Ethnopharmacologically important highly subsidized Indian medicinal plants: Systematic review on their traditional uses, phytochemistry, pharmacology, quality control, conservation status and future prospective

ETHNOPHARMACOLOGICAL RELEVANCE

India has an extensive reservoir of traditional wisdom and a diverse range of medicinal plants that enrich its heritage. Plants have actively been used for healthcare practices globally since the time immemorial. Medicinal uses of plants have been well recognized in India, evident from plant species documented in different traditional medicinal systems such as Ayurveda (1400-1800 species), Siddha (500-900 species), Unani (400-700 species), Homeopathy (about 372 species), and Sowa-Rigpa (about 250 species), etc. AIM OF THE STUDY: The primary purpose of this review is to provide systematic updated information on thirteen medicinal plants prioritized by the Indian government (providing75 % subsidy on cultivation cost) based on the availability and market demand of these plants. Updated information regarding the traditional uses, phytochemistry, pharmacology, quality control, and conservation status of these plants will help in understanding their pharmacological and commercial importance. This will also help in developing new strategies for their conservation.

MATERIAL AND METHODS

Online databases such as SciFinder, Web of Science, Pubmed, and Google Scholar were used to collect the electronically available literature on targeted thirteen plants. Also, different Indian government official websites such as AYUSH (https://www.ayush.gov.in); NMPB (National Medicinal Plants Board) (https://nmpb.nic.in); e.charak (https://echarak.in) were used for collecting information related to the amount of subsidy, trade and price related information of these plants.

RESULTS

To promote medicinal plant cultivation, the Indian government provides subsidies for cultivating some traditionally important medicinal plants. These plants are divided into three categories according to the subsidy provided to farmers, i.e., 30%, 50%, and 75% of the cost of cultivation. Thirteen medicinal plants which are provided 75% subsidy are Aconitum ferox Wall., Aconitum heterophyllum Wall., Aquilaria agallocha Roxb., Berberis aristata DC., Commiphora wightii (Arn.) Bhandari, Nardostachys jatamansi (D.Don) DC., Oroxylum indicum (L.) Benth. ex Kurz, Picrorhiza kurroa Royle ex Benth., Podophyllum hexandrum Royle, Pterocarpus santalinus L.f., Santalum Album L., Saussurea costus (Falc.) Lipsch., and Swertia chirayita (Roxb.) H.Karst. The literature survey reveals the enormous traditional medicinal importance, wide geographical distribution, diverse range of natural products, and broad spectrum of pharmacological activities of these plants.

CONCLUSION

A comprehensive literature survey revealed that although remarkable progress has been made in isolation, bioactivity evaluation, quality assessment, and conservation, there is still a lot of scope for further scientific interventions. Scientific validation of traditionally claimed medicinal potential is lacking for various bioactivities. Some of the bioactivities are performed just on extracts/fractions, so there is a need for proper phytochemical studies to identify active constituents responsible for the specific bioactivity. Further, quality assessment methods using both targeted and non-targeted tools are required to evaluate the quality of these highly-priced medicinal plants and their adulterants. Ultimately, to encourage the cultivation of these endangered medicinal plant species, it is imperative to implement proper legislation and employ in-situ and ex-situ conservation tools.

Anti-inflammatory and immune-modulatory impacts of berberine on activation of autoreactive T cells in autoimmune inflammation

Autoreactive inflammatory CD4+ T cells, such as T helper (Th)1 and Th17 subtypes, have been found to associate with the pathogenesis of autoimmune disorders. On the other hand, CD4+ Foxp3+ T regulatory (Treg) cells are crucial for the immune tolerance and have a critical role in the suppression of the excessive immune and inflammatory response promoted by these Th cells. In contrast, dendritic cells (DCs) and macrophages are immune cells that through their inflammatory functions promote autoreactive T-cell responses in autoimmune conditions. In recent years, there has been increasing attention to exploring effective immunomodulatory or anti-inflammatory agents from the herbal collection of traditional medicine. Berberine, an isoquinoline alkaloid, is one of the main active ingredients extracted from medicinal herbs and has been shown to exert various biological and pharmacological effects that are suggested to be mainly attributed to its anti-inflammatory and immunomodulatory properties. Several lines of experimental study have recently investigated the therapeutic potential of berberine for treating autoimmune conditions in animal models of human autoimmune diseases. Here, we aimed to seek mechanisms underlying immunomodulatory and anti-inflammatory effects of berberine on autoreactive inflammatory responses in autoimmune conditions. Reported data reveal that berberine can directly suppress functions and differentiation of pro-inflammatory Th1 and Th17 cells, and indirectly decrease Th cell-mediated inflammation through modulating or suppressing other cells assisting autoreactive inflammation, such as Tregs, DCs and macrophages.

