Hung Tuck Chan’s research while affiliated with University of the Ryukyus and other places

Glycosyl hesperidin (GH) or hesperetin rutinoside has been patented in 1997 and 2000, and has been endorsed as a novel food in 2024. A flavanone mostly from Citrus fruits, GH can be synthesized by adding one glucose molecule to hesperidin. Pharmacological properties of GH are diverse with anti-hypertension, antimicrobial, anti-inflammatory, and anti-obesity being the major activities. Food additives, functional food, beverage, health supplement, and cosmetics are some of the uses of GH. Now a commercial product, GH is being sold in Japan, Taiwan, and Korea as a dietary supplement. From 2004 to 2023, a total of 13 clinical studies involving GH were reported in the literature. All conducted in Japan, their area of study included arthritis, triglyceride, blood flow, obesity, lower leg swelling, vasodilation, vascular flexibility, and hepatic function. In the concluding remarks, the prospects and fields for further research of GH are suggested.

In this article, the diversity of mangrove and associate species with anticancer properties are reviewed. Information included their scientific names, synonyms, common names, families and life-forms. Their anticancer properties are documented with description on cancer cell types, effects and mechanisms. Mangroves are exclusive species confined to the mangrove habitat. Plants that occur in the coastal environment and also in mangroves are associates or non-exclusive species. In this article, species with anticancer properties are 20 mangrove species belonging to 13 genera and 11 families, and 26 associate species belonging to 24 genera and 17 families possess. Most reported mangrove species are Avicennia marina and Ceriops tagal with five and four studies, respectively. Associate species most reported are Talipariti tiliaceum or Hibiscus tiliaceus with five studies, followed by Anacardium occidentale, Artocarpus altilis, Ceriops manghas, Pluchea indica and Pongamia pinnata with four studies each. In the conservation of mangrove and associate species with anticancer properties, in in-situ conservation, species are protected in their natural surroundings as ecosystems (e.g., virgin jungle reserves and Ramsar sites) while in ex-situ conservation, species are protected outside their natural habitats (e.g., arboreta and botanical gardens).

In this article, the diversity of mangrove and associate species with anticancer properties are reviewed. Information included their scientific names, synonyms, common names, families and life-forms. Their anticancer properties are documented with description on cancer cell types, effects and mechanisms. Mangroves are exclusive species confined to the mangrove habitat. Plants that occur in the coastal environment and also in mangroves are associates or non-exclusive species. In this article, species with anticancer properties are 25 mangrove species belonging to 17 genera and 11 families, and 31 associate species belonging to 28 genera and 20 families possess. Most reported mangrove species are Avicennia marina and Ceriops tagal with five and four studies, respectively. Associate species most reported are Talipariti tiliaceum or Hibiscus tiliaceus with five studies, followed by Anacardium occidentale, Artocarpus altilis, Ceriops manghas, Pluchea indica and Pongamia pinnata with four studies each. In the conservation of mangrove and associate species with anticancer properties, in in-situ conservation, species are protected in their natural surroundings as ecosystems (e.g., virgin jungle reserves and Ramsar sites) while in ex-situ conservation, species are protected outside their natural habitats (e.g., arboreta and botanical gardens).

The rich chemical constituents and diverse pharmacological properties of Ramulus Mori (RM) or the twig of Morus alba with evidence supported by clinical trials and patents are reviewed. Known as Sangzhi in Chinese, RM is widely used in traditional Chinese medicine to treat gout, arthritis, and rheumatism. Chemical constituents include flavonoids, benzofurans, alkaloids, stilbenes, chalcones, phenolic acids, and coumarins. Bioactivities of RM include antidiabetic, anti-obesity, anti-inflammatory, antityrosinase, neuroprotective, antioxidant, hepatoprotective, cytoprotective, renoprotective, antihyperuricemic, analgesic, antifungal, DNA protective, anticancer, gastroprotective, cardioprotective, anti-hair aging, anti-arthritic, and antiplatelet aggregation properties. The most active compounds from RM are mulberrin, oxyresveratrol, and mulberroside A. All four clinical trials on RM are focused on the treatment of diabetes. The patents entail using RM extracts as cosmetics for skin whitening and as agents for hypoglycemia. Topics for further research on RM are suggested.

