A traditional anti-fertility agent and libido enhancer in Ayurveda, Holy Basil (also known as Tulsi) is currently being investigated for these two claims and its general health properties. A good source of dietary Ursolic acid, which may cause the anti-fertility aspects.
Sources and Composition
Holy Basil, also known as Tulsi, is an Ayurvetic plant traditionally used for general health and a long life. Traditionally, the active ingredient is an oil extract of the leaves, which although traditionally used for a myriad of reasons is most commonly regonized for anti-stress and pro-vitality properties.
Its herbal name is Ocimum Tenuiflorum, although Ocimum Sanctum is commonly seen as a synonym; these two terms as well as Holy Basil and Tulsi are all interchangeable in regards to supplementation.
Stress and Anxiety
Some components of ocimum sanctum, namely ocimarin and the ocimumosides A and B, appear to exert antistress activity when given to rats at the dose of 40mg/kg.
In otherwise healthy subjects given ocimum sanctum twice daily (500mg each time after meals) over the course of two months, supplementation appeared to reduce symptoms of generalized anxiety disorders as assessed by the BPRS.
Inflammation and Immunology
One human trial noted that after 4 weeks consumption of 300mg ethanolic extract of Tulsi leaves, that participants experienced an increase in some cytokines associated with the immune system; interferon-y (IFN-y), interleukin-4 (IL-4), as well as T-helper cells and NK-cells. No influence on Cytotoxic T-cells or B-cells were noted in this study. When cells were isolated from subjects and pro-inflammatory chemicals were added (LPS, phytohaemagglutinin) the immune cells of the Tulsi group were more effective in mounting an adaptive immune response via IFN-y and T-helper cells and NK-cells.
These immunomodulatory effects may be secondary to the flavonoid content of Tulsi.
Interactions with Hormones
The only noted effects of Holy Basil on testosterone levels are from a rabbit study ingesting 2g of Holy Basil per day. This study and previous ones noted reductions in sperm count and reproductive potential, which parallels studies with the component of Holy Basil Ursolic Acid.
A possible explanation being a possible androgenic analogue in Holy Basil which increases testosterone sufficiently enough to repress luteinizing and follicle-stimulating hormones significantly.
Peripheral Organ Systems
Holy Basil seems to be effective in preventing toxin-induced damage to the liver in doses of 100-200mg/kg bodyweight. These protective effects are due to a supposed membrane stabilizing effect of Holy Basil constituents.
Holy Basil, like other adaptogenic compounds, can reduce cadmium build-up in the body and protect the body from already placed cadmium toxicity and reverse build-up. The proposed mechanism was anti-oxidant flavonols also acting as metal chelators or otherwise alleviating oxidative stress of cadmium enough for other chelators to act before damage could occur.
Safety and Toxicity
Toxicity has been reported for the oil extract of Holy Basil (which contains 70+/-3% eugenol content) and has been found to be 42.5ml/kg bodyweight. Whereas the dry plant extract with a normal eugenol content has an LD50 of between 4600-6400mg/kg bodyweight in research animals.