Dengue infections are still a worldwide burden, especially in Indonesia. There is no specific medication against the dengue virus. Recently, many types of research have been conducted to discover a new drug for dengue virus using natural resource extracts. Indonesia, as a tropical country, has a wide biodiversity. There are several medicinal plants in Indonesia that are believed to possess anti-dengue activity, such as Myristica fatua, Cymbopogon citratus, and Acorus calamus plants. We conducted an in vitro laboratory experiment of several extracts from Indonesian herbs combined with in silico analysis. The extracts were evaluated for safety and antiviral activity in Huh7it-1 cell lines, using a single dose of 20 µg/mL and dose-dependent (5, 10, 20, 40, 80 and 160 µg/mL) of plant extracts against dengue virus serotype 2 (DENV-2) NGC strain. The DMSO 0.1% was used as a negative control. The cytotoxic aspect was assessed by counting the cell viability, while the antiviral activity was calculated by counting the average inhibition. The selectivity index (SI) of plant extracts were performed from a ratio of CC₅₀/EC₅₀ value. In silico analysis was conducted to determine the free energy of binding between NS5 of dengue virus with bioactive compounds contained in Myristica fatua, Cymbopogon citratus and Acorus calamus extract plants. We determined that all extracts were not toxic against Huh7it-1 cell lines. The methanolic extracts of A. calamus, C. citratus, and M. fatua showed inhibition of DENV-2 at a dose of 20 µg/mL to 96.5%, 98.9%, and 122.7%, respectively. The dose-dependent effects showed that M. fatua has the best inhibition activity towards DENV-2. Molecular docking result showed that artesunic acid within M. fatua has the best free energy of binding (−7.2 kcal/mol), followed by homoegonol (−7.1 kcal/mol) which was slightly different from artesunic acid among others. The methanolic extracts of A. calamus, C. citratus, and M. fatua showed prospective anti-dengue activities both in vitro and in silico. Future research should be conducted to find the pure extracts of all useful herbs as a new candidate of antiviral drug.

Even entering the third year of the COVID-19 pandemic, only a small number of COVID-19 antiviral drugs are approved. Curcumin has previously shown antiviral activity against SARS-CoV-2 nucleocapsid, but its poor bioavailability limits its clinical uses. Utilizing nanotechnology structures, curcumin-derived carbon-dots (cur-CDs) were synthesized to increase low bioavailability of curcumin. In-silico analyses were performed using molecular docking, inhibition of SARS-CoV-2 nucleocapsid C-terminal domain (N-CTD) and antiviral activity were assessed in dimer-based screening system (DBSS) and in vitro respectively. Curcumin bound with the N-CTD at ΔG = −7.6 kcal/mol, however modifications into cur-CDs significantly improved the binding affinity and %interaction. Cur-CDs also significantly increased protection against SARS-CoV-2 in both DBSS and in vitro at MOI = 0.1. This study demonstrated the effect of post-infection treatment of curcumin and novel curcumin-derived carbon-dots on SARS-CoV-2 N-CTD dimerization. Further investigation on pre-infection and in-vivo treatment of curcumin and cur-CDs are required for a comprehensive understanding on the carbon-dots enhanced antiviral activity of curcumin against SARS-CoV-2.

Physicochemical analysis for simplicia and extract, respectively: water content 2.12–4% for simplicia; drying losses 3.93–5.47% and 8.51–19.76%; total ash 5.14–9.41% and 6.22–17.07%; total ash acid-insoluble content 0.29–5.41% and 0.52–3.82%; total ash water-soluble content 1.26–7.14% and 1.43–8.54%; water-soluble content 19.60–39.43% and 58.45–77.51%; ethanol-soluble content 13.99–33.76% and 59.79–75.39%. The phytochemical analysis showed that the extracts contain alkaloids, flavonoids, saponins, tannins, and terpenoids. Total flavonoids and total phenolics content were 9.86–15.74% QE/g and 6.67–7.65% GAE/g, respectively. Based on LC-MS results, the extract contained emodin, kaempferol, kaempferol-3,7-diglucoside, and kaempferol-3-O-β-D-glucopyranoside. The extracts possessed antibacterial activity against bacteria tested.

Morinda citrifolia fruit (Noni) has been used as a folk medicine in several countries. Noni possessed various pharmacological activities such as; anticancer, antidiabetic, antihypertensive, antarthritic, and antioxidants. The present study evaluated pharmacognostic properties, profiling of active constituent through High-Performance Thin Layer Chromatography (HPTLC) and Liquid Chromatography-High Resolution Mass Spectrometer (LC-HRMS) run for quantitative and qualitative phytochemical analysis and determining angiotensin-converting enzyme (ACE) inhibitor activity of Noni from three different locations. The physicochemical parameters of crude drugs and extracts met the requirement of Indonesian Herbal Pharmacopeia. Total phenol content was 2.16-3.08 mg GAE/g extract and total flavonoid content was 0.11 - 1.58 mg QE/g extract. HPTLC analysis revealed that scopoletin content in Noni was in the range of 0.44 - 0.51%. The results were also corresponding well with LC-HRMS fingerprint analysis. In addition, Noni fruit extract from Bogor potential exhibited activity in inhibiting ACE with an IC50 value of 206.26 µg/mL.

In this study, multifunctional chitosan-pluronic F127 with magnetic reduced graphene oxide (MRGO) nanocomposites were developed through the immobilization of chitosan and an amphiphilic polymer (pluronic F127) onto the MRGO. Physicochemical characterizations and in-vitro cytotoxicity of nanocomposites were investigated through field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), Fourier-transform infrared (FTIR) spectroscopy, particle size analysis, vibrating sample magnetometer, Raman spectroscopy and resazurin-based in-vitro cytotoxicity assay. FESEM observation shows that the magnetic nanoparticles could tethered on the surface of MRGO, promoting the magnetic properties of the nanocomposites. FTIR identification analysis revealed that the chitosan/pluronic F127 were successfully immobilized on the surface of MRGO. Furthermore, α-mangosteen, as a model of natural drug compound, was successfully encapsulated onto the chitosan/pluronic F127@MRGO nanocomposites. According to in-vitro cytotoxicity assay, α-mangosteen-loaded chitosan/pluronic F127@MRGO nanocomposites could significantly reduce the proliferation of human breast cancer (MFC-7) cells. Eventually, it would be anticipated that the novel α-mangosteen-loaded chitosan/pluronic F127@MRGO nanocomposites could be promoted as a new potential material for magnetically targeting and killing cancer cells.