In this review, the botany, uses, bioactive metabolites, and health-promoting benefits of Undaria pinnatifida (wakame) and Saccharina japonica (kombu) are highlighted. Their clinical evidence is focused on clinical studies conducted in Japan and in other countries. These two species are brown seaweeds (Phaeophyta). In Japan, wakame and kombu seaweeds are popular food items consumed almost daily. Laboratory evidence shows that carotenoids (fucoxanthin and fucoxanthinol), polysaccharides (fucoidan) and sterols (fucosterol) are bioactive metabolites in wakame and kombu. Wakame displays antioxidant, anti-inflammatory, anticancer, antihypertensive, antidiabetic, antiviral, anticoagulant, antiosteoporotic, hepatoprotective, and antiobesity properties. Kombu possesses anticoagulant, antithrombotic, anticancer, hypolipidemic, hypoglycemic, antiobesity, antithrombotic, antiatherosclerosis, renal protective, vascular protective, antioxidant, antimicrobial, anti-inflammatory, immunomodulatory, gut biota regulatory, hypoglycemic, hypolipidemic, and neuroprotective activities. Clinical evidence on the effects of wakame intake was based on eight studies in Japan and eight studies in other countries. Clinical evidence on the effects of kombu intake was based on five studies in Japan. One case study on kombu dealt with severe alopecia areata. Some areas for future research on wakame and kombu are suggested. Information and data used in this review were from databases such as Google, Google Scholar, PubMed, PubMed Central, Science Direct, J-Stage, PubChem, China Academic Journals, and ClinicalTrials.gov.

Alpinia zerumbet or shell ginger is a ginger plant with diverse chemical constituents and medicinal and non-medicinal uses. Dihydro-5,6-dehydrokawain (DDK) and Dehydrokawain (DK) are two kavalactones (also known as kava pyrones or styrylpyrones) from A. zerumbet. Both DDK and DK have a carbonyl group at C2, a methoxy group at C4, and a double bond at C5 and C6. DK has a double bond at C7 and C8 that is absent in DDK. Quantity of DDK in A. zerumbet can be ranked as rhizome > leaf > flower > stem > seed. The pericarp and seed placenta of the fruit has higher quantity of DDK than the leaf. In most plant parts, the contents of DDK are higher than those of DK. Hispidin (HP) is synthesized from DK by hydrolysis. These three kavalactones from A. zerumbet have the most promising pharmacological properties that include insecticidal, fungicidal, antioxidant, inhibition of enzymes, inhibition of Advanced Glycation End-products (AGEs), inhibition of p21-activated kinase 1 (PAK1), inhibition of LIM domain kinase 1 (LIMK1), promotion of hair growth, anti-cancer, inhibition of melanogenesis, anti-inflammatory, anti-obesity, HIV-1 integrase inhibition, neuraminidase inhibition, osteogenic, anti-platelet aggregation, cytoprotective, anti-ulcerative, and singlet oxygen quenching activities. Some fields for further research are suggested. Sources of information in this review were from Google, Google Scholar, Science Direct, PubMed, J-Stage, China National Knowledge Infrastructure (CNKI), and PubChem.

This overview on Volkameria inermis (Lamiaceae) is the first in updating information on the chemical constituents and pharmacological properties of the species, notably on its unique ability in ameliorating motor tics. The information was procured from Google, Google Scholar, PubMed, PubMed Central, Science Direct, J-Stage, and PubChem. Previously named Clerodendrum inerme (Verbenaceae), V. inermis is a scrambling or scandent coastal shrub in the tropics and sub-tropics. From different parts of the plant, compounds such as flavonoids, diterpenes/diterpenoids, sterols, triterpenes/triterpenoids, iridoid glycosides, phenolic glycosides, phenylethanoid glycosides (PEGs), phenylpropanoid glycosides (PPGs), chalcones, and sesquiterpenes have been reported. Major pharmacological properties of V. inermis include anti-cancer, anti-inflammatory, antioxidant, hepatoprotective, analgesic, and antibacterial activities. Other properties include anti-tyrosinase, antifungal, neuroprotective, hypotensive, hypoglycemic, amyloid-β aggregation, wound healing, antipyretic, and larvicidal activities. A unique pharmacological property of V. inermis leaf extract, discovered by scientists from Taiwan, is the amelioration of motor tic disorders, a spectrum of Tourette syndrome. This property included a case report, three in vivo studies, and one patent. Areas of further research of V. inermis are suggested.

