Indian Journal of Natural Products and Resources, Vol. 4(4), December 2013, pp. 363-370 Evaluation of phytochemical, antioxidant and antimicrobial activities of Memecylon L. species from Western Ghats A R Sivu1, #, N S Pradeep1*, K B Rameshkumar2 and A G Pandurangan1 1Plant Systematic and Evolutionary Science Division, 2Phytochemistry and Phytopharmacology Division Jawaharlal Nehru Tropical Botanic Garden and Research Institute, Palode, Thiruvananthapuram-695 562, Kerala, India Received 18 April 2012; Accepted 29 July 2013 The genus Memecylon L. is a least explored group of plants and the present study reports the preliminary phytochemical and pharmacological evaluation of 32 Memecylon species collected from the Western Ghats. Among these 4 are rare and endangered and 16 endemic. The methanolic extracts of the leaves were evaluated for their phenolic and flavonoid contents, in vitro antioxidant and antimicrobial activities. Phenolic contents of the methanol extracts of leaves were comparatively low in the species, ranging from 89.86 mg/g (M. gracile Bedd.) to 05.04 mg/g (M. depressum Benth.). Flavonoid compounds were highest in M. grande Retz. (39.56 mg/g) and lowest in M. talboltianum Brandis (07.60 mg/g). The in vitro free radical scavenging assay was done using DPPH method and the results showed moderate activities to the leaf extracts. The highest antioxidant activity was observed for M. heyneanum Benth. (IC50=15.30 µg/mL). Antibacterial activity against three Gram- positive and six Gram- negative bacteria was tested by disc diffusion method and the leaf extracts showed remarkable broad spectrum antibacterial activity, especially for M. deccanense Clarke, M. terminale Dalzell, M. heyneanum Benth., M. clarkeanum Cogn. and M. sessile Benth. Keywords: Memecylon species, Western Ghats, Phenolics, Flavonoids, Antioxidant, Antibacterial. IPC code; Int. cl. (2011.01)−A61K 36/00. Introduction The genus Memecylon L. is among the least explored India has a rich floristic diversity with 46, 550 group of plants and hence an attempt has been made plant species that accounts for about 11% of the total to evaluate their phytochemical and pharmacological world flora, of which 28 % are endemic to the potential. 1 country . Among the four hot spots of floristic The genus Memecylon L., belonging to the diversity in India, the Western Ghats hosts nearly family Melastomataceae, is represented world over 4500 flowering plants are endowed with high by around 250 species of shrubs and trees in the endemism with nearly 1500 endemics. Most of paleotropical region3. They are distributed in all the floristic wealth, especially the endemic species types of habitats ranging from deciduous, semi remains unexplored regarding their potential utility evergreen, evergreen and montane forests with a wide and the chemical constituents or bioactivities. range of altitude from sea level to 2000 m. In India The wild underutilised plants have become an the genus Memecylon is represented by 39 species of interesting source of nutraceutical, healthcare, which 21 are endemic to the country and the Western cosmetic and food industries. Indiscriminate Ghats is reported to host 29 species4-8. However, exploitation, habitat destruction and introduction while studying the molecular taxonomy of the genus of exotic species lead to the reduction of population Memecylon L. of the Western Ghats, the authors did of the endemic, rare and endangered species and collect 3 more Memecylon species (M. procerum Thw., therefore there is an urgent need to conserve these M. clarkeanum Cogn. and M. parvifolium Thw.) as species along with evaluation of their potentialities. new records to India (Plate 1). Among 32 species —————— collected from the Western Ghats, 4 species, viz. *Correspondent author: M. lawsonii Gamble, M. lushingtonii Gamble, Phone: 0472 2869226 E-mail: [email protected] M. flavescens Gamble and M. sisparense Gamble # Present Address: Department of Botany, NSS College Nilamel, comes under rare and endangered categories (Plate 1), 9 Kollam-691 535, Kerala while 16 species are endemic to the region (Table 1). 