Informatics Publishing Limited

P. P. Bhojvaid , Seema Negi

Abstract

The effects of seasons and rooting hormone on air layering were investigated in Elaeocarpus ganitrus (Rudraksha). Trials were conducted in three different seasons , viz. premonsoon , monsoon and post-monsoon using Indole Butyric Acid (IBA) as the rooting hormone (control , 100 , 250 and 500 mg l^-1). Results reveal that IBA enhanced the root initiation and induced rooting in a shorter duration. Air layering trials in pre-monsoon season under 500 mg 1^-l) treatment exhibited maximum rooting percentage followed by monsoon and post-monsoon season under 500 mg l^-1 IBA treatment. Profuse rooting was observed in air layers treated with IBA in pre monsoon season. The callused and rooted air layers after detachment from the mother plants were transplanted separately in polyethylene bags in three different growing media [M₁ - Sand , Nursery soil and Farmyard manure (1 : 2 : 1) , M₂ - Sand and Nursery soil (1 : 1) and M₃ - Nursery soil] under nursery conditions. A highly significant variation (P < 0.05) was observed within the effect of season and callus formation as well as root initiation. Maximum survival of callused and rooted air layers (air layering conducted in Pre-monsoon season) was observed in the growing medium containing Sand , Nursery soil and Farmyard manure (1 : 2 : 1).

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Seema Negi ¹, Mohammad A. Akbarsha ², Rakesh K. Tyagi ¹

Affiliations
1 Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi – 110067, IN
2 Department of Animal Science, School of Life Sciences, Bharathidasan University Tiruchirappalli - 620 024, IN

Abstract

Pregnane and Xenobiotic Receptor (PXR), a vital xenosensor, acts as master regulator of phase-I (cytochrome P450) and phase-II enzymes (glutathione S-transferases, sulfotransferases, and uridine 5'-diphosphate glucuronosyltransferases) as well as several drug transporters (multi-drug resistance protein, and multidrug resistance-associated protein). PXR can bind to a variety of chemically distinct endobiotics (steroids, bile acids and their derivatives, vitamins, etc.) and xenobiotics (prescription drugs, herbal medicines, endocrine disruptors, etc.). Activation of PXR by various compounds leads to trans-activation of PXR-target genes involved in detoxification system (phase-I and phase-II enzymes, and efflux proteins). Herbal medicines are readily used without prescription under the belief that anything natural is safe. These medicines contain active chemical constituents which execute distinctly different or similar pharmacological response(s). But, like prescription drugs, herbal drugs also have both therapeutic and, sometimes, adverse effects. Some of the herbal drugs induce drug metabolizing enzymes (especially CYP3A4) and drug efflux proteins via activation of PXR. Phase-I enzyme CYP3A4 is involved in the metabolism of 50-60% of clinical drugs as well as the chemical ingredients in herbal medicines. In addition to this, 25-30% of these compounds are metabolized by the CYP2B isoenzymes. The combined metabolic effects of phase-I and phase-II enzymes and drug transporters, following induction by therapeutic molecules, constitute the molecular basis for many drug-herbal interactions. For example, if one drug activates PXR, it can encourage the elimination of a co-administered drug that is also metabolized and eliminated by PXR-target gene products, thereby affecting the therapeutic efficacy of the drug in the context of combination therapy. The present review highlights some of the recent clinical correlates in drug-herbal interactions mediated primarily via PXR and cytochrome P450.

Keywords

Drug-Herbal Interactions, Pregnane and Xenobiotic Receptor (PXR), Cytochrome P450 (CYP450), Drug Transporters.

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