The Whitening Properties of the Mixture Composed of Pomegranate, Osmanthus and Olive and the Protective Effects Against Ultraviolet Deleterious Effects

Allelopathic Substances of Osmanthus spp. for Developing Sustainable Agriculture

Osmanthus fragrans Lour. has been cultivated for more than 2500 years because of the fragrance and color of the flowers. The flowers and roots have been used in tea, liquors, foods, and traditional Chinese medicine. The species contains more than 180 compounds including terpenoids, phenylpropanoids, polyphenols, flavonoids, and sterols. However, there has been limited information available on the allelopathic properties and allelopathic substances of O. fragrans. We investigated the allelopathy and allelopathic substances of O. fragrans and Osmanthus heterophyllus (G.Don) P.S. Green, as well as Osmanthus × fortunei Carrière, which is the hybrid species between O. fragrans and O. heterophyllus. The leaf extracts of O. fragrans, O. heterophyllus, and O. × fortunei suppressed the growth of cress (Lepidium sativum L.), alfalfa (Medicago sativa L.), Lolium multiflorum Lam., and Vulpia myuros (L.) C.C.Gmel with the extract concentration dependently. The extract of the hybrid species O. × fortune was the most active among the extracts. The main allelopathic substances of O. × fortunei and O. fragrans were isolated and identified as (+)-pinoresinol and 10-acetoxyligustroside, respectively. (+)-Pinoresinol was also found in the fallen leaves of O. × fortunei. Both compounds showed an allelopathic activity on the growth of cress and L. multiflorum. On the other hand, several allelopathic substances including (+)-pinoresinol may be involved in the allelopathy of O. heterophyllus. O. fragrans, O. heterophyllus, and O. × fortunei are evergreen trees. but their senescent leaves fall and cover the soil under the trees. It is possible that those allelopathic substances are liberated through the decomposition process of the leaves into their rhizosphere soil, and that they accumulate in the soil and provide a competitive advantage to the species through the inhibition of the growth of the neighboring competing plants. Therefore, the leaves of these Osmanthus species are allelopathic and potentially useful for weed management options in some agriculture settings to reduce commercial herbicide dependency for the developing sustainable agriculture systems.

The melanin inhibitory effect of plants and phytochemicals: A systematic review

BACKGROUND

Melanin plays an important role in protecting human skin, while excessive synthesis of melanin can cause abnormal pigmentation and induce skin diseases. Long-term use of commercial whitening agents in managing skin melanin such as kojic acid and arbutin can lead to some negative effects such as dermatitis and liver cancer. Although past studies have researched the melanin inhibitory effect of plant extracts, the effective dose and mechanisms are not well summarized and discussed. This study aims to explore the melanin inhibitory property of phytochemicals and tries to answer the following research questions: (1) Which plant extracts and phytochemicals could inhibit melanin biosynthesis in the skin? what is the mechanism of action? (2) Have human trials been conducted to confirm their melanin inhibitory effect? (3) If not, which phytochemicals are recommended for further human trials? This article would provide information for future research to develop natural and safe skin whitening products.

METHODS

A preferred reporting items for systematic reviews and meta-analyses (PRISMA) systematic review method and OHAT risk-of-bias tool were applied to screen literature from 2000 to 2021 and 50 research articles met the selection criteria.

RESULTS

Flavonoids, phenolic acids, stilbenes and terpenes are main classes of phytochemicals responsible for the melanin inhibitory effects. The in vitro/in vivo melanin inhibitory effects of these plant extracts/phytochemicals are achieved via three main mechanisms: (1) the ethyl acetate extract of Oryza sativa Indica cv., and phytochemicals such as galangin and origanoside could manage melanin biosynthesis through competitive inhibition, non-competitive inhibition or mixed-type inhibition of tyrosinase; (2) phytochemicals such as ginsenoside F1, ginsenoside Rb1 and 4‑hydroxy-3-methoxycinnamaldehyde could inhibit melanogenesis through down-regulating microphthalmia-related transcription factor (MITF) gene expression via different signalling pathways; (3) the ethanolic extracts of Dimorphandra gardneriana, Dimorphandra gardneriana, Lippia microphylla and Schinus terebinthifolius have a good ultraviolet absorption ability and high sun protective factor (SPF) values, thereby inhibiting UV induced melanogenesis in the skin.

