Optimisation of the Microwave-Assisted Ethanol Extraction of Saponins from Gac (Momordica cochinchinensis Spreng.) Seeds

Qualitative, Quantitative, In Vitro Antioxidant Activity and Chemical Profiling of Leptadenia pyrotechnica (Forssk.) Decne Using Advanced Analytical Techniques

Leptadenia pyrotechnica Forssk. Decne (LP) is a medicinal herb from the Asclepiadaceae family with many advantageous properties. The goal of this research is to identify, quantify, and evaluate the antioxidant potential of LP to validate its remarkable therapeutic advantages. The hot soxhlet extraction method was employed to prepare different extracts of LP (stem and root). These extracts were evaluated physiochemically to check their impurity, purity, and quality; qualitatively to detect different phytochemicals; and quantitatively for phenol, saponin, tannin, flavonoid, and alkaloid contents. Then, the in vitro antioxidant potential was estimated by DPPH, NO, H2O2 scavenging assays, and MC and FRAP assays. The most prevalent phytochemicals of LP were then analysed by AAS, FT-IR, UV-visible, and GC-MS techniques. A higher extractive yield was shown by LPSE and LPRE (7.37 ± 0.11 and 5.70 ± 0.02). The LP stem showed better physicochemical and qualitative results than the root. The quantitative and in vitro antioxidant results indicated maximal phenols, tannins, and alkaloid contents in LPSE, which was further confirmed by UV-visible, FT-IR, and GC-MS results. The extraction methods (soxhlation or ultrasonication) were optimized by utilizing RSM to determine the impacts of multiple parameters. The study concluded that the plant has remarkable therapeutic advantages to promote additional clinical investigations and the mechanisms of its action.

A comprehensive review on bitter gourd (Momordica charantia L.) as a gold mine of functional bioactive components for therapeutic foods

Bitter gourd is a tropical wine grown mainly in India, China and South East Asia. The plant is cultivated mainly for its fruit part which is edible. Bitter gourd is unaccepted widely due to its bitter taste. Nevertheless, the fruit is a source of several key nutrients. The plant, as a whole contains, more than 60 phyto-medicines that are active against more than 30 diseases, including cancer and diabetes. Currently, the incorporation of the bioactive compounds isolated from bitter gourd into functional foods and beverages finds a new horizon. Nanoencapsulation and novel green extraction methods can be employed to improve the yield and quality of extracted compounds and their stability while incorporation into food products. The present review is an attempt to throw light to nutritional aspects, various bioactive compounds present and important nutraceutical properties of the bitter gourd plant in detail.

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Plant Polyphenols, More than Just Simple Natural Antioxidants: Oxidative Stress, Aging and Age-Related Diseases

The present editorial serves as an introduction to the Special Issue "Antioxidant and Anti-aging Action of Plant Polyphenols". It also provides a summary of the polyphenols, their biological properties and possible functions as medicines, the importance of traditional medicines as a source of inspiration, the rationalization of new uses of plant extracts which lead to applications in modern medicine, the status of modern green-chemistry extraction methods, and some reflections on future prospects. Here, the articles from this Special Issue, and the main aspects of the antioxidant and anti-aging effects of plant polyphenols are discussed in the form of seven questions.

Phytochemistry, Pharmacological Activities, Toxicity and Clinical Application of Momordica cochinchinensis

Momordica cochinchinensis (Lour.) Spreng (M. cochinchinensis) is a deciduous vine that grows in Southeast Asia. It is known as gac in Vietnam and as Red Melon in English. Gac is reputed to be extremely benificial for health and has been widely used as food and folk medicine in Southeast Asia. In China, the seed of M. cochinchinensis (Chinese name: Mu biezi) is used as traditional Chinese medicine (TCM) for the treatment of various diseases. More than 60 chemical constituents have been isolated from M. cochinchinensis. Modern pharmacological studies and clinical practice demonstrate that some chemical constituents of M. cochinchinensis possess wide pharmacological activities, such as anti-tumor, anti-oxidation, anti-inflammatory, etc. This paper reviews the phytochemistry, pharmacological activities, toxicity, and clinical application of M. cochinchinensis, aiming to bring new insights into further research and application of this ancient herb.

