The Benefits of Plant Extracts for Human Health
Nature has always been, and still is, a source of foods and ingredients that are beneficial to human health. Nowadays, plant extracts are increasingly becoming important additives in the food industry due to their content in bioactive compounds such as polyphenols [1] and carotenoids [2], which have antimicrobial and antioxidant activity, especially against low-density lipoprotein (LDL) and deoxyribonucleic acid (DNA) oxidative changes [3]. The aforementioned compounds also delay the development of off-flavors and improve the shelf life and color stability of food products. Due to their natural origin, they are excellent candidates to replace synthetic compounds, which are generally considered to have toxicological and carcinogenic effects. The efficient extraction of these compounds from their natural sources and the determination of their activity in commercialized products have been great challenges for researchers and food chain contributors to develop products with positive effects on human health. The objective of this Special Issue is to highlight the existing evidence regarding the various potential benefits of the consumption of plant extracts and
plant extract-based products, along with essential oils that are derived from plants also and emphasize in vivo works and epidemiological studies, application of plant extracts to improve shelf-life, the nutritional and health-related properties of foods, and the extraction techniques that can be used to obtain bioactive compounds from plant extracts.
In this context, Concha-Meyer et al. [4] studied the bioactive compounds of tomato pomace obtained by ultrasound assisted extraction. In this review, it was presented that the functional extract obtained by ultrasounds had antithrombotic properties, such as platelet anti-aggregant activity compared with commercial cardioprotective products. Turrini et al. [5] introduced bud-derivatives from eight different plant species as a new category of botanicals containing polyphenols and studied how different extraction processes can affect their composition. Woody vine plants from Kadsura spp. belonging to the Schisandraceae family produce edible red fruits that are rich in nutrients and antioxidant compounds such as flavonoids. Extracts from these plants had antioxidant properties and had shown also key enzyme inhibitions [6]. Hence, fruit parts other than the edible mesocarp could be utilized for future
food additives applications using Kadsura spp. rather than these being wasted. Saji et al. [7] studied the possible use of rice bran, a by-product generated during the rice milling process, normally used in animal feed or discarded due to its rancidity, for its phenolic content. It was proved that rice bran phenolic extracts via their metal chelating properties and free radical scavenging activity, target pathways of oxidative stress and inflammation resulting in the alleviation of vascular inflammatory mediators. Villedieu-Percheron et al. [8] evaluated three natural diterpenes compounds extracted and isolated from Andrographis paniculata medicinal herb as possible inhibitors of NFκB (nuclear factor kappa-light-chain-enhancer of activated B cells) transcriptional activity of pure analogues. Yeon et al. [9] evaluated the antioxidant activity, the angiotensin I-converting enzyme (ACE) inhibition effect, and the α-amylase and α-glucosidase inhibition activities of hot pepper water extracts both before and after their fermentation. These water extracts were proved to have potentially inhibitory effects against both hyperglycemia and hypertension. The hydrolyzed extracts of Ziziphus jujube fruit, commonly called jujube, were examined for their protective effect against lung inflammation in mice [10]. They contained significant amounts of flavonoids which inhibited cytokine release from macrophages and promoted antioxidant defenses in vivo. Tran at al. [11] examined the antidiabetic activity of spray-dried Euphorbia hirta L. herb extracts containing high concentrations of bioactive compounds such as phenolics and flavonoids. Li et al. [12] reported that intestinal microbiota is closely associated with the initiation and progression of diabetes mellitus and reviewed bioactive components which exhibited anti-diabetic activity by modulating these intestinal microbiotas. Essential oils have promising activity against antibiotic-resistant bacteria and chemotherapeutic-resistant tumors. This was supported by the study of Viktorová et al. [13] where lemongrass essential oil and especially citral, the dominant component, proved to have potential antimicrobial and anticancer activity. Additionally, Mitropoulou et al. [14] investigated the antimicrobial potential of Sideritis raeseri subps. raeseri essential oil against common food spoilage and pathogenic microorganisms and evaluated its antioxidant and antiproliferative activity. Salehi et al. [15] reviewed the Berberis plants, which contain alkaloids, tannins, phenolic compounds and essential oils, and their possible use in the food and pharmaceutical industry. Last but not least, Kiokias et al. [16] reviewed the naturally occurring phenolic acids from plants and their antioxidant activities in o/w emulsions and in vitro lipid-based model systems.
Still more research is needed to explore more and in depth the health beneficial effects of
garcinia extract powder, since nature certainly has more to give to humans.
The antioxidative activity of a total of 92 phenolic extracts from edible and
cosmetics raw material(berries, fruits, vegetables, herbs, cereals, tree materials, plant sprouts, and seeds) was examined by autoxidation of methyl linoleate. The content of total phenolics in the extracts was determined spectrometrically according to the Folin?Ciocalteu procedure and calculated as gallic acid equivalents (GAE). Among edible plant materials, remarkable high antioxidant activity and high total phenolic content (GAE > 20 mg/g) were found in berries, especially aronia and crowberry. Apple extracts (two varieties) showed also strong antioxidant activity even though the total phenolic contents were low (GAE < 12.1 mg/g). Among nonedible
plant oils, high activities were found in tree materials, especially in willow bark, spruce needles, pine bark and cork, and birch phloem, and in some medicinal plants including heather, bog-rosemary, willow herb, and meadowsweet. In addition, potato peel and beetroot peel extracts showed strong antioxidant effects. To utilize these significant sources of natural antioxidants, further characterization of the phenolic composition is needed.