Berberine: Botanical Occurrence, Traditional Uses, Extraction Methods, and Relevance in Cardiovascular, Metabolic, Hepatic, and Renal Disorders

Berberine-containing plants have been traditionally used in different parts of the world for the treatment of inflammatory disorders, skin diseases, wound healing, reducing fevers, affections of eyes, treatment of tumors, digestive and respiratory diseases, and microbial pathologies. The physico-chemical properties of berberine contribute to the high diversity of extraction and detection methods. Considering its particularities this review describes various methods mentioned in the literature so far with reference to the most important factors influencing berberine extraction. Further, the common separation and detection methods like thin layer chromatography, high performance liquid chromatography, and mass spectrometry are discussed in order to give a complex overview of the existing methods. Additionally, many clinical and experimental studies suggest that berberine has several pharmacological properties, such as immunomodulatory, antioxidative, cardioprotective, hepatoprotective, and renoprotective effects. This review summarizes the main information about botanical occurrence, traditional uses, extraction methods, and pharmacological effects of berberine and berberine-containing plants.

Herbicidal Spectrum, Absorption and Transportation, and Physiological Effect on Bidens pilosa of the Natural Alkaloid Berberine

Berberine is a natural herbicidal alkaloid from Coptis chinensis Franch. Here we characterized its herbicidal spectrum and absorption and transportation in the plant, along with the possible mechanism. Berberine showed no effect on the germination of the 10 tested plants. The IC₅₀ values of berberine on the primary root length and fresh weight of the 10 tested plants ranged from 2.91 to 9.79 mg L^-1 and 5.76 to 35.07 mg L^-1, respectively. Berberine showed a similar herbicidal effect on Bidens pilosa as the commercial naturally derived herbicide cinmethylin. HPLC and fluorescence analysis revealed that berberine was mainly absorbed by B. pilosa root and transported through vascular bundle acropetally. Enzyme activity studies, GC-MS analysis, and SEM and TEM observations indicated that berberine might first function on the cell membrane indicated by variation of the IUFA percent and then cause POD, PPO, and SOD activity changes and cellular structure deformity, which was eventually expressed as the decrease of cell adaptation ability and abnormal cell function and may even result in cell death. Environmental safety evaluation tests revealed that berberine was low in toxicity to Brachydanio rerio. These indicate that berberine has the potential to be a bioherbicide and/or a lead molecule for new herbicides.

Development and validation of a stability-indicating method for determination of free sterols in the Asian medicinal leech Hirudo manillensis

A rapid, simple, sensitive, selective, precise and robust thin-layer chromatography densitometric method for the determination of free sterols in leech was developed and validated on silica gel layer using carbon tetrachloride-methanol-formic acid (9.5:1.5:0.55, v/v/v). Spectrodensitometric scanning was carried using a Camag TLC scanner III at 366 nm after spraying 2% methanolic sulphuric acid, which gave compact spots for cholesterol (R(F) = 0.35 ± 0.02). The regression analysis data for calibration plot implied a good linear relationship (r(2) = 0.99958) between response and concentration over the range 100-600 ng per spot with respect to peak area. The limits of detection and quantification were found to be 13.8 ± 0.51 and 45.01 ± 1.29 ng per spot, respectively. Validation was in accordance to the International Conference on Harmonization guidelines. Cholesterol was subjected to forced stress conditions of oxidation, hydrolysis and heat. Degradation products resulting from the forced stress did not interfere with detection because the degradant peaks were well separated from the cholesterol peak. The densitometric method can be regarded as stability-indicating and can be used for quality control assay of cholesterol in leech extract.

Development and validation of HPLC method for simultaneous estimation of piperine and guggulsterones in compound Unani formulation (tablets) and a nanoreservoir system

An attempt has been made to develop and validate a simultaneous HPLC method for novel approach of drug release via oil-in-water (o/w) nanoemulsion formulation and Habb-e-Khardal Unani tablet containing piperine and guggul sterones E and Z as main ingredients. Nanoemulsion was prepared by titration method using sefsol-218 as an oily phase, cremophor-EL as a surfactant, transcutol as a co-surfactant and distilled water as an aqueous phase. The formulation was optimized on the basis of thermodynamic stability and dispersibilty test. The nanoformulation was evaluated for particle size, surface morphology, electrical conductivity and viscosity determination. The in vitro dissolution was carried out by dialysis bag method. Drugs were quantified using an HPLC method developed in-house with a C(18) column as stationary phase and acetonitrile and water as mobile phase at λ(max) of 240 nm. The optimized formulation showed higher drug release, lower droplet size and less viscosity as compared with the conventional Habb-e-Khardal Unani tablet. The present study illustrated the potential of nanoemulsion dosage form in improving biopharmaceutic performance of piperine and guggul sterone. The HPLC method was also found to be quite sufficient for the routine quality control of formulations containing piperine and guggul sterone E and Z as ingredients and also for in vitro drug release studies.