Physicochemical Properties of Gac (Momordica cochinchinensis (Lour.) Spreng) Seeds and Their Oil Extracted by Supercritical Carbon Dioxide and Soxhlet Methods

Gac seeds are high in oil, but there are few studies on its extraction and characteristics. This study aimed to characterise Gac seeds and investigate the physicochemical properties of Gac seed oil extracted with supercritical carbon dioxide (SC-CO2) and hexane (Soxhlet). The Gac seed kernel accounted for 66.4 ± 2.7% of the seed weight, and 53.02 ± 1.27% of it was oil. The SC-CO2 oil had a higher quality than the Soxhlet oil for important criteria, such as peroxide (0.12 ± 0.02 vs. 1.80 ± 0.01 meq O2/kg oil), free fatty acid (1.74 ± 0.12 vs. 2.47 ± 0.09 mg KOH/g oil) and unsaponifiable matter (33.2 ± 1.5 vs. 52.6 ± 2.4 g/kg) values, respectively. It also had a better colour (light yellow vs. dark greenish brown) and a higher antioxidant capacity measured with the DPPH (52.69 ± 0.06 vs. 42.98 ± 0.02 µmol Trolox equivalent/g oil) and ABTS (2.10 ± 0.12 vs. 1.52 ± 0.06 µmol Trolox equivalent/g oil) assays. However, a higher yield (53.02 ± 1.27 vs. 34.1 ± 0.8%) was obtained for the Soxhlet oil. Unless refined, the oils would not be edible due to their high unsaponifiable matter, but the SC-CO2 oil would need less refining. Alternatively, the high unsaponifiable matter in the oil, especially in the Soxhlet oil, may make it useful for medicinal purposes.

Bioactive Composition, Antioxidant Activity, and Anticancer Potential of Freeze-Dried Extracts from Defatted Gac (Momordica cochinchinensis Spreng) Seeds

Background: Gac (Momordica cochinchinensis Spreng) seeds have long been used in traditional medicine as a remedy for numerous conditions due to a range of bioactive compounds. This study investigated the solvent extraction of compounds that could be responsible for antioxidant activity and anticancer potential. Methods: Defatted Gac seed kernel powder was extracted with different solvents: 100% water, 50% methanol:water, 70% ethanol:water, water saturated butanol, 100% methanol, and 100% ethanol. Trypsin inhibitors, saponins, phenolics, and antioxidant activity using the 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS), the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and the ferric reducing antioxidant power (FRAP) assays; and anticancer potential against two melanoma cancer cell lines (MM418C1 and D24) were analysed to determine the best extraction solvents. Results: Water was best for extracting trypsin inhibitors (581.4 ± 18.5 mg trypsin/mg) and reducing the viability of MM418C1 and D24 melanoma cells (75.5 ± 1.3 and 66.9 ± 2.2%, respectively); the anticancer potential against the MM418C1 cells was highly correlated with trypsin inhibitors (r = 0.92, p < 0.05), but there was no correlation between anticancer potential and antioxidant activity. The water saturated butanol had the highest saponins (71.8 ± 4.31 mg aescin equivalents/g), phenolic compounds (20.4 ± 0.86 mg gallic acid equivalents/g), and antioxidant activity, but these measures were not related to anticancer potential. Conclusions: Water yielded a Gac seed extract, rich in trypsin inhibitors, which had high anticancer potential against two melanoma cell lines.

Effect of Solvents and Extraction Methods on Recovery of Bioactive Compounds from Defatted Gac (Momordica cochinchinensis Spreng.) Seeds

Gac (Momordica cochinchinensis Spreng.) seeds contain bioactive compounds with medicinal properties. This study aimed to determine a suitable solvent and extraction technique for recovery of important compounds, namely, trypsin inhibitors, saponins, and phenolics. The antioxidant capacity and total solids of derived extracts were also measured. Water with conventional extraction method gave the highest value of trypsin inhibitor activity (118.45 ± 4.90 mg trypsin g−1) while water-saturated n-butanol and methanol extracts were characterized by their highest content of saponins (40.75 ± 0.31 and 38.80 ± 2.82 mg AE g−1, respectively). Aqueous extract with microwave assistance achieved the highest phenolics (3.18 ± 0.04 mg GAE g−1). As a measure of antioxidant capacity, the 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) assay gave highest value to the aqueous microwave extract (23.56 ± 0.82 μmol TE g−1) while the ferric reducing antioxidant power (FRAP) assay gave highest values to water-saturated n-butanol and 70% ethanol extracts (5.25 ± 0.04 and 4.71 ± 0.39 μmol TE g−1, respectively). The total solids value was highest using water with microwave assistance (141.5 g kg−1) while ultrasound treatment did not improve any extractions. Therefore, trypsin inhibitors are suitably recovered using water while water-saturated n-butanol or methanol is for saponins, both using a conventional method. Microwave extraction is suitable for phenolics recovery. These conditions are recommended for an efficient recovery of bioactive compounds from defatted Gac seeds.