Evaluation of antioxidant and antiacne properties of terpenoidal fraction of Hemidesmus indicus (Indian sarsaparilla)

摘要

The present study was undertaken to evaluate the effect of terpenoidal fraction of the roots of Hemidesmus indicus roots (TFHI) on several in vitro antioxidant and antiacne activity. The in vitro antioxidant potential of TFHI was evaluated by various antioxidant assays, including DPPH radical scavenging, superoxide radical scavenging in riboflavin/light/ NBT, and nitric oxide (NO) scavenging activity in sodium nitroprusside/Greiss reagent system. Antiacne activity of TFHI was tested by disc diffusion and broth dilution methods against Propionibacterium acnes and Staphylococcus epidermidis which have been recognized as pus-forming bacteria triggering an inflammation in acne which are etiologic agents of acne vulgaris. Further, preliminary phytochemical analysis and TLC finger print profile of TFHI was established to characterize the terpenoidal fraction which showed antioxidant and antiacne properties. The TFHI was found to have different levels of antioxidant properties in the models tested. In scavenging DPPH and superoxide radicals, its activity was intense (EC50 = 18.7 and 19.3 μg/ml respectively) while scavenging NO radical was moderate. Based on a broth dilution method, the TFHI had the greatest antiacne properties. The MIC values were the same 38 μg/ml for both bacterial species and the MBC values were 38 and 46 μg/ml against Propionibacterium acnes and Staphylococcus epidermidis respectively. The antioxidant and antiacne activity could be attributed to non-polar terpenoidal fraction. Introduction Hemidesmus indicus (L.) Schult. (Asclepiadaceae) is a twining shrub which has been used as folk medicine and as ingredient in Ayurvedic and Unani preparations against disease of biliousness, blood diseases, diarrhea, skin diseases, respiratory diseases, fever, syphilis, bronchitis, eye diseases, loss of appetite, burning sensation rheumatism and gastric disorders 1, 2, 3. It has also been used in combination with other drugs for snake bite 4, 5. Recently, this plant was used to treat viper venom {haemotoxic} - induced lethality 6 Ethanolic extract of root was found to be Antihepatotoxic 7 and against ulcer 8. Methanolic root extracts are proved to have Antidiarrheal 9, 10, antioxidant activity 11. Renoprotective effect of Hemidesmus indicus is used in gentamycin induced renal toxicity 12. Some important chemical constituents of the root include hemidesmin1, hemidesmin 2, α-amyrin, β-amyrin, lupeol, 2-hydroxy—methoxy-benzoicacid and some triterpenes 13, 14. From the aerial parts of the plant several pregnan steroids have been isolated 15. Acne vulgaris is a most common skin disorder of Pilosebaceous unit. That affects areas containing the largest oil glands, including the face, back, and trunk 16. It is generally characterized by formation of seborrhea, comedone, inflammatory lesions and presence of bacteria Propionibacterium acnes, Staphylococcus epidermidis and Malassezia furfur in the follicular canal and sebum production 17. The role of free radicals in many disease conditions has been well established. In the recent years the areas which attracted a great deal of attention is antioxidants in the control of degenerative diseases in which oxidative damage has been implicated. Several plant extracts and different class of phytoconstituents have been shown to have antioxidant 18, 19 and antiacne activity 20. In the present paper, we report our work on establishing antioxidant activity of terpenoidal fraction of Hemidesmus indicus (TFHI), in quenching free radicals viz., DPPH, Superoxide and nitric oxide radicals that are generated in several in vitro models and antiacne activity by disc diffusion and broth dilution method. In the past fe years high performance thin layer chromatography (HPTLC) has emerged as a potential for rapid and efficient phytochemical evaluation of herbal drugs 21, 22. TLC fingerprinting profile is also established using HPTLC to characterize the extract which would facilitate the identification of TFHI.