Pharmacognostic Screening of Piper trichostachyon Fruits and its Comparative Analysis with Piper nigrum Using Chromatographic Techniques

BACKGROUND: Piper trichostachyon is a wild, endemic Piper species from Western Ghats of India. The folklore healers of Belagavi region use this plant, similar to Piper nigrum. AIMS: The present study investigates the comparison between P. nigrum and P. trichostachyon using pharmacognostic parameters. MATERIALS AND METHODS: Pharmacognostic evaluation was carried out in terms of morphological, microscopic characters, and phytochemical analysis using standard methods. Comparative physicochemical analysis between P. trichostachyon and P. nigrum was also carried out through estimation of micro-macro nutrients, high-performance thin layer chromatography (HPTLC) investigation and using piperine as a marker compound for reversed phase-ultra flow liquid chromatographic (RP-UFLC) technique. RESULTS: P. trichostachyon grows in the forests, and the fruits are morphologically similar to P. nigrum fruits, so the name in Kannada “Kaadu Kalu menasu” (wild/forest black pepper). The microscopy revealed the presence of stone cells, starch grains, oil cells and globules, beaker cells, and yellowish brown pigment layer, parenchymatous cells. The presence of alkaloids, oil, and tannins were observed in P. trichostachyon fruits. The HPTLC studies visibly indicated differences among two species with 12 peaks and varied banding pattern. RP-UFLC results showed less amount of piperine in P. trichostachyon (0.05 ± 0.002 mg/g) than in P. nigrum (16.14 ± 0.807 mg/g). CONCLUSION: The study reports on pharmacognostic parameters of P. trichostachyon for the 1(st) time and will be useful for the identification and authentication. The comparative HPTLC and RP-UFLC studies resolve the differentiation impasse among two species. However, further biological efficacy studies are required to establish its use in traditional medicine. SUMMARY: Piper trichostachyon grows in the forests, and the fruits are morphologically similar to Piper nigrum fruits. The microscopy of P. trichostachyon revealed the presence of stone cells, starch grains, oil cells and globules, beaker cells and yellowish brown pigment layer, parenchymatous cells. The high-performance thin layer chromatography studies visibly indicated differences among two species with varied banding pattern. Reversed phase-ultra flow liquid chromatographic results showed less amount of piperine in P. trichostachyon than in P. nigrum. Abbreviation used: HPTLC: High Performance Thin Layer Chromatography, RP-UFLC: Reversed phase-ultra flow liquid chromatographic analysis, DST: Length of line, Maj: Length of large half axis for ellipse RDS - radius for circle, Rf: Retention Factor, TS: Transverse Section, TLC: Thin Layer Chromatography.