Free Radical Scavenging Activity of Selected Medicinal Plants of Eastern Botswana

Abstract

Water and methanol extracts from roots of Ozoroa paniculosa (Anarcardiaceae); seeds of Colophospermum mopane (Caesalpiniaceae) and Cucumis metuliferus (Cucurbitaceae) ripe fruits were assessed for in vitro antioxidant activity. Free radical scavenging activity was measured spectrophotometrically as maximum fading power of DPPH at 525 nm. Water and methanol extracts of Ozoroa paniculosa exhibited higher scavenging potency than extracts of either Colophospermum mopane or Cucumis metuliferus at all tested concentrations. None of the extracts from Cucumis metuliferus exhibited any recognizable free radical scavenging activity. Above 50 microg mL(-1) both water and methanol extracts of Ozoroa paniculosa exhibited 91% scavenging activity similar to the control compounds L-ascorbic acid (91%) and (-) epicatechin (92%). Between 50-100 microg mL(-1), water and methanol extracts of Colophospermum mopane exhibited scavenging potency of < or = 70%. However, above 100 microg mL(-1), both water and methanolic extracts of C. mopane exhibited scavenging activity > 70%. Chloroform extracts of all the tested plants showed poor scavenging activity (< 30%). The order of scavenging potency for the tested samples was as follows: L-ascorbic acid > or = epicatechin > O. paniculosa (methanolic extract) > O. paniculosa (water extract) > O. paniculosa (ethylacetate extract) > C. mopane (methanolic extract) > C. mopane (water extract) > all extracts of C. metuliferus. These findings lend credence to the use of these plants as anti-inflammatory and antioxidant agents in folk medicine.

Evaluation of antioxidant, anti-inflammatory and analgesic potential of Citrullus lanatus seed extract in rodent model

“…The qualitative assay was performed according to the reported method (9,13). Two milligrams of the extract was diluted with 1 ml of the appropriate solvent, then small quantity of each dilution of the hexane, chloroform, ethyl acetate and methanol was carefully loaded individually into the baseline of the TLC plates (20 cm x 10 cm) and the sample was allowed to dry.…”

“…If free radicals are not inactivated, their chemical reactivity can damage all cellular macromolecules including proteins, carbohydrates, lipids and nucleic acids. Their destructive effect on protein may play a role in the causation of cataracts, damage to DNA which may cause cancer, effect on LDL cholesterol which is very much responsible for heart disease and free radicals are also involved in the inflammation processes like gout and asthma (8,9). The common link between free oxidant radicals and inflammatory reactions has been well established (9).…”

“…Their destructive effect on protein may play a role in the causation of cataracts, damage to DNA which may cause cancer, effect on LDL cholesterol which is very much responsible for heart disease and free radicals are also involved in the inflammation processes like gout and asthma (8,9). The common link between free oxidant radicals and inflammatory reactions has been well established (9). Natural medicines derived from plant extracts are being increasingly utilized to treat a wide variety of clinical diseases, though relatively little knowledge about their mode of action is available.…”

Antihepatotoxic and antioxidant defense potential of Mimosapudica

“…Antioxidants stop the free radical from forming in the first place or interrupt an oxidizing chain reaction to minimize the damage caused by free radicals [7]. Medicinal plants are considered to be an important source of antioxidant compounds and the therapeutic benefit of many medicinal plants in often attributed to their antioxidant properties [8]. Mimosa pudica is an annual shrub found through out India.…”

Biodiversity Studies in Key Species from the African Mopane and Miombo Woodlands

“…Bark and seeds: signiicant cytotoxicity against a human breast cancer cell line [48] Heartwood: mono-, di-, and trilavonoids; leaves: beta-sitosterol and stigmasterol; aerial part: essential oils that comprise mainly alpha-pinene and limonene; bark and seeds: diterpenes, including dihydrogrindelaldehyde [48] Allozyme markers [83] Seeds: anti-inlammatory and antioxidant activities [95] Bark and seeds: signiicant cytotoxic activity against a human breast cancer cell line (aldehyde) [96] Bark and seeds: three new diterpenes isolated [96] Oligomeric lavonoids [97] Leaves: antimicrobial activity [49] Seed husks and leaves: ive labdane (1)(2)(3)(4)(5), an isolabdane (6), and ive clerodane diterpenoids (7)(8)(9)(10)(11) [49] [35]. The bark is dark gray to brown, rough, and longitudinally issured.…”