent of choice. Therefore, 50% acetone is recommended for extraction of phenolic compounds, their secondary metabolites, saponins, and antioxidant capacity from the root of S. chinensis for further isolation and utilisation.]]> Wed 11 Apr 2018 13:41:31 AEST ]]> https://ogma.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://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:34580 Helicteres hirsuta Lour. (H. hirsuta L.) has been used as a traditional medicine for treatment of various ailments such as malaria and diabetes in Southeast Asian countries. This study aimed to optimize the conventional extraction conditions for obtaining the highest levels of phenolics, flavonoids, and antioxidant activities within H. hirsuta L. using response surface methodology. The Box–Behnken design was employed to evaluate the effects of extraction time, temperature, and the sample‐to‐solvent ratio on bioactive compound yield and antioxidant capacity of H. hirsuta L. The results indicated that the sample‐to‐solvent ratio had the strongest impact on bioactive compounds and antioxidant power of H. hirsuta L. and revealed the optimum extraction conditions to include temperature of 60 °C, time of 35 min at the sample‐to‐solvent ratio of 1 : 100 g/mL using 40% (v/v) methanol as the solvent. Under these conditions, the highest levels of total phenolic content and total flavonoid content were 16.87 mg GAE/g and 17.55 mg CE/g, respectively, significantly higher than the values obtained using water as the solvent. When preparing powered crude extract from H. hirsuta L., the ratio of 3 : 100 (g/mL) was suggested for the saving of 67% of solvent volume and energy required for solvent removal, as similar total phenolic content and total flavonoid content yield (86–87%) as well as antioxidant activities were obtained in comparison with the ratio of 1 : 100 (g/mL).]]> Wed 09 Feb 2022 15:55:50 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:33964 Helicteres hirsuta Lour. (H. hirsuta), which has been used as a traditional medicine for malaria and diabetes treatment. Results showed that either ultrasonic temperature or sample-to-solvent ratio had a greater influence on extraction efficiency of total phenolics, flavonoids and antioxidant capacity than that of methanol concentration. Optimal extraction conditions were determined to be ultrasonic temperature of 60 °C, ultrasonic time of 25 min, ultrasonic power of 150W, sample-to-solvent ratio of 3:100 g/mL, and a solvent composition of 40% (v/v) aqueous methanol. Under these conditions, 15.97 mg GAE/g of phenolics, 16.42 mg CE/g of flavonoids, and 13.34 g/100 g of extractable solids were obtained. The highest values for DPPH, ABTS and FRAP assays were also obtained under these conditions, with the exception of CUPRAC (88% maximum value). These optimal extraction conditions can be applied to prepare powdered crude extract for further isolation and purification of individual bioactive compounds for potential use in the pharmaceutical industry.]]> Wed 09 Feb 2022 15:54:39 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:50021 Tue 27 Jun 2023 15:37:42 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:54325 Tue 20 Feb 2024 15:58:35 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:26014 Tue 17 Mar 2020 11:33:29 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:48477 Tue 14 Nov 2023 15:30:07 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:47992 Leptospermum petersonii is an aromatic native Australian plant that has been traditionally used as a medicine and a tea; however, its application in food products is increasing. The aim of this study was to investigate the most suitable and energy-efficient drying conditions to retain phenolic compounds, antioxidant properties, and, color in dried Leptospermum petersonii leaves. In this study, six drying techniques were investigated including hot air, vacuum, microwave, freeze, sun, and shade. Results showed that freeze-drying retained maximum color, phenolic compounds, and, antioxidant capacity, however, it consumed the most time and energy. Conversely, microwave drying (960 W, 0.1 hr) used the least amount of time and energy yet retained the second-highest levels of phenolics and antioxidant capacity. In conclusion, microwave drying is suggested for large-scale drying. This method is economical and it is approximately 480 times and 1,700 times more time and energy efficient compared to freeze-drying.]]> Tue 14 Feb 2023 15:04:58 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:50041 Thu 29 Jun 2023 14:24:41 AEST ]]> https://ogma.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://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:23950 Paramignya trimera (Oliv.) Guillaum) has been used as an herbal medicine for the treatment of cancer or cancer-like diseases in recent years, particularly in Vietnam. Drying is an important step for preparation of dried materials for storage and further investigation; however, the effects of drying must be taken into account when processing samples, because this can have profound effects on the stability of phytochemical compounds and the biological activity of the dried P. trimera root. As such, this study assessed the effects of four different drying methods (conventional, hot air, vacuum, and microwave) on phytochemical retention and antioxidant capacity of P. trimera root, to identify an optimal drying method for P. trimera root. The results showed that the drying methods significantly affected phytochemical levels and antioxidant capacity of P. trimera root and that among the four drying methods tested, microwave drying (400 W) had the highest levels of phytochemical compounds, with total phenolic, total flavonoid, proanthocyanidin, and saponin contents of 11.27 mg GAE, 19.88 mg RE, 3.98 mg CE, and 267.15 mg EE/gram of dried sample, respectively. Dried sample prepared using this method had antioxidant capacity comparable to that of other drying methods. In addition, this method had the shortest drying time (0.28 h) and consumed the least energy (0.28 kWh). Therefore, microwave drying should be considered for drying P. trimera root for further investigation and utilization.]]