CONCLUSION

Although many plant extracts and phytochemicals have been found to inhibit melanin production, most of the results were only proved in cellular and/or animal models. Only the ethyl acetate extract of Oryza sativa Indica cv. panicle, and ginsenoside F1 were proved effective in human trials. Animal studies proved the effectiveness of galangin, origanoside, ginsenoside Rb1 and 4‑hydroxy-3-methoxycinnamaldehyde with effective dose below 3 mM, and therefore recommended for future human trial. In addition, cellular studies have demonstrated the effectiveness of oxyresveratrol, mulberroside A, kurarinol, kuraridinol, plumbagin, (6aR,11aR)-3,8-dihydroxy-9‑methoxy pterocarpan, ginsenoside Rh4, cardamonin, nobiletin, curcumin, β-mangostin and emodin in inhibiting melanin synthesis at low concentrations of 20 µM and proved the low SPF values of Dimorphandra gardneriana, Dimorphandra gardneriana, Lippia microphylla and Schinus terebinthifolius extracts, and therefore recommended for further animal and human trials.

Traditional uses, phytochemical constituents and pharmacological properties of Osmanthus fragrans: A review

ETHNOPHARMACOLOGICAL RELEVANCE

Osmanthus fragrans Lour., is a medicinal plant distributed widely in some Asian countries including Japan and Korea and southwestern China. It has been used traditionally for the treatment of weakened vision, halitosis, panting, asthma, cough, toothache, stomachache, diarrhea, rheumatism, physique pain and hepatitis.

AIM OF THE REVIEW

Recent advances in traditional uses, botanical characteristics, distribution, taxonomy, phytochemical constituents, biological effects as well as the toxicities of O. fragrans are comprehensively presented and critically evaluated, and the underlying mechanism associated with the bioactivities of extracts, essential oil and components from this plant is also well summarized. In order to provide comprehensive scientific basis for the medical application and help interested researchers discover food and medicinal natural products from O. fragrans.

MATERIALS AND METHODS

All information was systematically gathered from globally accepted scientific databases by Internet databases, including Elsevier, ScienceDirect, PubMed, Web of Science, Wiley, Springer, SciFinder, ACS Publications, CNKI, WanFang, Google Scholar, Baidu Scholar, The Plant List Database, and other literature sources (Ph.D. and MSc dissertations). All published contributions on O. fragrans different languages were included and cited. The chemical structures of all isolated compounds were drawn by using ChemBioDraw Ultra 14.0 software.

RESULTS

To date, more than 183 compounds were isolated and structurally identified from different plant parts of O. fragrans. Among them, ionone, ionol, flavonoids, polyphenols and iridoids, as the major bioactive substances, have been extensively studied and displayed the best bioactivity. Pharmacological studies demonstrated that O. fragrans and its active components had a wide range of biological activities, such as antioxidant, antitumor, anti-inflammatory, anti-hyperglycemic, anti-thrombotic, anti-melanogenesis, neuroprotective, and hepatoprotective activities, etc. CONCLUSION: O. fragrans, as a food and medicinal resource, has a good health care function and important edible and medicinal value, and thus has good prospects for utilization. However, many studies on biological activities were mainly based on extracts and the bioactive ingredients of this plant, and the mechanism responsible for these extracts and ingredients have not been well identified and there is a gap in research regarding clinical effect and safety. Therefore, the detail in vitro and in vivo studies on the mechanisms of action of the pure bioactive compounds and more clinical studies are encouraged to be conducted to ensure safety and effectiveness of the plant for human use.

Alaskan Bog Blueberry (Vaccinium uliginosum) Extract as an Innovative Topical Approach to Prevent UV-Induced Skin Damage

Our body is continuously exposed to various exogenous aggressors, and, in particular, the skin represents the main target for outdoor stressors, including ultraviolet (UV) radiation. UV exposure is well-known to be associated with the development/worsening of extrinsic photoaging and a multitude of skin conditions. Considering the role of photoprotection in skin health, the research of natural photoprotective molecules becomes of great importance. Therefore, in this work we wanted to evaluate the beneficial protective effects of ripe berries of Vaccinium uliginosum (Alaska bog blueberry (BB)) extract (100 μg/mL) for preventing the cutaneous oxidative, inflammatory, and structural damage induced by exposure to 200 mJ of UVA/UVB radiation. We observed that the topical application of BB extract on human ex vivo skin explants averted the UV-induced cutaneous OxInflammatory phenomenon by quenching the increase in the oxidative and inflammatory marker levels, such as 4-hydroxynonenal (4HNE), heme-oxygenase-1 (HO-1), cyclooxygenase-2 (COX2), and aryl hydrocarbon receptor (AhR); as well as by counteracting the loss of structural proteins (filaggrin and involucrin) induced by UV radiation. Our data propose the use of a topical application of Alaska bog blueberry extract as a natural and valuable approach to ensure photoprotection against UV-induced skin damage and premature aging.