"Confessions of an Ayurveda professor" - A wake up call.

Kishor Patwardhan's 'confession' in this journal [1] has initiated the expected debate, which I hope leads to some good developments for the teaching and practice of Ayurveda. Before, commenting on this issue, I should myself confess that I am neither formally trained in Ayurveda nor practising it. A basic research interest in Ayurvedic biology [2] led me to learn about the "fundamental principles" of Ayurveda and to experimentally examine effects of some Ayurvedic formulations using animal models like Drosophila and mouse at organismic, cellular, and molecular levels. During the past 16 to 17 years of my active engagement with Ayurvedic Biology, I had multiple opportunities to discuss the principles and philosophies of Ayurveda with formally trained Ayurvedacharyas and others who have an interest in this classical healthcare system. These experiences enhanced my appreciation of the wisdom of ancient scholars that led them to methodically compile the elaborate details of treatment for various health conditions in the classical Samhitas and, as noted earlier [3], gave me a "ring-side" view of Ayurveda. Despite the above limitations, an advantage of the "ring-side" view is the possibility of comprehending the philosophies and practices prevalent in Ayurveda in an unbiased manner and weighing them against contemporary practices in other disciplines.

Energetics of Excitatory and Inhibitory Neurotransmission in Aluminum Chloride Model of Alzheimer's Disease: Reversal of Behavioral and Metabolic Deficits by Rasa Sindoor.

Alzheimer's disease (AD) is an age-related neurodegenerative disorder, characterized by progressive loss of cognitive functions and memory. Excessive intake of aluminum chloride in drinking water is associated with amyloid plaques and neurofibrillary tangles in the brain, which are the hallmark of AD. We have evaluated brain energy metabolism in aluminum chloride (AlCl3) mouse model of AD. In addition, effectiveness of Rasa Sindoor (RS), a formulation used in Indian Ayurvedic medicine, for alleviation of symptoms of AD was evaluated. Mice were administered AlCl3 (40 mg/kg) intraperitoneally once a day for 60 days. The memory of mice was measured using Morris Water Maze test. The 13C labeling of brain amino acids was measured ex vivo in tissue extracts using 1H-[13C]-NMR spectroscopy with timed infusion of [1,6-13C2]glucose. The 13C turnover of brain amino acids was analyzed using a three-compartment metabolic model to derive the neurotransmitter cycling and TCA cycle rates associated with glutamatergic and GABAergic pathways. Exposure of AlCl3 led to reduction in memory of mice. The glutamatergic and GABAergic neurotransmitter cycling and glucose oxidation were found to be reduced in the cerebral cortex, hippocampus, and striatum following chronic AlCl3 treatment. The perturbation in metabolic rates was highest in the cerebral cortex. However, reduction in metabolic fluxes was higher in hippocampus and striatum following one month post AlCl3 treatment. Most interestingly, oral administration of RS (2 g/kg) restored memory as well as the energetics of neurotransmission in mice exposed to AlCl3. These data suggest therapeutic potential of RS to manage cognitive functions and memory in preclinical AD.

Amalaki Rasayana improved memory and neuronal metabolic activity in AbPP-PS1 mouse model of Alzheimer's disease.

Alzheimer's disease (AD) is the most common neurodegenerative disorder characterized by progressive loss of memory and cognitive function. The cerebral metabolic rate of glucose oxidation has been shown to be reduced in AD. The present study evaluated efficacy of dietary Amalaki Rasayana (AR), an Ayurvedic formulation used in Indian traditional system, in AbPP-PS1 mouse model of AD in ameliorating memory and neurometabolism, and compared with donepezil, a standard FDA approved drug for AD. The memory of mice was measured using Morris Water Maze analysis. The cerebral metabolism was followed by 13C labelling of brain amino acids in tissue extracts ex vivo using 1H-[13C]-NMR spectroscopy together with a short time infusion of [1,6-13C2]glucose to mice. The intervention with Amalaki Rasayana showed improved learning and memory in AbPP-PS1 mice. The 13C labelings of GluC4, GABAC2 and GlnC4 were reduced in AbPP-PS1 mice when compared with wild-type controls. Intervention of AR increased the 13C labelling of amino acids suggesting a significant enhancement in glutamatergic and GABAergic metabolic activity in AbPP-PS1 mice similar to that observed with donepezil treatment. These data suggest that AR has potential to improve memory and cognitive function in AD.

Ayurvedic Amalaki Rasayana promotes improved stress tolerance and thus has anti-aging effects in Drosophila melanogaster.

Amalaki Rasayana (AR) is a common Ayurvedic herbal formulation of Phyllanthus emblica fruits and some other ingredients, and is used for general good health and healthy aging. We reported it to improve life history traits and to suppress neurodegeneration as well as induced apoptosis in Drosophila. The present study examines responses of Drosophila reared on AR-supplemented food to crowding, thermal or oxidative stresses. Wild-type larvae/flies reared on AR-supplemented food survived the various cell stresses much better than those reared on control food. AR-fed mutant park13 or DJ-1 beta Delta93 (Parkinson's disease model) larvae/flies, however, showed only partial or no protection, respectively, against paraquat-induced oxidative stress, indicating essentiality of DJ-1 beta for AR-mediated oxidative stress tolerance. AR feeding reduced the accumulation of reactive oxygen species (ROS) and lipid peroxidation even in aged (35-day-old) wild-type flies while enhancing superoxide dismutase (SOD) activity. We show that while Hsp70 or Hsp83 expression under normal or stress conditions was not affected by AR feeding, Hsp27 levels were elevated in AR-fed wild-type control as well as heat-shocked larvae. Therefore, besides the known anti-oxidant activity of Phyllanthus emblica fruits, dietary AR also enhances cellular levels of Hsp27. Our in vivo study on a model organism shows that AR feeding significantly improves tolerance to a variety of cell stresses through reduced ROS and lipid peroxidation on the one hand, and enhanced SOD activity and Hsp27 on the other. The resulting better homeostasis improves life span and quality of organism's life.

