Remarks on “Tinospora cordifolia: One plant, many roles”
Sir, We read an article entitled “Tinospora cordifolia: One plant, many roles,” with great interest and would like to place few remarks on this.[1] The article is aptly written, informative and seems to be a product of a sincere effort of the researcher. The authors have aimed at encompassing the genetic diversity of the plant and they were also able to present the scarcity of reports on conservation strategies, propagation of the germplasm, morphological and physiological characters, and other characteristics of the plant. Unfortunately however, nothing has been discussed much about genetic diversity with special reference to Tinospora. Authors could have compiled reported studies on male and female varieties of Tinospora.[2,3]
Posological Considerations of Ocimum sanctum (Tulasi) as per Ayurvedic Science and Pharmaceutical Sciences
A study in 2010 reported that administration of 2 g of O. sanctum leaves for 30 days to laboratory male albino rabbits showed adverse effect on sperm count and male hormones. The dose and duration at which this testing was reported was commented upon as being high. It is learnt that basis this publication a few European regulators have imposed restrictions on usage of O. sanctum. Recognizing the need for evaluation, a review has been made of the posological considerations related to decision on dose of a drug in pharmaceuticals (drug development stages) and in Ayurvedic science as part of history of use and current usage. Specifically, we report the dose range as per documented tradition, marketed products containing O. sanctum as an ingredient and current clinical practice. Greater consultation is suggested before deciding the studies on Ayurvedic herbs. Regulatory action of banning use of O. sanctum needs a review and may need to be replaced with an advisory.
Negatively charged phospholipids trigger the interaction of a bacterial Tat substrate precursor protein with lipid monolayers.
Folded proteins can be translocated across biological membranes via the Tat machinery. It has been shown in vitro that these Tat substrates can interact with membranes prior to translocation. Here we report a monolayer and infrared reflection-absorption spectroscopic (IRRAS) study of the initial states of this membrane interaction, the binding to a lipid monolayer at the air/water interface serving as a model for half of a biological membrane. Using the model Tat substrate HiPIP (high potential iron-sulfur protein) from Allochromatium vinosum, we found that the precursor preferentially interacts with monolayers of negatively charged phospholipids. The signal peptide is essential for the interaction of the precursor protein with the monolayer because the mature HiPIP protein showed no interaction with the lipid monolayer. However, the individual signal peptide interacted differently with the monolayer compared to the complete precursor protein. IRRA spectroscopy indicated that the individual signal peptide forms mainly aggregated β-sheet structures. This β-sheet formation did not occur for the signal peptide when being part of the full length precursor. In this case it adopted an α-helical structure upon membrane insertion. The importance of the signal peptide and the mature domain for the membrane interaction is discussed in terms of current ideas of Tat substrate-membrane interactions.