Andrographispaniculata (Burm.f.) Nees has been used as a traditional medicine in Asian countries, especially China, India, Vietnam, Malaysia, and Indonesia. This herbaceous plant extract contains active compounds with multiple biological activities against various diseases, including the flu, colds, fever, diabetes, hypertension, and cancer. Several isolated compounds from A. paniculata, such as andrographolide and its analogs, have attracted much interest for their potential treatment against several virus infections, including SARS-CoV-2. The mechanisms of action in inhibiting viral infections can be categorized into several types, including regulating the viral entry stage, gene replication, and the formation of mature functional proteins. The efficacy of andrographolide as an antiviral candidate was further investigated since the phytoconstituents of A. paniculata exhibit various physicochemical characteristics, including low solubility and low bioavailability. A discussion on the delivery systems of these active compounds could accelerate their development for commercial applications as antiviral drugs. This study critically reviewed the current antiviral development based on andrographolide and its derivative compounds, especially on their mechanism of action as antiviral drugs and drug delivery systems.

Cyclooxygenase (COX) and lipoxygenase (LOX) enzymes play a pivotal role in producing pro-inflammatory eicosanoids, including prostaglandins (PGs) and leukotrienes (LTs), in the inflammation process. Mitragynine is a primary alkaloid contained in the kratom’s leaves and has been reported to show anti-inflammatory activity by suppressing COX-2 mRNA translation to lowering PGs synthesis. In this study, the Kratom’s alkaloid extract containing ~ 46% mitragynine was found to exhibit dual inhibition activity towards COX-2/5-LOX enzymes at concentrations below 25 ppm in the LPS-induced RAW 264.7 macrophage cells. At these levels, no cell toxicity was observed while the cells became death (e.g., 10–46% viability at 50–100 ppm) and only COX-2 inhibition activity was observed after exposed with more than 25 ppm of alkaloid extract. In contrast, the methanolic-crude extract of Kratom’s leaf containing ~ 5% mitragynine showed no inhibition toward COX-2/5-LOX enzymes and did not toxic onto the cells, even after treated at 100 ppm. The alkaloid extract suppressed several antiinflammation parameters, including ROS (64% reduction at 25 ppm), NO (30% reduction at 25 ppm), TNF-α (~ 50% reduction at 25 ppm), and IL-6 production (60% reduction at 6.25 ppm). In silico molecular studies indicated strong binding affinity of Kratom alkaloids to COX-2 and 5-LOX active sites, supporting the Kratom’s alkaloids to have great potential dual inhibition activity towards COX-2/5-LOX enzymes and to be developed as a safer NSAIDs with fewer side effects.

Antimicrobial activity of gold nanoparticles synthesized by Streptomyces monashensis MSK03 on drug-resistant strains of Pseudomonas aeruginosa and Acinetobacter baumannii.

Antibiotic-resistant strains are a global health-threatening problem. Drug-resistant microbes have compromised the control of infectious diseases. Therefore, the search for a novel class of antibiotic drugs is necessary. Streptomycetes have been described as the richest source of bioactive compounds, including antibiotics. This study was aimed to characterize the antibacterial compounds of Streptomyces sp. PJ85 isolated from dry dipterocarp forest soil in Northeast Thailand. The 16S rRNA gene sequence and phylogenetic analysis showed that PJ85 possessed a high similarity to Streptomyces actinomycinicus RCU-197^T of 98.90%. The PJ85 strain was shown to produce antibacterial compounds that were active against Gram-positive bacteria including methicillin-resistant Staphylococcus aureus (MRSA). The active compounds of PJ85 were extracted and purified using silica gel column chromatography. Two active antibacterial compounds, compound 1 and compound PJ85_F39, were purified and characterized with spectroscopy, including liquid chromatography and mass spectrometry (LC–MS). Compound 1 was identified as actinomycin D, and compound PJ85_F39 was identified as dihomo-γ-linolenic acid (DGLA). To the best of our knowledge, this is the first report of the purification and characterization of the antibacterial compounds of S. actinomycinicus.