Azadiradione ameliorates polyglutamine expansion disease in Drosophila by potentiating DNA binding activity of heat shock factor 1.

Aggregation of proteins with the expansion of polyglutamine tracts in the brain underlies progressive genetic neurodegenerative diseases (NDs) like Huntington's disease and spinocerebellar ataxias (SCA). An insensitive cellular proteotoxic stress response to non-native protein oligomers is common in such conditions. Indeed, upregulation of heat shock factor 1 (HSF1) function and its target protein chaperone expression has shown promising results in animal models of NDs. Using an HSF1 sensitive cell based reporter screening, we have isolated azadiradione (AZD) from the methanolic extract of seeds of Azadirachta indica, a plant known for its multifarious medicinal properties. We show that AZD ameliorates toxicity due to protein aggregation in cell and fly models of polyglutamine expansion diseases to a great extent. All these effects are correlated with activation of HSF1 function and expression of its target protein chaperone genes. Notably, HSF1 activation by AZD is independent of cellular HSP90 or proteasome function. Furthermore, we show that AZD directly interacts with purified human HSF1 with high specificity, and facilitates binding of HSF1 to its recognition sequence with higher affinity. These unique findings qualify AZD as an ideal lead molecule for consideration for drug development against NDs that affect millions worldwide.

Suppression of induced but not developmental apoptosis in Drosophila by Ayurvedic Amalaki Rasayana and Rasa-Sindoor.

Earlier we showed formulation-specific beneficial effects of dietary supplement of Ayurvedic Amalaki Rasayana (AR, a herbal formulation) and Rasa-Sindoor (RS, a mercury-based organo-metallic formulation) on various biological parameters in Drosophila, parallel to traditional Ayurvedic literature. These formulations also suppressed cell death and pathology in fly models of neurodegeneration. To understand basis of inhibition of apoptosis, we examined effects of AR and RS on induced and developmental apoptosis in Drosophila. Dietary AR or RS significantly reduced apoptosis induced by GMR-GAL4-, sev-GAL4- or hs-GAL4-directed expression of Rpr, Hid or Grim (RHG) proapoptotic proteins or by GMR-GAL4-directed DIAP1-RNAi, resulting in significant restoration of organism's viability and eye morphology. AR or RS supplement enhanced levels of inhibitor of apoptosis proteins, DIAP1 and DIAP2, and of Bancal/Hrb57A, while the levels of RHG proteins and of initiator Dronc and effecter Drice caspases were reduced in non-apoptotic wild type as well as in RHG over-expressing tissues. Levels of Dronc or Drice remained unaffected in cells developmentally destined to die so that developmental apoptosis occurred normally. Elevated levels of DIAPs and reduced levels of RHG proteins and caspases reflect a more robust physiological state of AR or RS fed organisms allowing them to tolerate greater insults without triggering the cell-death response. Such homeostatic effects of these Rasayanas seem to contribute to 'healthy ageing', one of their effects suggested in traditional Ayurvedic practices.

In vivo effects of traditional Ayurvedic formulations in Drosophila melanogaster model relate with therapeutic applications.

BACKGROUND: Ayurveda represents the traditional medicine system of India. Since mechanistic details of therapy in terms of current biology are not available in Ayurvedic literature, modern scientific studies are necessary to understand its major concepts and procedures. It is necessary to examine effects of the whole Ayurvedic formulations rather than their "active" components as is done in most current studies. METHODS: We tested two different categories of formulations, a Rasayana (Amalaki Rasayana or AR, an herbal derivative) and a Bhasma (Rasa-Sindoor or RS, an organo-metallic derivative of mercury), for effects on longevity, development, fecundity, stress-tolerance, and heterogeneous nuclear ribonucleoprotein (hnRNP) levels of Drosophila melanogaster using at least 200 larvae or flies for each assay. RESULTS: A 0.5% (weight/volume) supplement of AR or RS affected life-history and other physiological traits in distinct ways. While the size of salivary glands, hnRNP levels in larval tissues, and thermotolerance of larvae/adult flies improved significantly following feeding either of the two formulations, the median life span and starvation resistance improved only with AR. Feeding on AR or RS supplemented food improved fecundity differently. Feeding of larvae and adults with AR increased the fecundity while the same with RS had opposite effect. On the contrary, feeding larvae on normal food and adults on AR supplement had no effect on fecundity but a comparable regime of feeding on RS-supplemented food improved fecundity. RS feeding did not cause heavy metal toxicity. CONCLUSIONS: The present study with two Ayurvedic formulations reveals formulation-specific effects on several parameters of the fly's life, which seem to generally agree with their recommended human usages in Ayurvedic practices. Thus, Drosophila, with its very rich genetic tools and well-worked-out developmental pathways promises to be a very good model for examining the cellular and molecular bases of the effects of different Ayurvedic formulations.