| ''Rasayana'' and ''vajikarana'' therapies have common aim to provide positive health and prevention of diseases by increasing vigor of healthy person and so, [[Vajikarana]] is described just after [[Rasayana]] chapter. Health scientists are showing great interest in screening classical ''rasayana'' drugs for their antioxidant activity and research reveals good results. Studies on ''amalaki rasayana'' <ref>Dwivedi V, Anandan EM, Mony RS, Muraleedharan TS, Valiathan MS, Mutsuddi M, et al. In vivo effects of traditional Ayurvedic formulations in Drosophila melanogaster relate with therapeutic applications. PLoS One. 2012;7:e37113.</ref> shows increased longevity and on Drosophila melanogaster <ref> Fontana L, Partridge L, Longo VD. Extending healthy life span – From yeast to humans. Science. 2010;328:321–6.</ref> there is reduced oxidative damage to extend lifespan. Many drugs are described as ''rasayanas'' and ''vajikara'' both. Reactive oxygen species (ROS) has deteriorating effect on sperm. This has been increasing due to changing lifestyle and exposure to environmental pollution. Spermatozoa normally produce ROS in a normal physiological process. The amount of ROS produced is to be carefully controlled. Imbalance between the generation and scavenging of ROS may lead to damage to DNA or other important structures. Spermatozoa lack cytoplasmic defensive enzymes, such as catalase, glutathione peroxidase, which are involved in the protection of most cell types from ROS induced peroxidative damage. Large amounts of unsaturated fatty acids are observed in plasma membranes of spermatozoa, those are particularly vulnerable to free radical attack.<ref>Jones R and Mann T (1973) Lipid peroxidation in spermatozoa. Proc R Soc Lond B Biol Sci 184,103–107.</ref> The subfertile men have higher concentrations of ROS in seminal plasma, whereas an inverse correlation exists between ROS concentration and motility.<ref>Carlsen E, Giwercman A, Keiding N, Skakkebaek NE, Review Evidence for decreasing quality of semen during past 50 years. BMJ. 1992 Sep 12; 305(6854):609-13</ref> Many ''rasayanas'' act as antioxidants, so they can also be used to enhance sperm quality and quantity. Thus, mutual correlation and common mode of action justifies description of ''vajikarana'' just after ''rasayana'' therapy. | | ''Rasayana'' and ''vajikarana'' therapies have common aim to provide positive health and prevention of diseases by increasing vigor of healthy person and so, [[Vajikarana]] is described just after [[Rasayana]] chapter. Health scientists are showing great interest in screening classical ''rasayana'' drugs for their antioxidant activity and research reveals good results. Studies on ''amalaki rasayana'' <ref>Dwivedi V, Anandan EM, Mony RS, Muraleedharan TS, Valiathan MS, Mutsuddi M, et al. In vivo effects of traditional Ayurvedic formulations in Drosophila melanogaster relate with therapeutic applications. PLoS One. 2012;7:e37113.</ref> shows increased longevity and on Drosophila melanogaster <ref> Fontana L, Partridge L, Longo VD. Extending healthy life span – From yeast to humans. Science. 2010;328:321–6.</ref> there is reduced oxidative damage to extend lifespan. Many drugs are described as ''rasayanas'' and ''vajikara'' both. Reactive oxygen species (ROS) has deteriorating effect on sperm. This has been increasing due to changing lifestyle and exposure to environmental pollution. Spermatozoa normally produce ROS in a normal physiological process. The amount of ROS produced is to be carefully controlled. Imbalance between the generation and scavenging of ROS may lead to damage to DNA or other important structures. Spermatozoa lack cytoplasmic defensive enzymes, such as catalase, glutathione peroxidase, which are involved in the protection of most cell types from ROS induced peroxidative damage. Large amounts of unsaturated fatty acids are observed in plasma membranes of spermatozoa, those are particularly vulnerable to free radical attack.<ref>Jones R and Mann T (1973) Lipid peroxidation in spermatozoa. Proc R Soc Lond B Biol Sci 184,103–107.</ref> The subfertile men have higher concentrations of ROS in seminal plasma, whereas an inverse correlation exists between ROS concentration and motility.<ref>Carlsen E, Giwercman A, Keiding N, Skakkebaek NE, Review Evidence for decreasing quality of semen during past 50 years. BMJ. 1992 Sep 12; 305(6854):609-13</ref> Many ''rasayanas'' act as antioxidants, so they can also be used to enhance sperm quality and quantity. Thus, mutual correlation and common mode of action justifies description of ''vajikarana'' just after ''rasayana'' therapy. |