title: Humic acid inhibits HBV-induced autophagosome formation and induces apoptosis in HBV-transfected Hep G2 cells.
abstract: Hepatitis B Virus (HBV) utilizes several mechanisms to survive in the host cells and one of the main pathways being autophagosome formation. Humic acid (HA), one of the major components of Mineral pitch, is an Ayurvedic medicinal food, commonly used by the people of the Himalayan regions of Nepal and India for various body ailments. We hypothesized that HA could induce cell death and inhibit HBV-induced autophagy in hepatic cells. Incubation of Hep G2.2.1.5 cells (HepG2 cells stably expressing HBV) with HA (100 μM) inhibited both cell proliferation and autophagosome formation significantly, while apoptosis induction was enhanced. Western blot results showed that HA incubation resulted in decreased levels of beclin-1, SIRT-1 and c-myc, while caspase-3 and β-catenin expression were up-regulated. Western blot results showed that HA significantly inhibited the expression of HBx (3-fold with 50 μM and 5-fold with 100 μM) compared to control cells. When HA was incubated with HBx-transfected Hep G2 cells, HBx-induced autophagosome formation and beclin-1 levels were decreased. These data showed that HA induced apoptosis and inhibited HBV-induced autophagosome formation and proliferation in hepatoma cells.
authors.affiliation: Faculty of Life Sciences and Biotechnology, South Asian University, Akbar Bhawan Chanakyapuri New Delhi, India.
authors.forename: Kishor
authors.initials: K
authors.lastname: Pant
authors.affiliation: Faculty of Life Sciences and Biotechnology, South Asian University, Akbar Bhawan Chanakyapuri New Delhi, India.
authors.forename: Ajay K
authors.initials: AK
authors.lastname: Yadav
authors.affiliation: Faculty of Life Sciences and Biotechnology, South Asian University, Akbar Bhawan Chanakyapuri New Delhi, India.
authors.forename: Parul
authors.initials: P
authors.lastname: Gupta
authors.affiliation: Faculty of Life Sciences and Biotechnology, South Asian University, Akbar Bhawan Chanakyapuri New Delhi, India.
authors.forename: Abhishek Singh
authors.initials: AS
authors.lastname: Rathore
authors.affiliation: Department of Gastroenterology and Human Nutrition, All India Institute of Medical Sciences, New Delhi, India.
authors.forename: Baibaswata
authors.initials: B
authors.lastname: Nayak
authors.affiliation: Faculty of Life Sciences and Biotechnology, South Asian University, Akbar Bhawan Chanakyapuri New Delhi, India.
authors.forename: Senthil K
authors.initials: SK
authors.lastname: Venugopal
mesh_terms: D017209:Apoptosis / Q000187:drug effects* / Q000235:genetics; D056945:Hep G2 Cells; D006509:Hepatitis B / Q000235:genetics / Q000378:metabolism*; D006515:Hepatitis B virus / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D006812:Humic Substances; D014162:Transfection
chemical_list: D006812:Humic Substances