Plant Source Foods
Chuong Pham-Huy, Bruno Pham Huy in Food and Lifestyle in Health and Disease, 2022
The gymnosperms are non-flowering or seed-producing plants such as Cycas, Pinus, Ginkgo in which ovules are not enclosed by any ovary wall; hence they are called naked-seeded plants. In angiosperms or flowering plants, the male sex organs (stamen) and female sex organs (pistil) are borne in a same flower. The anther produces pollen grains (male gametophyte). The pistil consists of an ovary enclosing one to many ovules. Within the ovule is the female gametophyte or embryo sac which contains the egg cell. The angiosperms are divided into two classes: the monocotyledons or monocots (seed with a single cotyledon or one embryonic leaf) and the dicotyledons or dicots (seed having two cotyledons or two embryonic leaves) (2). They range in size from tiny, aquatic Wolffia to tall trees of Eucalyptus (over 100 m). Plants provide us with food, fodder, fuel, medicines, and several other commercially important products (2).
Scheme for Investigating Sexual Assault Cases
Paul T. Jayaprakash in Crime Scene Investigation and Reconstruction, 2023
Pollen is a fine-to-coarse powder, and the pollen grains are small in size—usually between about 20 µm and 60 µm. They form effective transferred trace evidence since they can stick to objects in the scene of crime without any visible sign that they have stuck. In addition, the intricate and species-specific structural variations in pollen grains enable identification of origin from different plant sources. Analysis of pollen evidence enables in establishing possible contact among a victim, suspect, and the scene of crime. Pollen can also be useful in describing the location of dust samples including dust on clothing (Mildenhall et al., 2006; Walsh and Horrocks, 2008). Pollen need not be restricted to crime activity undertaken outdoor since pollen transfer has been noted from indoor flowers also (Mildenhall et al., 2006).
Fluorescence in Phytopreparations
Victoria Vladimirovna Roshchina in Fluorescence of Living Plant Cells for Phytomedicine Preparations, 2020
Pollen grains which are generative, microspores with male gametes are important for humans for many reasons. First, they define the normal breeding of forests and herbs, economic and medicinal plant species. Most significant is the maturing and fertility of pollen as the male gametophyte for the fertilization of the female gametophyte, leading to the formation of fruits and seeds (Stanley and Linskens 1974; Kabailiene 2010; Heslop-Harrison 2014). Pollen grains are carriers of the plant’s genetic material needed for pollination, and these plant male spores are a part of sexual plant reproduction. However, due to their microcapsular organization, it is possible to use them in pharmacy as drug transporters (Diego-Toboada et al. 2014). The external shells of such materials have many properties, such as good elasticity, physical and chemical resistance, UV shielding capability, and antioxidant activity. These properties enable the plant to protect its genetic material from external factors, such as oxidation by air, sunlight, and physical stress. This shell has two distinct layers: the inner layer, called the intine, which is composed largely of cellulose, and an external layer, called the exine, which consists mainly of a polymer known as sporopollenin. This polymer is composed of carbon, hydrogen, and oxygen, and although its exact structure remains unknown, it has been described as an oxidative polymer of carotenoids or polyunsaturated fatty acids as well as conjugated phenols.
Purified and specific cytoplasmic pollen extract: a non-hormonal alternative for the treatment of menopausal symptoms
Published in Gynecological Endocrinology, 2020
Andrea Genazzani, Nick Panay, Tommaso Simoncini, Herman Depypere, Alfred Mueck, Christian Egarter, Nicoletta Biglia, Tomas Fait, Martin Birkhaeuser, Sven O. Skouby, Mark Brincat, Steven Goldstein, Xiangyan Ruan, Cuauhtémoc Celis-Gonzales, Santiago Palacios
Pollen (from the Greek ϖάλη [pale]: flour or dust) constitutes the male gametophyte of the flower. It is composed of minuscule ovoid grains measuring 20–55 μm in diameter that are initially contained at the end of stamens and are surrounded by a shell called an exine. The function of this pollen shell is to protect the genetic material. Well-known allergens are located on the external shell, whereas the center of the pollen contains the cytoplasm [7]. Germination occurs when the pollen is transported by wind or bees to a compatible female pistil. The male gametophyte produces a pollen tube that transfers the sperm to the egg, which contains the female gametes. Pollen has long been used for therapeutic purposes by various civilizations (e.g. Ancient Egypt and China, as far back as 200 BC). The chemical composition of pollen depends largely on the plant source and geographic origin, together with factors such as climatic conditions, soil type, and the activity and race of the bees. However, since pollen may be of unspecific origin (from unknown plants) and may be mixed with other bee products, standardization is difficult [8]. In addition, when the grain is unopened, its components can be partially assimilated because the pollen shell cannot be damaged by stomach acid [9,10]. The shell proteins are meant to be highly allergenic [9,10]. Gôsta Carlsson, a Swedish gynecologist, is considered the ‘father’ of the pollen extraction method. In the 1940s, he took an empirical approach to this field, with the hypothesis that the administration of pollen extracts could return strength and vigor to elderly patients.
Safety of non-hormonal medications for managing hot flashes
Published in Expert Opinion on Drug Safety, 2022
Pasquale De Franciscis, Maurizio Guida, Antonio Schiattarella, Gaetano Riemma, Nicola Colacurci
The word ‘pollen’ is derived from Greek (‘flour’ or ‘dust’) and represents the microgametophytes of seed plants. It comprises grains containing externally vegetative and non-reproductive cells, within a generative cell [32]. The chemical composition largely depends on the plant source and geographic origin along with climatic conditions, soil type, and bees’ activity and species. The commercially available product is a combination of purified pollen/pistil cytoplasmic extracts. The ability of pollen extracts to relieve menopausal complaints is based on a free-estrogenic action. Although the exact mechanism is not well-understood, pollen extract seems to have a selective serotonin reuptake inhibitor (SSRI)-like effect [32] expressed in different ways: an increased serotonergic signal with the blockage of the relapse, a stimulation of hypothalamic serotonergic neurons due to the action of precursor substances of serotonin (tryptophan and methyl-serotonin), and a reduced conversion of serotonin into its inactive 5-hydroxyindoleacetic acid metabolite due to monoamine oxidase inhibitors [32,33].
Extracts of different pollen species and their effect on human tear fluid and an epithelial cell line
Published in Cutaneous and Ocular Toxicology, 2019
Dieter Franz Rabensteiner, Jasmin Rabensteiner, Jutta Horwath-Winter, Doris Lang-Loidolt, Andreas Wedrich, Andrea Heidinger, Gerold Schwantzer, Otto Schmut
Dried pollen getting in contact with any fluid, immediately bloat and release their content through small pores in their outer membrane into the environment. Our biochemical investigation of pollen species from different plant families confirmed the presence of various pollen proteins among other substances. Zymography identified some of the proteins as proteolytically active proteases. Depending on the type of proteases, their enzymatic activity varied1,16,28–31. PAGE revealed the degradation of tear fluid proteins by most of the pollen species from different plant families. Interestingly, there were almost no visible bands in the zymography and PAGE of European chestnut, European hornbeam and Maple. A possible explanation might be the increased presence of lipids in the coating of some of the pollen species compared to others, thus making it more difficult to obtain the content of the pollen for the generation of pollen extracts. A limitation of our study is, that only tear fluid from a few subjects has been studied. Especially, for the comparison between allergic and nonallergic subjects a larger sample size is warranted.
Related Knowledge Centers
- Dietary Supplement
- Ploidy
- Sperm
- Sporopollenin
- Gamete
- Meiosis
- Paleontology
- Forensic Science
- Micrograph
- Meiocyte