Induction of Autophagy and Apoptosis by the Extract of Solanum nigrum Linn in HepG2 Cells

Abstract

Solanum nigrum L. (SN) has been used in traditional folk medicine to treat different cancers. It is also used as a hepatoprotective and anti-inflammatory agent. In this study, we demonstrated that the extract of SN (SNE) induced a strong cytotoxic effect toward HepG2 cells but much less to Chang liver and WRL-68 cells. The mechanisms of the cytotoxic effect were concentration-dependent. High doses of SNE (2 and 5 mg/mL) induced apoptotic cell death in HepG2 cells, as evidenced by increases in the expressions of p-JNK and Bax, mitochodrial release of cytochrome c, and caspase activation. On the other hand, cells treated with low concentrations of SNE (50-1000 microg/mL) revealed morphological and ultrastructural changes of autophagocytic death under electron microscopic observation. Furthermore, these cells showed increased levels of autophagic vacuoles and LC3-I and LC3-II proteins, specific markers of autophagy. The levels of Bcl-2 and Akt that have been implicated in the down-regulation of autophagy were decreased upon SNE treatment. Taken together, these findings indicate that SNE induced cell death in hepatoma cells via two distinct antineoplastic activities of SNE, the ability to induce apoptosis and autophagocytosis, therefore suggesting that it may provide leverage to treat liver cancer.

Anti-cancer potential of South Asian plants

“…Moreover, Ma et al 100 isolated a panel of withanolides from this plant, which have moderate cytotoxic activity against human colorectal-carcinoma HCT-116 and human non small-cell lung-cancer NCI-H460 cell lines. 106,107 . Actually, a low dose treatment induced only autophagy, while high dose treatment induced both of autophagy and apoptosis.…”

Plants from Solanaceae family with possible anxiolytic effect reported on 19th century's Brazilian medical journal

“…In a study made by Perez et al (1998), an ethanol extract of the fruit of S. nigrum did not show any sedation and motor coordination, but decreased the spontaneous motor activity of the experimental animals and potentiated the pentobarbitalinduced hypnosis, indicating a central depressant effect. S. nigrum contain many polyphenolic compounds (Lin et al, 2007), including gallic acid, protocatechuic acid, catechin, caffeic acid, epicatechin, rutin, and naringenin, besides other flavonoids such as, luteolin, quercetin, apigenin, kaempferol and hesperetin (Huang et al, 2010). Flavonoids could to be a subtype-selective partial agonist of GABAA receptors that exhibit anxiolytic effects without sedative, amnesic, myorelaxant, motor incoordination, or anticonvulsant effects, being a promising drug candidate for the treatment of anxiety-like disorders.…”

“…Patents that were reported, both in the European Patent Office and the Brazilian National Institute of industrial Property databases, most of which concern inflammatory, allergic, parasitic, infectious or digestive diseases, including extracts from P. angulata (Balbani et al, 2009 (Zakaria et al, 2006); can cause a central nervous system depression which may be correlated with an increased parasympathetic tone (Perez et al, 1998), antioxidant (Al-Fatimi et al, 2007); antipyretic and anticancer agent (Hsieh et al, 2008;Hsu et al, 2009;Yang et al, 2010;Li et al, 2008;Li et al, 2009), mutagenic activity (Almeida et al, 2010). Phytochemical: glycoalkaloids (El-Ashaal et al, 1999), tropane alkaloids (Oksman-Caldentey, 2007;Grynkiewicz & Gadzikowska, 2008;Nash et al, 1993), nicotine alkaloids (Oksman-Caldentey, 2007;Boswell et al, 1999), flavonoids (Wollenweber et al, 2005;Huang et al, 2010), sterols (Amir & Kumar, 2004), steroidal saponins (Ikeda et al, 2000;Nakamura et al, 2008;Zhou et al, 2006;Ferreira et al, 1996), pregnane saponins (Zhou et al, 2007), volatile oils and anthocyanins (Jainu & Devi, 2006), steroidal alkaloids, such as solamargine, solasonine and solanine (Sanchez-Mata, et al, 2010;Cornelius et al, 2010;Suthar & Mulani, 2008;Chen et al, 2010) and deacetoxysolaphyllidine-3-O-β-Dglucopyranoside (Colmenares et al, 2010); phenolic compounds with strong oxidative effects (Mimica-Dukic et al, 2005;Lin et al, 2007;Huang et al, 2010;…”

Mutation of the gene encoding a major outer-membrane protein in Xanthomonas campestris pv. campestris causes pleiotropic effects, including loss of pathogenicity

“…Bacteria incubated in LB broth were washed with PBS and fixed overnight with 2 % (w/v) glutaraldehyde, 4 % (v/ v) paraformaldehyde and 1 % (w/v) tannic acid in 0.1 mol cacodylate buffer l 21 , pH 7.4. After washing with PBS, cells were stained and prepared as described by Lin et al (2007). Treated cells were viewed in a JEOL T300 electron microscope.…”