Ethnoveterinary medicinal plants at Bale Mountains National Park, Ethiopia.

Herbal formulations have reached extensive acceptability as therapeutic agents for several diseases. The development of authentic analytical methods which can reliably profile the phytochemical composition, including quantitative analyses of marker/bioactive compounds and other major constituents, is a major challenge to scientists. Standardization is an important step for the establishment of a consistent biological activity, a consistent chemical profile, or simply a quality assurance program for production and manufacturing of herbal drugs. WHO specific guidelines for the assessment of the safety, efficacy and quality of herbal medicines as a prerequisite for global harmonization are of utmost importance. An overview covering various techniques employed in extraction and characterization of herbal medicines as well as herbal nanomedicines standardization is reported. In addition, phytosomes increased bioavailability, bhasma as a metal nanocarrier drug delivery system, potential of metabolomics in the development of improved phytotherapeutic agents, DNA based molecular markers in distinguishing adulterants, and SCAR markers for authentication and discrimination of herbs from their adulterants are reported. The extraction of high-valued herbal compounds using microwave‐assisted extraction and supercritical phase extraction technology followed by the standardization utilizing various spectroscopic, chromatographic and thermogravimetric techniques individually and/or in combination has been discussed in relation to herbal drugs. Capillary electrophoresis and polarographic techniques contributions towards standardization of herbal drugs is also reported. Nanotechnology based Chinese herbal drugs possess improved solubility and enhanced bioavailability.

An overview of advances in the standardization of herbal drugs

Drought (D) stress effects on growth, photosynthetic pigments, photosynthetic electron transport, thylakoid polypeptides and phytochemical variations of Withania (Solanaceae), a tropical medicinal herb were studied. Exposure of plants to D-stress led to noticeable decrease in leaf area, photosynthetic pigments, root and shoot lengths and photosynthetic activity. Well-watered plants maintained high content of total chlorophyll (Chl), root and shoot lengths, leaf area and photosynthesis. We analysed alterations at cellular level of the D-stress-associated proteins at different time intervals. A set of proteins in the range of 34 to 40 kDa showed variations in response to D-stress. Qualitative high performance thin layer chromatography (HPTLC) analysis of root extract obtained from control and D-stressed plants showed quantitative and qualitative variations. Withaferin A content increased 5% under D-stress as compared to control.

	 

	Key words: Carotenoids, chlorophyll, fluorescence, leaf area, pigments photosynthesis.

Drought induced changes in physiological, biochemical and phytochemical properties of Withania somnifera Dun.

A simple, sensitive and accurate high performance thin layer chromatographic (HPTLC) method has been developed for the estimation of withaferin-A and withanolide-A in different plant parts such as, leaf, root, stem and fruit of two morphotypes of Withania somnifera. HPTLC of W. somnifera methanolic extract was performed on Si 60 F254 (20 cm × 20 cm) plates with toluene:ethyl acetate:formic acid (5:5:1), as mobile phase. Quantitative evaluation of the plate was performed in the absorption-reflection mode at 530 nm. The method was validated for precision, repeatability, and accuracy. The average recovery of withaferin-A and withanolide-A in two levels were 96.0 and 96.7%, showing the excellent reproducibility of the method. The calibration curves were linear for both in the range of 200–3,200 ng. The technique has been applied, for the first time, for the estimation of withaferin-A and withanolide-A in different parts of the two morphotypes of Withania somnifera. The method is simple, precise, specific, sensitive and accurate and can be used for routine analysis as well as for quality control of raw materials and herbal formulations.

A Validated and Densitometric HPTLC Method for the Quantification of Withaferin-A and Withanolide-A in Different Plant Parts of Two Morphotypes of Withania somnifera

For successful conservation and breeding of a medicinal species, it is important to evaluate its genetic diversity as well as its content of phytochemical compounds. The aim of the present study was to investigate the genetic variation of Iranian natural populations of W. somnifera and W. coagulans, using the RAPD (random amplified polymorphic DNA) markers, and their withaferin A content. Using 16 RAPD primers, a total of 282 RAPD bands were achieved. The highest and lowest percentages of polymorphism were observed with primers OPAD-15 (100.0%) and OPC-06 (75.0%), respectively. Cluster analysis of the genotypes was performed based on data from polymorphic RAPD bands, using Dice's similarity coefficient and the UPGMA clustering method. Variations in the RAPD results were found to reflect geographical distribution and genetic factors of the plant populations. The HPTLC analysis of the studied samples revealed the presence of withaferin A in W. coagulans and W. somnifera. Moreover, the concentration of withaferin A had a range from 2.2 to 32.5 microg/g DW and was higher in the aerial part than in the root in all used samples. The results of the present study show that there is a high level of variation in the Iranian natural population of Withania, which is significant for conservation and breeding programs to improve production of withaferin A.

https://journals.sagepub.com/doi/pdf/10.1177/1934578X0900400307

Genetic and withaferin A analysis of Iranian natural populations of Withania somnifera and W. coagulans by RAPD and HPTLC.

Withania somnifera has been used in Ayurvedic medicine for treatment of depression and inflammation, and as an aphrodisiac. It contains many phytochemicals such as Withaferine A, withanine, anahygrine, tropine, and withanolides. Of these, withaferine A is considered to be the most active compound. Withaferine A was estimated in herbal extract and polyherbal formulations by high performance thin layer chromatography (HPTLC). As there is no official HPTLC protocol for quantitation of the above phytochemicals, an attempt was made to quantify withaferine A in herbal extract and polyherbal formulations produced from Withania somnifera. Precoated silica gel G (aluminium backed) plates were used as stationary phase and toluene:ethyl acetate: formic acid (50 : 15 : 5) was used as mobile phase. Detection and quantification were performed by densitometry at λ 213 nm. The linear range was 1 μg to 3 μg. This HPTLC method was found to be reproducible, accurate, and precise.

P. Kasar Rahul

Papers

HPTLC analysis of Withaferine A from an herbal extract and polyherbal formulations