Pharmacognostic standardization of Aralia cachemirica: a comparative study

Abstract

Background

Aralia cachemirica Decne. is an endemic and an important medicinal plant species of Kashmir Himalaya. Despite having immense medicinal importance, little information is available on the standardization parameters of the species. For this reason, present work was carried out for providing comprehensive report on the quality control and standardization parameters of A. cachemirica. In this connection, different parts (leaves, stem, and root) of the plant were examined. Methods like microscopy and macroscopy, physicochemical parameters, extractive values, and fluorescence analysis were used to establish pharmacognostical standards.

Results

The macroscopic, microscopy, and physicochemical parameters of different parts of A. cachemirica revealed various diagnostic characteristics in the species.

Conclusion

This is the first study providing complete pharmacognostic profile of A. cachemirica and hence will be useful for correct identification and authentication of the species for future studies.

Background

Plants happen to be serving human beings as a natural source of cure for various ailments and diseases since ages. The world has seen huge increase in plant research in recent times, and numerous evidences show vast potential of medicinal plants used in various traditional systems [1]. In Ayurveda, about 2000 plant species are labeled as source of medicinal value, while in Chinese Pharmacopoeia 5700 traditional medicines are listed [2], most of which are still used in conventional medical practice [3]. These are now getting more attention than ever because they have potential of multitude benefits to society or indeed to all mankind, especially in medicine and pharmacological studies [4]. Therefore, there is a need to evaluate phytoconstituents obtained from traditional medicines, based on various phytochemical screening and pharmacological and analytical methods [5]. The World Health Organization (WHO) supports, suggests, and encourages traditional/herbal remedies in national health care programs as these drugs are easily available at low cost, safe, and people have reliance in them [6]. Proper identification, quality assurance, and establishing pharmacognostic standards are very important parameters for evaluation of medicinal plants. Macroscopic and microscopic characters, physicochemical studies, and fluorescence analysis of these are prime steps for their evaluation. According to the WHO, the macroscopical and microscopical account of a medicinal plant is the first step towards ascertaining the identity and the degree of purity of such material [6].

Aralia cachemirica Decne. is commonly known as “Kashmir spikenard” and locally known as “khoree”. It is a shrubby herb, 1 to 3-m tall, growing at various altitudes, and belongs to the family Araliaceae. It is found distributed in temperate Himalayas from Kashmir to Sikkim at 2100 to 4000-m altitude [7, 8]. The following phytoconstituents have already been isolated from the plant: octadec-6-enoic acid, 8-primara-14, 15-diene-19-oic acid, aralosides A&B [9, 10]. Nonane, a hexacosane derivative, petroselinic acid, stigmasterol, and β-sitosterol [10, 11] are other phytoconstituents isolated from the plant. Anti-inflammatory activity also has been reported in this plant [10]. Bhat et al. [10] reported hypoglycemic activity from the roots of Aralia cachemirica. Furthermore, isolation of continentalic acid from A. cachemirica and its immunomodulatory activity has already been reported [12].

Despite having great medicinal importance, little information is available on the standardization parameters of A. cachemirica. Hence, present work can only be an attempt for providing comprehensive report on the quality control and standardization parameters of A. cachemirica. In this connection, different parts (leaves, stem, and root) of the plant were examined. Methods like microscopy and macroscopy, physicochemical parameters, extractive values, and fluorescence analysis were used to establish pharmacognostical standards. These parameters in turn can facilitate the quality of the drug and be helpful for the assemblage of appropriate monograph for its proper identification.

Methods

Preparation for pharmacognostic studies

Healthy and disease-free plants of A. cachemirica were collected from Ferozpur Nallah area of Jammu and Kashmir. The collected specimens were identified and deposited in Kashmir University Herbarium (KASH) under voucher number 2689-KASH. The plant collections were made quite judiciously throughout the course of the present study. The plant materials were fragmented into different parts (leaves, stem, and root) and dried under shade at room temperature for 15–20 days. After shade drying, the plant materials were pulverized to coarse powder using grinder and stored under proper conditions for future use. The pharmacognostic studies were carried out on different parts (leaves, stem, and root) separately.

Organoleptic evaluation

It refers to the evaluation of plant material by color, odor, taste, shape, texture etc. Different dried parts of A. cachemirica were considered for macroscopical evaluation [13].

Macroscopic evaluation

Fresh and healthy plants of A. cachemirica were assessed for their external characteristics.

Microscopic evaluation

Anatomy

Transverse sections of fresh materials of different parts of A. cachemirica were cut with the help of sharp blades. Peels were obtained from fresh leaves by forceps. Different sections/peels were stained with safranin and observed under microscope and photographed.

Powder microscopy

For the analysis of plant powder, pinch of fine powder is taken in a test tube and boiled in chloral hydrate solution for few minutes. A few drops of powder were smeared on a slide mounted with phloroglucinol followed by few drops of concentrated HCl [13]. The prepared slides were then observed under a microscope and photographed.

Physicochemical parameters

Various physicochemical parameters (foreign matter, moisture content, ash value, fat content, pH, swelling index, foaming index, fluorescent analysis, extractive value) were analyzed [13,14,15,16,17].

Results

Macroscopic and organoleptic description

The macroscopic and organoleptic description of various parts of A. cachemirica is presented in Tables 1 and 2 and Fig. 1a–e.

