Background: The present study was conducted to evaluate the in vitro and in vivo antioxidant properties of aqueous extract of Podophyllum hexandrum. The antioxidant potential of the plant extract under in vitro situations was evaluated by using two separate methods, inhibition of superoxide radical and hydrogen peroxide radical. Carbon tetrachloride (CCl₄) is a well known toxicant and exposure to this chemical is known to induce oxidative stress and causes tissue damage by the formation of free radicals. Methods: 36 albino rats were divided into six groups of 6 animals each, all animals were allowed food and water ad libitum. Group I (control) was given olive oil, while the rest groups were injected intraperitoneally with a single dose of CCl₄ (1 ml/kg) as a 50% (v/v) solution in olive oil. Group II received CCl₄ only. Group III animals received vitamin E at a concentration of 50 mg/kg body weight and animals of groups IV, V and VI were given extract of Podophyllum hexandrum at concentration dose of 20, 30 and 50 mg/kg body weight. Antioxidant status in both kidney and lung tissues were estimated by determining the activities of antioxidative enzymes, glutathione reductase (GR), glutathione peroxidase (GPX), glutathione-S-transferase (GST) and superoxide dismutase (SOD); as well as by determining the levels of reduced glutathione (GSH) and thiobarbituric acid reactive substances (TBARS). In addition, superoxide and hydrogen peroxide radical scavenging activity of the extract was also determined. Results: Results showed that the extract possessed strong superoxide and hydrogen peroxide radical scavenging activity comparable to that of known antioxidant butylated hydroxy toluene (BHT). Our results also showed that CCl₄ caused a marked increase in TBARS levels whereas GSH, SOD, GR, GPX and GST levels were decreased in kidney and lung tissue homogenates of CCl₄ treated rats. Aqueous extract of Podophyllum hexandrum successfully prevented the alterations of these effects in the experimental animals. Conclusion: Our study demonstrated that the aqueous extract of Podophyllum hexandrum could protect the kidney and lung tissue against CCl₄ induced oxidative stress probably by increasing antioxidant defense activities.

The protective activity of the methanolic extract of the Crataegus songarica leaves was investigated against CCl₄- and paracetamol-induced liver damage. On folklore levels, this plant is popularly used to treat various toxicological diseases. We evaluated both in vitro and ex vivo antioxidant activity of C. songarica. At higher concentration of plant extract (700 µg/ml), 88.106% inhibition on DPPH radical scavenging activity was observed and reducing power of extract was increased in a concentration-dependent manner. We also observed its inhibition on Fe²⁺/ascorbic acid-induced lipid peroxidation on rat liver microsomes in vitro. In addition, C. songarica extract exhibited antioxidant effects on calf thymus DNA damage induced by Fenton reaction. Hepatotoxicity was induced by challenging the animals with CCl₄ (1 ml/kg body weight, i.p.) and paracetamol (500 mg/kg body weight) and the extract was administered at three concentrations (100, 200, and 300 mg/kg body weight). Hepatoprotection was evaluated by determining the activities of liver function marker enzymes and antioxidant status of liver. Administration of CCl₄ elevated the levels of liver function enzymes, SGOT, SGPT, and LDH. We also observed a dramatic increase in ALT, AST, bilirubin, and alkaline phosphatase levels in rats administered 500 mg/kg body weight of paracetamol. Decreased antioxidant defense system as glutathione (GSH), catalase (CAT), glutathione peroxidase (GPX), glutathione reductase (GR), glutathione-S-transferase (GST), and superoxide dismutase (SOD) were observed in rats treated with CCl₄ and paracetamol. Pretreatment with the extract decreased the elevated serum GOT, GPT, LDH, bilirubin, and alkaline phosphatase activities and increased the antioxidant enzymes in a dose-dependent manner. Therefore, C. songarica methanol extract may be an effective hepatic protective agent and viable candidate for treating hepatic disorders and other oxidative stress-related diseases.

To evaluate in vitro antioxidant and antibacterial activity of methanolic extract of Arnebia benthamii (A. benthamii) whole plant. Plasmid damage was analyzed by agarose gell electrophoresis. Calf thymus DNA was monitored by TBARS formation. DPPH, reducing power and lipid peroxidation was evaluated by using standard procedures. Antibacterial assay was monitored by disc diffusion method. DPPH radical scavenging and hydroxyl radical scavenging potential of the plant revealed that the extract to be active radical scavenger. Reducing (Fe(3+)-Fe(2+)) power and lipid peroxidation inhibition efficiency (TBARS assay) of the extract was also evaluated and the extract showed promising activity in preventing lipid peroxidation and might prevent oxidative damages to biomolecules. The extract offered a significant protection against plasmid and calf thymus DNA damage induced by hydroxyl radicals. The extract was also evaluated on different bacterial strains and the maximum antibacterial activity was exhibited against Escherichia coli (E. coli) when compared with standard drug. These findings demonstrate that the methanol extract of A. benthamii has excellent anti-oxidant activities and could be considered as a potential source of lead molecules for pharmaceutical industries.

The present study was undertaken to evaluate the effect of the aqueous extract of Podophyllum hexandrum against free radical-mediated damage and also explore its anticancer activity. The extract exhibited significant activity in scavenging 1, 1-diphenyl-2-picryl-hydrazyl radicals, ^•OH radical-mediated DNA damage, and lipid peroxide production in rat liver microsomes. The extract was also tested for its reducing abilities. The activity of liver marker enzymes and antioxidant defense enzymes in rat liver homogenate was assessed in control and carbon tetrachloride (CCl₄)-treated animals. It was observed that CCl₄-induced changes viz., increases in the activities of aspartate aminotransferase, alanine aminotransferase, and lactate dehydrogenase, a decrease in reduced glutathione as well as decreases in the activities of superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, and glutathione-S-transferase. All these parameters showed reversal when pretreated with aqueous extract of P. hexandrum. Podophylotoxin and etoposide are the two known anticancer agents derived from P. hexandrum and interestingly the aqueous extract of P. hexandrum showed a typical DNA ladder formation in HL-60 cells confirming its role as an inducer of apoptosis. The results obtained suggest that the plant extract exhibits inhibition of and free radical production and lipid peroxidation, increase in antioxidant enzyme activities, revealing its antioxidant properties, and is also able to show potent anticancer activity as depicted by its ability to cause fragmentation of DNA.