Analysis of Phytonutrients, Anti-Mutagenic and Chemopreventive Effects of Tropical Fruit Extracts

Optimized Conditions for the Extraction of Phenolic Compounds from Aeginetia indica L. and Its Potential Biological Applications

Aeginetia indica L., a parasitic root in the Orobanchaceae family, is used as a food colorant in traditional Thai desserts. However, scant information is available on its food applications as well as medicinal properties, while overharvesting by the local people has severely depleted wild plant populations. This research, thus, aimed to extract optimized total phenolic content (TPC) in varying extraction conditions using response surface methodology (RSM) and the Box-Behnken design (BBD). Results indicated that an extraction temperature of 90 °C, 80% (v/v) aqueous ethanol, and 0.5% (w/v) solid-to-liquid ratio yielded the highest TPC at 129.39 mg gallic acid equivalent (GAE)/g dry weight (DW). Liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) identified the predominant phenolics as apigenin (109.06 mg/100 g extract) and luteolin (35.32 mg/100 g extract) with trace amounts of naringenin and rutin. Under the optimal extraction condition, the plant extract exhibited antioxidant activities of 5620.58 and 641.52 µmol Trolox equivalent (TE)/g DW determined by oxygen radical absorbance capacity (ORAC) and ferric ion reducing antioxidant power (FRAP) assay, while the scavenging capacity of total radicals at 50% (SC50) was determined to be 135.50 µg/mL using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay. The plant extract also exhibited inhibitory activities against the key enzymes relevant to type II diabetes, obesity, and Alzheimer's disease, suggesting the potential for medicinal applications.

Phenolic profiles and in vitro biochemical properties of Thai herb ingredients for chronic diseases prevention

Traditional remedies using natural ingredients have been handed down over generations, providing collective information for the development of modern therapeutics. These natural products have a long history of safe consumption with curative effects but lack of scientific-based evidence hinders the mass production of new remedies containing active ingredients with particular medicinal properties. This research investigated the phenolic profiles and biochemical properties of 29 herbal ingredients identified in two traditional Thai remedies, Prasachandaeng (PSCD) and Chantaharuethai (CHRT), and their effectiveness in combating chronic diseases. These two traditional remedies are used to reduce fever but some ingredients have been previously reported to possess other health-related properties. Statistical analysis by TOPSIS indicated that Biancaea sappan (L.) Tod. extract exhibited the highest overall closeness coefficient (C) score analyzed from all variables including total phenolic contents, antioxidant potentials, and enzyme inhibitions. Bouea macrophylla Griff. extract showed potential as an effective agent against diabetes through inhibition of two carbohydrate degrading enzymes, α-glucosidase and α-amylase, while Dischidia major (Vahl) Merr. showed strong properties as an anti-angiotensin-converting enzyme, leading to the control of hypertension. Dracaena cochinchinensis (Lour.) S.C. Chen effectively controlled the progression of Alzheimer's disease through the inhibition of cholinergic and β-amyloid formation enzymes. These results can be used as preliminary data for the development of new remedies to prevent or treat particular chronic diseases.

Optimization of Phytochemical-Rich Citrus maxima Albedo Extract Using Response Surface Methodology

In the present study, response surface methodology (RSM) and Box-Behnken design (BBD) were employed to optimize the conditions for the extraction of C. maxima albedo from agricultural waste, to obtain notable phytochemicals. Ethanol concentration, extraction temperature, and extraction time were included as key factors contributing to the extraction. The results showed that the optimum extraction condition for C. maxima albedo was 50% (v/v) aqueous ethanol at 30 °C for 4 h, which provided total phenolic contents and total flavonoid contents at 15.79 mg of gallic equivalent/g dry weight (DW) and 4.50 mg of quercetin equivalent/g DW, respectively. Considerable amounts of hesperidin and naringenin at 161.03 and 3430.41 µg/g DW, respectively, were detected in the optimized extract using liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS). The extract was later subjected to a test for its enzyme-inhibitory activities against key enzymes relevant to Alzheimer's disease (AD), obesity, and diabetes as well as for its mutagenicity potential. Among enzyme inhibitory activities, the extract showed the highest inhibitory strength against β-secretase (BACE-1), which is a drug target for AD treatment. The extract was also devoid of mutagenicity properties. Overall, this study demonstrated a simple and optimal extraction procedure for C. maxima albedo with a significant quantity of phytochemicals, health benefits, and genome safety.

