Anaerobic co-metabolic biodegradation of pharmaceuticals and personal care products driven by glycerol fermentation

Anaerobic digestion in two sequential phases, acidogenesis and methanogenesis, has been shown to be beneficial for enhancing the biomethane generation from wastewater. In this work, the application of glycerol (GOH) as a fermentation co-substrate during the wastewater treatment was evaluated on the biodegradation of different pharmaceuticals and personal care products (PPCPs). GOH co-digestion during acidogenesis led to a significant increase in the biodegradation of acetaminophen (from 78 to 89%), ciprofloxacin (from 25 to 46%), naproxen (from 73 to 86%), diclofenac (from 36 to 48%), ibuprofen (from 65 to 88%), metoprolol (from 45 to 59%), methylparaben (from 64 to 78%) and propylparaben (from 68 to 74%). The heterotrophic co-metabolism of PPCPs driven by glycerol was confirmed by the biodegradation kinetics, in which kbio (biodegradation kinetics constant) values increased from 0.18 to 2.11 to 0.27-3.60 L g-1-VSS d-1, for the operational phases without and with GOH, respectively. The assessment of metabolic pathways in each phase revealed that the prevalence of aromatic compounds degradation, metabolism of xenobiotics by cytochrome P450, and benzoate degradation routes during acidogenesis are key factors for the enzymatic mechanisms linked to the PPCPs co-metabolism. The phase separation of anaerobic digestion was effective in the PPCPs biodegradation, and the co-fermentation of glycerol provided an increase in the generation potential of biomethane in the system (energetic potential of 5.0 and 6.3 kJ g-1-CODremoved, without and with GOH, respectively). This study showed evidence that glycerol co-fermentation can exert a synergistic effect on the PPCPs removal during anaerobic digestion mediated by heterotrophic co-metabolism.

Trigonella stellata reduced the deleterious effects of diabetes mellitus through alleviation of oxidative stress, antioxidant- and drug-metabolizing enzymes activities

ETHNOPHARMACOLOGICAL RELEVANCE

Genus Trigonella has a history of folkloric medicinal uses in China, Japan, Egypt and India. There are a variety of therapeutic actions of Trigonella including hypocholesterolemia, hypoglycemia, antibacterial, antiviral, anti-inflammatory activities, antioxidants and appetite stimulant.

AIM OF THE STUDY

The prevalence of diabetes mellitus is increasing annually. The present study aims at investigating the protective effects of Trigonella stellata against the adverse effects of diabetes mellitus through investigation of the changes in phase I & II drug-metabolizing enzyme activities, protein expression of cytochrome P₄₅₀ isoenzymes [CYP2E1 & 3A4], oxidative stress, antioxidant enzymes as well as histopathology of both liver and kidney tissues.

METHODS

GC-MS and MALDI-TOF were used to analyze the main constituents of the aqueous and the ethanolic extract of Trigonella stellata. Western immunoblotting technique used to show the protein expression of CYP₄₅₀ isozymes in different groups. Spectrophotometric- and fluorophotometric techniques were also used for assessment of different hepatic integrity enzymes. Histopathological techniques used to illustrate the changes in the tissues of both livers and kidneys after different treatments.

RESULTS

Trigonelline was found to be the main constituent of both aqueous and ethanolic extract of Trigonella stellata. Administration of the aqueous and/or the ethanolic extracts of Trigonella stellata to the diabetic rats was found to decrease the blood glucose level, the biochemical markers of both liver (transaminases activities, Lactate dehydrogenase, gamma-glutamyl transferase) and the renal functions (urea, creatinine and bilirubin) which were increased in diabetic-treated rats relative to their normal levels. Diabetes mellitus potentially induced the oxidative stress, and also activities of dimethylnitrosamine N-demethylase I, cytochrome c-reductase, ethoxyresourfin O-deethylase, and the total hepatic content of cytochrome P₄₅₀. On the other hand, the activity of catalase [CAT], superoxide dismutase [SOD], glutathione S-transferase [GST], glutathione reductase [GR], glutathione peroxidase [GPx] and levels of reduced glutathione [GSH] were potentially inhibited in diabetic rats compared to the control rats. However, treatments of diabetic rats with either aqueous and/or ethanolic extracts of Trigonella stellata restored such changes caused by diabetes almost nearly to their normal levels compared to the control group. Supporting the activity of dimethyl nitrosamine N-demethylase I activity, the protein expression of CYP2E1 was also induced in diabetic rats. However, the aqueous extract of Trigonella stellata was more effective than ethanolic extract in restoring the changes in the protein expression of CYP2E. On the other hand, the protein expression of CYP3A4 was markedly decreased in diabetic rats, and this decrease was partially restored to its normal level after treatment of diabetic rats with aqueous and/or ethanolic extracts. In addition, Trigonella stellata extracts alleviated the histopathological changes in livers and kidneys caused by diabetes mellitus.