364 INDIAN J NAT PROD RESOUR, DECEMBER 2013 Plate 1—Common Memecylon species (a: M. umbellatum, b: M. edule and c: M. randerianum); Rare and endangered species (d: M. sisparense, e: M. lawsonii, f: M. flavascence and g: M. lushingtonii); New records to India (h: M. parvifolium, i: M. procerum and j: M. clarkeanum) SIVU et al.: PHYTOCHEMICAL, ANTIOXIDANT AND ANTIMICROBIAL ACTIVITIES OF MEMECYLON L. SPECIES 365 Memecylon species are utilized world wide as (locally known as Kasavu, Kayampoo, Kanalei). The timbers, ornamentals, source of edible fruits and plant is popular as ornamental tree and widely used in yellow dye in addition to their medicinal properties3. traditional medicines and also as source of food, dye Among the different Memecylon species, M. umbellatum and timber. The pulpy, astringent ripe berries of the Burm., is the most common species (Plate 1), distributed tree are edible and are eaten in time of famine. in India and Sri Lanka and known as ‘iron wood tree’ The leaves yield a yellow dye and in combination Table 1—Total phenolic, flavonoid compounds and DPPH scavenging activity of the leaf methanol extracts of Memecylon species M. sp. Memecylon species Voucher Total Total IC50 values ID No Phenolics Flavonoids (µg/mL) M 1 M. agastyamalaianum Santhosh et al * 65102 38.03 ± 0.02 08.40 ± 0.04 87.01 ± 0.01 M 2 M. angustifolium Wight 65106 23.97 ± 0.02 10.03 ± 0.04 87.08 ± 0.02 M 3 M. capitellatum L. 63524 06.04 ± 0.02 31.93 ± 0.04 115.37 ± 0.04 M 4 M. depressum Benth. * 61748 05.04 ± 0.01 17.76 ± 0.03 128.13 ± 0.03 M 5 M. flavescens Gamble* 65126 05.05 ± 0.01 11.23 ± 0.04 115.17 ± 0.04 M 6 M. gracile Bedd. * 65104 89.86 ± 0.04 08.42 ± 0.01 58.56 ± 0.04 M 7 M. grande Retz. 61736 09.90 ± 0.04 39.56 ± 0.04 64.00 ± 0.02 M 8 M. heyneanum Benth. 63543 61.06 ± 0.03 12.40 ± 0.04 15.30 ± 0.03 M 9 M. clarkeanum Cogn. 63600 59.96 ± 0.04 11.30 ± 0.03 97.37 ± 0.01 M 10 M. lushingtonii Gamble 65146 10.13 ± 0.03 16.70 ± 0.03 148.23 ± 0.04 M 11 M. malabaricum (C. B. Clarke.) Cogn. 63518 25.76 ± 0.03 12.56 ± 0.05 207.24 ± 0.03 M 12 M. rivulare Bremer 61767 15.83 ± 0.04 13.63 ± 0.03 141.20 ± 0.02 M 13 M. sessile Benth. 65120 82.83 ± 0.03 09.16 ± 0.04 40.10 ± 0.04 M 14 M. sisparense Gamble* 65124 30.36 ± 0.06 09.13 ± 0.04 44.06 ± 0.02 M 15 M. sivadasanii Mohanan et al * 61775 14.06 ± 0.01 10.80 ± 0.02 55.10 ± 0.03 M 16 M. subramanii Henry* 63564 09.46 ± 0.04 14.96 ± 0.04 91.06 ± 0.03 M 17 M. talboltianum Brandis* 65161 11.03 ± 0.05 07.60 ± 0.03 114.0 ± 0.02 M 18 M. terminale Dalzell* 65162 65.96 ± 0.15 10.60 ± 0.02 232.47 ± 0.03 M 19 M. umbellatum Burm. 61751 10.10 ± 0.03 15.33 ± 0.05 62.43 ± 0.04 M 20 M. wightii Thw. 63584 06.78 ± 0.03 09.56 ± 0.04 77.21 ± 0.02 M 21 M. mundanthuraianum Viswanathan & Manik.* 65116 51.76 ± 0.04 07.53 ± 0.03 214.27 ± 0.05 M 22 M. bremeri Viswanathan 65136 10.75 ± 0.03 20.33 ± 0.04 53.90 ± 0.03 M 23 M. manickamii Murugan et al * 65171 14.10 ± 0.03 12.50 ± 0.04 85.37 ± 0.03 M 24 M. courtalensis Manickam et al * 63540 05.63 ± 0.05 09.00 ± 0.02 74.22 ± 0.02 M 25 M. tirunelvelicum Murugan et al * 65121 23.73 ± 0.05 13.53 ± 0.04 149.97 ± 0.04 M 26 M. royenii Blume 65138 07.83 ± 0.03 12.50 ± 0.04 145.17 ± 0.04 M 27 M. deccanense Clarke* 65165 67.06 ± 0.01 08.46 ± 0.04 110.00 ± 0.05 M 28 M. edule Roxb. 63558 08.73 ± 0.04 14.36 ± 0.03 82.43 ± 0.03 M 29 M. parvifolium Thw. 63563 64.10 ± 0.03 10.40 ± 0.05 162.37 ± 0.05 M 30 M. procerum Thw. 61752 05.90 ± 0.10 18.20 ± 0.03 103.97 ± 0.03 M 31 M. lawsonii Gamble* 61761 08.83 ± 0.03 12.43 ± 0.04 114.17 ± 0.02 M 32 M. sylvaticum Thw. 61726 15.86 ± 0.02 15.30 ± 0.05 78.13 ± 0.02 * Endemic to the Western Ghats. Phenolic contents: mg gallic acid equivalent per g dry weight of leaves methanol extract. Flavonoid contents: mg quercetin equivalent per g dry weight of leaves methanol extract. Values are mean ± SD of triplicate experiments. 366 INDIAN J NAT PROD RESOUR, DECEMBER 2013 with myrobalans and sappan wood it produces oleanolic acid, ursolic acid, sitosterol-β-D-glucoside bright red tinge10. In traditional medicines, leaves of and umbelactone have been isolated from the aerial M. umbellatum has been used as a cooling astringent, parts of M. umbellatum Burm.35. The roots yielded, in conjunctivitis as a lotion and given internally in octocosonoic acid, cerotic acid, ethyl palmitate, leucorrhoea and gonorrhoea11. The leaves are also palmitic acid and butyric acid36. used for the treatment of diabetes12, in the treatment The present study reports the quantitative estimation of bone fracture13, herpes 14, skin diseases15 and snake of the phenolic compounds and flavonoids of the bite16. The leaves and barks are applied to bruises10. methanol extracts of the leaves of 32 Memecylon The decoction of the root is used in excessive species distributed in the Western Ghats region of menstrual discharge17,18.