Natural Terpenes Prevent Mitochondrial Dysfunction, Oxidative Stress and Release of Apoptotic Proteins during Nimesulide-Hepatotoxicity in Rats

Nimesulide, an anti-inflammatory and analgesic drug, is reported to cause severe hepatotoxicity. In this study, molecular mechanisms involved in deranged oxidant-antioxidant homeostasis and mitochondrial dysfunction during nimesulide-induced hepatotoxicity and its attenuation by plant derived terpenes, camphene and geraniol has been explored in male Sprague-Dawley rats. Hepatotoxicity due to nimesulide (80 mg/kg BW) was evident from elevated SGPT, SGOT, bilirubin and histo-pathological changes. Antioxidants and key redox enzymes (iNOS, mtNOS, Cu/Zn-SOD, Mn-SOD, GPx and GR) were altered significantly as assessed by their mRNA expression, Immunoblot analysis and enzyme activities. Redox imbalance along with oxidative stress was evident from decreased NAD(P)H and GSH (56% and 74% respectively; P<0.001), increased superoxide and secondary ROS/RNS generation along with oxidative damage to cellular macromolecules. Nimesulide reduced mitochondrial activity, depolarized mitochondria and caused membrane permeability transition (MPT) followed by release of apoptotic proteins (AIF; apoptosis inducing factor, EndoG; endonuclease G, and Cyto c; cytochrome c). It also significantly activated caspase-9 and caspase-3 and increased oxidative DNA damage (level of 8-Oxoguanine glycosylase; P<0.05). A combination of camphene and geraniol (CG; 1∶1), when pre-administered in rats (10 mg/kg BW), accorded protection against nimesulide hepatotoxicity in vivo, as evident from normalized serum biomarkers and histopathology. mRNA expression and activity of key antioxidant and redox enzymes along with oxidative stress were also normalized due to CG pre-treatment. Downstream effects like decreased mitochondrial swelling, inhibition in release of apoptotic proteins, prevention of mitochondrial depolarization along with reduction in oxidized NAD(P)H and increased mitochondrial electron flow further supported protective action of selected terpenes against nimesulide toxicity. Therefore CG, a combination of natural terpenes prevented nimesulide induced cellular damage and ensuing hepatotoxicity

A mutagenicity and cytotoxicity study on Limonium effusum aqueous extracts by Allium, Ames and MTT tests

Nowadays plants or plant extracts have become very important for alternative medicine. Plants and their extracts have many therapeutical advantages but some of them are potentially toxic, mutagenic, carcinogenic and teratogenic. Root, stem and leaf parts of Limonium effusum were used in this study and this species is an endemic species for Turkey. Mutagenic and cytotoxic effects of root, stem and leaf aqueous extracts were observed with Allium, Ames and MTT tests. Allium root growth inhibition test and mitotic index studies showed that aqueous extracts have dose-dependent toxic effects. Chromosome aberration studies indicated that especially sticky chromosome, anaphase-telophase disorder and laggard chromosome anomalies were highly observed. Ames test performed with Limonium effusum root aqueous extracts, showed weak mutagenic effects in Salmonella typhimurium TA98 strain with S9. MTT test based on mitochondrial activity indicated that most of the aqueous extracts have cytotoxic effects. This study aimed to determine the possible mutagenic and cytotoxic effects of L. effusum aqueous extracts by using bacterial, plant and mammalian cells. This research showed that some low concentrations of the L. effusum extracts have inhibited cytotoxic effects but high concentrations have induced cytotoxicity. On the other hand only a weak mutagenic activity was identified by Ames test with TA98 S9(+).В настоящее время растения или экстракты растений стали очень важными для альтернативной медицины. Растения и их экстракты имеют много терапевтических преимуществ, однако некоторые из них являются потенциально токсичными, мутагенными, канцерогенными и тератогенными. Корни, стебли и листья Limonium effusum, эндемичного вида Турции, были изучены в этой работе. Мутагенные и цитотоксические эффекты водных экс-трактов корней, стеблей и листьев Limonium effusum были изучены с помощью Allium-теста, теста Эймса и МТТ-теста. Тест на ингибирование роста корней лука и определение митотического индекса показали, что водные экстракты имеют дозозависимый токсичный эффект. При изучении хромосомных аберраций обнаружено большое количество таких аномалий, как слипшиеся хромосомы, нарушения анафазы-телофазы и отставшие хромосомы. Тест Эймса, проведенный на водных экстрактах корней Limonium effusum, показал слабо выраженный мутагенный эффект по отношению к Salmonella typhimurium, штамм TA98 с S9. МТТ-тест, основанный на митохондриальной активности, показал, что большинство экстрактов имели цитотоксические эффекты. Цель этого исследования изучить возможные мутагенные и цитотоксические эффекты водных экстрактов L. effusum с использованием бактериальных, растительных клеток и клеток млекопитающих. Определенные низкие концентрации экстрактов L. effusum ингибировали цитотоксические эффекты, а высокие концентрации индуцировали цитотоксичность. Слабая мутагенная активность была определена только при помощи теста Эймса с TA98 S9(+)