cis-Clerodane-type diterpenoids from Tinospora crispa and their anticancer potential

Tinospora crispa (Menispermaceae) has been traditionally consumed as a functional food and herbal remedy in Southeast Asia, notably in Thailand and India. cis-Clerodane-type diterpenoids represent the characteristic and predominant metabolites of the genus Tinospora. Chemical investigation of a MeOH extract of T. crispa leaves, guided by LC/MS analysis coupled with an in-house UV spectral library, led to the isolation of five compounds (1-5), including four new cis-clerodane-type diterpenoids (1-4). Their structures were elucidated by 1D and 2D NMR spectroscopy, high-resolution mass spectrometry (HR-ESIMS), interproton distance analysis using NOE peak amplitude normalization for improved cross-relaxation (PANIC), Snatzke's method, and computational ECD and DP4⁺ probability calculations. The isolated compounds (1-5) were evaluated for their anticancer potential in both liver (Hepa1c1c7, Hepa1-6) and lung (LLC1, A549) cancer cell lines. All compounds 1-5 reduced A549 cell viability by approximately 70%, at 200 μM and showing comparable activity in LLC1. Molecular analyses showed that compound 3 affected downstream Hippo signaling components (YAP, TAZ, pan-TEAD) in liver cancer cells and inhibited pro-survival pathways-including phosphorylated AKT-in lung cancer cells, where it also elevated apoptotic markers Bax and cleaved caspase-3 while reducing anti-apoptotic BCL-2. Overall, compound 3 exhibited the most consistent and potent cell-line specific anticancer effects across both models, highlighting its potential as a promising lead candidate for further anticancer drug development. Collectively, these results suggest concentration-dependent anticancer activity of T. crispa diterpenoids in liver and lung cancer models and further support compound 3 as promising leading candidate targeting key survival signaling pathways in cancer.