> Thu 17 Feb 2022 09:26:20 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:52211 Thu 05 Oct 2023 10:24:26 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:29651 Sat 24 Mar 2018 07:41:56 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:27402 Phyllanthus amarus (P. amarus) has been used as a herbal medicine, particularly for liver support, in many countries and its extracts have been shown to possess potent antioxidant and anticancer properties in vitro. The preparation of dried sample is crucial for further extraction and isolation of phytochemicals. In this study, the effects of six different drying methods (hot air, low-temperature air, infrared, microwave, sun, and vacuum drying) on the phytochemical yield and antioxidant capacity were determined to identify the optimal drying method for P. amarus. The results showed that different drying methods, as well as different drying conditions within each method, significantly affected phytochemical yield and antioxidant capacity of P. amarus extracts. Infrared drying at 30°C was the best method for both retention of bioactive compound yield and antioxidant capacity of P. amarus extract, with 12 compounds were identified. In contrast, low-temperature-air drying at 25°C not only required the longest drying time but also significantly reduced the levels of bioactive compounds and antioxidant capacity of P. amarus. Therefore, infrared drying at 30°C is suggested for drying P. amarus for subsequent assessment of bioactivity.]]> Sat 24 Mar 2018 07:34:08 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:23861 Sat 24 Mar 2018 07:12:11 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:54740 Mon 11 Mar 2024 14:19:28 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:33071 Hormosira banksii is a rich source of polyphenols, which can be utilized in the food or pharmaceutical industries. This study aimed to determine the impact of six drying methods on properties of the alga H. banksii. Our data revealed that drying conditions significantly affected recovery yield, residual moisture, extraction yield, total phenolic content (TPC) as well as antioxidant capacity of H. banksii (P < 0.05). Optimal conditions for oven, vacuum and de‐humidification were 40, 50 and 50C, respectively, and microwave power is 840 W. Under optimal conditions, H. banksii prepared by freeze, de‐humidification and vacuum had significantly higher levels of TPC, total flavonoid content (TFC) and proanthocyanidins as well as possessing stronger antioxidant capacity in comparison with those prepared by sun, microwave and oven drying methods. As freeze drying is costly and time‐consuming, de‐humidification (50C, air in and out of 11.1 and 15.4%) and vacuum (50C, 10 psi) were recommended for drying H. banksii. Practical Applications: Algae possess various antioxidants with potential benefits for health. Drying is considered as a method for preserving materials, transport with low costs and especially first step for extraction, isolation and purification of active compounds. Thus, it is important to investigate the effects of drying conditions on the properties of the dried alga H. banksii. From the findings, the different drying conditions significantly affected the phytochemical profile and antioxidant activity of the dried alga and the optimal drying conditions could be applied for preparation of dried H. banksii for further processing (extraction, fractionation and isolation of bioactive compounds) as well as potential industrial applications (as a reference for drying H. banksii and other algae).]]> Fri 24 Aug 2018 13:45:06 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:33068 Hormosira banksii for total phenolic content (TPC) and antioxidant activities including total antioxidant capacity (ABTS), DPPH free radical scavenging capacity (DPPH) and ferric reducing antioxidant power (FRAP) using response surface methodology (RSM). Box–Behnken design was employed to assess the effect of ultrasonic temperature, time and power on the TPC and antioxidant activities of the extracts. The results showed that RSM was an accurate and reliable method in predicting TPC and antioxidant activities (ABTS, DPPH and FRAP) of the extracts with R² values of 0.97, 0.96, 0.92 and 0.94, respectively. The ultrasonic temperature and time had the significant impact on TPC and antioxidant capacities. The optimal UAE conditions for the maximal values of TPC and antioxidant activities were of 30 °C, 60 min and power 60%, or 150 W. The values of TPC and antioxidant activities (ABTS, DPPH, FRAP) achieved under these parameters were 23.12 (mg GAE g⁻¹), 85.64 (mg TE g⁻¹), 47.24 (mg TE g⁻¹) and 12.56 (mg TE g⁻¹), respectively. UAE was found to be more efficient in comparison to conventional extraction, with shorter time for extraction and higher of TPC level and antioxidant activities. Therefore, ultrasonic-assisted extraction using RSM is effective for extraction and further isolation and purification of phenolic compounds from H. banksii. In addition, this alga could be a potential rich source of natural antioxidants applied in food and pharmaceutical fields.]]> Fri 24 Aug 2018 13:44:59 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:54944 Fri 22 Mar 2024 15:20:51 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:40015 Helicteres hirsuta Lour. (H. hirsuta) has been traditionally used in many countries for the treatment of various ailments, indicating that it contains potential therapeutic agents. This study aimed to derive different fractions from the saponin-enriched extract of H. hirsuta stem using RP-HPLC and examine the in vitro anti-pancreatic cancer activity of the derived fractions (F0–F5). With the exception of F0, the five fractions (F1–F5) possessed strong inhibitory activity against PC cells at IC50 values of 3.11–17.12 μg/mL. The flow cytometry assays revealed the active fractions caused cell cycle arrest at S phase and promoted apoptosis in MIAPaCa-2 PC cells. The LC/MS analysis revealed that the isolated fractions contained bioactive compounds, such as caffeic acid, rosmarinic acid, sagerinic acid, usnic acid, cucurbitacins and absinthin. It can be concluded that the fractions isolated from H. hirsuta stem exhibit potent in vitro anti-pancreatic cancer activity and thus warrant further in vivo studies to assess their activity against PC followed by isolation of individual bioactive compounds and the evaluation of their anti-pancreatic cancer activity.]]> Fri 22 Jul 2022 13:06:36 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:48911 Fri 14 Apr 2023 18:33:01 AEST ]]> https://ogma.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 ]]>