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This review article attempts to correlate Ayurvedic pharmacology and therapeutic claims for Tinospora cordifolia (Tc) with the evidence generated using scientific research methodology. In the present paper, a brief description of Ayurvedic pharmacology of the plant is presented. The work carried out by researchers using extracts of Tc in various areas such as diabetes, liver damage, free radical mediated injury, infections, stress and cancer have been reviewed. Also discussed are the immunomodulatory, diuretic, antiinflammatory, analgesic, anticholinesterase and gastrointestinal protective effects. An attempt has been made to provide the readers with the array of outcome variables, which can be further worked upon in clinical studies. Finally, this paper puts forth issues that need to be addressed by researchers in the future.

Ashwagandha (Withania somnifera) (WS), a “rasayana” drug, is recommended for balavardhan and mamsavardhan. The study was intended to evaluate dose-related tolerability, safety, and activity of WS formulation in normal individuals. The design was prospective, open-labeled, variable doses in volunteers. Eighteen apparently healthy volunteers (12M:6F, age:18-30 years, and BMI: 19-30) were enrolled. After baseline investigations, they received WS capsules (Rx) (aqueous extract, 8:1) daily in two divided doses with increase in daily dosage every 10 days for 30 days (750 mg/day ×10 days, 1 000 mg/day × 10 days, 1 250 mg/day × 10 days). Volunteers were assessed for symptoms/signs, vital functions, hematological and biochemical organ function tests. Muscle activity was measured by hand grip strength, quadriceps strength, and back extensor force. Exercise tolerance was determined using cycle ergometry. Lean body weight and fat% were computed from skin fold thickness measurement. Adverse events were recorded, as volunteered by the subjects. Repeated measures ANOVA, McNemar's test, and paired t test were employed. All but one volunteer tolerated WS without any adverse event. One volunteer showed increased appetite, libido, and hallucinogenic effects with vertigo at the lowest dose and was withdrawn from study. In six subjects, improvement in quality of sleep was found. Organ function tests were in normal range before and after the intervention. Reduction in total- and LDL- cholesterol and increase of strength in muscle activity was significant. Total body fat percentage showed a reduction trend. WS, in escalated dose, was tolerated well. The formulation appeared safe and strengthened muscle activity. In view of its traditional Rasayana use, further studies are planned to evaluate potential of this drug in patients of sarcopenia.

Experimental studies conducted earlier have proved that Phyllanthus emblica (Pe), Plumbago zeylanica (Pz) and Cyperus rotundus (Cr), plants from the medohara group of Ayurveda possess antiatherosclerotic activity. As inflammation is also one of the pathophysiological factors, it was of interest to evaluate whether these drugs exhibit any antiinflammatory activity. Two models of acute inflammation, namely carrageenan induced rat paw edema and acetic acid induced peritonitis in mice were used. In the model of carrageenan induced paw edema Pe, Pz and Cr showed a trend to reduce the edema while the combination of Pe + Pz (PI: 20.64%) showed results comparable to aspirin (23.74%). Whereas in a model of acetic acid induced peritonitis, all the plant drugs i.e. Pe, Pz, Cr and a combination of Pe + Pz showed a significant decrease in the protein content of the peritoneal exudates compared with the disease control group (p < 0.05), however, only Pe + Pz exhibited activity comparable to aspirin.

Plants from all over the world such as Eleutherococcus senticosus, Panax ginseng, Raponticum carthamoides, Rhodiola rosea, Withania somnifera and Ocimum sanctum have been extensively evaluated for their adaptogenic potential. However, none of them has been successfully introduced as an adaptogen in the clinic. This paper discusses some of the problems in evaluation of adaptogens which have precluded their inclusion as clinically useful drugs. We further discuss our results with six rasayana plants from Ayurveda, which were studied for their adaptogenic potential. The whole, aqueous, standardized extracts of selected plants (Tinospora cordifolia, Asparagus racemosus, Emblica officinalis, Withania somnifera, Piper longum and Terminalia chebula) were administered orally to experimental animals, in a dose extrapolated from the human dose, following which they were exposed to a variety of biological, physical and chemical stressors. These plants were found to offer protection against these stressors, as judged by using markers of stress responses and objective parameters for stress manifestations. Using a model of cisplatin induced alterations in gastrointestinal motility, the ability of these plants to exert a normalizing effect, irrespective of direction of pathological change was tested. All the plants reversed the effects of cisplatin on gastric emptying, while Tinospora cordifolia and Asparagus racemosus also normalized cisplatin induced intestinal hypermotility. Tinospora cordifolia was also tested for its ability to modulate the changes occurring in the phagocytic activity of peritoneal macrophages after exposure of rats to either carbon tetrachloride or horse serum. It was found to normalize the phagocytic function irrespective to the direction of change, complying to the definition of an adaptogen. All the plant drugs were found to be safe in both acute and subacute toxicity studies. Studies on the mechanisms of action of the plants revealed that they all produced immunostimulation. The protection offered by Tinospora cordifolia against stress induced gastric mucosal damage was lost if macrophage activity was blocked. Emblica officinalis strengthened the defence mechanisms against free radical damage induced during stress. The effect of Emblica officinalis appeared to depend on the ability of target tissues to synthesize prostaglandins. Recent data obtained with Tinospora cordifolia suggest that it may induce genotypic adaptation, further opening the arena for more research and experimentation.