Effect of Thermal Processes on S-Allyl Cysteine Content in Black Garlic

As a key component of black garlic (BG) products, S-allyl cysteine (SAC) is useful in reducing oxidative stress and inflammation. Several BG products with a high SAC content have been developed by thermal processing; however, the optimum conditions for thermal treatment for producing Thai garlic (multicloves) with a high SAC content compared to Chinese garlic (single clove) are still unknown. Moreover, the mechanism underlying the increase in SAC content in BG is unclear. Thus, this study aimed to investigate the optimum thermal condition for developing Thai BG with high SAC content base on methods A (70 °C and 80% RH) and B (60–75 °C and 80–85% RH). The total phenolic contents and antioxidant activities of Thai fresh garlic, Thai BG, and their powder forms were also compared. Method A worked the best for both types of garlic. The results indicated that the SAC content increased significantly after 7 days of fermentation and decreased drastically afterward with prolonged heat treatment. The optimum thermal condition for producing Thai fresh garlic and Chinese fresh garlic with high SAC content was 70 °C and a relative humidity of 80% for 12 days in an industrial fermentation chamber. The SAC content of Thai BG and Chinese BG increased approximately 139- and 122-fold, respectively. Furthermore, significant antioxidant capabilities determined by ferric ion-reducing antioxidant power, 2,2-diphenyl-1-picrylhydrazyl radical scavenging, and oxygen radical absorbance capacity assays were 34-, 6-, and 3-fold higher, respectively, than those of fresh garlic.

Nutrients, Phytochemicals and In Vitro Disease Prevention of Nephelium hypoleucum Kurz Fruit

Nephelium hypoleucum Kurz is an evergreen tree in the Sapindaceae family, mostly found in the forests of some Southeast Asia countries, especially Thailand. The lack of biological information regarding this tree has led to inappropriate agricultural management, conservation and utilization. Thus, this study aims to examine the nutritional composition, organic acid and phenolic profiles and in vitro health properties through several key enzyme inhibitions against some civilization diseases including Alzheimer's disease (β-secretase (BACE-1), butyrylcholinesterase (BChE) and acetylcholinesterase (AChE)), obesity (lipase), hypertension (angiotensin-converting enzyme (ACE)) and diabetes (dipeptidyl peptidase-IV (DPP-IV), α-amylase and α-glucosidase) on the aril (flesh) part of N. hypoleucum Kurz fruit. The remaining fruit parts including the pericarp (peel) and seed were also assessed as sources of potential phenolics as well as key enzyme inhibitors. As results, carbohydrate (17.18 g) was found to be a major source of energy (74.80 kcal) in the aril (100 g fresh weight), with trace amounts of protein (0.78 g) and fat (0.32 g). The fruit aril also contained high insoluble dietary fiber (5.02 g) and vitamin C (11.56 mg), while potassium (215.82 mg) was detected as the major mineral. Organic acid profile indicated that the aril was rich in citric acid, while the phenolic profile suggested predominant quercetin and kaempferol. Interestingly, high gallic acid contents were detected in both pericarp and seed, with the latter 3.2-fold higher than the former. The seed also possessed the highest total phenolic content (TPC, 149.45 mg gallic acid equivalent/g dry weight), while total anthocyanin content (TAC, 0.21 mg cyanidin-3-O-glucoside equivalent/g dry weight) was only detected in pericarp. High TPC also led to high enzyme inhibitory activities in seed including BACE-1, AChE, BChE, ACE, DPP-IV and α-glucosidase. Interestingly, aril with the highest α-amylase inhibition suggested strong inhibitory distribution, predominantly from quercetin and kaempferol. Lipase inhibitory activities were only detected in the aril and pericarp, suggesting the biological function of these two phenolics and possibly anthocyanins.

Phenolic Profiles and Bioactivities of Ten Original Lineage Beans in Thailand

Legumes and pulses are important food components with various phytochemicals and health benefits. However, the health-related bioactivities of some underutilized species remain uninvestigated. To breed a new bean lineage with particular health-related properties, this study investigated phenolics (specifically, isoflavones) and the in vitro inhibitory activities of the enzyme relevant to some non-communicable diseases in underutilized cultivars of Phaseolus lunatus (lima beans), compared to the commonly consumed P. vulgaris (red kidney bean) and beans in the Glycine and Vigna genera. The results indicated that soybeans in the Glycine genus contained the highest isoflavone contents, especially glycitein (1825-2633 mg/100 g bean) and daidzein (1153-6471 mg/100 g bean), leading to potentially higher enzyme inhibitory activities (25-26% inhibition against α-amylase, 54-60% inhibition against α-glucosidase, 42-46% inhibition against dipeptidyl peptidase IV, 12-19% inhibition against acetylcholinesterase and 20-23% inhibition against butyrylcholinesterase) than those from other genera. Interestingly, lima beans with low isoflavone content (up to 2 mg/100 g bean) still possessed high inhibitory activities against lipase (12-21% inhibition) and β-secretase (50-58% inhibition), suggesting that bioactive compounds other than the isoflavones might be responsible for these activities. Isoflavone contents and enzyme inhibitory activities in Vigna beans were diverse, depending on the particular cultivars. The information gained from this study can be used for further investigation of bioactive components and in-depth health properties, as well as for future breeding of a new lineage of bean with specific health potentials.

