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Liu, L. T.-C.

Publications and source records attributed to Liu, L. T.-C..

2 recordsLinked to original sources

Centella asiatica Tissue Culture-Derived Extracellular Vesicles: A Multifaceted Approach to Skincare Applications

BackgroundCentella asiatica has long been used as a medicinal herb in traditional Asian medicine. Its wound healing, skin improvement, and neuroprotective properties have been widely studied. Extracellular vesicles (EVs) are secreted by cells and contain bioactive components with therapeutic properties. ObjectivesThis study aims to characterize EVs isolated from C. asiatica tissue culture and investigate their therapeutic properties using in vitro assays and a UVB-induced damage mouse model. MethodsEVs were isolated from C. asiatica tissue culture and characterized by nanoparticle tracking analysis (NTA) and scanning electron microscopy (SEM). Cytotoxicity, anti-oxidation, anti-melanin, and anti-inflammation of the EVs were evaluated by MTT assay, tyrosinase assay and RT-qPCR in chemical or in vitro assays. A UVB-induced photodamage mouse model was established to assess the anti-inflammation effect of EVs in vivo. Gels with or without EVs were applied to the damaged site and skin appearance was observed daily and skin histopathology was analyzed on day 7 by H&E and immunohistochemical staining. ResultsC. asiatica EVs were found to contain high levels of polyphenols and mitigate hydrogen peroxide-induced intracellular ROS. The EVs were further able to reduce intracellular melanin content and tyrosinase activity, and exhibited anti-inflammatory effects by downregulating the expression of pro-inflammatory genes COX2 as well as nitric oxide production. In mice with UVB-induced skin damage, daily application of C. asiatica EV gel reduced skin epidermis thickness and inflammation compared to UVB-only or blank gel at seven days after UV irradiation. ConclusionsThe beneficial effects of C. asiatica EVs on skin quality warrant further studies as promising agents in skin care applications.

pharmacology and toxicology↗

Neutralization of SARS-CoV-2 Omicron BA.4/BA.5 subvariant by a booster dose of bivalent adjuvanted subunit vaccine containing Omicron BA.4/BA.5 and BA.1 subvariants

The dominance of SARS-CoV-2 variants of concern (VoC), such as the Omicron subvariants, is a threat to the current vaccination scheme due to increased resistance to immune neutralization and greater transmissibility. To develop the next generation of prefusion SARS-CoV-2 spike protein (S-2P) subunit vaccine adjuvanted with CpG1018 and aluminum hydroxide, mice immunized with two doses of the adjuvanted ancestral Wuhan strain (W) followed by the third dose of the W or Omicron variants (BA.1 or BA.4/BA.5) S-2P, or a combination of the above bivalent S-2Ps. Antisera from mice were tested against pseudovirus neutralization assay of ancestral SARS-CoV-2 (WT) and Omicron BA.4/BA.5 subvariant. Boosting with bivalent mixture of Omicron BA.4/BA.5 and W S-2P achieved the highest neutralizing antibody titers against BA.4/BA.5 subvariant pseudovirus compared to other types of S-2P as boosters.

immunology↗