Introduction

In world of Ayurveda, ancient system of traditional medicine, concept of Shodhan^[1] or purification of Visha Dravya (toxic substances) holds profound importance. Rooted in centuries-old wisdom, it involves meticulous process of purifying substance that could be toxic to produce its potential healing powers while minimizing harmful effects. This critical review strives to explore intricacies of Shodhan^[2], covering traditional practices, scientific rationale, and contemporary relevance in context of modern healthcare. Despite fact that most of plant drugs are safe, yet some of these are toxic for human health. Any poison if processed or used properly is potential medicine and any medicine with improper use is fatal poison.^[3]

Table 1: Visha and Upavisha

Table 2: Ayurvedic poisonous plant listed in the schedule E of drugs and cosmetics Act 1940 and rule 1945.

Various Toxic Medicinal Plants and their Shodhana Process

Aconitum species

Numerous species under the Aconitum genus, such as Aconitum ferox Wall., Aconitum napellus Linn., and Aconitum chasmanthum Holmes ex. Stapf., are commonly referred to as "Aconite" in English and "Vatsanabha" in Sanskrit. All three of the plants' roots are highly toxic, however they may be used to cure a number of illnesses, including fever, rheumatoid arthritis, sciatica, and hypertension. After being detoxified, the roots also function as "Rasāyana" (immunomodulators).

At larger concentrations, the majority of the alkaloids found in the root of Aconitum species have been shown to have neurotoxic and cardiotoxic effects. The major causes of severe aconite poisoning are overindulgence in an herbal decoction prepared from the roots of the aconite plant or inadvertent intake of wild plants. A dosage of 2 mg of the isolated chemical aconite from Vatsanabha can be deadly, whereas 1 g of Vatsanabha is lethal to humans. Tribes utilized the root of Vatsanabha as poison in the past to hunt animals. Traditional Ayurvedic formulations of Vatsanabha when overdosed might result in bidirectional tachycardia, bradycardia, or hypotension. Owing to these factors, the Ayurvedic medical system recommends a therapeutic dosage of Vatsanabha of 8–16 mg per day. Its purifying procedure is Svedana^[9] (boiling) in a Dola yantra with Godugdha for three hours every day for three consecutive days, followed by three water washes and sun drying.

Gunja

After being processed by Shodhana, the roots, seeds, and leaves of Gunja (Abrus precatorius Linn., Family: Fabaceae) have been utilized historically for their purgative, emetic, tonic, aphrodisiac, and hair growth encouraging effects. It has been used for poisoning humans and livestock for illicit purposes, as well as fish and arrow poisoning, from ancient times. Abrus seeds contain a number of substances that might cause abortion, including a poisonous lectin, an albumotoxin called abrin, an enzyme that splits fat, a glucoside called abrussic acid, urease, abarnin, trigonelline, choline, hypaphorine, and steroidal oil. Boiling the seed is said to make it innocuous, however 0.1–1 μg/kg of abrin is deadly for humans.

Bhallataka

The fruit of Bhallataka (Semecarpus anacardium Linn., Family: Anacardiaceae) is an effective medication for rheumatism, asthma, sciatica, epilepsy, and a host of other conditions. The fruit's pericarp is filled with tarry oil that is 90% anacardic acid and 10% cardol. Semecarpol, anacardol, and bhilawanols (also known as urushiols) are other identified chemical components. The phytoconstituents bhilawanol and anacardic acids are in charge of causing irritation, blisters, toxicity, and contact dermatitis. The Shodhana process of Bhallataka^[13] involves rubbing the fruits on brick gravel after soaking them in Gomutra, Godugdha. The fruits are stored in either Gomutra or Godugdha for seven days after the thalamus sections are removed, and then they are finally cleaned with water. oravels (for three days), scrubbed well, and let to dry. After three days, the seeds are moved to a bag filled with brick gravel, properly cleaned, and allowed to dry. In order to lower the risk of dermatitis, coconut oil is applied to the exposed body areas of those participating in the Shodhana of Bhāllataka procedure. The observed decrease in weight following Shodhana might perhaps be attributed to the fruits' decreased oil content. Soaking the fruits in the Gomutra or Godugdha may result in a higher proportion of oil being decreased. Brick powder absorbs irritating oils from fruit due to its adsorbent properties.

Karavira

The plant Karavira (Nerium indicum; Family: Apocynaceae) possesses properties that include anti-inflammatory, antifungal, cardiotonic, neuroprotective, and anti-stress effects. The cardenolides, namely neriine and oleandrin, are among the harmful cardiac glycosides present in this plant. Godugdha is used in the Svedana method for three hours to purify the roots of N. indicum in the Dolā Yantra. The roots are dried after being Shodhana and cleaned with water.

Langali

The semi-woody herbaceous climber Gloriosa superba Linn. (family Liliaceae) is used to treat fever, rheumatoid arthritis, gonorrhea, inflamma-tions, and labor pains. There have been reports of the harmful consequences, particularly cardioto-xicity, of colchicine found in this plant. Gloriosine is another poisonous alkaloid found in the species.

Conclusion

According to Ayurvedic philosophy, "if processed and administered properly, even a strong poison can be converted into an excellent medicine." However, if used improperly, even the most beneficial medication might turn toxic. Ayurvedic practitioners have worked to create a variety of age-old techniques over time to transform hazardous medicinal herbs into beneficial medications. It's likely that ancient healers were unaware of the chemical makeup of the therapeutic plants they used to create concoctions. Ayurveda treats human problems with a variety of hazardous natural medications, either in their raw form or via Shodhana procedures. It is possible to draw the conclusion that the traditional purification method (Shodhana) can affect the phytochemical, pharmacological, and toxicological profiles of plant-based medications, which can help to improve the medications' effectiveness and safety profile. Adopting the Shodhana techniques from the Indian medical system is beneficial for creating herbal compositions and using contemporary technologies to evaluate their safety and effectiveness. Research has indicated that the harmful ingredients are incorporated into the medium, making the medication non-toxic. Undoubtedly, certain media plays a significant part in ensuring that a medicine acts without producing negative side effects.

This critical review serves as a testament to the enduring legacy of Ayurveda and the ongoing evolution of its pharmacological principles, offering insights into the purification of Visha Dravya and its implications for Ayurveda healthcare practices.

References