Table 1 Macroscopical attributes of Aralia cachemirica

Table 2 Organoleptic evaluation of different parts of Aralia cachemirica

Fig. 1

Morphological attributes of A. cachemirica. a Habit (perennial herb). b Leaf ovate. c Inflorescence umbel. d Ovary 6–locular. e Purplish black fruit

Microscopy

Anatomy

The anatomical studies of different parts of A. cachemirica revealed presence of various diagnostic features as depicted in Fig. 2a–e.

Fig. 2

Anatomical features of A. cachemirica leaf. a A patch of stomata (× 10). b Anomocytic stomata with wavy epidermal cells (× 100). c 1 Unicellular trichome (× 40), 2 glandular trichome. Anatomical features of A. cachemirica stem. d Transverse section of stem (× 10): 1 epidermis, 2 hypodermis, 3 cortex, 4 sclerenchymatous sheath, 5 phloem, 6 xylem, 7 pith. Anatomical features of A. cachemirica root. e Transverse section of root (× 10): 1 phellem, 2 phelloderm, 3 intercellular spaces, 4 cortex, 5 mucilage canal, 6 phloem, 7 xylem

Powder microscopy

The result of powder microscopy of different parts of A. cachemirica revealed many important features which are illustrated in the Fig. 3a–h.

Fig. 3

Powder microscopy of A. cachemirica leaf. a Stomata with wavy epidermal cells (× 40). b Unicellular trichome (× 40). Powder microscopy of A. cachemirica stem: c reticulate parenchyma (× 40), d bordered pitted xylem vessel (× 40), e scalariform vessel (× 40). Powder microscopy of A. cachemirica root: f lignified cork cells (× 40), g pitted vessel (× 40), h parenchyma cells (× 40)

Physicochemical parameters

The results attained from various physicochemical parameters in different parts of A. cachemirica are presented in Table 3. The detailed results of cold extraction, hot extraction, and successive extraction values are presented in Table 4. The fluorescence characteristics of powdered leaves, stem, and root of A. cachemirica were observed in visible, short, and long UV light. The observations are presented in Tables 5, 6, and 7 showing the variation in color.

Table 3 Physicochemical analysis of different parts of Aralia cachemirica

Table 4 Extractive values of Aralia cachemirica various parts using different solvents

Table 5 Fluorescence analysis of Aralia cachemirica leaf

Table 6 Fluorescence analysis of Aralia cachemirica stem

Table 7 Fluorescence analysis of Aralia cachemirica root

Discussion

Proper identification, quality assurance, and establishing pharmacognostic standards are very significant factors for evaluation of medicinal plants. According to the World Health Organization (WHO), the macroscopical and microscopical account of a medicinal plant is the first step towards ascertaining the identity and the degree of purity of such material and should be accomplished before any tests are undertaken [6, 13].

Microscopic assessment of the plant material is crucial for the detection of source materials. The anatomical attributes are employed as a criterion for unraveling the species, genera, and even families. Also, anatomy gives the idea of diagnostic features of a plant material such as cork cells, cortex, secondary phloem, and fibers which forms the vital factors for the quality control and standardization of herbal drugs [18]. Investigations of the powdered plant material offer the comprehensive structural information of the raw drugs by discovering the identified histological characters in the drugs. The powdered examination of herbal material is based on the cyto-morphological parameters, for instance collenchyma, parenchyma, trichomes, vessels, and secretory cells, and cell inclusions, viz., pollen grains, starch grains, and calcium oxalate crystals [19, 20].

Physicochemical parameters are also vital for the standardization and quality control of herbal drugs which included foreign matter analysis, loss on drying, ash content, pH, swelling index, and foaming index. Herbal materials should be devoid of any kind of contamination, so foreign matter analysis of powdered drugs can be considered as an important parameter in order to check the purity of herbal drugs [21]. Loss on drying is commonly used test procedure for determination of moisture content in a powdered sample. Moisture content of drugs should be at minimal level to discourage the growth of bacteria, yeast, or fungi during storage [22]. Ash values are used to determine quality and purity of crude drug. It indicates presence of various impurities like carbonate, oxalate, and silicate. The water soluble ash is used to estimate the amount of inorganic compound present in drugs. The acid insoluble ash consist mainly silica and indicate contamination with earthy material [22]. The pH values provide information about acidic or basic nature of the chemical constituents present in the crude drug. Foaming index is seen to be less than 100 in all the parts of the select species which reveals absence or very little amount of saponins. Swelling index indicates the presence of gums and mucilage, hemicellulose, or pectin in the natural drug [21]. Estimation of extractive values determines the amount of the active constituents in a given amount of plant material when extracted with a particular solvent. The extractions of any crude drug with a particular solvent yield a solution containing different phytoconstituents. The compositions of these chemical constituents depend upon the nature of the drug and the solvent used. It also provides an indication whether the crude drug is exhausted or not [22, 23]. Fluorescence analysis is also an important pharmacognostic parameter. Some constituents show fluorescence in the visible range in daylight. The ultraviolet light produces fluorescence in many natural products which do not visibly fluoresce in daylight. If substance themselves are not fluorescent, they may often be converted into fluorescent derivatives or decomposition products by applying different reagents. Hence, crude drugs are often assessed qualitatively in this way, and it is an important parameter for pharmacognostic evaluation of crude drugs [24, 25].

Conclusion

The study may possibly provide a foundation for further undertakings towards generating understanding about medicinal plants of Kashmir Himalaya. The pharmacognostic studies are the first step towards ascertaining the identity and the degree of purity of herbal materials. The pharmacognostic analysis is not reported previously in this plant species thus making this first report which provides inclusive pharmacognostic profile of A. cachemirica and thereby will be helpful for correct identification and authentication of the species for future studies.