Bioactivity evaluation of least explored traditionally acclaimed medicinally potent herb Nanorrhinum ramosissimum(Wall. ) Betsche

Abstract Present study analysed the therapeutic potential of traditionally acclaimed medicinal herb Nanorrhinum ramosissimum, using plant parts extracted with different solvents (10 mg/mL). Shoot extracts exhibited comparatively better antimicrobial properties, in comparison to root extracts. Total phenolic content was estimated, to ascertain its dependency on antioxidant properties of plant extracts. Antioxidant assay revealed promising results in comparison to IC50 value of standard ascorbic acid (52.2±0.07 µg/mL), for methanolic extracts of shoot (61.07±0.53 µg/mL and 64.33±0.33 µg/mL) and root (76.705±0.12 µg/mL and 89.73±0.28 µg/ mL) for in vivo and in vitro regenerants respectively. Correlation coefficient R2 values ranged between 0.90-0.95, indicating a positive correlation between phenolic contents and antioxidant activity. Plant extracts were also able to inhibit DNA oxidative damage again indicating their antioxidative potential. Antidiabetic potential was confirmed by alpha amylase inhibition assay where shoot methanolic extracts (invivo, in vitro) exhibited the best IC50 values (54.42±0.16 µg/mL, 66.09±0.12 µg/mL) in comparison to standard metformin (41.92±0.08 µg/mL). Ethanolic extracts of roots (in vitro, invivo) exhibited the relative IC50 values (88.97±0.32µg/mL,96.63±0.44 µg/mL) indicating that shoot parts had a better alpha amylase inhibition property; thus proving the herb's bioactive potential and its prospective therapeutic source for curing various ailments.

Isolation, characterization, and plant growth-promoting activities of endophytic fungi from a wild orchid Vanda cristata.

Endophytism is one of the widely explored phenomena related to orchids and fungi. Endophytic fungi assist plants by supplementing nutrient acquisition, and synthesis of plant growth regulators. Vanda cristata is an epiphytic orchid that has a great diversity of endophytic fungi. Endophytic fungi were isolated from roots, stems, and leaves of V.cristata and identified by both morphological and molecular study. Furthermore, the isolated endophytic fungi were subjected to auxin synthesis, phosphate solubilization, ammonia synthesis, and elicitor growth test for understanding their growth-promoting effect in a qualitative and quantitative manner. Altogether, 12 different endophytic fungi were isolated from roots, stems, and leaves of V. cristata of which most species belonged to Ascomycota. Unidentified II fungi were found to be most effective for auxin synthesis and phosphate solubilization while Agaricus bisporous and Mycolepto discus were most effective for ammonia synthesis. We have tested the plant growth-promoting activity of the twelve isolated endophytic fungi on Cymbidium aloifolium protocorms (12 weeks old). All the endophytic fungi showed growth-promoting activity. Plant growth of Cymbidium aloifolium was found higher on the MS medium supplemented with all fungal elicitors. Fungal elicitor CVS4, however, showed the highest plant growth-promoting activity toward C. aloifolium.