Production of gymnemic acid depends on medium, explants, PGRs, color lights, temperature, photoperiod, and sucrose sources in batch culture of Gymnema sylvestre

Biotechnological approaches for the production of gymnemic acid from Gymnema sylvestre R. Br

Diabetes is a chronic disease that affects several organs and can be treated using phytochemicals found in medicinal plants. Gymnema sylvestre (Asclepiadaceae) is one such medicinal plant rich in anti-diabetic properties. The plant is commonly known as madhunashini in Sanskrit because of its ability to cure diabetes (sugar). Gymnemic acid (GA) is a phytochemical (a triterpenoid saponin) responsible for the herb's main pharmacological activity. This secondary metabolite has a lot of potential as a phytochemical with pharmacological properties including nephroprotection, hypoglycemia, antioxidant, antimicrobial, and anti-inflammatory. Gymnema has acquired a lot of popularity in recent years due to its low side effects and high efficacy in healing diabetes, which has led to overexploitation by pharmaceutical enterprises for its biomass in the wild for the purification of gymnemic acid. Modern biotechnological techniques involving the establishment of cell and organ cultures from G. sylvestre will assist us in fulfilling the need for gymnemic acid production. The present review provides insights on the establishment of cell and organ cultures for the production of a potent antidiabetic molecule gymnemic acid. Further, the review also delves into the intricacies of the different strategies for improved production of gymnemic acid using various elicitors. There is huge potential for sustainable production of gymnemic acid which could be met by establishment of bioreactor scale production. Understanding and engineering the biosynthetic pathway could also lead to improved GA production. KEY POINTS: • Gymnemic acid is one of the potential anti-diabetic molecules from madhunashini • Cell and organ culture offers potential approach for gymnemic acid production • Elicitation strategies have improved the gymnemic acid production.

Effects of light, sucrose concentration and repetitive subculture on callus growth and medically important production in Justicia gendarussa Burm.f

Objective

This research aimed at the discovering the effects of light, sucrose concentration and repetitive subculture on the growth of Justicia gendarussa Burm.f. calluses based on biomass, morphological characters and metabolic profiles.

Methods

The second and third leaves of young J. gendarussa Burm.f. were isolated and cultured in solid Murashige and Skoog (MS) medium with the addition of 1 mg/L 2,4-dichlorophenoxyacetic acid (2,4-D) and 0.5 mg/L benzyl amino purine (BAP). Different sucrose concentrations, varying from 0 to 5%, were included in the medium. The cultures were incubated under light and dark conditions for 6 weeks. Repetitive subculture was carried out every 2 weeks for a total of four times, and 3% sucrose gave the best callus growth. Dry calluses were extracted with methanol, and their metabolic profiles were analyzed using gas chromatography/mass spectrometry (GC/MS). Compound identification was performed by comparing the mass spectra to references from the WILEY version 7n.1 library.

Results

Among the 12 conditions tested for the prolonged 6-week culture, the 2-5 % sucrose treatments under light and 3-5 % sucrose treatments under dark exhibited the highest dry weight. For repetitive subculture, the highest wet and dry weights were identically detected under both light and dark conditions after the second repetitive subculture. A total of 19 metabolites was identified by GC/MS, with major compounds being taraxasterol, monoplex D, 2-methoxy-4-vinylphenol, and palmitic acid.

Conclusion

Light, sucrose concentration, and repetitive subculture all significantly impacted the growth and metabolic profiles of J. gendarussa Burm.f. calluses. A concentration of 3% sucrose demonstrated the best growth of callus and could be further applied for mass production.

Phytochemical analysis, antioxidant and antimicrobial activity of wild and in vitro derived plants of Ceropegia thwaitesii Hook - An endemic species from Western Ghats, India

Ceropegia thwaitesii Hook (Asclepiadaceae), an endemic plant species, due to habitat destruction and over exploitation has a very restricted distribution in the Western Ghats of Tamil Nadu, India. The present wrok aimed to determine the chemical composition, the total phenolic (TPC), flavonoid (TFC) and tannin content (TEC), and to assess the antioxidant properties of various extracts of in vivo plants (IVP) and in vitro regenerated plants (IRP) of C. thwaitesii. Some phenolic compounds like gallic acid, cathechol, vanillin and salicylic acid were identified and quantified by HPLC. All the extracts possessed relevant radical scavenging activity on DPPH, Superoxide radical scavenging activity, and Nitric oxide radicals as well as total antioxidant ability. DPPH assay of in vitro methanol stems extracts and ethanol leaves extracts revealed the best antioxidant properties with important IC50 values of 0.248 ± 0.45 µg/mL and 0.397 ± 0.67 µg/mL, respectively, whereas in vivo chloroform stems extracts showed a lower antioxidant activity (IC50 of 10.99 ± 0.24 µg/mL). The IRP methanol extracts of stem and leaves had good inhibitory activity against all tested microorganisms in a dose-dependent manner. These results suggested that in vitro raised plants of C. thwaitesii are an excellent source of antioxidant compounds to be exploited on an industrial level as food additive.