Papaya (Carica papaya L.) for cancer prevention: Progress and promise

Cancer is a leading cause of morbidity and mortality across the globe. Emerging evidence suggests that consumption of a well-balanced diet containing a wide variety of vegetables, fruits, and whole grains can prevent the development of, halt, or reverse cancer progression. Carica papaya L. (papaya) has a wide distribution throughout many countries. Although the fruits of C. papaya are primarily consumed as food, various parts of this tree, including the bark, fruits, latex, seeds, and roots, have been used in traditional medicine for health promotion and disease mitigation. While numerous individual studies have investigated anticancer efficacies of various products and constituents of C. papaya, an up-to-date, comprehensive, and critical evaluation of available research data covering its role in the prevention and intervention of various human malignancies has not been conducted according to our knowledge. The purpose of this review is to present a systematic, comprehensive, and critical analysis of the cancer-preventive potential of C. papaya extracts, fractions, and isolated phytochemicals with a special emphasis on the cellular and molecular mechanisms of action. Moreover, the bioavailability, pharmacokinetics, and safety profiles of individual phytochemicals of C. papaya, as well as current limitations, challenges, and future directions of research, have also been discussed.

Mangifera indica ‘Namdokmai’ Prevents Neuronal Cells from Amyloid Peptide Toxicity and Inhibits BACE-1 Activities in a Drosophila Model of Alzheimer’s Amyloidosis

Alzheimer’s disease (AD) is a progressive neurological illness with few effective treatments. Thus, ameliorating the effects of AD using natural products has attracted global attention with promising efficacy and safety. In this study, ten tropical fruits including Ananas comosus ‘Phulae’, Ananas comosus ‘Pattavia’, Carica papaya ‘Khaekdum’, Carica papaya ‘Khaeknuan’, Durio zibethinus ‘Monthong’, Durio zibethinus ‘Chanee’, Psidium guajava ‘Kimju’, Psidium guajava ‘Keenok’, Mangifera indica ‘Kaew’ and Mangifera indica ‘Namdokmai’ were screened for their inhibitory activities against the key enzymes, cholinesterases and β-secretase (BACE-1), involved in AD pathogenesis. The top three fruit extracts with promising in vitro anti-AD activities were further investigated using rat pheochromocytoma PC-12 neuronal cell line and Drosophila AD model. Data showed that M. indica ‘Kaew’, M. indica ‘Namdokmai’ and P. guajava ‘Kimju’ reduced Aβ1–42-mediated neurotoxicity by promoting glutathione-dependent enzymes, while M. indica ‘Namdokmai’ limited Aβ1–42 peptide formation via BACE-1 inhibition and amended locomotory behavior of the Drosophila AD model. Results indicated the potential anti-AD properties of tropical fruits, particularly M. indica ‘Namdokmai’ in the prevention of Aβ1–42-mediated neurotoxicity and as a BACE-1 blocker.

Impact of Drying Processes on Phenolics and In Vitro Health-Related Activities of Indigenous Plants in Thailand

Thailand has vast areas of tropical forests with many indigenous plants, but limited information is available on their phytochemical profile and in vitro inhibitions of enzymatic and nonenzymatic reactions. This study investigated phenolic profiles using liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS), antioxidant activities, and in vitro inhibitory activities of 10 indigenous plants on key enzymes related to obesity (lipase), diabetes (α-amylase and α-glucosidase), and Alzheimer's disease (cholinesterases and β-secretase). The nonenzymatic anti-glycation reaction was also investigated. The 10 indigenous plants were Albizia lebbeck (L.) Benth, Alpinia malaccensis (Burm.) Roscoe, Careya arborea Roxb., Diplazium esculentum (Retz.) Swartz, Kaempferia roscoeana Wall., Millettia brandisiana Kurz., Momordica charantia, Phyllanthusemblica L., Zingiber cassumunar Roxb, and Zingiber citriodorum J. Mood & T. Theleide. Preparations were made by either freeze-drying or oven-drying processes. Results suggested that the drying processes had a minor impact on in vitro inhibitions of enzymatic and nonenzymatic reactions (<4-fold difference). P. emblica was the most potent antioxidant provider with high anti-glycation activity (>80% inhibition using the extract concentration of ≤6 mg/mL), while D. esculentum effectively inhibited β-secretase activity (>80% inhibition using the extract concentration of 10 mg/mL). C. arborea exhibited the highest inhibitory activities against lipase (47-51% inhibition using the extract concentration of 1 mg/mL) and cholinesterases (>60% inhibition using the extract concentration of 2 mg/mL), while Mi. brandisiana dominantly provided α-amylase and α-glucosidase inhibitors (>80% inhibition using the extract concentration of ≤2 mg/mL). Information obtained from this research may support usage of the oven-drying method due to its lower cost and easier preparation step for these studied plant species and plant parts. Furthermore, the information on in vitro inhibitions of enzymatic and nonenzymatic reactions could be used as fundamental knowledge for further investigations into other biological activities such as cell culture or in vivo experiments of these health-beneficial plants.