Tinospora cordifolia and arabinogalactan exert chemopreventive action during benzo(a)pyrene-induced pulmonary carcinogenesis: studies on ultrastructural, molecular, and biochemical alterations.

The aim of the present study was to unveil the chemopreventive potentials of aqueous Tinospora cordifolia stem extract and its active component viz. Arabinogalactan against Benzo(a)pyrene-induced pulmonary carcinogenesis. Animals were divided into six groups: (I) Control, (II) aqueous Tinospora cordifolia (200 mg/kg b.wt, p.o.), (III) arabinogalactan (7.5 mg/kg b.wt, p.o.), (IV) benzo(a)pyrene (50 mg/kg b.wt, i.p.) at second and fourth week of study, (V) benzo(a)pyrene + aqueous Tinospora cordifolia, and (VI) benzo(a)pyrene + arabinogalactan. The benzo(a)pyrene treatment resulted in severe alterations in the cellular arrangement and morphology of the alveolar tissue in benzo(a)pyrene group. However, benzo(a)pyrene + aqueous Tinospora cordifolia and benzo(a)pyrene + arabinogalactan groups revealed classical features of apoptosis including chromatin condensation and formation of apoptotic bodies. Furthermore, Fourier transform Infrared spectroscopy analysis showed disturbed phospholipid saturation and protein secondary structures in benzo(a)pyrene treated animals. Depletion in relative glycogen and enhancement in total nucleic acid content was observed in benzo(a)pyrene treated animals, and the same was found to be restored upon arabinogalactan and aqueous Tinospora cordifolia supplementation. Benzo(a)pyrene insult also upregulated the phase I carcinogen metabolizing enzymes and differentially modulated the phase II metabolizing enzymes during pulmonary carcinogenesis. Also, depleted (reduced glutathione) and increased lipid peroxidation levels were observed in benzo(a)pyrene treated animals, which was found to be normalized upon aqueous Tinospora cordifolia and arabinogalactan administration. Clastogenic damage inflicted by benzo(a)pyrene was also reversed in benzo(a)pyrene + aqueous Tinospora cordifolia and benzo(a)pyrene + arabinogalactan group. Thus, the present study infers that aqueous Tinospora cordifolia and arabinogalactan showed promising anticancer activity against lung tumorigenesis in terms of ultrastructural, biochemical, and biomolecular aspects.