Globally, there are eight species of Avicennia with five species (A. alba, A. integra, A. marina, A. officinalis and A. rumphiana) in East Africa and Indo-Pacific, and three species (A. bicolor, A. germinans and A. schaueriana) in the New World and West Africa (Duke, 1991; Spalding et al., 2010). Avicennia species occur in tropical, subtropical including temperate tidal habitats. Found on the mudflats of the foreshore, Avicennia species are the most widely distributed among the mangrove species. Among species of this genus, the geographical distribution of A. marina is the broadest due to its ability to adapt a wide range of environmental conditions (Baba et al., 2016). Trees of Avicennia are generally 10−25 m tall with some reaching up to 30 m. Leaves are simple, opposite, oval to pointed in shape, and have glands to secrete salt. Their pencil-like pneumatophores protrude above the ground, sprouting from underground cable roots. Inflorescences produce small clustered yellow flowers. Propagules are small, vary in shape, and are semi-viviparous with single seeds germinating promptly upon dispersal. Botanical descriptions of Avicennia are from Tan (2013). The wide spectrum of medicinal and non-medicinal uses of Avicennia species has been reviewed by Thatoi et al. (2016). Among the Avicennia species, A. rumphiana is localized in its distribution, reported in the Asia-Pacific countries of Indonesia, Malaysia, Papua New Guinea, Philippines, and Singapore. Thailand is the latest country where A. rumphiana occurs. Chemical compounds isolated from A. rumphiana include terpenoids, sterols and flavonoids. Recently, new and known naphthofuranquinones have been reported. From endophytic fungi, naphthofuranquinones and dihydroisocoumarins have been identified. Pharmacological properties of A. rumphiana include anti-quorum sensing, antioxidant, antibacterial, anti-trypanosomal and anti-cancer activities.

This chapter on Mangroves of Malaysia begins with a brief introduction on the geography of Malaysia, consisting of Peninsular Malaysia, Sabah, and Sarawak separated by the South China Sea. Information on the population, land area, and area of mangroves in Malaysia is presented. The largest area of mangroves is in Sabah, followed by Sarawak and Peninsular Malaysia. Globally, Malaysia’s mangroves rank sixth in country area after Indonesia, Brazil, Australia, Mexico, and Nigeria. In Malaysia, mangroves are classified into permanent forest reserves (PFRs) which consist of protection forest reserves, domestic forest reserves, mangrove forest reserves (MFRs), virgin jungle reserves (VJRs), and wildlife reserves. The other categories are state land mangroves and gazetted conservation areas. The other main sections of the chapter are Biodiversity; Livelihoods; Threats to Mangrove Ecosystems; and Restoration, Conservation, and Management. These sections are strengthened by six case studies. They include proboscis monkeys of Labuk Bay, Sabah; new genus and species of mangrove crab; mangrove wood carvings by the Mah Meri tribe; charcoal production in Matang, Peninsular Malaysia; wood vinegar production in Matang, Peninsular Malaysia; and long-term ecological research at Sepilok Laut, Sabah. These case studies highlight the sound management of mangroves in Malaysia. The section on Restoration, Conservation, and Management includes a success story of mangrove rehabilitation at Sungai ISME (International Society of Mangrove Ecosystems), a collaboration between the Sabah Forestry Department (SFD) and the International Society of Mangrove Ecosystems (ISME). Compared to mangrove rehabilitation projects in Kiribati and Gujarat implemented by ISME, the project in Sabah scores strongly in accessibility, collaboration, objectives, publicity, capacity building, voluntary participation, and sustainability. Learning from these examples can help in the development of a mangrove action plan (MAP) for Malaysia where a policy of integrated coastal management ensures the sustainability of mangrove ecosystems and their ecological services.