Background

Sarpagandha is an important Ayurveda drug used for treating many diseases including high blood pressure. Rauvolfia serpentina is the genuine source plant for Sarpagandha and it is a critically endangered species belonging to the family Apocynaceae. The present study is aimed at finding out an appropriate substitute for the endangered species R. serpentina by evaluating the phytochemistry and biological activities of allied species such as Rauvolfia tetraphylla L, Rauvolfia hookeri S.R.Sriniv. & Chithra, Rauvolfia micrantha Hook.f., and Rauvolfia verticillata (Lour.) Baill.

Results

The result indicated that the root of R. serpentina is phytochemically similar with that of R. tetraphylla. Chemical profiling using HPTLC showed similar chemical profiles for R. serpentina and R. tetraphylla. LC/MS characterization of various species showed that most of the active alkaloids are common for both R. serpentina and R. tetraphylla. Anti-hypertensive activity and analgesic activity were evaluated in experimental animal model. Rauvolfia serpentina and R. tetraphylla showed comparatively significant reduction in systolic and diastolic pressure. Comparable analgesic activity was also shown by R. serpentina and R. tetraphylla.

Conclusion

On the basis of phytochemical and pharmacological evaluation, it was concluded that the root of R. tetraphylla can be used as a validated substitute for Sarpagandha.

Graphical abstract

Background

In AyurvedaSarpagandha is used for the treatment of high blood pressure, insomnia, asthma, acute stomach ache and painful delivery and for mental illness such as neuropsychiatric disorders, psychosis, and schizophrenia. The root of Rauvolfia serpentina is the genuine source drug of Sarpagandha. It is also used in the treatment of snake-bite, insect stings, mental disorders, gastric tumor, general weakness, goiter, hysteria, insomnia, insanity, lipoma, paraplegia, paratyphoid, piles, pneumonia, splenomegaly, stomach disorder, tonsillitis, traumatic wound, tuberculosis, and vertigo [1].

Genus Rauvolfia, belonging to the family Apocynaceae, comprises more than 80 species, which are distributed in tropical climatic conditions. Rauvolfia serpentina is well known for the presence of indole alkaloids. Reserpine is the most prominent of these alkaloids and is useful in the treatment of hypertension, cardiovascular diseases, nervous disorders, and as a tranquilizing agent that is in great demand by modern pharmaceutical industries [2].

Rauvolfia tetraphylla popularly known as “devil pepper” is a woody shrub commonly available in India. It is native to West Indies but naturalized in South India [3]. It is an ethnomedicinally important plant and is used against snakebite, to stimulate uterine contraction and to facilitate difficult childbirth cases. Rauvolfia hookeri is a large dichotomously branched shrub belonging to the family Apocynaceae. It is an endemic south Indian species containing many indole alkaloids [2]. Rauvolfia micrantha is an annual shrub, reaching up to 1.5 to 2 m high. Stems are sparingly branched. Leaves are simple, alternate, elliptic lanceolate, 5-10 cm × 3-4 cm, acuminate, peduncle terminal, erect, 4-6 flowered. Rauvolfia verticillata is an erect shrub growing up to 3 m tall and also a prolific source of heterocyclic indole alkaloids [4].

Nowadays, the herbal drug industry is getting often disrupted due to non-availability of good quality raw materials for manufacturing drugs. The acute shortage of plant raw materials is adversely affecting the quality of finished herbal products, as manufacturers are forced to buy sub standard raw material at double the prices pushing many manufacturers at the brink of shutting down of their industry. The habitat loss by export of medicinal plants collected from wild sources finally leads to severe and irreplaceable loss of genetic stock of many of these species. In India, the Ministry of Environment and Forests has banned export of 29 species including some popularly used drugs in Ayurvedic formulations like Sarpagandha [5].

Rauvolfia serpentina is identified as a critically endangered species [6]. Due to high demand and unavailability, the roots of Rauvolfia serpentina are usually adulterated with other species like Ophiorrhiza mungos, white-flowered and red-flowered Clerodendrum species and Tabernaemontana divaricata. Substitutes were used and recommended in the ancient texts for plants that were scarce to obtain. In this way, different regions in the country have come to use different botanical sources for some of the classical plants [7]. In industry, Sarpagandha is commonly substituted with the root of other Rauvolfia species.

Identification of a scientifically validated substitute from allied/related species for the endangered medicinal plant has a great importance in the herbal drug industry as it exterminates the unauthorized substitution and adulteration. The unscientific substitution may affect the quality of herbal preparations adversely. No previous scientific studies are available regarding the identification of substitute for this selected species. The objective of the present study is to find out an appropriate substitute for the root of R. serpentina by evaluating the phytochemical and pharmacological properties of its allied species.

To read the preprint of the article, please click on the link below

https://bjbas.springeropen.com/articles/10.1186/s43088-020-00069-5

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