This reprint presents a curated selection of peer-reviewed studies originally published within the Special Issue on Recent Advances in Medicinal Plants and Natural Products. Together, these contributions offer a technically rigorous overview of the molecular, biochemical, and mechanistic dimensions that define contemporary research in natural product science. This reprint emphasizes the characterization of bioactive metabolites, including phenolics, terpenoids, alkaloids, and volatile constituents, through advanced analytical strategies such as chromatographic separation, high-resolution mass spectrometry, and nuclear magnetic resonance techniques. Several works examine structure-activity relationships, focusing on the influence of extraction parameters, compound stability, and synergistic interactions on biological efficacy. Across the collected articles, researchers investigate antioxidant, antimicrobial, anti-inflammatory, and cytoprotective properties using in vitro biochemical assays and cellular models designed to elucidate pathways related to oxidative stress, membrane integrity, and molecular signaling. As the Special Issue is now closed, this reprint serves as a consolidated technical resource capturing the state of progress achieved during its publication window. It provides an integrated reference for scientists working at the intersection of natural product chemistry, molecular biology, and therapeutic innovation.