CONCLUSION

It is concluded that diabetes mellitus induced changes in oxidative stress, phase I & II drug-metabolizing enzymes, and antioxidant enzymes activities, whereas both extracts of Trigonella stellata alleviated such changes. Alterations in cytochrome P₄₅₀ system should be considered when therapeutic drugs are administered to diabetic patients since most of xenobiotic are mainly metabolized by this system.

Clarithromycin enhances the antimalarial efficacy of mefloquine via its increased bioavailability and disrupting P. falciparum apicoplast

AIM

Many important drugs like mefloquine are not being used because of the development of resistance and other related issues. In the present study, we aimed to control drug resistance by using combination therapy and tried to understand the mechanism involved.

MATERIAL AND METHODS

We have explored in vitro interaction of clarithromycin (CLTR), and mefloquine (MQ) against Pf3D7 and PfK1 strains. Bioavailability of MQ in parasitized RBC lysate was checked in the presence/absence of CLTR using HPLC method. Further tufA mRNA/protein expression was investigated to know the effect of both drugs on apicoplast by using qPCR and Western blotting.

KEY FINDINGS

MQ and CLTR inhibited growth of Pf3D7 and PfK1. CLTR showed its delayed antimalarial effect by its low IC50 values in the second cycle which indicates its effect on apicoplast. Downregulation of tufA expression on both mRNA and protein level supports this hypothesis. MQ and CLTR showed synergism/additiveness (mean ∑FICs = 0.89 and 1.26) against Pf3D7 and PfK1 respectively. It is evidenced from HPLC data that CLTR might have reduced metabolism of MQ in Plasmodium falciparum, leading to increased levels of MQ to produce enhanced antimalarial activity. The metabolism of CLTR is also reduced may be due to competitive metabolism of MQ via CYP3A4.

SIGNIFICANCE

The present study reveals that broad spectrum biological activities (i.e. antimalarial and antiviral) of MQ can be saved by using suitable partner drug like CLTR. This study also shows that CLTR increases the concentration of MQ and disrupts the apicoplast.

Models of hepatotoxicity and the underlying cellular, biochemical and immunological mechanism(s): a critical discussion

Liver is a primary organ involved in biotransformation of food and drugs. Hepatic diseases are a major worldwide problem. Hepatic disorders are mainly caused by toxic chemicals (alcohol), xenobiotics (carbon tetrachloride, chlorinated hydrocarbons and gases CO₂ and O₂) anticancer (azathioprine, doxorubicin, cisplatin), immunosuppressant (cyclosporine), analgesic anti-inflammatory (paracetamol, thioacetamide), anti-tubercular (isoniazid, rifampicin) drugs, biologicals (Bacillus-Calmette-Guerin vaccine), radiations (gamma radiations), heavy metals (cadmium, arsenic), mycotoxin (aflatoxin), galactosamine, lipopolysaccharides, etc. Various risk factors for hepatic injury include concomitant hepatic diseases, age, gender, alcoholism, nutrition and genetic polymorphisms of cytochrome P450 enzymes have also been emphasized. The present review enumerates various in vivo animal models and in vitro methods of hepatic injury using diverse toxicants, their probable metabolic pathways, and numerous biochemical changes viz. serum biomarkers enzymes, liver function, oxidative stress associated events like free radicals formation, lipid peroxidation, enzyme antioxidants and participation of cytokines (tumour necrosis factor-α, transforming growth factor-β, tumour necrosis factor-related apoptosis inducing ligand), and other biomolecules (Fas and C-jun N-terminal kinase) are also discussed. The underlying cellular, molecular, immunological, and biochemical mechanism(s) of action responsible for liver damage (toxicity) are also been discussed. This review should be immensely useful for researchers especially for phytochemists, pharmacologists and toxicologists working on hepatotoxicity, hepatotoxic chemicals and drugs, hepatoprotective agents and drug research organizations involved especially in phytopharmaceuticals and other natural products.