This investigation examined the molluscicidal and larvicidal activity of eight plants that are used in the traditional medicine of the Pankararé indigenous people in the Raso da Catarina region, Bahia state, Brazil. The tested plants were chosen based on the results of previous studies. Only those plants that were used either as insect repellents or to treat intestinal parasitic infections were included in the study. Crude extracts (CEs) of these plants were tested for their larvicidal activity (against Aedes aegypti larvae in the fourth instar) and molluscicidal activity (against the snail Biomphalaria glabrata). The plant species Scoparia dulcis and Helicteres velutina exhibited the best larvicidal activities (LC50 83.426?mg/L and LC50 138.896?mg/L, resp.), and Poincianella pyramidalis, Chenopodium ambrosoides, and Mimosa tenuiflora presented the best molluscicidal activities (LC50 0.94?mg/L, LC50 13.51?mg/L, and LC50 20.22?mg/L, resp.). As we used crude extracts as the tested materials, further study is warranted to isolate and purify the most active compounds.
The Brazilian northeast is the poorest region of Brazil and has the worst Human Development Indices [1]. Most of this population is subjected to neglected tropical diseases that predominantly affect the poorest and most vulnerable groups, contributing to the perpetuation of poverty, inequality, and social exclusion [2].
Schistosomiasis and dengue fever cause major public health concerns in Brazil and other tropical developing countries. Schistosomiasis is caused by the parasite, Schistosoma mansoni, which uses the Biomphalaria glabrata snail as an essential intermediate host in its life cycle. Dengue fever is caused by an arbovirus of the Flaviviridae family and is transmitted by the mosquito, Aedes aegypti.
The number of cases of dengue has grown in Brazil, with epidemics in the most densely populated urban areas. However, natural products with different biocidal activities can help to fight parasite vectors at the adult or larval stages and can act as alternatives to synthetic products due to their rapid biodegradation and lower cost [3].
Molluscicides have been used as a general strategy to eliminate the snail that transmits schistosomiasis [4]. According to the World Health Organization (WHO), the use of drug therapy in conjunction with the use of molluscicides is the use the most valuable method to control schistosomiasis in areas with intermediary hosts. The synthetic substance, niclosamide (Bayluscide), has been used as the standard molluscicide since the 1960s, as it is efficient in controlling snails; however, the high cost of niclosamide and the fact that it decomposes rapidly in the presence of sunlight have limited the use of this drug [5].
Popular knowledge has been an important source of information for scientific research in several areas of study. Ethnopharmacological and ethnobotanical investigations have been used as the main strategy for selecting medicinal plants, thereby shortening the time for the discovery of new drugs, whereas ethnodirected research consists of selecting species based on information from population groups [6].
Evidence for the efficacy and safety and the immediate availability of plant-derived products for the control or eradication of such diseases would be of great value because part of the population living in the affected areas use plants and animals as one of the few options for disease treatment [7–9].
Studies have found evidence that standard methods control the dengue-related mosquito larvae with low efficacy, a situation that demonstrates the need for other means to fight the proliferation of dengue [10] given the fact that results in epidemiology are context-dependent [11]. Similarly, despite the fact that a national schistosomiasis control program was implemented in 1975, the disease still occurs in 19 states and is endemic to eight states.
Ethnobiological studies have been carried out on the indigenous Pankararé people since 1993 [12]. In 2006 [13], the use of 64 plants was reported, 20 of which were used for medicinal purposes. Indeed, there is evidence that the Pankararé—in the Esta??o Ecologica Raso da Catarina (a conservation area), Bahia state—have a profound knowledge regarding the benefits of plants.
This study examines the molluscicidal and larvicidal effects of eight plants used by the Pankararé indigenous people for medicinal purposes. The aim of the study is to look for evidence of alternative methods to fight vectors of schistosomiasis and dengue, taking into account local potentialities.
The indigenous lands of the Pankararé are located in one of the driest of the Brazilian regions, with an average annual rainfall of between 450 and 600?mm [14] and an average annual temperature of 25°C; the climate is arid and semiarid. The natural vegetation is tropical dry forest of the type hyperxerophylous steppic savanna.
The Pankararé have a long history of interaction with their regional neighbors and are a peasant social group that sees itself as a distinct ethnic group among the regional populations (from the social organization standpoint, this is termed Indigenous Peasantry). In Brazilian indigenous communities, the central political figure is the Cacique [15]. The Pankararé comprise a very poor group that has a long history of territorial disputes. They practice subsistence agriculture, farm livestock on a small scale, and engage in other activities, such as hunting, the collection of honey and wild fruits, and handicrafts [16].